Review of Literature - INFLIBNETshodhganga.inflibnet.ac.in › bitstream › 10603 › 15708 › 8 › 08...17 Chapter 2 Review of Literature Agroforestry systems are land-use systems

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Chapter 2

Review of Literature

Agroforestry systems are land-use systems that combine the cultivation of

trees and the husbandry of farm animals on the same land area (Fernandes and

Nair, 1986). Agroforest systems are viewed as an alternative to the ever

increasing demand for food (Soemarwarwoto et al., 199285), and a pragmatic

solution that associates scientific as well as traditional techniques to diversify

production. For Nair (1991), the agroforest concept implies that these systems:

(1) involve two or more species of plants (or animals and plants); (2) always have

two or more outputs; (3) have cycles longer than one year; and (4) are

ecologically more complex than monocultures. In addition to these general

characteristics, Alcorn (1990) includes seven more traits of indigenous (or

traditional) agroforest systems: (1) integration of species from the native

vegetation; (2) the farmers take advantage of the natural environmental variations

present; (3) processes of natural succession are used as management tools; (4)

these systems include a large number of species; (5) integration of agroforest

areas into a diversified farm; (6) variety is seen amongfarm ers usingthe same

system; and (7) each farm is designed to satisfy the necessities of a family,

independent of land-use patterns of the local community.

Homegardens are traditional agroforestry systems characterized by the

complexity of their structure and multiple functions. Homegardens can be

defined as ‘land use system involving deliberate management of multipurpose

trees and shrubs in intimate association with annual and perennial agricultural

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crops and invariably livestock within the compounds of individual houses, the

whole tree-crop animal unit being intensively managed by family labour’

(Fernandes and Nair, 1986). Homegardens have attracted considerable research

attention during the past three decades (Wojtkowski, 1993), mainly due to the

following reasons: (i) they contain characteristics which make them an interesting

model for research and the design of sustainable agroecosystems, including

efficient nutrient cycling, high biodiversity, low use of external inputs and soil

conservation potential (Torquebiau, 1992; Jose and Shanmugaratnam, 1993); and

(ii) homegardens have been shown to provide a diverse and stable supply of

socio-economic products and benefits to the families that maintain them

(Christanty, 1990).

Homegardens are the closest mimics of natural forests in their structure

and usually have 3–4 vertical canopy layers. Besides the vertical structure,

homegardens also have distinct horizontal structure which together help in the

efficient utilization of water, light and space, and support diverse wildlife species

besides meeting various social and basic needs of families. Homegardens are

important in situ conservation sites and in accordance with the Convention of

Biological Diversity Article 7,8 and 10(c), inventorization of such areas can help

in the identification and conservation of biodiversity while assessing the

sustainability of the system. In order to understand the structure and function of

homegardens, it is necessary to analyse both socio-economic and biophysical

aspects of these systems. A number of studies on the complete inventory of

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homegardens have been done, including the structure, species composition1,

socioeconomic aspects and management zones (Mendez et al., 2001).

Nearly 80% of the people living in developing countries depend on

medicinal plants (MPs) for primary healthcare, and homegardens are an

important source of production of these plants. Homegardens can fulfill the dual

role of production and in situ conservation of MPs to overcome their dwindling

supplies and threat of extinction from natural sources. MPs in homegardens are

either deliberately cultivated or they come up spontaneously. They are an

important constituent of homegardens, next only to food crops and fruit trees; yet

their economic value is not fully recognized, let alone exploited. Homegardens

offer an economically and socially viable option for large-scale production of

phytochemicals from important MPs under organic cultivation. Promoting

organic production of selected commercially valuable species of MPs through

homegardening can, thus, augment the farmers’ income, enhance rural

employment opportunities, and help reduce migration of rural youth to urban

centers in search of jobs. Research is needed to improve the existing germplasm,

introduce suitable commercial MPs in different agroecosystems, and develop

cultivation and processing techniques to increase yield and improve product

quality, and exploit indigenous knowledge and market opportunities (Rao and

Rao, 2006). Additionally, the merits of homegardens in terms of subsistence food

for families, flexibility in production, reduced external-input requirements,

enhanced aesthetic-, landscape-, and societal values, should also be incorporated

into such an analysis (Torquebiau and Penot, 2006).


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2.1. Homegardens of Brazil

Despite their importance, homegardens have not been extensively studied

in Brazil. Most previous studies were carried in humid forest regions, such as the

state of Amazonas, and dry forests may be considered the orphans of the

Brazilian eco-regions. Most studies of Brazilian homegardens present qualitative

descriptions of their structure, composition, organization, and management

(Winklerprins, 2002; Albuquerque et al. 2005Anderson et al., 1985; Emperaire

and Pinton, 1986; Guillaumet et al., 1990; Saragoussi et al., 1990; Bahri, 1992,

1993a, b, 1996). There is little quantitative data available, nor detailed

descriptions of their structure or management.

