Journal of Aquatic Ecosystem Health 1: 59--68, 1992. M. Munawar (ed.), Assessing Aquatic Ecosystem Health: Rationale, Challenges, and Strategies. © 1992 Kluwer Academic Publishers. Printed in the Netherlands. 59

Restoring ecosystem health and integrity during a human population increase to ten billion

John Cairns, Jr. 1 & James R. Pratt 2 1 University Center for Environmental and Hazardous Materials Studies, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061-0415, U.S.A. 2 School of Forest Resources and Graduate Program in Ecology, Pennsylvania State University, University Park, PA, 16802, U.S.A.

Keywords: global change, ecosystem restoration, human population growth

Abstract. Human population growth and the improving condition of human populations in developing countries affect ecological health and integrity. Agricultural development co-opts increasing amounts of global primary production, degrading lands, and reducing species richness. The development of human populations and associated increasing demands for energy assures disposal for increasing amounts of waste, further damaging local ecosystems. Global climate change resulting from diffuse pollutants will affect even the most pristine ecosystems. The human challenge is to maintain ecological integrity and restore ecosystems in the face of accelerating development. The present level of ecosystem protection in not sufficient. Only integrated means of assessing recovery potential and acting to restore ecological productivity can assure continued availability of ecosystem services ranging from free production of food and fiber by plants and animals to final waste assimilation. Restoring ecosystems presumes that species sources are available and that adequate management is in place to monitor and manage recovery. Today, even in the most advanced societies, management is fragmented by non-integrative thinking and the failure to realize that the human scale of political decision-making and management is inappropriate to assure ecosystem restoration. Only by adopting radically new ideas integrating management and ecosystem science can ecological integrity be maintained.

'To say that if the world's food were equitably distributed and everyone became a vegetarian the world would support another billion people is simply wrong. Overpopulation is defined by the species that occupy the planet, behaving as they naturally behave, not by a hypothetical group that might be substituted for them!' (Modified with permission, Ehrlich & Ehrlich, 1990, p. 41.)

1. Introduction

World population will reach ten billion in the next century, even if the number of children per family is drastically reduced 0Ehrlich & Ehrlich, 1990). The reason for this is the several generations required for a predominantly young population (characteristic of rapidly developing countries) to be replaced by a population with a more even age distribution. Among the themes of this conference are aquatic ecosystem health and management, ecosystem restoration, maintenance of ecological integrity, assessing ecosystem health, and related topics. The purpose of this paper is to explore, in very general terms, how the terms ecosystem health and integrity and ecosystem restoration

might be defined and, equally importantly, how these attributes might be managed.

Many of the world's ecosystems have been seriously damaged, and practically all are not furnishing the ecosystems services that they might well furnish in more robust condition. Restoration or rehabilitation ecology will be essential, particu- larly in view of the threats of global warming and other indications of global ecological imbalance. However, it would be futile to base policy in these areas on an idealistic view of how people should act as opposed to the way they do act in carrying out their daily lives. If present behavior can be changed, as it is quite clear it must, it will only be done when the benefits of so doing are clearly apparent to all. Without the cooperation of the de- veloping countries, global environmental prob- lems cannot be solved. Failure to reach a global consensus will ensure that ecosystem health and integrity will be even more seriously impaired. Methane from cattle or carbon dioxide from inefficient furnaces in a developing country will definitely have an impact on the world's climate, and, since many of the pollinators and insect

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eaters are migratory, destruction of their habitat in one part of the world will mean their elimination in another part. For example, many of the song- birds inhabiting the United States reside in Central America during a significant portion of the year. Those that consume vast quantities of insects may be lost to the northern ecosystems if the Central American ecosystems are destroyed. Loss of regulators of the insects that eat vegetation will seriously impair northern terrestrial ecosystem health and integrity.

Science and technology cannot furnish all the answers and solutions; few of these problems have technical solutions (Hardin, 1968). As Luna B. Leopold (1990) persuasively noted, there must be a set of guiding beliefs or ethos, and concomi- tantly, a sense of fairness or equitability in all of our environmental decisions. (We urge that Leopold's thoughts on 'Ethos, Equity and the Water Resource' be read in full because they are central to the theme of this meeting.)

