Landscape Ecology as an Emerging Branch of Human Ecosystem Science

ZEV NAVEH

I. Introduction. . . . . . . . . . . . . . . . 189 . . . 190

A. Some Definitions of Landscape and Landscape Ecology . . . . 190 B. Some Relevant Conceptual and Methodological Contributions . . 193 C. Towards a General Biosystems Theory . . . . . . . . 197 D. The Role of Landscape Ecology as a Human Ecosystem Science . . 204

111. Practical Contributions of Landscape Ecology . . . . . . . 210 A. Major Contributions in Central Europe . . . . . . . . 210 B. Landscape Ecological Studies in Israel . . . . . . . . 222

IV. Landscape Ecology and Environmental Education . . . . . . 228 V. Summary and Conclusions . . . . . . . . . . . . 229

Acknowledgements . . . . . . . . . . . . . . . 230 References . . . . . . . . . . . . . . . . . 230

11. The Conceptual and Theoretical Basis of Landscape Ecology

I. INTRODUCTION

In Central and Eastern Europe, landscape ecology has gained general recog- nition as a branch of modern ecology, dealing as it does with the interrelations between man and his open and built-up landscapes. There are chairs of landscape ecology in several universities in West Germany and a Federal Institute for Nature Conservation and Landscape Ecology in Bad Godesberg. In 1968, a symposium on landscape ecology was held (Tuxen, 1968) and many papers are devoted to this subject at meetings of the German Society for Ecology.

The English-speaking world, and especially the United States, is almost totally unaware of these developments. In a recent critical review of human ecology (Young, 1974), landscape ecology was not mentioned at all, in spite of long discussions on related subjects, such as landscape architecture, land planning, nature conservation and applied ecology in general. Although more than 400 references were cited, there was not a single, relevant non-English one among them.

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The object of this paper is to bridge this gap by reviewing some of the recent developments in landscape ecology in Europe and Israel and, at the same time, to make a first attempt at outlining the unifying principles and concepts of landscape ecology as an emerging human ecosystem science.

11. THE CONCEPTUAL AND THEORETICAL BASIS OF LANDSCAPE ECOLOGY

A. Some Definitions of Landscape and Landscape Ecology Probably the earliest literary reference to landscape was in the Book of Psalms, 48:2, where the beautiful view over Jerusalem from Mount Zion is mentioned.

The meaning of the term ‘’landscape’’ has undergone great changes (Whyte, 1976), but the original visual-perceptual and aesthetic connotation from the Bible is still used in literature and art and by most landscape architects and designers (Young, 1974). In recent years, highly sophisticated statistical methods and advanced psychological theories have been used to evaluate landscapes, but an ecological perception has been lacking (see Arthur et al., 1977; Zube et al., 1975 for reviews).

In the Germanic languages, Landschaft-landscape, derived from “land” and sometimes identical to it, can also mean a certain geographical-political area. It has been adopted by geographers as a synonym for geomorphological landforms and has become a scientific term.

Russian geographers were the first to broaden the narrow geomorpho- logical definition of landscape. They included both inorganic and organic phenomena of the earth’s crust and called the study of its totality “landscape geography” (Troll, 197 1). The Russian term “biogeocenose” (Sukachew, 1960) has a broader geographical-regional meaning than the English “ecosystem” as introduced by Tansley (1935). Russian ecologists also emphasize the active and very often positive role of modern man in shaping the landscape, and use for this the term “culture-biogeocenose”. In marked contrast, in the Western world, under the dominating influence of Clementsian climax theories, man is still viewed solely as an external, destructive agent.

The semantic polarity between natural-unspoiled-wilderness+limax, on the one hand, and man-made-spoiled-artificial, on the other, is so deeply ingrained in Western ecological ideology, that a holistic landscape concept is not easily accepted. This in spite of the fact that one of the outstanding North American ecologists, Dansereau (1957), introduced it in an English textbook. In the introductory chapter to his pioneering Biogeography, an ecological perspective, he stressed that the crux of ecological thinking is “the

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holocenotic point of view”, in which the ecologist views the environment as a whole. He considered the landscape to be the object of study at the highest integrative level of environmental processes and relationships, namely the industrial level. The science covering this is human ecology, which has affinities with anthropology, agriculture, forestry, human geography, soci- ology and history and studies the influence of man on the landscape as he uses the land and its resources. He devoted the last chapter of this book to the subject of man’s impact on the landscape and described six successional phases of use, in which man gained increasing control: gathering, hunting, herding, agriculture, industry and urbanization. Man achieved this by upsetting natural balances and creating completely new ecosystems on the one hand, and by deliberately moulding the evolutionary forces in living organisms (including himself), on the other. In Dansereau’s opinion, through this new and highest level of landscape modification, man has inaugurated a new geological epoch in the exploitation of environmental resources: the “noosphere”. This term was first suggested by Vernadsky (1945) and re-evaluated by Teilhard de Chardin (1966) as a major evolutionary advance of mankind and his “co- reflexive self-evolution”.

More recently, Dansereau (1966) added atmospheric control and extra- orbital travel to the six successive phases of human interference in the land- scape. He was not aware of the science of landscape ecology in Europe, but, in discussing the new technological methods of inquiry into conservation and multiple land use, he stated that we are now entering the engineering phase, which acknowledges the fact that virtually all landscapes in the world are under some kind of management. This must be a rationally scientific, eco- logical landscape management and “not merely applied ecology, any more than medicine can be reduced to applied biology”.

German biogeographers, especially Troll and Schmithusen, further devel- oped the Russian geographers’ holistic interpretations of the landscape. Schmithusen (1936) defined it as “the whole Gestalt of any part of the geosphere of relevant order of size which can be perceived according to its total character as a unit”. He distinguished between the pristine Urlundschuf, the natural Naturlundschuft and the cultural Kulturlandschuft. According to Schmithusen (1 96 I ) , more extensive Nuturlundschuften can be found where the nature of the land precludes man’s permanent habitation, such as ice and sand deserts, high alpine mountains and certain parts of the tropical rain- and mountain-forests, and the boreal forests and tundra. The Kulturlundschuft is dominated by the naturally-conditioned spatial order only to a limited extent. Here, different principles of order, determined by human requirements, are operating and the question of what part the vegetation plays in the landscape from an ecological, functional and spatial point of view, should be considered separately.

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According to Buchwald (1963), we are living in a Kulturlandschaji which has been shaped by man over centuries. A state of equilibrium has been established between Kulturlundschaft, population density, landscape potential and requirements of society for living space; these factors find their external expression in the spatial order of this living space, its life system and its scenery. Buchwald views the landscape as the total living space and as a multi-layered Wirkungsgefuge: an interacting structure of both the geosphere and the biosphere. He designated to landscape ecology the important task of overcoming the tensions between modern society and its landscapes. Tensions which result, in his opinion, from the discrepancy between the rapidly increas- ing demands of the industrial society and the natural potentials of the land.

The term landscape ecology was introduced by Troll (1939), who realized the great potential of aerial photography to obtain an overall view of the landscape. He proposed to combine the “horizontal” approach of the geo- grapher, who examines the spatial interplay of natural phenomena, with the “vertical” approach of the ecologist, who studies the functional interplay at a given site-“ecotope”-as an ecological system. Later Troll (1 968) defined landscape ecology as “the study of the main complex of causal relation- ships between living communities and their environment in a given section of landscape. These relationships are expressed regionally in a definite distribution pattern and landscape mosaic and in a natural regionalization of various orders of magnitude”.

An important, first attempt at system-theoretical and cybernetic inter- pretation of landscape ecology was made by Langer (1970). He defined land- scape ecology as “a scientific discipline, dealing with the internal functions, spatial organization and mutual relations of landscape-relevant systems”. Like Dansereau, he considered the landscape-ecological system as the highest integrative level, above the autecological “monocene” system and the syneco- logical “holocene” system. This regional-ecological system integrates ecotopes as the smallest landscape elements. The term ecotopes has been proposed by Troll (1950) as a complex of biotopes and has both spatial-geographical and ecological dimensions.

Langer stated that the problems arising in the Kulturlandschuft are related not only to the natural sciences, but also to the social and cultural sciences, and he stressed the importance of the study of human influences through utilization and other anthropogenic impacts. In his opinion, landscape ecology can provide an overall view only in natural landscapes; in cultural landscapes it can merely define natural potentials of the anthropogenically influenced Wirkungsgefuge.

Langer (1973) also distinguished between bio-ecology and human ecology from a system-theoretical point of view, claiming that the man-environment system presents a special field of ecological observation: the “geo-social

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environment”, which is also relevant in planning processes. This has much in common with the techno-ecosystems referred to below, but lacks integration with a higher level of organization (see Section 1I.C).

In his 1970 paper, Langer cited Focker-Hanke (1959) who stated that “in the Kulturlandschaf, anthropogenic elements do not just join natural ones, but form units at a higher level: a true integration”. Langer, however, did not attempt to classify Natur and Kulturlandschaften from a system- theoretical point of view and this will be done in Section 1I.D.

B. Some Relevant Conceptual and Methodological Contributions

2. The Broadening of Phytosociology

In its formative stage, landscape ecology was conceived largely as a bio- geographical discipline. However, plant ecologists’(and in Central Europe this means phytosociologists and geobotanists), because of their field-oriented outlook and their concern with the open landscape and its natural and man- modified vegetation, quickly took a leading position in this field. They were joined by applied ecologists, foresters, agronomists and gardeners, as well as landscape architects and planners with an ecological outlook.

Without doubt, one of the central features in the theory of landscape ecology was the recognition of the dynamic role of man in the landscape and the quest for systematic and unbiased study of its ecological implications. For this purpose it was essential to eliminate preconceived Clementsian climax-succession dogmas from any methodological and practical con- siderations. These dominated not only American ecology, but were accepted almost without criticism by the Braun-Blanquet school of phytosociology. It was also important to broaden the scope of this methodology itself, from its sole reliance on floristic species composition, to include causal ecological relations between vegetation and environment, based on ecophysiological studies and insight. This has been achieved, to a large extent, through the contributions of some outstanding German ecologists, who educated a new generation of plant ecologists and others in related fields, who now occupy leading positions in landscape ecology.