Recent study on Species composition and structure as well as plant uses,

diversity, and variability of 31 homegardens in a dry forest region in the

municipality of Alagoinha, Pernambuco, Northeastern Brazil by Albuquerque et

al. (2005) reported that all together, 54 woody species were found to be used for

numerous purposes, especially as food sources. Prosopis julifora is the principal

tree species in local homegardens. This species is thoroughly disseminated

throughout Brazilian Northeast, and constitutes the majority of the total

population of homegarden trees in the region. It was observed that the size of the

homegardens varied greatly, but was related only to the number of individual

plants present, not species richness. The floristic structure of homegardens is also

very variable, but there is a core group of very frequent species, with significant


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representation of the local flora. This suggests that the homegardens may

contribute to the conservation of native species.

The division between rural and urban sectors of the landscape in many

parts of the world is increasingly blurred. House-lot or homegardens offer a

perspective on understanding rural-urban linkages since they are frequently a

landscape feature in both settings and the exchanges of their products link the

two. House-lot gardens are an under- researched component of the agricultural

repertoires of smallholders in many parts of the world. Urban house-lot gardens

in particular, have until recently not received much attention despite their critical

importance to urban livelihoods. This paper presents findings from research on

house-lot gardens in rural and urban zones of Santar´em, Par´a, Brazil, one of

Amazonia’s largest municipalities. The research demonstrates that garden

products are important for household subsistence, but even more importantly

product exchanges between rural and urban kin households help sustain critical

social networks that subsidize urban life. Gardens are a link between urban and

rural settings as products, germplasm, and household members move between the

two. People are urban and rural at the same time which demonstrates that

households can be multi-local (Winklerprins, 2002).

2.2. Homegardens of Tanzania

Homegarden agroforestry system has successfully been practiced in

Bukoba district, North-West Tanzania for some centuries. High productivity of

the farming system in the past made Bukoba district one of the most densely

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populated areas. Apart from banana and coffee, which are the principle crops,

various other crops and tree species are found in homegardens (Rugalema et al.

(1994).

2.3. Javanese homegardens

Quantification of nutrient flows, including nutrient inputs from

precipitation and nitrogen fixation in- and outputs from water channels, losses in

drainage, the fluxes between plant and soil and the agricultural production of the

Javanese homegardens has been used as an example of a type of system that has

proven its sustainability, by existing for hundreds of years on sloping lands

without any apparent decreases of production (Jensen, 1993).

2.4. Homegardens of Indonesia

With rapid development of Indonesia’s agricultural sector in response to

market pressures, homegardens and other traditional forms of agriculture are

increasingly being transformed into income-generating enterprises through the

introduction of cash crops. We examined the impact of this commercialization on

the structure and function of homegardens in the upland area of the Citarum

watershed, West Java, Indonesia, and analyzed the ecological, social, and

economic implications of these changes. Results of a vegetation survey and a

survey of 94 respondents indicated plant diversity in commercialized (intensively

managed) homegardens decreased owing to the introduction of commercial

crops. The change from subsistence to commercial farming was accompanied by

decreased plant diversity, higher risks, higher external input use, increased


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instability, and reduced social equitability. The needs and preferences of the

owners and market pressures were the main factors that triggered the

development of intensive agriculture and increased the commercialization of

homegardens. Commercialization adversely impacted the socio-cultural value

that homegardens have traditionally provided to the society. Likewise, the long-

term impacts and sustainability of commercial homegardens are also uncertain

(Abdoellah et al., 2006).

Diversity and change in homegarden cultivation in Indonesia was done by

Wiersum (2006) and summarized that the structure and composition of

homegardens depend both on their position in the overall farming system and on

livelihood strategies of the managers. Rural transformations result in changes in

livelihoods and farming systems, and have impacts of homegarden function and

composition.

2.5. Homegardens in the Pacific Islands

Pacific islanders traditionally had abundant, predominantly rural,

agroforestry systems that provided a wide array of products for meeting the

necessities of life, and conducive environments for the rich Pacific island

cultures. In recent years, however, increasing urbanization and accompanying

removal of trees and perennial agroforests (“agrodeforestation”) have resulted in

the breakdown of these traditional agroforestry systems, accompanied by

increasing economic, cultural, nutritional, and environmental problems,

particularly in the urban areas. A critical analysis of the nature and future


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prospects of the urban and homegarden agroforestry systems in these rapidly

urbanizing islands suggests that intensification and enrichment of these systems

could serve as an important foundation for sustainable development. In addition

to addressing the nutrition-related health problems, food security, poverty

alleviation, and trade deficits, these systems also help protect and enrich the

cultural traditions of Pacific peoples who are increasingly out-migrating from

rural areas and embracing urban living (Thaman et al., 2006).