2. Ecosystem health and integrity

Ecological health, like human health, is difficult to define even though the absence of health is often easily recognized. Changes related to altered ecosystem health are now well known (Odum, 1985; Schindler, 1987; Schaeffer et al., 1988; Pratt, 1990), and it is incorrect to assume that ecologists cannot measure effects such as changing numbers of species and interruption of normal energy and material processing. However, there is great functional plasticity in natural communities, and small changes are often ecologically equivocal. A more pertinent definition is that of ecological integrity, because healthy ecosystems can with- stand and recover from any natural and human- induced perturbations. In this sense, the definition of biotic integrity proposed by Karr & Dudley (1981)* seems appropriate: 'a balanced, integrated, adaptive community of organisms having a species composition, diversity, and functional organiza- tion comparable to that of natural habitat of the

* An updated but conceptually similar article is Karr, J. R. 1991. Biological integrity: a long-neglected aspect of water re- source management. Ecological applications 1(1).

region.' These conditions are clearly not met in many ecosystems, and many biotic communities are at risk in most regions of the earth.

3. The population problem

What are the causes of observed ecological disrup- tions and what can be done to restore biotic integrity? While the penultimate causes of ecosys- tem degradation can be attributed to waste dis- charge, poor land use practices, habitat alteration, and other influences, the ultimate cause is human population growth. The growing human popula- tion co-opts significant ecological resources (pri- mary production), reducing the natural produc- tivity of ecosystems. Currently, estimates of the diversion of primary production to humans range from 20--30 percent of global primary production (Vitousek et al., 1986; Wright, 1990). As the human population continues to increase, greater diversion can be expected with concomitant alter- ation of more and more ecosystems.

Ecologists, already in a state of controlled panic about the rate of species loss globally and the reckless expenditure of ecological capital (topsoil, forests, groundwater, and pure air), are outraged. The present population of roughly 5.5 billion is only partially sustained by reckless expenditure of ecological resources that have accumulated over millennia. If one adds to this the prolific expendi- ture of fossil fuels that permits the present lifestyle of the United States and other industrialized countries, the sense of helplessness for the knowl- edgeable increases further. One of the primary reasons for this is that the attempts of the People's Republic of China and of India to double their per capita energy consumption by the year 2000 would make the prospects of global warming much more likely (Table 1). These and other countries are unlikely to curtail their per capita use when the per capita use in the United States is roughly an order of magnitude larger. The de- struction of tropical rain forests and other forests, loss of topsoil, atmospheric pollution, depletion of groundwaters, and increased problems from im- proper storage of persistent hazardous and radio- active wastes have not yet been resolved, yet other problems are added daily. Our throw-away society can trade in a car when the maintenance and

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restoration costs become uneconomical, but one cannot trade in a planet -- it is the only one we have.

Assuming a constant production of food at the rate in 1986 (the world's peak), the planet would support roughly, six billion people if food were equitably distributed and everyone ate a vegetarian diet. In fact, the amount of food per capita has been decreasing steadily since 1984 because, although 1986 was a record food production year, the population has grown strikingly since 1984.

Ultimately, the human population of the earth will either be stabilized non-randomly by epidemic diseases, starvation, and the like, or deliberately by enlightened human self interest. Unfortunately, there are still people, including many world leaders, who believe the earth's population will stabilize instantly when each couple limits family size to two children. This will not occur (Ehrlich, 1968). Therefore, the short-term problem (which could last as long as a human lifetime) is to add to our ecological capital through ecosystem restora- tion and rehabilitation while the population stabi- lizes following a markedly reduced birth rate. The

restoration of ecological capital must be global and not restricted to small patches; but the highest priority, which will only succeed if human popula- tion is stabilized, is to reverse the ratio between the rate of ecosystem destruction and the rate of ecosystem restoration. We need to be able to say that for every ecosystem destroyed -- through an accidental spill or overharvesting or the like -- ten or more times as much ecosystem both in quality and quantity has been restored. This restoration need not be to prehuman settlement conditions, but the rate of topsoil loss, groundwater recharge, forest growth, and the like must exceed by a very substantial margin the rates of loss. Ultimately, of course, a new equilibrium situation will develop, but that will be many human generations from now even if we are extraordinarily fortunate.