A first, important step in this direction was the replacement of the term “climax” by the more meaningful “potential natural vegetation”. This was suggested by Tuxen (1956) and adopted by Schmithusen as the “potential Naturlandschaft”. It refers to the composition of the vegetation which would become established if man suddenly disappeared. It is based on current know- ledge of actual existing vegetation potential, its developmental tendencies and site relationships.

Ellenberg (1963, 1978) has shown that the vegetation of Central Europe

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is the result of thousands of years of human history and its impact of hunting, gathering, burning, cutting, coppicing, trading etc. “which did not leave a single spot in its original state”. It should, therefore, be considered as an old Kulturlandschaft and, because of the far-reaching changes in habitat con- ditions, it is impossible to reconstruct the pristine Urlandschaft. At most a reconstruction of the potential Naturlandschaft, sensu Tuxen, can be at- tempted, with the help of ecological, historical and geographical data, but even so, information is missing for many densely populated areas.

In Germany maps showing potential vegetation have been drawn, using phytosociological methods of the Zurich-Montpellier school (Trautmann, 1966). They have yielded important information for landscape planning and management and their interpretation had benefited much from the pioneering work of Ellenberg (1950) on man-modified pastoral and weed associations and the introduction of “ecological species groups” as criteria for plant com- munity classification. It was found that these could be used as indicators of climatic and edaphic conditions and thus the basis was laid for a successful synthesis with other classification and ordination methods which have become important in integrated landscape-ecological surveys. Ellenberg’s (1 956) summary of his methods has been revised and enlarged in an attempt to produce an integrated synthesis of European and Anglo-American ap- proaches (Muller-Dombois and Ellenberg, 1974). In recent years, Ellenberg has devoted himself to broadening the scope of ecology in Central Europe by initiating integrated ecosystem studies, especially the Solling project (Ellen- berg, 1971), which has become one of the most comprehensive multi- disciplinary forest and grassland ecosystem studies within the International Biological Program.

Ellenberg (1972) proposed the following definitions of the environmental burdens on ecosystems:

Landscapes, in general, are composed of mosaics of ecosystems which form a more or less closely integrated whole through their mutual relations. These can then be considered as ecosystems of a higher order. Burden (6): impact of factors, such as air pollution by SOz, or complex of factors, which do not belong to the normal natural system and are mostly man-induced. Liability to burden (D): liability of a certain ecosystem to be harmed by burdens on the landscape, e.g. a steep slope is more susceptible to water erosion than a less inclined one. Liability to temporary burden (L): extent and rate of changes in the equilibrium of the constituents, caused by burden in a certain ecosystem and/or in their abiotic conditions. It is the reciprocal value of the resilience or buffering against disturbance of the equilibrium by burden.

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Susceptibility to temporary burden (a: product of liability and temporary burden lability, S = D x L. If D and L are rated on a scale of 10, then S,,, = 100. Regeneration capacity and temporary load (R): the extent and rate of regeneration of an ecosystem which has been distorted by burden. Burden carrying capacity (B): A measure of the susceptibility of ecosystems to burden and their regeneration capacity expressed as B = kR( 100 - E), with k = 0.1 or 0.01, and R rated on a scale of 10. The kind of burden can be expressed by indices, such as bS02, D s o ~ , S S O ~ , Bso,, Snoiso etc.

As an example of this quantitative rating system, Ellenberg (1972) estimated for the first time the relative impact of SO2 in different ecosystems.

2. The Introduction of Ecophysiology and Dynamic Ecology One of the greatest influences in modifying the scholastic Clementsian and Braun-Blanquet dogmas, was H. Walter, who introduced eco-physiological methods into geobotany. In his Standortlehre, an analytical-ecological geo- botany with a holistic treatment of ecological factors, including the anthro- pogenic one, Walter ( 1960) prepared the ground for integrated ecosystem studies. In his monumental Die Vegetation der Erde in oeko-physiologischer Betrachtung (Walter, 1964, 1970), he provided a world-wide view of land- scapes, as covered by intricate patterns of dynamic vegetation types, for- mations and ecosystems, determined not only in floristic composition but also in structure, stability, diversity and productivity by regional climate, local site conditions, biotic interactions and human modification. In his intro- duction he refuted the theories of climax and primary succession and stated that even the “zonal vegetation”, typical of distinct climatic zones, corresponds to the climax concept only in a very limited way:

All attempts to save the climax concept by establishing a poli-climax term or by introducing climax groups or clusters are not satisfactory, because they still include the concept of primary succession. A certain dynamic view of the vegeta- tion is indeed justified. It should, however, not leave the ground of reality and lose itself in speculations. In this book, neither climax and succession stages, nor hierarchical plant

community classifications were mentioned, but the importance of burning, grazing and human intervention in shaping and maintaining these vegetation types was stressed, as was the need for continuous management as an eco- logical means of conservation, e.g. in the case of the Caluna and Erica heather formations.

3. The “Dutch School” of Landscape Ecology In the Netherlands a sound theoretical framework for landscape ecology and its practical, large-scale application has been provided by work conducted in

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the Botanical Institute of the University of Nijmegen and the RIN State Institute for Nature Conservation at Leersum. Those involved in landscape ecology have been inspired by the work on nature conservation and land- scape management and planning of Westhoff (1969, 1970, 1971), Moerzer Bruyns (1967) and Benthem (1952). Landscape ecology is firmly established in the extensive research carried out in the field of vegetation science. As in Germany, this has been based on the phytosociological methodology of the Zurich-Montpellier school, but original and highly advanced quantitative methods have been developed (Van der Maarel, 1969; Westhoff and Van der Maarel, 1978), and close links maintained with the applied fields of forestry, agriculture, hydrology, regional and town planning and land reclamation, as well as with geography and pedology. Dutch landscape ecologists with their good knowledge of English and German, have been able to incorporate into their methodology the most valuable concepts and techniques, not only from European, but also from Anglo-American sources and from modern ecology as a whole.

A central feature in Dutch landscape ecology is the recognition of the dynamic role which man has played over many centuries in creating diversity and stability. Van Leeuwen (1966, 1973) interpreted this role in a cybernetic way and formulated the “general relation theory” of pattern (changes in space) and processes (changes in time), and established the inverse relation between spatial and temporal variety. Westhoff (1971) and Van der Maarel(l971) have illustrated this theory with many examples. They distinguished two contrast- ing types of environmental boundary: the limes convergens or ecocline, characterized by (1) sharp boundaries between contrasting, adjacent sites, which fluctuate in time, (2) coarse-grained vegetation patterns, and (3) low alpha diversity (sensu Whittaker, 1972); and the limes divergens or ecotone, characterized by (1) gradual changes from one site type to another, (2) a fine- grained pattern and (3) high alpha diversity. The ecotone is maintained chiefly by small-scale, spatial changes in the environment, causing numerous small, stable boundaries, and was favoured by the former agricultural and mining systems. Ecoclines are currently being created through abrupt changes in management: cessation of grazing or mowing, burning and change of owner- ship, and are therefore highly undesirable for nature conservation when defined as the conservation of the highest potential landscape diversity.

In combining the ecological classification of landscapes according to naturalness (Westhoff, 1971) with a scale of the human influences on man- modified landscapes and ecosystems in Germany (Sukopp, 1972), Van der Maarel(l975) distinguished seven stages from “natural” to “cultural” in which both flora and fauna, vegetation and soil structure were controlled by man. Superimposing on this the stages of successional development from pioneer to mature, he arrived at an interesting three-dimensional ordination, which

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could be helpful in appraising landscapes for conservation and management purposes.

Van der Maarel(l975) claimed that over the previous 25 years European vegetation science had helped to show that a subtle balance existed between natural and cultural demands which enriches man’s biotic environment. He distinguished on the one hand “man-made natural ecosystems”, sharing pro- perties of the mature, resistant ecosystems, called by him “internally stable” and, on the other hand dynamic, elastic systems, called by him “externally stable”. He based practical suggestions for landscape management on this.

Van der Maarel made a plea to face the challenge of the very complex, interrelated patterns of man and his natural ecosystems at the landscape level. He referred to landscape ecology as the relevant science to deal with this challenge and complained of the little attention paid to it during the first INTECOL congress where he delivered his paper.

4. Conclusions

Landscape ecology views the landscape not just as an aesthetic asset and as part of the physical environment but as the total spatial and functional component of man’s living space, integrating geosphere with biosphere and noospheric, man-made artefacts. Landscape ecology thus extends beyond the purely natural realm of classical, biophysical and bio-ecological science and enters the realm of man-centred fields of knowledge, such as the socio- psychological, techno-economical, cultural and historical aspects involved in modern land uses. The question arises whether it thereby also approaches the definition of an interdisciplinary, human, ecological science with all the philosophical-epistomological and methodological implications, pointed out by Young (1974) in such a comprehensive way.

This can be comprehended only within the framework of a unified, eco- logical theory. Moreover, since Young’s (1974) review, several important developments have taken place in general systems theory, biocybernetics and eco-systemology which may contribute much towards advancing such a unified ecological theory and the role which landscape ecology could play in it.

C. Towards a General Biosystems Theory

1. New Insights into the Holistic Axiom

The relations between ecology and general systems theory have been discussed from the point of view of natural resources management by Schultz (1967) and from the point of view of human ecology by Young (1974). For landscape

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ecology both approaches are equally important and therefore should be amalgamated and used as a joint basis for future studies.

At the First International Meeting of Human Ecology in Vienna in 1975, organized by the Society for Human Ecology (Knotig, 1975), two sessions were devoted to the theoretical background of human ecology and its relations to ecology and other sciences. Although the terms systems, ecosystems and human ecosystems were mentioned in several papers and attempts were made to define their role in a theory of human ecology, the only contribution approaching the problem from a truly system-oriented point of view was that by Bierter (1975).

The philosophical basis of a general systems theory is the holistic approach to a hierarchical organization of nature as open systems with increasing complexity through the evolution of emergent qualities at each higher level of organization (Von Bertalanffy, 1968; Weiss, 1971). Egler (1942) was the first ecologist to recognize this approach, which is now generally accepted in ecology, as a central feature in vegetation science (Rowe, 1961; Dansereau, 1975; Buchner, 1971). Koestler (1969) introduced the term holon to charac- terize the unique nature of the systems at each integrative level of the hier- archical order: they are intermediary entities, functioning as self-contained wholes relative to their subordinates, but at the same time depending on entities at the next higher hierarchical level of integration. As Bierter (1975) pointed out, the term holon is most valuable to describe the comple- mentary aspects of being-part-of and wholeness, of differentiation and inte- gration in ecological systems and it will be used in our further discussion.