2.6. Homegardens of Mesoamerica

A vast area of what is known today as Mesoamerica was the home of the

Mayan civilization. The region of Mesoamerica is densely populated and it

suffers from poverty and malnutrition both in urban and rural areas. It is home to

the Mayan civilization that practiced sustainable agricultural systems, involving

many native crops and soil conservation strategies, for centuries. The

homegardens, which provide the household with a basic food source as well as

high value products to generate cash income are important in Mesoamerica, and

are often used as tools in development projects that promote food security,

especially in the poorest areas of Mesoamerica. The Mesoamerican homegardens

are quite diverse in vertical and horizontal structure and species composition.

Both exotic and native plants are used, with emphasis on fruit trees. Domestic

animals, especially chickens and pigs, add protein to a diet that is generally

protein-deficient. Many indigenous communities (descendants of the ancient

Maya) still manage these homegardens using techniques that include residue

management and ash deposition, thus enhancing nutrient recycling and


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conservation. Carbon sequestration may be important due to the efficient capture

of solar radiation in the multi-layered homegardens, although its global or

regional importance is minimal due to the relatively small area under the

homegarden system. Management strategies that promote nutrient recycling and

maintain high species diversity should be encouraged to ensure sustainability of

homegardens in the region (Montagini, 2006).

2.7. Agroforestry Systems in Melanesian Islands

Coconut (Cocos nucifera)-based agroforestry systems hold promise as a

sustainable land use activity in the Melanesian islands, where food dependency

on foreign sources and land shortages are increasing dramatically. The dynamics

of these smallholder production systems in the Malo Island of northern Vanuatu

(Melanesia), where a dual economy operates in which resources are dedicated to

both subsistence and commercial production. The floristic elements found in the

coconut plantations were typical of those described in the humid tropical

homegardens elsewhere, with an average of 12 tree species per plot. Mean

Shannon Weaver index was 1.57 with the vertical profile of vegetation having

one-to-five strata. Although the coconut palms dominate these production

systems, in certain cases other trees may dominate it. Situations in coconut plots

evolve throughout the development phase of the palms. Based on that, five types

of smallholder coconut-based agroforestry systems were recognized, which falls

into two main evolutionary patterns: (1) a perennial occupation of the cultivated

land by coconut trees, because of coconut replanting, and (2) a gradual return to

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tree fallow in which the coconut palms gradually disappear because of changes in

the complex multistrata vegetation (Lamanda et al., 2006).

2.8. Homegardens of Southern Ethiopia

Most homegarden studies have focused on Asia, where homegardens

constitute a component of a spatially separated farming system consisting of

cultivated fields with staple food and/or commercial crops away from homes

complemented by the homegardens with supplementary crops such as fruits and

vegetables surrounding residential houses. In the highlands of East and Central

Africa, another type of homegarden is found in the form of an integrated farming

system within itself and without additional cultivated fields. In these ‘integral’

homegardens, not only supplementary crops such as fruits and vegetables, but

also staple food crops and cash crops are grown. The enset (Enset ventricosum)

and coffee (Coffea arabica) homegarden system in southern Ethiopia is a typical

example of such integral homegardens. An assessment of 144 of these

homegardens was made to gain insights into their structure and vegetation

composition and the relation between composition and geographic and

socioeconomic factors. Four specific garden types are identified, which vary in

commercial crop composition and diversity. These variations are related to farm

size and access to roads and markets, and illustrate the dynamic character of

homegardens. Overall, the diversity of the integral homegarden system seems to

be somewhat lower than that of the ‘complementary’ homegarden systems in


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Asia, probably due to the inclusion of light demanding staple food crops and a

relatively large number of commercial crops. The dynamic pathways of the

integral homegarden systems because of commercialization appear similar to

reported trends in the ‘complementary’ homegarden systems in Asia. Although

the composition of the homegardens is influenced by socioeconomic dynamics,

overall the Ethiopian homegardens can be characterized as being ecologically and

socioeconomically sustainable. This can be attributed not only to species

diversity but also to the presence of two keystone species—coffee and enset

(Abebe et al., 2006).

2.9. Homegardens in Amazon

Homegardens represent a traditional form of land use common in tropical

regions of the world. Species composition, structure and function of three

villages in the Peruvian Amazon in which homegardens were studied differed in

terms of cultural background, distance to urban markets and the influence of

tourism (Lamont et al., 1999).