4. The Netherlands fallacy

The deputy editor-in-chief (Forbes, 1989) of Forbes magazine wrote, in connection with the plea for more population growth in the United

Table 1. Global primary energy consumption per capita, 1984. (With permission from World Com- mission on Environment and Development, 1987.)

World Bank GNP GNP per Energy Mid- 1984 Total economy capita consumption 1 population consumption category ( 1984 S) (million) (Terawatt)

Low income 260 0.41 2390 0.99 Sub-Saharan

Africa 210 0.08 258 0.02

Middle income 1250 1.07 1188 1.27 Lower-middle 740 0.57 691 0.39 Upper-middle 1950 1.76 497 0.87 Sub-Saharan

Africa 680 0.25 148 0.04

High-income Oil exporters 11 250 5.17 19 0.10

Industrial Market Econ. 11 430 7.01 733 5.14

East European Non-market Econ. -- 6.27 389 2.44

World -- 2.112 4718 9.94

1 kW years/year per capita. 2 Population-weighted average energy consumption (kW/capita) for first three main categories is

0.654 and for industrial market and East European categories is 6.76.

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States: 'If all the people from China and India lived in the continental U.S. (excluding Alaska), this country would still have a smaller population density than England, Holland, or Belgium.' It is especially ironic that Forbes does not consider The Netherlands to be overpopulated. This is such a common error that it has been known for two decades as the 'Netherlands Fallacy' (Ehrlich & Ehrlich, 1972).

The Netherlands can support 11,031 people per square mile only because resources are sent there from other parts of the world. In 1984--86, The Netherlands imported almost 4 million tons of cereals, 130,000 tons of food oils, and 480,000 tons of pulses (peas, beans, and lentils). During this period, The Netherlands also extracted a half million tons of fishes from the sea and imported more in the form of fish meal. The Netherlands is also a major importer of minerals and other raw materials and built wealth using imported energy. However, in the 1970's a large gas field was discovered in the northern part of The Nether- lands, giving a 20-year net energy balance. When this is gone, the Dutch will again be heavily dependent on the rest of the world for fossil fuels or uranium.

Another example of interconnectedness of regions is the restoration of prairie potholes in the midwestern United States. Of course, prairie potholes have a regional importance as part of a local ecological mosaic. Beyond that, however, they are extremely important, though not con- tinually used, as ecological 'stepping stones' for migratory birds, particularly water fowl. Here, the time scale becomes important because a particular pothole might not be used every year, or at least not used heavily every year. However, given the patchiness of regional conditions, localized droughts or other episodic events may make an infrequently used pothole of exceptional impor- tance in a particular year. The mosaics under discussion, both social and ecological, have time and spatial scales that are invariably larger than those ecologists feel comfortable examining! In fact, the present migratory flyways may be vastly constricted from their original breadth. This could be due to the major alterations made in the hydrologic cycle, including the filling in of wet- lands and the translocation of water from its original drainage basin to other regions.

The effects of water management practices (e.g. damming) on aquatic ecosystems provide another example of short-term, non-integrated develop- ment, and these practices will have significant effects on the potential for recovery of linked stream-bottomland ecosystems. Streams may re- cover comparatively quickly from even large insults (e.g., Cairns et al., 1973). Stream ecosys- tems serve as pollutant conduits and, assuming that upstream degradation is minimal, recovery of stream biota can be expected if species sources are available and residual pollutant impacts are minimal, unless physical habitat alteration has occurred.

The floodplain ecosystems of stream bottoms are unlikely to recovery quickly. Stream regulation is so widely practiced that normal flood cycles are effectively eliminated. Therefore, the transport of propagules to the bottomlands is limited, and in- place pollutants are unlikely to be quickly re- moved or buried. The disturbance of normal hydrologic processes, explainable in human terms as flood protection, water storage, and irrigation potential, acts to profoundly alter the floodplain. Human settlements encroach on or expand along streams, the natural water storage capacity of the floodplain is reduced (resulting in more damming downstream), and the natural productivity of these ecosystems deteriorates.