The holistic axiom that the whole is more than its parts, has been restated in quantitative terms by Mesarovic et al. (1970). Using a quantitative description, Weiss (1969) has shown that because of the constraints on the degrees of freedom of component parts as a result of system behaviour, the variance of the total system V, is less than the sum of the variances of its elements (V,,, vb, V,, . . . V,,): V, < V,, + Vb + V, . . . V,,. Thus, coordination and control become the emergent qualities of the new holon.

An example of this holistic axiom has been cited by Lorenz (1973). He referred to the work of Hassenstein (1970) which showed, by means of a simple electronic model, how the coupling of two independent electric circuits cause the sudden, flash-like emergence of a new system with its own qualities and behaviour. Lorenzcalled the sudden birth ofa system with new properties, which cannot be expected or predicted from the properties of each holon, fulguration (jiulguratio = lightning flash), and attached great importance to its occurrence in evolution. He stated that “cybernetics and system theory have freed this sudden creation of a system with new properties and new function from the odium of a miracle”.

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2. Living Systems and Ecological Systems- “Biosystems ”

In recent years, general systems theory has been expanded into general living systems theory. Miller (1975a, b) has distinguished between abstract, con- ceptual systems and concrete systems, as real entities which have definable space and time relations. He identified seven levels of living systems, with the cell as the lowest and the supranational system as the highest, whilst Rowe (1961) pointed out that ecosystems integrate these living systems and their physical environment, and should be considered as a higher level of inte- gration.

As open systems, ecological systems as well as living systems exchange energy, matter and information with their environment which enables them to renew their components and to maintain their structure in a state of dynamic flow-equilibrium. But as a result of the fulguration process, whereby a system with new properties evolves as a result of system interaction, new isomorphs arise from the integration of these living systems and their environ- ment. These are the main subjects of ecological research. It would be most revealing to identify, on a similar basis to that used by Miller, the isomorphs of the most critical subsystem of both natural and human ecosystems. If this were achieved, it would prepare the ground for a truly integrated theory of living and ecological systems or biosystems.

3. Reductionistic Tendencies and Cybernetic Approaches

Young (1974), in discussing the relationship between general systems theory and human ecology, warned that “a general system approach could return us to a discarded mechanistic focus, ignoring the reality of man”. He also doubted whether the methods of definition and measurement utilized in biological ecology were acceptable to human ecology and whether such techniques as the mathematical analyses of ecosystems might not be directly applicable to human systems. Egler (1970) expressed a further serious warning that “the scientific and ecological concepts may wither and only the dry technology of system analyses be left”. He claimed that the advent of the computer had often “encouraged the trivialization of scholarship and the belief that the things that count are those that can be counted”.

There are real dangers in this. There is a reductionistic tendency which depicts energy exchange as the only basic process, not only in natural eco- systems, but also in human systems. However, energy flow diagrams and models (Odum, 197 1) provide only simplistic “ecological” explanations of human systems which could be interpreted as a new kind of neo-materialistic “energy marxism”. As Ellenberg (1973) rightly remarked, this would be harmful both to ethics and to ecosystem research. In order to avoid this

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danger, it should be emphasized that the quantitative and functional energetic aspects, measured by energy and matter flow in ecosystems, must be comple- mented by a qualitative description of the structural aspects of regulation, as measured by information exchange.

Cybernetics, the scientific discipline dealing with regulation of ecological systems, was developed by Wiener (1948) for system engineering and com- munication and extended to biology by Ashby (1963). It is now also widely used in the rapidly growing field of mathematical ecology and in system analysis (e.g. Dale, 1970 Patten, 1971; Caswell et al., 1972). Its scope has been considerably broadened in Germany, as is demonstrated by the excellent Worterbuch der Kybernetic (Klaus, 1969) and, with a “marxist-dialectic’’ interpretation, it has also become an important scientific discipline in Eastern Europe.

Important contributions on the application of cybernetics to human biology, ecology and environmental education have been made by Schaefer (1972,1977) and to the theory of landscape ecology by Langer (1970) and Van Leeuwen (1966). Cybernetic-mathematical models have been suggested in landscape ecological studies by Bauer et al. (1973), but of greater significance is the biocybernetic approach to human ecology and environmental planning by Vester ( 1 976).

Lorenz (1973) approached the problems of energy, information and evolu- tion from a cybernetic point of view. He stressed that the gain and storage of information relevant for survival of the species in evolution is as vital a process as that of gain and storage of energy and that these two processes are coupled by positive feedback loops. This coupling within a cybernetic cycle results in a synergistic effect. It is the prerequisite for life, provides an explanation of how “life is able to hold its ground facing the superior force of the merciless inorganic world”. It also helps to provide a solution to the riddle of speed and direction of evolution. Life can be regarded as gain of information, that is a cognitive process together with an economical one.

According to Lorenz, the high organization of social cooperation in primates was the prerequisite for the creation of human society, a “fulgura- tion”, which resulted in the integration of conceptual thinking, syntactical language and a cumulative tradition in cognitive performance. The concrete realization of such a supra-individual system is called a culture. However, Lorenz emphasized that although there is the same positive feedback coupling information and energy gain, in the formation of a culture as in the survival of a non-social organism, the transfer of acquired knowledge is done by a different mechanism. Man is the only living creature who mobilizes energy, apart from solar energy which enters the living cycle through photosynthesis. Our planet now faces the results of this positive coupling of gain of informa- tion and energy by homo industrialis. We shall refer to it below in discussing

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our man-made and driven techno-ecosystems as lacking negative feedback coupling, and therefore also lacking in homeostatic regulation.

4. Prigogine’s Theory of Selforganization and Human Systems

A major breakthrough has occurred recently in the field of non-equilibrium thermodynamics with the discovery of the principle of “order through fluctuation” (Prigogine and Nicolis, 197 1; Prigogine, 1975; Prigogine et al., 1972; Nicolis and Prigogine, 1977). This principle may cast some doubts on the validity of the Second Law of Thermodynamics as interpreted by Boltzman’s ordering principles and perhaps resolve the apparent contradiction between the general trend of increase in entropy and dissipation of structure and the increase of neg-entropy towards higher levels of organization of life and creation of structure in the evolutionary process. Contemporary reductionistic biologists, like Monod (1970), have tried in vain to explain this by the process of random fluctuations, which would result in the random formation of macromolecules and in the process of evolution. However, according to Prigogine’s theory of “order through fluctuation”, systems which are partly open to the inflow ofenergy, matter and information, are in a non-equilibrium state. They tend to move through a sequence of transitions to new regimes which in each case generate the conditions of renewal of high entropy pro- duction within a new and higher regime of organization and thus open up possibilities for the continuation of metabolizing activity for life. The recog- nition of behaviour of such “dissipative structures” has opened the way for a new theory of self-organization of physical systems. As Prigogine (1976) and Nicolis and Prigogine (1977) have shown this theory is valid not only in the physical domain but also in the biological and ecological domain, and according to Jantsch (1975) also in the social and spiritual realm of man. He pointed out that “order through fluctuation” seems to be a basic mechan- ism, penetrating all hierarchical levels of human systems, organizations, insti- tutions and cultures, as well as the overall dynamic regimes of mankind as a whole, which evolved from hunting and fruit collecting to primitive agriculture and hence to our global systems of cooperation. In his opinion, social sciences had recognized only external, “Darwinian” factors and he tried, successfully, to shed some light on internal factors in the evolution of human systems which have great relevance to this discussion.

Jantsch distinguished three basic types of internal self-organizing be- haviour:

(1) Mechanistic systems, which do not change their internal organization. (2) Adaptive (or organismic) systems, which adapt to changes in the environ- ment through changes in their internal structure in accordance with pre- programmed information (e.g. engineered or genetic templates); to these

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belong all non-human bio-systems and we shall refer later to this type of information as “biophysical information”. (3) Inventive or human action systems, which change their structure through internal generation of information (invention) in accordance with their intentions to change the environment. Such information is generated within the system and in feedback interactions with the environment. The evolutionary time scale for adaptive systems in the biological domain corresponds to what Teilhard de Chardin called the “unfolding of bio- genesis”, whereas for inventive systems in the human domain it would correspond to noogenesis (referred to as “cultural information”).

In relation to planning, this implies, according to Jantsch, our integral participation as regulators in the system to be regulated.

5. Bio-cybernetic Regulation and the Total Human Ecosystem Concept

Vester (1976) has stressed the high technological efficiency characteristic of the use of energy/matter and cybernetic information in biosystems, in contrast to the low efficiency of human technology and has described both in terms of certain basic biocybernetic rules which all viable biosystems obey. Amongst these are negative feedback coupling, to ensure that the system settles down to a stable equilibrium, recycling, re-use of everything produced, and the highly efficient and economical utilization of energy, particularly where sources other than direct solar energy are involved, e.g. energy in cascades, chains and coupling; the principle whereby force is not combatted with a counterforce, but is merely diverted and controlled cybernetically and is thus utilized for the purpose of the receiver, e.g. as in jiu-jitsu. These laws also include symbiosis and the principle of multiple use. The final rule, also to be applied in human systems, is the basic biological design, bringing organizational cybernetics together with creative “bionics”. This is the exploitation of the information gained from biological systems for techno- logical purposes (Vester, 1974) so that every product, function and organiza- tion should be compatible with the biology of man and nature.

Vester made the suggestion that these rules are the internal rules of all viable biosystems from the cell up to the largest ecosystem, the biosphere, and that they should also apply to the system of human civilizations, which according to his definition, is one subsystem of the biosphere. He argued that they should provide a far better guarantee for survival and further evolutionary development than, for instance, “such a stupid premise as a single-tracked compulsion towards economic growth”.

This evolutionary strategy implies the ability of biosystems to alter their

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behaviour and “jump to a higher organizational level, when reaching critical stages of density”. In Vester’s view these stages have been reached now:

Humanity and its man-made artificial systems (roads, towns, factories, mines, agriculture, etc.) were for a long time located relatively far apart on earth. However, due to the increasing population density, these systems have been crammed together so closely that a multitude of chemical, physical, energetic and social interactions have emerged between these, man and the biosphere. Inter- actions which have led to a new subordinate system: that of human civilization on this planet!