Agroforestry systems developed by the Japanese immigrants and their

descendants in the Eastern Amazon region have been the focus of attention as a

model for sustainable rural development in the humid tropics. Potential crop

species – native as well as exotic – were gathered and nurtured by the farm

families in these homegardens of size 1 to 3 ha. Although the Tomé-Açu

Multipurpose Agricultural Cooperative (CAMTA) had experimental nurseries

and the Japanese public agencies established local agricultural research stations



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for supporting emigrant farmers in the Amazon, the homegardens functioned as

individual validation fields where the farmers ‘experimented’ with new crops.

Homegardens were also used for improvement and propagation of nursery stock

making them on-farm laboratories for adaptive research and extension. The

immigrants with the traditional tokun (master farmer) education of East Asia

analyzed the local environment and ‘experimented’ with various plant

associations and management techniques, which led to the evolution of the

exceptionally successful and popular multistrata agroforestry systems in the

Eastern Amazon region (Yamada and Osaqui, 2006).

Swidden cultivation is the traditional agricultural system in most parts of

the Amazonian rainforest, and in many situations swiddens lead to the

establishment of homegardens. In a remote area of the Manu National Park, Peru,

such a system was investigated in two indigenous Matsiguenka communities for

diversity of cultivated plants on swidden fields and in homegardens. The

cultivated plants were identified from two to four plots per field in 46 fields in a

total of 126 survey plots and 19 homegardens. Altogether 71 species were found

in the homegardens and 25 in the swidden fields. Cassava (Manihot esculenta)

was dominant in the cultivated fields, whereas fruit trees such as peach palm

(Bactris gasipaes), guava (Psidium guajava), and Inga edulis; and cotton

(Gossypium barbadense) and a medicinal plant (Cyperus sp.) predominated more

than 75% of the homegardens. Species diversity increased steadily with age

(length of cultivation) of the swidden fields. Diversity of species cultivated in the

homegardens was low compared to other studies reported from the Amazon. This

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seemed to be due to remoteness from urban areas, relative isolation and

consequently little interaction of the farmers with outside communities, and easy

availability of plant products from nearby forests. Although these findings appear

to contradict the premise that subsistence farming in such remote areas

encourages farmers to produce a broad variety of species and, therefore,

remoteness from urban centers increases species richness on farms; the extent to

which the situation is impacted by easy availability of plant products from nearby

forests, however, was not investigated in this study. In contrast to the

homegardens, swidden fields in this study did not show any difference in species

richness compared to other reported studies (Wezel and Ohl, 2006).

Understanding the historical development of indigenous systems will

provide valuable information for the design of ecologically desirable agroforestry

production systems. Such studies have been relatively few, especially in

Amazonia. The agroforestry systems in Amazonia follow a trail that begins with

the arrival of the first hunter-gatherers in prehistoric times, followed by the

domestication of plants for agriculture, the development of complex societies rich

in material culture, the decimation of these societies by European diseases,

warfare, and slavery, the introduction of exotic species, and finally, the present-

day scenario of widespread deforestation, in which agroforestry is ascribed a

potential role as an alternative land use. Despite the upheavals which occurred in

colonial times, greatly reducing the population of native tribes, a review of

anthropological and ethnobiological literature from recent decades indicates that

a great variety of indigenous agroforestry practices still exist, ranging from

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deliberate planting of trees in homegardens and fields to the management of

volunteer seedlings of both cultivated and wild species. These practices result in

various configurations of agroforestry systems, such as homegardens, tree/crop

combinations in fields, orchards of mixed fruit trees, and enriched fallows.

Together they constitute a stock of knowledge developed over millenia, and

represent technologies that evolved along with the domestication of native forest

species and their incorporation into food production systems. This knowledge is

the basis for the principal agroforestry practice employed by farmers in

Amazonia today, the homegarden, and has potential to contribute to the

development of other agroforestry systems (Miller and Nair, 2006).

2.10. Homegardens in Latin America

Structure, composition, and functions of homegardens are said to be

closely related to the social structure of households, but this issue is not often

researched. An analysis of the literature on swidden and homegardens in Latin

America shows that such interrelationships become transparent when examining

the gender division of labor, gendered access to garden resources including land,

trees, and other plants, and gendered control over subsistence and cash crops and

income derived from them. Social status related to gardening, gendered

knowledge distribution and transmission, and social dynamics leading to change

in gardening and gardens are also important parameters in this matrix. A review

of 39 Latin American case studies dealing with swidden or homegardens revealed

that women are by far the prominent garden managers across its sub-regions.

Aside from the multiple material benefits provided by gardens, other drivers that

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tend to ensure that women will strive to maintain them include their emotional

and spiritual values and the positive social status that productive and beautiful

gardens confer. Homegardening is a ‘respectable’ way for women to contribute to

subsistence production and manifest specialized knowledge and skills without

competing with men. However, commercialization may be undermining both

women’s control and the benefits they derive from homegardening as well as the

complex structure and function of homegardens (Howard, 2006).