Damming streams has been viewed as relatively benign except in the most unusual cases. Human influence has overridden natural processes. In fact, impounding water is now so common that cur- rently stored supplies could cover most of the contiguous United States with from 6 to 17 cm of water (Table 2). Dam storage is most significant in the western United States, especially in the moun- tain states, but, with the exception of those states bordering the Laurentian Great Lakes and areas with large numbers of natural lakes (mostly of glacial origin), there are few free-flowing streams of any size (Benke, 1990). For example, the state of Pennsylvania has over 2500 'lakes,' of which only about 50 are natural. Of over 2000 lakes in Virginia, only two are natural (Mountain Lake and the Great Dismal Swamp). The number of unnatu- ral lakes formed by major storage dams continues to rise, from fewer than 200 before the great depression to over 700 in the 1980's. Water storage capacity has risen linearly since the

Table 2. Effect of stream impoundment on water storage in the continental United States (Council on Environmental Quality, 1989). Regional data show storage capacity and estimated water depth if the entire landscape were covered by stored water.

US Storage capacity Equivalent depth region (acre-feet/sq. mi.) (cm)

New England 225 10.7 Central U.S. 135 6.3 Tennessee 225 10.7

Valley Far West 225 10.7 Rocoy Mtns. 336 17.4

(Colorado)

1930's, although the average storage capacity of dams has decreased significantly since the major dam building boom of the 1960's (Council on Environmental Quality, 1989). The water stored in unnatural ecosystems contains sediment, silt, and nutrients that otherwise would have been deposited in the floodplain.

5. The recovery problem

Protecting self-maintaining ecosystems is the initial step towards a world that runs itself. The second step is repairing the self-maintaining eco- systems presently damaged by hazardous wastes, clear-cutting, and other anthropogenic activities so that they are capable of either essential self- maintenance or self-maintenance to a greater degree than is presently possible. Damaged eco- systems probably cannot be restored to predis- turbance condition, but they certainly can be restored to an ecologically superior condition than their present damaged state. The third step then becomes the establishment of a quality control monitoring system that prevents ecological dam- age or, at least, gives an early warning of deleteri- ous change.

5.1. No-net loss of species

As Aldo Leopold pointed out, the first rule of intelligent tinkering is to keep all the pieces. Some

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ecosystems (e.g., tropical rain forests) have more parts than other ecosystems (e.g., Arctic tundra). Ecosystems function well despite anthropogenic onslaughts because of the functional redundancy of the system, which is not the case for mechanical objects. In ecosystems, a number of species may be transforming detritus, although they may not do so in identical ways. As a consequence, the loss of one component may not be as critical as it might appear. On the other hand, ecosystems adjust to change because there is a species X more suited to the new conditions than was species Y, the original inhabitant of that particular ecological niche. The successional process requires that replacement species become available when particularly favor- able (to them) environmental changes occur. Eco- logical islands (e.g., the tops of mountains) are also required where these species may persist in small numbers until their 'ecological time' comes again. Furthermore, when these new conditions develop, the species best suited for them must be able to get there from the ecological islands they now inhabit.

The strategy for both protecting and repairing self-maintaining ecosystems requires that a pool of suitable species (e.g., widely varied genetic infor- mation) be available to occupy a wide variety of habitats and that the species be able to get to the habitats when favorable conditions develop. Eco- systems that are protected to some degree, such as national parks, national forests, nature conserva- tion tracts, and the like, occupy less than 3 percent of the land masses of the planet. An uncharitable person would put the figure much lower. This is simply not an adequate species pool to fill the requirements just described. Action must be taken with the other 97 percent of the land mass -- sufficient species must be saved from the rapidly disappearing pool to establish truly self-maintain- ing systems capable of responding to change, such as global warming.

The re-introduction of the wolf to a portion of its former range in the United States (even when this is designated a wilderness area) is an excellent illustration of this point. Despite the fact that the wolf is a relatively shy creature, fears of attacks on tourists, livestock, etc. may preclude the re-intro- duction or greatly restrict the number of sites for re-introduction. The fact that the wolf belongs there and that, even after the re-introduction, the truly wild areas will be geographically small and

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ecologically widely spaced is not persuasive to many in the general public or the decision makers.

The case of the spotted owl in the Pacific Northwest is an even better illustration of society's intolerance for wildness (e.g., Gup, 1990). The spotted owl cannot injure people or livestock or damage anything of commercial value. Unfortu- nately the spotted owl requires old growth forests of substantial size (i.e., wildness) and is, therefore, an obstacle to the lumbering industry and the unions that wish to preserve a few lumbering jobs for a short period of time. The wildness will lose and so, ultimately, will human society, which places a short-term economic gain against the survival of a fellow species.