This system is not necessarily stable and viable. It may destroy itself and be eliminated from the biosphere, if it does not obey the above-mentioned funda- mental roles.

The main reasons for the ecological, sociological, economic and political prob- lems, such as man has never known before, are a lack of knowledge of these laws or failure to observe them. As long as our changed situation is not compre- hended and the interlaced network is not realized-and even when these changes are realized, they are described in such a complicated way that they cannot be understood-we will continue to suffer ever greater setbacks and be forced to redouble our efforts in order to carry on just a little longer in the old way, all the time increasing our energy and raw material consumption. To put it briefly, what we need are new decision-making aids.

These should also be used in integrated land use planning and as an educational illustration of this, Vester used an environmental simulation game in which a simple but ingenious cybernetic sensitivity matrix of environmental interactions at the landscape level is applied.

As already mentioned, Egler (1942) was one of the first to realize the holistic nature of ecology and he criticized the conceptual and methodological weak- ness of contemporary plant ecology in failing to take account of this. More than 20 years later, Egler (1964) used the example of the failure to cope with the pesticide problem through scientific, ecological information to demon- strate the urgent need for holistic human-ecosystem ecology as the highest “ninth” level of integration, above the biocommunity and ecosystem level. In this “man-plus-his-total-environment form a single whole in nature that can be, should be and will be studied in its totality”. Egler (1970) called this the total human ecosystem and stated:

The chief goal of human ecosystem science is a knowledge of, and man-oriented technology towards, a permanent balance between man and his total environ- ment, both operating as part of a single whole, that will afford a life of the highest quality.

As a highly qualified plant ecologist, Egler has devoted much of his energy in the past 30 years to the development of “vegetation management”. He summarized his experience in this field in what could be considered one of the

204 ZEV NAVEH

first human ecosystem science books (Egler, 1975). He thereby became one of the first human-ecosystem/landscape ecologists in the United States.

D. The Role of Landscape Ecology as a Human Ecosystem Science

I . The Ecosystem Classification of Ellenberg

In the foregoing section, attention has been focused on certain conceptual developments which have occurred almost simultaneously and which have contributed much, in my opinion, to the consolidation of a general biosystems theory, and serve as a basis for a unified ecological theory and for the inter- disciplinary concepts of human ecology.

This is a holistic, scientific theory of hierarchic order of open, living and ecological systems as holons with biocybernetic self-regulation and feedback control, and with the total human ecosystem as its highest level of integration.

That such an integration is conceivable is clearly indicated by the thermo- dynamic findings of Prigogine on “order through fluctuation of dissipative structures”, as a “fulguration” envisaged by Lorenz in a cognitive process in human cultural evolution, in Jantsch’s socio-ecological terms as noogenesis in “inventory human systems”, or, in Vester’s biocybernetic language, as a “jump to a higher system level of organization”. That this should be the chief aim of human-ecosystem ecology has been stated clearly by Egler.

After having outlined the broad framework of such a biocybernetic system- theoretical and ecological philosophy, or human ecosystemology, there is need for elucidating the role of landscape ecology and this can be accomplished only after a more concise definition than has been attempted to date, has been given of the semantic relations between natural and human ecosystems and of natural and cultural landscapes within a classification or ordination system. In this respect the recent ecosystem classification, proposed by Ellen- berg (1973) is of great value and can be used as a starting point for our considerations.

According to his definitions, “ecosystems are Wirkungsgefuge, interacting structures, formed by living organisms and their abiotic surroundings, which are to a large extent self-regulatory”. As functional units, ecosystems cannot be typified and ordinated in the same way as some of their components and therefore existing classifications of communities, climatic and edaphic types etc. can only assist, but not determine this classification. Because of our very limited knowledge of the diverse, smaller ecosystems, Ellenberg proposed an inductive, hierarchical classification, starting from the most extensive and complex ecosystems. His first grouping relates to their similarity in main

LANDSCAPE ECOLOGY 205

functional criteria, e.g. dominant life media (air, water, soil), primary pro- ducers and their limiting factors for production, material gains and losses, relative role of micro- and macroconsumers and the role of man in creating a particular ecosystem and its energy and raw material cycling, especially with regard to additional energy sources. The term “ecosystem” has no rank and can be used in the abstract, according to the classification hierarchy and nomenclature e.g. “limnic ecosystem”, and in the concrete, sensu Miller, e.g. “Lake of Galilee limnic ecosystem”.

Contrary to the widely held misconception, the biosphere should not be regarded, according to Ellenberg, as a higher level of integration on its own, but as the most extensive and diverse concrete global ecosystem. It has been subdivided by Ellenberg into two major groups, namely natural ecosystems, which more or less depend on solar energy, and urban-industrial ecosystems, which depend on fossil energy (and increasingly on nuclear energy). In this classification, Ellenberg has dealt only with subdivisions of the first group, according to size and function.

2. Bio-ecosystems and Techno-ecosystems as Holons of the Total Human Ecosystem

When we clarify the fundamental functional differences between the two groups of ecosystems, we must conclude that the biosphere can be regarded only as the largest natural or, more precisely, biological ecosystem, in short bio-ecosystem. On the other hand, the urban-industrial or technological ecosystems, techno-ecosystems, in lacking the biological function of photo- synthetic conversion of solar energy, cannot be regarded as part of the biosphere. Thus, in accordance with the definition that ecosystems have no rank, the latter form the largest global techno-ecosystem or the technosphere. Consequentially, the largest entity embracing both biosphere and techno- sphere, together with relevant parts of the geosphere, is the ecosphere. In the technosphere, man with his technological skills, has overstepped the eco- logical and spatial limits set to life in the biosphere and thus, the ecosphere of “homo industrialis” includes all those parts of the geosphere, the atmos- phere, lithosphere and hydrosphere, which are directly or indirectly influenced by him. He has also overstepped the limits of the geosphere in the stratosphere, with far-reaching ecological consequences for life on earth.

All natural or man-modified ecosystems should thus be regarded as bio- ecosystems in which autotrophic organisms are the primary basis for pro- ductivity. These are maintained by inputs of solar energy, natural biotic and abiotic material resources and are regulated chiefly by bio-physical informa- tion. On the other hand, techno-ecosystems are designed, made, maintained and controlled by man through inputs of fossil energy, man-made or con-

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verted material from the geosphere and biosphere and are regulated by cultural noospheric (scientific, political, spiritual, technological etc.) informa- tion, processed by human industrial civilizations.

As mentioned in the previous section, biocybernetic feedback control has evolved as one of the structural features of higher complexity during the long evolution of natural bio-ecosystems, ensuring their viability. Techno- ecosystems, on the other hand, are the very recent creation of man’s civilization and as such they are fed on positive feedback loops of energy/ matter and cultural information, but lack the biocybernetic feedback control, inherent in “adaptive biological systems”, sensu Jantsch.

Since the second industrial revolution they have grown rapidly into pro- gressively larger urban-industrial complexes, showing not only symptoms of what Vester (1976) called the “urban crisis” syndrome, but threatening at the same time the bio-ecosystems with direct replacement, environmental pollution and what Naveh (1973a) called the “syndromes of neo-technological landscape degradation”.

However, man as a biological creature is dependent for his existence on the viability of natural and agricultural bio-ecosystems. His techno-ecosystems cannot survive without the biosphere, and their exponential growth may endanger not only the biosphere but also the technosphere itself.

Modern man occupies a dual position, serving as a receiver of vital inputs from the biosphere and geosphere but, through the outputs of the techno- sphere, concurrently modifying the biosphere and the geosphere. He is thus

Fig. 1. Modern man-the affector and the affected.

LANDSCAPE ECOLOGY 207

affecting and being affected by these modifications (Fig. 1). This dichotomy in man’s position, of dependence and independence, has probably been the major cause of the vague semantic and conceptual differentiation between human and biological ecosystems. It is a result of his closely interwoven bio- logical and cultural evolution, his biogenesis and noogenesis. For millions of years, primeval man was an integral part of natural bio-ecosystems, until his cultural evolution added unique psycho-sociological and techno-economical dimensions to his biophysical nature. This lead in very general terms to the creation of both an abstract system, the noosphere (or if the sociosphere is regarded as a separate entity, of two abstract systems), and a concrete, spatial and physical system, the technosphere, in addition to the existing bio- sphere and geosphere.

More detailed discussions of the complex, cybernetic nature of human systems are given by Lazlo (1972) and Jantsch (1975). The latter sketched these basic systemic dimensions in relation to a hierarchy of natural systems (physical, biological, social and spiritual, named by Lazlo “cognitive”) and stressed their dynamic and simultaneous interplay.

From the ecological point of view this dichotomy of man’s position in nature can be resolved only by recognizing the holon properties of man, biosphere and technosphere as autonomous wholes towards their sub- ordinates, but at the same time as dependent parts of a higher controlling whole, integrating man and his total environment, the biosphere, techno- sphere and geosphere, i.e. the ecosphere, into the total human ecosystem, as termed by Egler (Fig. 2).

3. Re-dejinition of Landscape and Landscape Ecology

The visual and spatial integration of biosphere, technosphere and geosphere already exists in the landscape. But now we can redefine it as the concrete, space/time entities of the total human ecosystem, with the ecotope as the smallest and the ecosphere as the largest, global landscape unit.

In Fig. 3 an attempt has been made to present a model of the relation- ships between different, major ecosystems holons and their concrete landscape units. These are distinguished as different types of open, cultural and built-up landscapes according to the kind and size of energy, material and information inputs from these holons and the increasing dominance of man-made artifacts. They can be viewed as a continuum of increasing modification, conversion and replacement of natural bio-ecosystems. At the present rate of exponential urban-industrial expansion, there is an alarming tendency towards the lower left corner of this ordination and towards the creation of more and more monotonous cultural landscapes. It is now obvious that this “neo- technological landscape degradation” is characterized by an increasing input

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Ecosphere

Natural and Semi- Natural Bio-Ecosystem

Agricultural and Seml- Agricultural

Bio-Ecosystem

Geosphere

0 u

Geosphere

Ecnsohere

Urban Industrial Techno - Ecosystem

Rural Techno

Ecosystem

Fig. 2. The ecosphere and its holons as concrete systems of the total human ecosystem. To the left of the Geosphere is the Biosphere, and to its right is the Technosphere.

of cultural information, fossil energy and man-made waste material from urban-industrial techno-ecosystems, together with the loss of natural and spontaneously occurring organisms and the natural negative feedback loops which ensure environmental stability and resilience (Holling, 1973). These are substituted by agro-technical, chemical and engineering feedbacks which are not a subordinate part of the hierarchy of homeostatic feedback controls of the biosphere and cause “side effects” of environmental pollution. At the same time, the vital role of the natural vegetation canopy in this homeostatic control which acts as a “living sponge” and ensures the closed loops of bio- geochemical cycles, is diminished more and more.