2.11. Medicinal Plants in Tropical Homegardens

Nearly 80% of the people living in developing countries depend on

medicinal plants (MPs) for primary healthcare, and homegardens are an

important source of production of these plants. Homegardens can fulfill the dual

role of production and in situ conservation of MPs to overcome their dwindling

supplies and threat of extinction from natural sources. MPs in homegardens are

either deliberately cultivated or they come up spontaneously. They are an

important constituent of homegardens, next only to food crops and fruit trees; yet

their economic value is not fully recognized, let alone exploited. Homegardens

offer an economically and socially viable option for large-scale production of

phytochemicals from important MPs under organic cultivation. Promoting

organic production of selected commercially valuable species of MPs through

homegardening can, thus, augment the farmers’ income, enhance rural

employment opportunities, and help reduce migration of rural youth to urban

centers in search of jobs. Research is needed to improve the existing germplasm,

introduce suitable commercial MPs in different agroecosystems, and develop

32

cultivation and processing techniques to increase yield and improve product

quality, and exploit indigenous knowledge and market opportunities (Rao and

Rao, 2006).

Ecology vs. Economics in Homegardens

Homegardens and other multistrata agroforests are often described as

ecologically sound, economically viable, and socially equitable land use

activities. As in a majority of sustainable management situations, there are no

widely accepted norms for a “perfect” combination of these attributes; what is

often envisaged is a compromise among them. We argue that the development of

ecological features of homegardens can be fostered by an “innovative” economic

analysis. Performance of homegardens cannot be fully assessed by using

conventional economic criteria and approaches such as yield, cost-benefit

analysis, and net present value. Alternatively, if micro- and meso-level economic

analyses (farming systems and upper level systems) are applied, the

internalization of externalities such as agrobiodiversity management, carbon sink

value, improved nutrient cycling or integrated pest management may turn

homegardens into highly profitable ventures. Economic analysis methods should

integrate risk buffering, outputs of mixtures of plants with different cycles, and

allow to take into account farming strategies with long-term objectives as well as

the patrimonial (asset inheritance) components. Additionally, the merits of

homegardens in terms of subsistence food for families, flexibility in production,

reduced external-input requirements, enhanced aesthetic-, landscape-, and

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societal values, should also be incorporated into such an analysis (Torquebiau

and Penot, 2006).

Homegardens of Thailand

Gajaseni and Gajaseni (1999) studied the ecological rationalities of the

traditional homegarden system in the Chao Phraya Basin, Thailand. The major

factor that determines species selection in Thailand homegardens is the utilization

of the products, while the various practices within the homegardens are

determined by such factors as the species, the system, and the environment. All

homegardens had four vertical stratifications, with physical structures almost

similar to that of dry dipterocarp forest, but with lower height for each layer,

lower diversity of plants, and sparser crown layer. The analysis also shows a high

possible utilization efficiency for space, light, water and nutrients in the soil in

the homegardens. Shannon-Wiener’s indices of species diversity of the

homegardens were close to those of dipterocarp forest. The homegardens are in-

situ reservoirs for biodiversity at genetic-, species-, and ecological levels. There

was no complete harvesting from these homegardens. This practice ensured

minimal nutrient export from the systems, while high amounts and diversity of

litter biomass should contribute to high efficiency of nutrient cycling.

Futhermore, phosphorus availability could be better in homegardens. The

homegardens had more favorable microenvironment with lower soil and

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atmospheric temperature and higher relative humidity than outside. There has

been no single incident of a pest outbreak at a threatening level.

2.12. Cuban Homegardens

Cuban homegardens are called 'conucos'. On the basis of new case studies

additional information is provided about these 'conucos', their history,

composition and importance. They and other gardens of similar type are

characterized as suitable environment for in situ conservation and for the

continuation of evolutionary processes (Esquivell and Hammer, 1992).

The cultivation of different plants in homegardens for self-sufficiency has

a long tradition in Cuba, but knowledge about homegardens in Cuba is small. To

analyse this more deeply, cultivated plants of 31 homegardens were surveyed in

three villages in eastern Cuba in 2001 by (Wezel and Bender, 2003). Two of the

study villages were located in a humid area with an annual precipitation of about

2200 mm. The third village was situated in a semiarid area with about 450 mm

precipitation. The plants studied in the homegardens included those for human

consumption such as fruits, vegetables, tubers and cereals as well as spices and

medicinal plants. In total, 101 different plant species were found with an average

number of 18 to 24 species per homegarden for the three villages. A broad range

of species was found in all villages, because irrigation is used under semiarid

conditions, which lead to a relative high similarity in species composition

between the villages.