Fragmentation is fatal to effective integrated environmental management, which requires that interactions of technology and natural systems be carefully documented and the impact of tech- nology on global biodiversity and integrity of natural systems not be deleterious on a short- or long-term basis. Additionally, maintenance of the integrity of natural systems requires that they be fragmented as little as possible by highways, forestry practices, urban and regional develop- ments, and the like (Soule et al., 1988).

5.2. Managing and guiding the recovery process

If an ecosystem is displaced in structure and function, its ability to return to a condition approximating the former state depends on sev- e rn factors (Cairns & Dickson, 1977). While the relative importance of the various factors listed below differs according to ecosystem characteris- tics and the nature of the displacing force, each factor must be considered in estimating recovery. It is generally not true that knowledge of a par- ticular ecosystem is insufficient to evaluate re- covery potential. The ability of managers to apply appropriate scientific evidence, however, often falls far short of the needed rigorous analysis. Managers, guided by laws and regulations, have frequently failed to apply good science for good management. Scientists, guided by the need to fund research groups, have often called for more studies rather than applying existing knowledge (Giesy, 1990).

Table 3 lists several criteria for assessing the potential for successful recovery. Items 1 and 2

Table 3. Criteria for assessing the recovery potential of ecosystems (based on Cairns & Dickson, 1977).

Criteria Score

(1) The presence of unaffected areas 1 2 3 that can serve as species sources

(2) The transportability of propagules 1 2 3 and dissemules

(3) The general condition of the habitat 1 2 3 following removal of the displacing force

(4) The presence of residual toxicants 1 2 3 or other stressors

(5) The chemical and physical state of 1 2 3 the system

(6) The organization capabifities for 1 2 3 immediate and direct control of the restoration effort

are biological characteristics, and recovery will depend on the extent to which information is available on the former species composition. For example, stream drainage basins may contain refugia that can supply colonists, or these colonists may arrive through drift or normal migration and reproduction of extant species. However, in eco- systems where propagules of species may rely on other species for dispersal (e.g., seed dispersal by birds), recolonization may be limited.

Items 3, 4, and 5 relate to chemical and physical characteristics (including a knowledge of the regional landscape), which could affect the integ- rity of the recovering biota. Removing an external force will often be sufficient to allow recovery to proceed. For example, physical processes will often remove fine particulates from a stream if erosion is controlled. However, long-term stresses such as acidic deposition may have severely depleted soil cations that affect recovery of both upland and aquatic communities.

Item 6 is a human characteristic requiring the ability and motivation to manage restoration. Managing the restoration effort requires monitor- ing the state of the system through time and acting to introduce species or assist recolonization. Inte- grating management across landscapes (not politi- cal divisions) will be needed. River basin commis- sions are currently playing a role in integrating management efforts in the face of the fragmented

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legal and regulatory field previously described, and similar transboundary efforts will be needed within and between nations to achieve acceptable sustainability of ecosystems.

An index of recovery potential can easily be developed from the product of scores

R = (1) (2) (3) (4) (5) (6),

with the index scores interpreted as follows:

R > 400 = excellent potential for re- covery,

55 < R < 399--fa i r to good potential for recovery,

R < 55 = poor potential for recovery.

Regardless of the index used, elements of the recovery process assume that, for a local ecosys- tem, species sources are available elsewhere to re-establish the native community. As time pro- gresses, this assumption will be increasingly prob- lematic if the species are endangered or if climate change progresses to the point that the native community will clearly not survive. Further, if the species sources are in other states or countries (and presumably outside of management jurisdic- tion), political barriers may inhibit recovery if propagules cannot be easily (or legally) trans- ported. The current fragmentation of ecosystem management does not lend itself well to respond- ing to a pending global ecological crisis.

There is no empirical evidence to support the particular form of the index that is based on a simple rating scheme. However, any modification of such a scheme would probably retain the multiplicative nature of the index. The criteria represent factors necessary for successful ecosys- tem recovery and are listed in approximate order of ecological importance. The value of the re- covery score is constrained by those factors that are 'limiting.' For example, if no organizational capabilities exist to control restoration efforts, one might be tempted to assign a score of zero to this variable, resulting in a total recovery score of zero. Realistically, however, recolonization of some sort will occur in all but the most devastated land- scapes, so criterion scores of zero are probably inappropriate.