It has recently become apparent (Woodwell, 1978) that the large-scale reduction and harvesting of dense forests or their replacement by agricultural crops may have disastrous long-term effects on global stability by disturbing the carbon cycle. The contribution to the steady increase in atmospheric CO2 made by the reduction in forest cover is even greater than that made by industrial fuel burning.

We come to the conclusion that to ensure our survival and that of our techno-ecosystems, their visual and spatial integration in the landscape with biosphere and geosphere must be complemented by a functional and struc- tural integration through change towards a new dynamic regime at a higher state of complexity. As Prigogine has shown for dissipative structures such as

LANDSCAPE ECOLOGY 209

I

( Semi-agricultural

\ landscape

\

- - Rural \ landscape

I I \

Urban-industrial landscape L - - - - - -L - -landscape Bio- where Techno- sphere

Built \ \ I landscape

Cultural 1

Modification-Conversion-Replacement of natural bio-ecosystems A Bio-physical information and control ACultural information and control 0 Natural organisms *Man- made artifacts G.olar energy NFOSSII fuel energy

Fig. 3. Ordination model of major landscape units as concrete systems of total human-ecosystem holons.

open ecological systems, this new dynamic flow equilibrium should not be considered as a stationary state but as a flow process. For its preservation in epigenesis and evolution Waddington (1970) has coined the term homeo- rhesis and Jantsch (1975) suggested its use also for the evolution of human systems, instead of the term “homeostasis” which may lead to the mistake of assuming that a stationary equilibrium of our “world model” can be reached.

By supplying regulative feedback in the decision-making process landscape ecology could play an important role by furthering the functional and struc- tural integration of the concrete spatial entities of the human ecosystem holons at their most critical interphase with man, namely land use. Indeed, this should be the chief goal of landscape ecology as a human ecosystem science.

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111. PRACTICAL CONTRIBUTIONS OF LANDSCAPE ECOLOGY

A. Major Contributions in Central Europe

1. Landscape Ecology as Part of Landscape Care and Management

According to the Handbuch f i r Landschaftspfege und Naturschutz (Buchwald and Englehart, 1968), landscape ecology provides on the one hand, if protec- tion of the organic world of plants and animals takes precedence, the scientific basis for nature conservation and, on the other hand, if the function of the landscape as a living space for man is to take precedence, the scientific basis for landscape care. Landscape care is considered together with nature con- servation and arrangement of green areas as part of land care (Table 1).

The following definitions have been given (Woebse, 1975): Landespjlege, land care: to protect, care for and develop all the natural

life supports of man in residential, industrial, agricultural and recreational areas. It aims at a balance between the natural potential of the land and the demands of society.

Landschaftspjlege, landscape care: to protect, care for and develop land- scapes for optimal sustained productivity by man. Management with this objective aims to prevent damage to nature’s system and landscape scenery and to repair damage already done. It requires that the historical, biological, ecological, social and economic factors which cause changes in the landscape, be investigated. Such investigations involve landscape analysis and diagnosis and an understanding of landscape construction and use with care (pfegliche Nutzung), of the natural resources in the open landscape.

Grinordnung, green arrangement: to safeguard the spatial and functional arrangement and coordination of all green areas and green plantings within the urban development which are essential for man’s spiritual and physical well-being. It is done on the basis of social, biological-ecological and economic considerations. It includes analysis and diagnosis of the contribution of green areas and their maintenance at city boundaries integrated with landscape care.

Nature conservation is carried out both in open and settled landscapes. It aims to safeguard landscapes and landscape units which are worthwhile for cultural, scientific, social and economic reasons and includes care for endangered animal and plant species and their habitats. It can be achieved through general landscape protection as well as through the establishment of protected areas.

Table 1 Land care and management (LandespJege).

Land care

Arrangement and planning of green Landscape care: land protection, areas planning and design; ecological landscape units and conservation

engineering (bio-engineering) Management

Nature conservation: protection of

Designing Maintenance

Built-up landscape Open landscape

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2. Ecological Design and Planning Woebse (1975) has made some important statements on ecological design which clearly illustrate the differences between the European landscape- ecological approach and the purely architectural aesthetic approach prevalent amongst landscape architects in the English-speaking world.

Amongst Europeans the following criteria are used for the evaluation of landscape quality:

( 1 ) The maintenance of natural functions, structure and ecological equi- librium. To do this the designer must be well-versed in natural sciences, understand ecological principles, the natural potentials of the landscape and the changes in the equilibrium which are induced by economic use.

(2) Site factors of climate and soil. (3) Geology and geomorphology. (4) The present shape of the land with vegetation and cultural artifacts.

Evolution must take into consideration dynamic changes occurring in the landscape and these contrast with the static endproduct of architectural design.

In recent years it has become increasingly apparent that the problems of landscape care and landscape planning and thereby also of landscape ecology, are closely interwoven with other inter-disciplinary aspects of regional and urban planning. In Germany, this has led to a broadening of the basic concepts.

The study group TRENT (1973) reviewed some hundred landscape plans carried out between 1967 and 1972 in West Germany. They stressed the need for revision of the foregoing criteria to ensure that landscape planning becomes closely integrated with regional planning:

Landscape planning must define in a more specific way its status between spatial planning (Raumordnung), and the contact-professional branches of planning, such as leisure-time planning, agricultural planning etc. It must abandon its defensive position in order to fulfil the requirements of dynamic development plans and to provide the foundation for the decision-making process in land use, to improve its methodology.

It was proposed to change the term Landschaftspflege into Landschafts- plannung, landscape planning, and to abandon the distinction between open landscapes and built-up green planning. One of the most far-reaching decisions was to regard ecological planning as the central tool of landscape planning. As such it should not be concerned directly with the “use with care of natural resources” (see above, because this is the aim of the specific professional disciplines, such as forestry, agronomy, water engineering etc., but it should judge the impact on “the natural foundation” (impact analysis). However, an optimal design cannot be achieved if impact analysis is limited

LANDSCAPE ECOLOGY 21 3

exclusively to material loadings. The scenic appearance (Erscheinungsbild) of the geofactors and their protection must be included in the analysis. In this way landscape design and nature and landscape protection are objectives of the overall plan.

3. Landscape Ecology, Planning and Management

In the past many landscape ecology studies have been carried out as integral parts of landscape planning projects, some on a large scale as for example in the Netherlands, Switzerland, Belgium, West Germany, Sweden and in various East European countries. These have been ordered by federal, regional or local authorities and carried out by special government agencies, uni- versities or private landscape planners. A survey of these studies was published in the Proceedings of a German Society for Ecology meeting at Erlangen, in 1974.

Langer (1970) discussed the relationship between landscape care and land- scape ecology and regarded the planning-oriented landscape ecology as both a scientific and practical part of landscape care and management which was involved in three problem areas: (1) to determine the functional aspects of the loading which anthropogenic influences place on the landscape and to define the need for special care of landscape components and ecosystems; (2) to determine the spatial aspects of landscape ecology assessment in regional planning requirements, and (3) to examine the methodological aspects of land-use planning and management in relation to landscape ecology. The Federal Institute for Nature Conservation and Landscape Ecology at Bad Godesberg, Bonn, has played a leading role in the introduc- tion and formulation of landscape ecology principles and methods and their practical application in regional planning and development (Olshowy, 1972).

Olshowy (1975) has described in some detail the contribution of landscape planning related landscape ecology through inventories (analysis) and evaluations (diagnosis) of landscapes. Such inventories are carried out both on large scale maps, 1 : 200,000, and on more detailed, regional maps, 1 : 25,000, and include maps of natural vegetation and the distribution of wild flora and fauna, current agricultural, forestry and other land uses, protection areas, areas with extensive damage by soil erosion and local climate. The landscape diagnosis is intended for nature conservation, recreation, agriculture, forestry as well as for settlement, traffic and other land uses (Bauer, 1973; Dahmen, 1973; Olshowy, 1973).

One of the most relevant contributions is the preparation of maps of the potential natural vegetation of West Germany, which covered some 4000 km2 by 1970. They serve as valuable guides for regional and local planning for landscape development, agriculture, reforestation and revegetation, planning

214 ZEV NAVEH

of highways and waterways, mining operations etc. and are used to guide the selection of trees and shrubs (Trautmann, 1973; Olshowy, 1973).

At the same time, actual vegetation maps are widely used and, with other aids (e.g. remote sensing), have been applied in Scandinavia for multiple-use planning (Schiirholz et al., 1972). The interpretation of vegetation types through aerial photography has, as predicted by Troll (1939) offered a wide scope for an ecologically based land appraisal (e.g. Schneider, 1973). The use of aerial photography interpretation methods in landscape ecology studies and elsewhere has been discussed by Zonneveld (1972) (see also Whyte, 1976).

An important abstracting service in landscape ecology and related subjects is provided by the Federal Institute for Nature Conservation and Landscape Ecology through its Dokumentationen fur Umweltschutz und Land- schaftspjege. Established in 1950, i t had reviewed 13000 studies by 1972.

An important contribution to the development of landscape ecology as a scientific and practical discipline has been the establishment of special chairs of landscape ecology in universities. At the Technical University of Aachen the department is closely connected with the Faculty of Architecture. Its main achievements are in the field of landscape planning and design and in the education of regional planners. Amongst the many research and planning projects (reviewed by Pflug, 1973), one of special interest is the study of the city of Aachen and its natural supplying and compensatory regions. For this study, a system-analytical model was prepared which described the specific needs for natural resources of this industrial town of 160000 inhabitants, the flow of goods from and to the built-up area and the network of interdependence and influences of all natural factors in the surroundings.