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2.13. Homegardens in Nicaragua

The choice of plant species, their arrangement and management varies

between and within tropical homegardens in the same community. Relationships

between agroecological and socioeconomic characteristics of 20 homegardens

were examined at Masaya, Nicaragua. Variables analyzed were microzonation

(area allocation to specific uses and management), plant use and diversity,

occupation, labor investment, and product, benefit and income generation. Ten

different micro-zones and nine plant uses were identified. Fruit trees, shaded

coffee and ornamentals were the most important zones. Plant diversity was high,

with a sample total of 324 species. Homegardens were an important occupation,

with average labor investments of 32.6 h family–1 week–1. Families obtained at

least 40 different plant products from homegardens, as well as the benefit of

space for working and socializing. Six homegarden types were identified using a

cluster analysis based on biophysical variables. Types reflected the relationship

between income generation and the number and types of zones and plant species

present. Labor inputs were high considering the small size of the homegardens

(average size 3,240 m2), although no clear relationships between labor

investment and plant and zone type or number were observed. Homegarden

management strategies of plant selection and zonation were affected both by

family choices and external forces. Although dependence on homegardens may

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vary according to specific conditions at a given time, they seem to be a

consistent, flexible resource used to meet a diversity of needs. The

methodological approach used in this paper may be appropriate for the study of

other traditional agroecosystems since it includes both biophysical and

socioeconomic variables, essential for understanding these complex systems

(Mendez et al., 2001).

2.14. Homegardens in Bangladesh

In managed landscapes, tree-dominated habitats often show promise for

biodiversity conservation. In Bangladesh where natural forest cover is less than

10 percent, homegardens, which are maintained by at least 20 millions

households, represent one possible strategy for biodiversity conservation. Kabir

and Webb (2008 and 2009) investigated the floristic and structural diversity of

402 homegardens from six regions across southwestern Bangladesh. All plants

were censused, totaling 419 species (59% native), including six IUCN Red

Listed. The median homegarden (800 m2) contained a mean of 34 species. Each

region contained a mean of 293 species in a mean of 67 homegardens. A total of

49,478 individuals (107 per homegarden and 1003 per hectare) of trees and

shrubs were counted from 45.2 ha total sampled area. Thus, significant botanical

richness was exhibited in the homegardens across southwestern Bangladesh.

However, most species were rare: 82 percent of all species including 189 native

were found in 50 or fewer homegardens, and 63 species (36 native) were found in

only one or two homegardens. Sixty percent of all tree and shrub species had 50

or fewer individuals each. Thus, whereas richness across the landscape was high,


37

serious effort must be made to increase the populations of most species. The

study propose three main conservation activities: (1) awareness building; (2)

protection of existing individuals of rare species; and (3) propagation. Overlaying

all of these activities is the inclusion of local communities in the process, who

were the ones to retain these species in homegardens in the first place, and the

stakeholders who will determine whether homegardens indeed act as long-term

repositories to biodiversity conservation.

2.15. Homegardens of Sri Lanka

Multilayered homegardens are a common agroforestry system, which covers a

considerable part of the Central Province of Sri Lanka, dominated by deep rooted

trees (De Costa et al., 2006).

2.16. Homestead Agroforestry in Andaman Islands

While reviewing the homegardens of Andaman and Nicobar group of

islands, Pandey et al. (2002a,b and 2006) investigated the structure and economic

viability of homegardens in south Andaman; observed the homegardens were

composed of five components namely, plantation trees (Orchards), temporal

organization of crops, livestock, poultry and fish pond. They also conducted a

survey in 19 homegardens and 10 forest home gardens in south Andaman to

elucidate species structure and diversity in their floristic composition and

observed that the diversity of plant species was greater in home-forest garden

whereas equitability, concentration of dominance and species richness in

homegarden.


38

Further, they also investigated the influence of biophysical and socio-

cultural factors on composition, diversity and distribution of plant species in the

homegardens of the Andaman and Nicobar archipelago of India (Padndey et al.

20072006). The study also examines component interactions and productivity of

the system. Four hundred and thirty homegardens were surveyed from six islands,

four from Andaman (South Andaman, North Andaman, Middle Andaman and

Little Andaman) and two from Nicobar district (Car Nicobar and Nancowry). In

Nicobar, an aboriginal tribe, the Nicobari, predominates. The Nicobaries are

Christians. However, people from different parts of the Indian subcontinent were

rehabilitated in the Andamans in the mid twentieth century. A mixed culture

prevails in South Andaman, but in the other Andaman islands either Bengali or

Tamil culture predominates. Biophysically, South Andaman is hilly whereas

Nicobar is flat. The other islands lie in between the two extremes. All are similar

climatically. Twelve to thirty-four plant species were encountered in the

homegardens that were planted, cared for and harvested. These plants categorized

as palm, fruit, spice and forest trees, formed a three-storey structure in Andaman

and a two-storey structure in Nicobar’s homegardens. The floristic similarity

between the homegardens of the Andamans was 82–92%. However, it was only

12–18% between the homegardens of Andaman and Nicobar. Compared to

Nicobar, species richness was greater in the homegardens of the Andamans.