Clearly, as experience with restoration and recovery of damaged ecosystems increase, we may have rational reasons for weighting the criterion

scores to account for those that are most impor- tant or have the greatest predictive power. For example, it is possible (and increasingly likely) that refuge areas do not exist to provide natural sources of propagules to damage sites. Since recovery will depend on a sufficient supply of colonists, we might weight this first criterion as more important than the sixth criterion regarding organizational capabilities, although more man- agement will be needed as our expectations increase for the quality and diversity of restored areas. Until experience improves the restoration data base, the conceptual model presented here can serve as a straw man for the development of more specific predictors of restoration success.

6. The fragmentation problem

6.1. Fragmentation in the regulatory community

In the United States (and other countries), govern- ment agencies are funded item by line item. No substantial funding is given for integration, and, although sometimes interagency efforts are highly publicized, behind the scenes these interagency efforts generally represent turf battles between warring groups. Leopold notes in his superb Abel Wolman Distinguished Lecture, February, 1990, to the National Research Council: ' . . . the prolif- eration of public agencies dealing with water has led to a dissociation of their policies, their pro- cedures, and their outlook from the operational health of the hydrologic system. Everything one entity does affects many other entities, yet each entity operates as if it alone is the flower facing the sun. There is no guiding belief, no ethos involving the natural world. There is no concern for the common -- as Garrett Hardin expressed it -- no overriding responsibility for the whole.'

Orr (1990) points out that those who lived sustainably in the Amazon rain forests and else- where on Earth could not read (but were not uneducated in the broad sense). In contrast, those whose decisions are destroying the planet are not uncommonly very well educated. Clearly, it is the type of education (highly specialized-technology oriented) that is at fault, not education itself. Education should take students beyond analysis to synthesis. It should not permit compartmentaliza-

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tion of desciplines that isolates those responsible for development and utilization of technology from those interested in preserving and protecting Earth's biodiversity. But even this is not enough; both groups should base their decisions on a guiding set of beliefs (which the Greeks called 'ethos') and a sense of equity or fairness. This would involve yet another set of disciplines in the humanities. The present system of 'higher educa- tion' is shamefully inadequate in this regard.

6.2. Fragmentation in the political system

Special interest groups dominate the political system in the United States, and, although oppos- ing forces may reluctantly compromise, they do so predominantly to achieve some of their goals rather than to maintain the well being of the larger system. In fact, short-term gain is the name of the game, whether it means a profit for a particular industry or getting re-elected. But the well being of the complex multivariate systems, such as Planet Earth, so that long-term sustained beneficial use is possible requires a perspective measured in centu- ries, not months or years. This is evident in such situations as global warming where the probability of rates of temperature increase and climatic change capable of disrupting the agricultural system and the lives of people living in coastal areas are sufficient to justify taking steps to buy more time by reducing the probable rate of change as much as possible. Rather than offend special interest groups in the short-term, major gambles are being taken with long-term prospects. A harmonious relationship between technology and the maintenance of global biodiversity and integ- rity is simply not possible when a short-range view dominates, and long-range planning is given either lip service or no attention whatsoever. The frag- mentation of the political system into special interest groups is one of the major obstacles to developing a strategy for using technology without destroying the integrity of natural systems. Since nations seem unable to control the effects of fragmentation or the forces affecting global bio- diversity, it comes as no surprise that the United Nations is no better at this, although some heartening efforts are under way. Just as the federal government of the United States must occasionally override states that are not acting in

the long-term enlightened self interest of their own citizens or the nation to which they belong, so the United Nations may serve a similar function when nations are not acting to preserve the integrity of the global ecosystem life support functions.

Fragmentation of the academic enterprise which is responsible for much of the basic and applied science useful in environmental problem solving is so pervasive that it will not be discussed in detail here. Simply stated, universities share in the mission-oriented constraints that hamper the political and regulatory processes. The pace of change in universities is so slow that satellite laboratories have developed to respond in orches- trating interdisciplinary research. No such moves are common in the academic training grounds. Universities are particularly unprepared to change to respond to societal needs.