The Institute for Landscape Ecology at the Technical University of Miinchen at Freising Weihenstephan, has closer links with agriculture and forestry and in addition to academic teaching, research and planning activities, much effort is devoted to formulate and apply multiple-use politics (Haber, 1971). This institute produced an outstanding example of a landscape ecology study in using hydrophytic plants and communities as bio-indicators of eutrophication and pollution of the Mosach river system. This served as a basis for practical recommendations for control and landscape reclamation measures (Haber and Kohler, 1972).

At the University of Miinster on the other hand, the chair for landscape ecology and “geo-ecology” is attached to the Institute of Geography, so keeping alive the tradition of the late G. Troll. In a memorial lecture Schreiber (1977a) stated: “The basic concept of the science, named landscape ecology by G. Troll, has remained the same, despite the present pre-occupation with environmental conservation. It consists in the exploration, within a given landscape, of the total environmental interaction patterns of all inter- dependent factors, including man”.

LANDSCAPE ECOLOGY 215

In this lecture, Schreiber stressed the “open plan” character of the landscape and the functional interconnection of different, sometimes widely distant eco- systems. He also suggested that the concepts underlying the techniques for the assessment and presentation of ecological structures are still in the early stages of development. He applied a geographical approach to defining ecological- spatial units in a landscape classification designed for use in planning (Table 2). Identification of the smallest workable units is determined by criteria of homogeneity within and between units. In general, ecological field methods used to map forests and agricultural resources, yield small ecological regions or ecotopes. These are sometimes confusing for the planner and Schreiber proposed to combine these into larger regions according to contiguity and similarity of the landscape. He did this (Schreiber et a!., 1976) in the ecological delineation of agricultural potentials within the framework of comprehensive agricultural planning for Baden-Wiirttenberg. However, he remarked that for hydrological purposes the catchment area and its watersheds “cut right across ecological unit patterns and landscapes, conceived in the geographical sense, and at times can connect parts of different landscapes with each other. In this context, the patterns of water flow have dictated a functional con- sideration instead of any other spatial linkage”.

At present, landscape planning is used chiefly as a tool for making decisions about the impact at landscape level of different land uses and the conflicts arising from these. In Schreiber’s opinion it should take into consideration the flow of resources, connecting individual areas and regions. However, even the most sophisticated, computerized methods of landscape analysis cannot overcome the main problem in landscape ecology, namely the lack of basic ecological data on the functional and structural features of bio-ecosystems and whole landscapes. This shortage of data exists for both the energy pro- duction aspects of ecology and the regulatory, compensatory “life support” and environmental-protection aspects. This information should be collected, stored, computed and modelled in such a way that it could provide more reliable answers on the most pressing questions about the present burdens on the landscape and predict its behaviour under future ones. Although many studies are carried out which use modelling and simulation methods to arrive at such predictions, especially on water quality, they lack this compre- hensive landscape ecology approach and their translation into practical planning and decision making terms is very difficult. A striking example of the kind of basic information on flow of resources is the watershed ecosystem con- cept study by Bormann and Likens (1968) of the Hubbard Brook Experi- mental Forest in New Hampshire.

Schreiber (1977b) used the annual phenological development of the plant cover as a measure for the thermal scales and demarcations of climatic regions in Switzerland and was thereby able to delineate topoclimatic problem areas

Table 2 Order of work, results and aims of a classical ecological landscape classification (I, 11) and present utilization (111). As an aid in deciding on the utilization alternatives and to help resolve the conflict of aims within the framework of a complete ecological landscape plan (IV), there must be an evaluation of the ecological consequences of a particular use and also a spatial demarcation

of use (Schreiber, 1977).

I I1 I11 IV Classification of Demarcation of natural Evaluation of natural Evaluation of the ecoloeical

Order the natural of conditions work Landscape

ecological analysis

conditions

Landscape ecological synthesis

Y

potential utilization

Ecological re-modelling Problem-oriented ecological-

consequences of a particular form of utilization

effect analysis

Soil Water budget

Contents Vegetation and Micro-climate results Topography

etc.

Aims

Prognostication variable For: In relation to: Agricultural cultivation The ecological spatial unit

Hydrology (Hydrotop) eco- Forestry Related or inter-connected Vegetation (Phytotop) logical Melioration spatial units

Morphology (Morphotop) units Infrastructures demands etc. Storage of waste

Soils (Pedotop)

Climate (Klimntop)

etc. (Ecotop, Habitat, etc., with nearly Recreation identical conditions and identical etc. ecological potential.)

spatial Building Other uses or utilization

1

1 Association with ecological units Inclusion in specialized planning, Formation of functional spatial (Ecotop pattern) e.g.: units classified according to inter- Demarcation of natural spatial Utilization plan for agri- connection through the flow of units classified by internal cultural areas matter (catchments, smoke locational interaction, natural Utilization plan for forestry emissions, etc., including the spatial units and land- Regional agricultural planning extent of the effects)

character. etc. scapes of a certain (focal points of cultivation) 1

Inclusion in ecological landscape + planning

LANDSCAPE ECOLOGY 217

of which particular account must be taken in planning considerations. He also stressed the importance of biological indicators with integral characters to which quantitative expression can be given. He adopted a dynamic approach both to nature conservation, demanding active interference in order to con- serve what seems most worthwhile from the ecological point of view (Schreiber, 1977c) and to the controversial problem of soziul Bruche, thou- sands of acres of derelict agricultural land lying fallow because to cultivate it is no longer profitable. More basic knowledge is required before deciding whether to leave this land until it reaches a final “climax” stage, to preserve it by simulation of previous agricultural and pastoral practices, as for example, in the Netherlands and the UK with certain types of grassland and heather, or to transform it by extensive afforestation or other means into a new recreational landscape. Therefore a series of long-term secondary succession studies is being carried out (Schreiber, 1976) in which the effect on vegetation and soil of all types of management practices, such as burning, grazing, killing weeds, mulching, cutting, etc. are carefully investigated.

Schreiber (1977a) summarized the most relevant contributions of landscape ecology to the field of planning and environmental protection as follows:

(1) Establishment of a new concept of a functionally oriented ecological landscape classification.

(2) Cooperation in experimental investigations into different aspects of ecosystem research, in order to obtain the basis for an ecological landscape classification, particularly for problem oriented ecological impact analyses of certain types of landscape uses.

(3) Cooperation in the development and application of simple and quick methods for the characterization of important parameters of landscape structure.

4. Ecological Methods for Landscape Evaluation

Kiemstedt’s (1967) method which provides a quantified measurement of the recreational suitability of landscape units, was a first and important step in replacing general and sometimes vague statements. In this method the close interconnection between the natural parameters and the human perceptual and cultural content of landscape values are realized. In the choice of para- meters he took into consideration the following factors:

(1) With respect to man’s recreation: (a) their effectiveness as indicators of sensual and visual experience; (b) feasibility of utilization; (c) whether or not they might have a direct influence on man (e.g.

climatic effects). (2) With respect to practical application:

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(a) how widespread the factors were; (b) how effectively they could be quantified so permitting simple

He combined all “recreationally effective” landscape factors and elements

(1) Forest border lines (in m km -2).

(2) Shorelines of lakes and rivers (in m km-*). (3) Relative differences between the highest and lowest point in the area as

(4) Types of land use in bordering areas such as fields, green areas, forests,

( 5 ) Bioclimatic regions. Multiplying each factor by a coefficient according to its relative importance,

he arrived at V the diversity value (Vielfiiltigkeit):

forest ecotone + water ecotone + relief + utilization 100 x climatic factor

statistical calculations.

into a formula based on the following scaling factors:

“relief energy” (in m).

bogs, heaths etc. (in percentages).

V =

This method has proved efficient and is now widely used. In a more recent large scale application in Sauerland, Kiemstedt (1975) modified the evaluation procedure:

(1) The manifold single criteria were grouped and presented in such a way that they could still be recognized in each step of the evaluation and checked.

(a) the larger areas of general suitability of the landscape; (b) the water ecotones; (c) the typification of each location.

(2) Three main evaluation areas were distinguished:

Kiemstedt (1971) has made a second important contribution to broadening the bio-ecological scope of ecological planning and so reducing the polarity between Naturplan and Kulturplan in the planning process. He introduced the concept of an evaluation matrix between the spatial demands of the user and a series of influencing natural factors. This was based on the assumption that the user will find the location best suited to his needs where it is least restricted by the constraints of natural factors and where it will cause least interference to other users. In this way, a differentiation can be made between those that cause the restricting effects on nature and those that are affected and this goes far beyond the term “landscape damage” which is laden with ideological misconceptions.

More recently, a “second generation” of this method has been applied by Bachfischer et al. (1977) as a quantified, ecological risk analysis in regional planning in Southern Germany. The method was developed to appraise the alternative effects of different land uses and to plan feasibility studies. In this

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particular study, different conflict areas between the basic natural factors and the way in which the landscape was used were tested: soil/water, climate/air, biotopes/recreation. The intensity of potential restrictions were weighed against the different demands, using indicators. All single indicators were aggregated to show “intensity of potential restriction” versus “sensitivity to the restriction” and combined into a value expressing the risk connected with each specific restriction. As a detailed example and because of its decisive ecological importance, the conflict areas of groundwater were presented. Five degrees of risk intensity were used for mapping and on the basis of these three alternative regional development options in the urban conglomeration of Nurnberg were discussed.

Bechmann (1977) has reviewed these and other methods developed for combined landscape evaluation and land use approaches. In many respects they resemble the methodology of the “environmental impact” studies carried out in the USA and elsewhere (Welch, 1976). However, in contrast to most of the latter, the former were not initiated as particular responses to particular proposals for land or industrial development, but existed as important parts of the general planning and decision making machinery on federal, regional and local levels.

Krymanski (1971) discussed the “utilitarian” and integrated ecological, social, economic and cultural approach towards the open landscape and its implementation for planning and land management. He made comparisons between attitudes and approaches towards the landscape and methods for its planning in Germany and the English-speaking world.

5. Landscape Ecology Studies in the Netherlands

Van der Maarel and Stumpel (1974) presented an impressive picture of the wide application of an integrated ecological approach to planning in the Netherlands, where five out of the eleven provinces and many other official agencies require landscape ecological inventories in the making of which inter-disciplinary teams of biologists, geographers and pedologists were employed. By 1974, 60 different projects had been undertaken. In 1971 a working group for landscape ecology, the WLO, was founded with about 100 members to organize scientific meetings and issue a special bulletin.