However, diversity was higher and evenness lower in the homegardens of


39

Nicobar. All plant species in the homegardens of Nicobar are spontaneous in

regeneration. For the Andamans, the proportion of spice trees was higher in the

homegardens of South Andaman, mango and citrus in North Andaman, and

pineapple and vegetables in Little Andaman. High plant diversity in these

homegardens serves subsistence needs and provides income to most of the

households as well. Net income in the homegardens of Andaman was 6.9 times

higher compared to that in the homegardens of Nicobar.

2.17. Homegardens in Northeast India

In northeast India traditional homegardens have been maintained as a part

of rural survival over generations, with a part of complex vegetational structure

harboring diverse type local diverse type of local plant species with multiple

functions. Das and Das (2005) inventoried the plant biodiversity in homegarden

in Barak valley, Assam, northeast India and found that the homegardens are the

sites of conservations of large diversity of plants both wild and domesticated

because their uses in households.

In the homegardens of Barak Valley, bamboos form an integral

constituent (Nath et al., 20062008) as in the homegarden systems of Kerala

(Kumar, 1997). Bamboo grove is a separate zone within the homegarden or in the

adjoining land parcels where bamboo is grown either in pure stands or mixed

with dicot tree species like Lagerstroemia, Bombax, Erythrina, and the like. The

villagers manage these bamboo groves for commercial purposes whereas the

homegarden bamboos are essentially for meeting the felt needs of the rural


40

households (Nath and Das, 2008). However, farmers in homegarden practice

selective felling and maintain a growing stock throughout the year (see Nath et

al. 20062008) that can provide long term carbon storage in homegardens

compared to bamboo groves where a clear-felling strategy of bamboo harvesting

is practiced. A shift in the utilization pattern of bamboos growing in the rural

landscape especially in bamboo grove from paper industry to household, craft

sector through value addition can enhance the carbon stock and carbon

sequestration potential through longer lives of its materials/products (Nath et al.,

2008). A survey of plant species in the traditional homegardens of Meitei

community was conducted in Rajubari village of Cachar district in Barak Valley

(southern Assam), in northeast India (Devi and Das, 2010).

Tangjanj and Arunachalam (2009) investigated the role of traditional

homegardens system in Arunachal Pradesh, northeast India among three different

farming communities (Nyishis, Apatanis and Kalitas) in the preservation and

management of their traditional values, faith and indigenous knowledge system

contribute to ex situ conservation of local plant diversity and can also serve as

gene pools of the eroding indigenous plant species. The study recommended that

the induction of more indigenous plant species such as, leguminous plants,

bamboos, palms and medicinal plants also prove vital for the sustainability of the

agroforestry system.

Tynsong and Tiwari (2010a) investigated the plant species diversity and

inventoried 197 plant species belonging to 77 families in homegardens and their

contribution towards livelihoods of War Khasi community of Meghalya. The


41

study revealed that they are rich repository of wild as well as domesticated plants.

Homegardens harbour species found in the wild and also provide habitat for

cultivation of economically useful plants. Thus these predominantly man made

ecosystems can be placed between forest and agriculture ecosystems in the forest-

agriculture continuum, that provide food security to the people and act as safety

net in cases of exigency.

In south Meghalaya, farmers maintain a variety of economically

important plant species in arecanut gardens. The study conducted by Tiwari and

Tynsong (2010b) brings fore that the plant species composition of arecanut

gardens of south Meghalaya and encountered 160 plants, which included 83 tree

species, 22 shrub species, 41 herb species and 14 climber species; provide cash

income, medicine, timber, fuelwood and edibles for household consumption as

well as for sale. The findings of the study conclude that these agroforestry

systems serve as home for many economically important plant species, harbour

rich biodiversity and mimic the natural forests both in structural composition as

well as ecological and economic functions.

2.18. Homegardens of Kerala

Homegardens in Kerala, India, have long been important multipurpose

agroforestry systems that combine ecological and socioeconomic sustainability.

These traditional homegardens, however, are subject to changes consequent to

various on-going socioeconomic transformations. These homegardens had been

studied to some extent and the pioneer studies on the species diversity in the

42

homegardens of Kerala by Babu and his coworkers in 1982. Nair and Sreedharan

(1986) reviewed the Agroforestry farming systems in the homesteads of Kerala,

South India. Ninez (1987) regarded homegarden as perpetual ‘experimenters’ as

they constantly try and test new species and varities and their management. Jose

and Shanmugaratnam (1993) emphasized that these gardens are effectively serve

as human ecosystems with their low input demand, staggered supply of outputs

and enhancement of habitat quality. Kumar et al. (1994) studied the diversity

structure and standing stock of wood in the homegardens of Kerala.