The major question is whether a civilization can develop in which wildness can endure. Wildness is used in the sense that Thoreau used it; that is, a natural system unadjusted to the needs of human society by nature trails, parking lots, and conces- sion stands. Environmentalists have often been accused of being closed to compromise that is so characteristic of reasonable people. Unfortunately, all the major environmental compromises possible have been made. These have resulted in less than 3 percent of the globe's land mass remaining in what Thoreau would have accepted in his most charit- able mood as wildness.

A world that runs itself is fading from memory. In its place is a "managed" environment super- vised by governments that cannot balance budgets. If technology, the human population, and natural biodiversity are to co-exist, the technology must be one that wildness can endure. Ecologists perpetually talk about the interdependence of nature, and lip service is given to this notion on Earth Day, but, in practice, environmental prob- lems are approached one fragment at a time, not as a complex, multivariate, interdependent land- scape. The co-existence of technology and biodi- versity depends on switching from a fragmented to a landscape view.

Fragmented decision making has produced a fragmented environment incapable of providing the necessary ecosystem services (e.g., carbon dioxide storage, degradation of wastes) produced a decade or two earlier. For large ecosystems, the

cumulative impact of a series of individually minor (fragmented) decisions may be disastrous. Deci- sion makers have focused on societal needs such as an extension of an airport runway through a wetland, the fragmentation of a wilderness area by access roads, the reduction of old growth forests to keep the lumbering industry economically viable, and a number of other similar considera- tions. Efforts to avoid this, such as the Endangered Species Act, assume that species can be protected one at a time while their overall habitat is being destroyed. This zoo mentality that assumes a wild thing can survive in an urbanized environment is simply wrong. The development of a strategy for maintaining, restoring, and protecting ecosystems must view the entire ecological landscape and must include more truly wild areas than the landscape now possesses.

7. Concluding remarks

Human population growth and dependence on fossil fuels are the clear causes of real or potential global climate change. Regardless of the validity of predictions of global warming related to historical and future assaults on the atmosphere, the con- tinued growth of the human population will have dramatic effects on local ecosystems. Population growth is most dramatic in developing countries where infrastructure is unavailable to deal with the clearest ecological threats. In most of the devel- oped countries, population is stable or declining.

A larger human population will require the dedication of an even greater fraction of global primary production to perpetuate itself. This means more habitat modification, more agricul- ture, more pesticides and more fertilizer, even though western nations now expend more calories (in fossil fuel) growing crops than the food and fiber calories harvested. More energy (regardless of form) will be needed to meet the demands of agriculture. A colleague recently commented that we already have sustainable agriculture: it can be sustained as long as we are willing to continue to pour fuel calories into it.

If energy resources are not expanding, then growth will be limited by the global availability of fuels to fire development. For developing nations with some level of energy independence, the

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future road will be clear and the input of combus- tion products will increase or the products of nuclear fission will need new burial grounds. For example, the People's Republic of China is ap- proaching energy independence using its own coal reserves, and its effect on global warming will increase.

Associated with human population growth and the likely expansion of technological societies are all the problems that employ the environmental industry. More people produce more sewage. And, since everything goes somewhere, that sewage will likely go to the nearest stream. Devel- oping industries will place wastes (often untreated) in these same streams. These streams will irrigate the fields, co-opting even more natural primary production and reducing even further the species pool in local ecosystems.

The plight of the underprivileged of earth is probably the single most important barrier to keeping our planet habitable. Without the coop- eration of the poor, the most important global environmental problems cannot be solved; unfor- tunately, at the moment, the poor have very little incentive to cooperate in this effort. However, both poor and rich nations have the same basic choice: either to shift in an orderly, planned way to a sustainable human life support system or to be brutally forced into the shift by nature. Instead, each nation seems bent on competing for and quarrelling over pieces of the shrinking resource pie, diverting large portions of it into armament for wasteful conflicts, or at best away from natural resource protection and rehabilitation.

8. Acknowledgements

We thank Paul Ehrlich, Anne Ehrlich, John Harte, and Hans Lokke for helpful discussions. Darla Donald provided editorial assistance in the pre- paration of this manuscript for publication. We are most grateful to Dr M. A. Mehlman for permission to use in this manuscript substantial portions of an article entitled 'Developing a Strategy for Protect- ing and Repairing Self-Maintaining Ecosystems' that appeared in Journal of Clean Technology and Environmental Sciences, Vol. 1, No. 1, 1991.

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