The ecotope is used as the basic unit for soil and vegetation mapping and several ecotopes are combined into landscape units or geotopes. As in Germany, the basis for this work is formed by phytosociological surveys of natural, semi-natural and other vegetation types (see Section 1I.B). Zoological data are based on larger units. All phytosociological, pedological, geomorpho- logical and landscape historical data are graded according to evaluation criteria or parameters and interpreted as to their final overall diversity value,

220 ZEV NAVEH

as in Kiemstedt’s system. The biotic parameters include criteria for variety and rarity of plant communities and ecotopes and for maturity or irreplace- bility. Relationships between diversity and stability are also considered. At the top of the scale of ecological components is the most natural region and at the bottom is the least natural region of the country. The recommendations for land use planning are based on interpretation of these values: land with the highest value, 5, is highly recommended for complete protection and optimal nature management. That with the lowest value, 1, is rarely con- sidered as valuable for conservation and few restrictions are placed on it for utilization. In addition, special recommendations are given on specific land uses, such as for the building of roads and towns, agriculture etc. Indicator plants and communities are used for the evaluation of these changes. Recom- mendations for the development of highly modified systems towards semi- natural and close-to-natural systems are based on the ecological theory of Van Leeuwen (1966, 1973). Advanced integrated evaluation methods are also applied in the Netherlands for outdoor recreation planning, especially in forests close to urban areas (Bijkerk, 1975).

Amongst the many projects carried out, the integrated Kromme Rijn project (Tjallingli, 1974), which was initiated by student groups from the University of Utrecht and the Department of Geography is particularly worthy of mention. It is an outstanding example of using landscape ecology both for actual regional planning and for multidisciplinary environmental education, to which I refer in more detail in the following section.

6. Landscape Ecology and Landscape Reclamation

The term landscape care implies active development and management; land- scape ecology provides the scientific basis for landscape care. Ecological management, development and reclamation are directly concerned not only with a specific economic use of natural resources, although this may be one of the final reclamation aims, but also with those open, disturbed or destroyed landscapes which should be managed and/or reconstructed for maximum overall ecological benefit.

In addition to the ecological management of existing vegetation in nature reserves and parks, this includes the management and reconstitution of rights- of-way and highway embankments, shorelines of lakes, rivers and other waterways, quarries and mines, protective plantings against wind and water erosion and avalanches, and against environmental pollution. The major technology developed by landscape ecologists such as trained foresters, garden-architects, agronomists and engineers, is living construction (Lebens- bau or Lebendverbau), or green construction (Grunverbau) and “engineering biology” or “vegetation engineering”.

LANDSCAPE ECOLOGY 22 1

These achievements have been surveyed by Woebse (1975) and reviewed by Bittman (1968) and Schluter (1971). The techniques particularly applicable for coal mining reclamations have been reviewed by Darmer (1972) and those for protection measures in the landscape by Schiechtl (1973). The latter, working in the Austrian alpine region, demonstrated the potentials of com- bining biological-ecological principles and biotechniques with advanced highway engineering methods in the protective and scenic “regreening” of the Brenner Pass highway. He applied his patented Schiechtl mixtures of seed and mulching material by hydroseeding methods. The development of these methods, widely used in landscape reconstruction projects and promoted by the German Federal Institute for Highway Construction, has been reviewed by Strunk (1972). In contrast to similar methods used in the US with agronomic pasture and turfgrass mixtures, as well as with ornamental plantings along highways, the landscape construction and reclamation work in Central Europe is mainly concerned with the reconstruction of the actual and potential natural vegetation and with ecological and not purely archi- tectual and functional landscape design. This applies not only to natural parks and reserves, but also to cultural landscapes. Thus, when travelling on the major German highways from east to west and north to south one can study a transect through the major forest formations by observing the verges on either side.

Darmer (1974) broadened the bio-ecological aims of landscape reclamation from phytosociological considerations to the reconstruction of a diversified biotope. In this, the re-establishment of plants creates sheltered habitats and refuge sites for animals. Pioneer plants for recultivation are chosen according to their “degree of biocenotic efficiency” and bearing in mind the ultimate use of the reclaimed site: either for nature conservation, recreation or multiple functions. The chief aim, however, is to ensure the highest biotic diversity.

To illustrate this, Darmer used the reclamation of coal spoil heaps in the Rhine-Ruhr region, one of the largest and most successful landscape re- clamation projects carried out since 1951 within the framework of the regional planning project of the Ruhr (Olshowy, 1973). The same principles were applied to the reclamation of the close-to-natural biotopes on the re- alignment of the Elbe Canal near Berlin and the artificial lake created there (Jacob, 1972).

A further impressive example of large scale ecological and scenic integration and of a successful compromise between the demands of landscape and of technology, has been the reclamation carried out following the re-alignment of the river Mosel, as part of the Rhine-Rh6ne Canal, to make it navigable to bigger ships. Dams were built and the narrow, winding riverbed was broadened. The Mosel is considered the most scenic river in Germany and great care was taken in construction, reclamation and earthwork to cause

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as little damage as possible. This was achieved with the help of comprehensive landscape development plans (Pflug and Bittman, personal communication) which contained detailed instructions for engineering constructions and build- ings, for the biological reclamation of disturbed slopes, the disposal of earth- work and for the protection of the shoreline from the heavier waves by planting the more resilient hydrophytic Carex species.

In Germany, as described by Mathe (1973), much attention has been paid to protective plantings along roads and in urban-industrial regions and to their protective beneficial functions in the reduction of noise, dust and air pollution. His own work is concerned with the role of trees in this respect. He emphasized the importance of the use of bio-indicators, either as sensitive plants or as accumulators of dust, fluoride or heavy metals. Probably the most significant contribution to the development of quantitative, biological monitoring systems, which supplement chemical-physical measurements made in the Rhine-Ruhr region, has been made by the Landesanstaltfir Immissionschutz des Landes Nordrhein- Westfalen in Essen (Scholl and Schon- beck, 1973; Schonbeck and Von Haut, 1973; Prinz and Scholl, 1975).

In recent years, foresters have also emphasized that forests have a role to play in protecting the environment in densely populated regions, as well as to produce timber (Briinig, 1972). The findings of Knabe (1973), that a forested strip, 2 to 3 km wide, could reduce the average SO2 concentration in the industrial Rhine-Ruhr region from 0-2&0*11 mg m-3, are of special interest.

Important work is also carried out in landscape ecology, planning and development and in what Vanicek (1 977) has called “eco-engineering” in Czechoslovakia. This has been extensively reviewed by Vanicek and Hrabel (1974).

B. Landscape Ecological Studies in Israel

1. Arthur Glickson, the “Father” of Landscape Ecology in Israel

Glickson was a farsighted and ecology-minded architect, whose vision of ecological planning and design was one in which “the landscape should be useful and beautiful at the same time; a resource of life and its renewal”. He was most influential in formulating principles of comprehensive ecological and regional landscape planning (Glickson, 1964, 1966) and his views on comprehensive multiple-use recreational planning were expressed as early as 1956 (Thomas, 1956). He was the first to use “environmental quality” in defining objectives in land use planning and management and was the first to state the need for ecological integration of the open and built-up land- scapes and their ecosystems. This he considered was the greatest challenge for the regional planner: “There is no place for a separate ecology of the rural

LANDSCAPE ECOLOGY 223

or urban environment. No viable urban development can take place if not on the basis of its surrounding, regional life-sustaining landscapes”. He con- sidered that a similar integration was needed in the reconstruction of the landscape, for which he used the term “geotechnics”, first conceived in Scot- land by Patrick Geddes.

In the reconstruction of landscape, cooperation between town and country and among professions would recreate a fertile and habitable environment. It would be the greatest enterprise of planned environmental change since neolithic times and the best act of social creation we can imagine. With the help of science, man reconstructs nature in its own image, which is at the same time his own best image (Glickson, 1956).

2. The Degradation of Mediterranean Landscapes

The process of man-induced desiccation of the Meditteranean landscape in Israel has been described by Naveh and Dan (1973) as seven degradation and aggradation cycles of anthropogenic biofunctions. These correspond to seven main phrases of landscape modification and land use. They commence with the use of fire by Pleistocene hunters and gatherers and continue with increas- ing intensity at the present time. As in Europe, but for a much longer period and with much greater intensity, the primeval landscape, its forests, woodlands and semi-arid steppe grasslands have been converted into a semi-natural landscape, with a dynamic, multi-layered and rich vegetation, containing mosaics of regeneration and degeneration phases, as described by Walter (1968) for the Mediterranean Basin as a whole.

One of the main conclusions to be drawn from the study of the mountainous region of Israel is that during the long phase of agricultural decay and population decline, a new equilibrium has been established in the non- cultivated upland ecosystems which are neither overgrazed nor heavily coppiced, nor yet completely protected. This man-maintained equilibrium between trees, shrubs, herbs, grasses and flowering geophytes has contributed much to the biological diversity, stability and attractiveness of the Mediter- ranean landscape. It is without doubt a most important asset for recreation and tourism. However, it is now endangered not only by the population explosion and increasing intensity of traditional land use, but also by the accelerated speed of urban sprawl and neo-technological despoilation, pol- lution and erosion.

If the recent trends of landscape degradation proceed unhindered and with their present speed and intensity, the few open unspoiled landscapes that are left will be turned into overcrowded recreational slums. This condition has already been reached on the shores of the Mediterranean Sea and inland waters, areas which rank highest in outdoor-recreation demand.

A special challenge faces landscape ecologists in developing countries,

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including Israel and others in the Mediterranean Basis (Naveh, 1978a). In such regions most efforts are directed towards the development of the most productive agricultural areas, where the ratio between investment in research and resources and expected economic benefits seems most favourable. On the other hand, the less fertile and marginal lands, which comprise more than 50% of the total land surface of most countries in the Mediterranean, are not developed. They are used mainly for grazing and are encroached upon by uncontrolled urban and recreational developments.