A number of inventories of socioeconomic and environmental aspects of

homegardens in Kerala are available (Krishnankutty, 1990; Chandrashekara,

1995; Sankar and Chandrashekara, 2002; Peyre et al., 2006a; Chandrashekara,

2007). Issac and Nair (2006) studied the litter dynamics of six multipurpose trees

in a homegarden in Southern Kerala and noted that the higher rates of decay and

nutrient turnover in Mangifera indica, Artocarpus heterophyllus and Anacardium

occidentale foliage indicated the potential of these species’ litter as nutrient input

in agriculture while Artocarpus triphysa, A. hirsutus and Swietenia macrophylla

perform better as organic mulches taking a longer time for decay and hence

nutrient release.

The study of structural and functional dynamics of homegardens offers an

opportunity to understand the trends in socioeconomic sustainability in relation to

their ecological sustainability. These dynamics were studied in a survey of 30

homegardens. Based on a cluster analysis of tree/shrub species density and a

subsequent grouping using homegarden size, six homegarden types were


43

differentiated, and these were assessed for structural, functional, and managerial

characteristics, besides their dynamics. Four development stages of homegardens

were found along a gradient from traditional to modern homegardens. Fifty

percent of the homegardens still displayed traditional features, whereas 33%

incorporated modern practices. The process of modernization includes a decrease

of the tree/shrub diversity, a gradual concentration on a limited number of cash

crop species, an increase of ornamental plants, a gradual homogenization of

homegarden structure and an increased use of external inputs. A traditional

homegarden combining multispecies composition and intensive management

practices could, however, offer an alternative development path to modern

homegardens in adapting homegardens to changing socioeconomic conditions

(Peyre et al., 2006b).

Mohan et al. (2006) assessed the financial analysis of homegardens of

Thrissur district, Kerala state, India, used inventories, survey information and

market data to estimate the productivity of 75 homegardens, and applied benefit-

cost analysis to ascertain the current financial values of these systems. All

homegardens were found to be economically profitable and also to be of better

economic utility to the farmer than selling or leasing the land. Sensitivity

analyses indicated that these systems were easily resilient to 10% shifts in the

prices of hired labor and in the prices of the three most economically important

crops: coconut (Cocos nucifera), arecanut (Areca catechu), and banana (Musa

spp.). Profit value of the gardens tended to increase with holding size and with

increasing years of cultivation. Labor hours (both household and hired) and



44

gender of the decision-maker were not suitable predictors of profit. Intensity of

profit generation was highest in the smaller gardens, thus perhaps indicating both

adaptive management to land constraints, and the presence of other intangible

benefits that might affect land management strategies.

Regeena (2007) surveyed the homestead farms of the south zone of

Kerala comprising of the three districts of Thiruvananthapuram, Kollam and

Pathanamthitta and the data revealed that the homegardens, though under threat

from monocultures of commercial crops like Hevea brasiliensis, were

repositories of plant biodiversity and warranted to be documented and conserved.

Bamboos occur widely both in the homegardens of Kerala (Kumar and

Divakara, 2001). Due to over-exploitation, however, this resource has declined

substantially. For example, the thorny bamboos [Bambusa bambos (L.) Voss],

once widely distributed in the homegardens of Kerala, of late has become a

shrinking resource base (Kumar, 1997). Bamboo trade, however, has been

flourishing in central Kerala and most of the rural bamboo traded is sourced from

Palakkad, Malappuram, and Thrissur districts (Krishnankutty, 2005). The

quantitative estimate on the bamboo stocks available in Thrissur districts was

done by Kumar et al., (2005a). Kumar (2008) assessed the standing stock of

Bambusa bambos through a two stage stratified random sampling scheme in the

homegardens of Palakkad and Malappuram district in Kerala.

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Recently, Chandrashekara (2009) conducted a survey on the diversity of

fruit trees with respect to abundance, distribution patterns, fruit collection and

their management in coffee based homegardens in high altitude agro-climatic

zones of Kerala; shows that certain non-crop fruit trees such as Baccaurea

courtallensis, Carissa carandus, Chrysophyllum roxburghii, Feronia elephantum,

Garcinia xanthochymus, Madhuca indica, M. longifolia, Mimusops elengi,

Zizyphus mauritiana and Z. rugosa are widely distributed in the homegardens and

are being managed for a multitude of reasons such as shade, fuelwood, timber,

soil fertility, fencing and edible fruits. The study suggested that tree

improvement, domestication and sustainable cultivation of some of these species

in homegardens and other agroforestry system can provide better oppurtunitites

for commerce to conserve crop diversity, enhance economic value of their crop

plants and ensure food security.

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