Landscape ecologists should focus their attention on this marginal and untillable land and find practical ways of reconciling the need for con- servation and reconstitution of the open landscape, its biotic resources, the socio-economic needs of its inhabitants and the national economy. Trans- formation of the intangible, ecological, scenic and recreational “non-economic riches” into workable quantitative parameters, based on integrated ecological studies is no less urgent in these regions than in the developed, industrial countries.

3. Ecological Management of Untillable Uplands

Investigations have been made along a climatic and anthropogenic gradient in the maquis belt of the problems of conservation and management of nature reserves and parks and the effect of anthropogenic interference (fire, cutting, grazing) on biotic diversity (Naveh, 1971; Naveh et al., 1976; Naveh, 1977a). In a more recent study these results have been compared with other Mediterranean landscapes in which similar trends are apparent (Naveh and Whittaker, 1979). Figure 4 shows that high structural, floristic and animal diversity can only be maintained by ensuring the specific defoliation pressure, through burning, grazing, coppicing, cutting etc. under which the communities evolved. The process of structural, floristic and faunistic impoverishment which leads to stagnation, high inflammability and therefore instability, runs contrary to classical climax-succession theories according to which “the well- developed maquis is removed by human intervention from its final succes- sional and relatively stable climax stage” (Zohary, 1962). It was concluded that rather than just passive protection, active scientific ecological management was required to simulate these optimum defoliation pressures and so conserve abundance in plant and animal species and structural richness.

For the management and improvement of degraded Mediterranean uplands, outside of nature reserves, a closely interwoven network of multiple land uses was suggested (Naveh, 1974; 1978b). This was based on dynamic vegetation management by manipulation of the soil-plant-animal complex (Naveh and Ron, 1966) and on the results of multi-purpose environmental landscaping and afforestation trials in typical, degraded and rocky, untillable

N

ME MU FO

Annual Farbs Annual Legumes

Annual Grasses

Perennial Herbs

Woody Vegetation

N SlCExpH

00

Closed Moqui Semi-open Maqui

G I BT

Shrub Grassland Open Woodland

Fig. 4. Structural and floristic diversity of mediterranean shrub and woodland as affected by protection, as opposed to disturbance and grazing (Naveh, 1977a). Note that protected ME and MU has chiefly woody vegetation, but lowest diversity; disturbed FO and BO has also chiefly woody vegetation but much higher diversity; disturbed GI with shrub-grass has high diversity, but heavily disturbed BT low diversity; moderately grazed AL and AA with chiefly herbaceous vegetation have the highest diversity.

226 ZEV NAVEH

0

6 0 -,

0 0

5 Very high 4 High 3 Medium 2 LOW

I Very low

land-uses environ- mentol functions

I Environmental woler- shed protectim

2 Fire hozord resis10nCe

3 Biotic diversity

4 Recreol\on amenity 5 Llveslo€h production 6 Forestry protection 7 Water yields

from oquifer

wild life

I Monogement types]

4 Protection Misuse

Multipurpose euxystern + monogement 4 Multipurpose envimnmentol

offorestotion -C+ Pine offorestotion

Fig. 5. Management flow diagram of Mediterranean upland ecosystems (Naveh, 1978b).

hill land in Northern Israel. Intensive treatment is essential for revegetation of denuded slopes and for fire protection and buffer zones.

Alternative management strategies (Fig. 5 ) would convert the presently misused, low value uplands (a), into existing alternatives of protected, im- penetrable and monotonous maquis and forest reserves (b), into dense, chiefly mono-culture pine forests (c), into the new options mentioned above, as recreation forests and woodlands (dl), multiple use forests, woodlands and shrublands (d2) or fodder shrublands, woodlands and grasslands (d3), or into semi-natural, multi-layered forests, parks and woodlands with suitable indigenous and exotic drought and limestone tolerant trees and shrubs, used chiefly for recreation (e,) for pasture (e3) or as flexible multi-purpose systems

LANDSCAPE ECOLOGY 227

Fig. 6. A cybernetic interaction model of land use factors (Naveh, 1978b). A Environ- mental and watershed protection. B Fire hazard resistance. C Biotic diversity and wildlife. D Recreation amenity. E Livestock production. F Forestry production. G. Water yields from aquifer. AS Active sum. PS Passive sum. Q Quotient AS : PS. 0 No influence. 1 Slight influence. 2 Medium influence. 3 Strong influence. Active element: Highest Q : F (F). Passive element: Lowest Q : G (D).

(ez). The highest overall multiple benefits can be expected from the latter. They include environmental and watershed protection, resistance to fire hazard, biotic diversity, recreation amenity and plant and animal production. As a tool for evaluating the degree to which all factors influence each other, a cybernetic interaction matrix can be constructed (Fig. 6) (Vester, 1976). This permits a more accurate determination of the most active and critical variables that have the greatest effect on all other variables, in this example forest and to a lesser degree livestock production and recreation, and the most passive variables, which change greatly under the slightest influence of all other variables, in this case water yields. At our present stage of knowledge, management strategies aiming at multi-purpose options dz and ez are preferable. However, these results should be considered as a first approxi- mation and a major task is to express these relative values by actual quan- titative data, which would permit optimization in planning and actual implementation of multiple-use strategies. For this purpose, combined re- search and demonstration teams of foresters, livestock and wildlife specialists and landscape ecologists and planners would be most desirable.

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Special attention has been devoted to the role of fire in Mediterranean landscapes, both from the ecological (Naveh, 1973b; 1975b; 1977c) and from the planning and landscape management points of view (Derman and Naveh, 1977).

The model for multi-purpose land use in the dry maquis described above has considerable benefits for fire protection. There is a very real conflict between the pastoralists, burning shrub and woodland to increase the sparse pasture understorey and the foresters who try, in vain, to protect nearby, highly inflammable and valuable pine forests. Its representation to Mediter- ranean foresters (Naveh, 1977b) contributed to the formulation of new, multiple use strategies in which fire and fuel management are combined with grazing and thinning of maquis for recreation.

4. Landscape Ecology Studies in Intensively Used Landscapes

The ecological restoration of cultural Mediterranean landscapes degraded or destroyed by neo-technology has been attempted with the help of drought resistant and low-maintenance plants (Naveh, 1975a). Both local and exotic hardy herbaceous and woody species were selected for the reclamation and revegetation of slopes, highway embankments and limestone quarries. These are established as mixtures of fast-growing and soil-protecting, low cover “pioneer” plants, and slower growing, but taller and more persistent, soil ameliorating shrubs and trees. A condensed successional process is achieved by “vegetation engineering”, hydroseeding and afforestation methods. Pro- mising results of these studies and reclamation projects point to the great scope of woody plants from local origin, as well as from the Western Mediterranean, Australia, South Africa, South America and California for biological, scenic and economic enrichment of degraded Mediterranean land- scapes.

IV. LANDSCAPE ECOLOGY AND ENVIRONMENTAL EDUCATION

As an holistic, task-solving oriented science, landscape ecology is especially suitable for fulfilling an important educational function. With its trans- disciplinary and multidimensional outlook it can help to break down the thick walls surrounding the ivory towers of three cultures in which plant and animal ecologist-biologist, the environmental engineer-technologist and the socio- logist and economist-humanist are still functioning. The intention is not only to teach landscape ecology as an academic discipline in universities, but as a major content in environmental and conservation education of middle and

LANDSCAPE ECOLOGY 229

higher school education. Promising beginnings in this direction have been made in Israel (Shachak et al., 1975) and were reported in more detail in a special symposium on environmental education at the Second International Congress of Ecology held in Jerusalem, 1978 (Bakshi and Naveh, 1980).

V. SUMMARY AND CONCLUSIONS

This paper, firstly, reviews the development of landscape ecology in Central Europe, secondly offers a revision of its principles and concepts in the light of recent insights in general systems theory and human ecology, and thirdly presents some of its contributions as an emerging, inter-disciplinary ecosystem science.

Landscape ecology has its roots in Central and Eastern Europe, where biogeographers have viewed the landscape not just as an aesthetic asset or as part of the physical environment, but as the total spatial and visual entity of human living space, integrating the geosphere with the biosphere and the noospheric man-made artifacts.

This holistic viewpoint of the landscape has been adopted by ecologists well versed in vegetation science, or trained originally as agronomists, foresters, gardeners or planners who abandoned the sometimes narrow restrictions of their respective professions outlooks for a modified phyto- sociological methodology of integrated field surveys and ecosystem studies.

The development of landscape ecology in the Netherlands, where it has had its greatest influence on actual large-scale regional planning, was inspired by achievements in nature conservation management, landscape planning and reclamation on the one hand and by cybernetic theories of pattern and pro- cess in vegetation on the other. By bridging the communication gap between the English and German languages, Dutch vegetation ecologists have broad- ened both the scope of quantitative phytosociology and landscape ecology.

Currently, landscape ecology in Europe is viewed as the scientific basis of land and landscape planning, management, conservation, development and reclamation, and as such it has overstepped the realm of classical bio- ecological sciences and entered the realm of man-centred fields of knowledge, the socio-psychological, economic, geographical and cultural sciences in as far as they are connected with modern land uses.

This is reflected in the broad range of landscape ecology and landscape planning oriented studies of the complex interrelationships between modern man and his open, cultural and built-up landscapes. These aim at a com- promise between conflicting natural, cultural and socio-economic demands and, at the same time, at an enrichment of man’s biotic environment.

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An attempt has been made to outline the major principles of a general biosystems theory. A central feature is the recognition of the total human ecosystem as the highest level of integration, with the ecosphere as the largest, concrete, global landscape entity and the ecotope as the smallest. The visual and spatial integration of the bio-, techno- and geospheres must be complemented by their functional and structural integration through the creation of a new equilibrium at a higher level of organization and com- plexity.

Landscape ecology is contributing to this goal by supplying scientific, ecological and educational information. Its foremost future tasks are three- fold:

(1) To increase the number of integrated, multidisciplinary, long-term ecosystem studies of man’s land uses and their impacts.

(2) To replace degraded and destroyed natural bio-ecosystems by new semi- natural, attractive, diverse and stable bio-ecosystems.

(3) To achieve recognition of the important role of landscape ecology in the process of cultural evolution and noogenesis, as a basis for interdisciplinary, task-oriented, environmental education.

ACKNOWLEDGEMENTS

I acknowledge with gratitude the efforts spent on critically reviewing and editing this article by the editors and Mrs M. Cannell.

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