Does ‘jungle rubber’ deserve its name? An analysis of rubber agroforestry systems in southeast Sumatra

Jungle rubber is a blanced, diversified system derived from swidden cultivation, in which man-made forests with a high concentration of rubber trees replace fallows. Most of the income comes from rubber, complemented with temporary food and cash crops during the early years. Perennial species that grow spontaneously with rubber provide fruits, fuelwood and timber, mostly for household consumption. Jungle rubber enables lower incomes per land unit or man-day than weed-free plantations using selected rubber clones. Yet it requires much less input and labour since wild woody species protect rubber from grass weeds and mammalian predators. With a structure and biodiversity similar to that of secondary forest in its mature phase, jungle rubber belongs to complex agroforestry systems. It has accommodated increasing population densities, while preserving a forest-like environment.Yet farmers' income from jungle rubber is declining due to the exhaustion of forest reserves and reduced land availability. New research and extension options could help in improving the productivity of jungle rubber. Better transportation and marketing are needed for increasing the income from non-rubber output. Short-term, small-scale credit schemes could help farmers adopt high-yielding rubber varieties. Research should participate in creating new management methods for selected rubber based on agroforestry to reduce maintenance costs, enabling smallholders to plant high-yielding rubber at lower cost, and without losing too much of the present biodiversity and economic diversity.

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Résumé Dérivées de l'essartage, les forêts à hévéa forment un système de culture équilibré et diversifié, où le recrû forestier est remplacé par une forêt anthropique à forte concentration d'hévéas. L'essentiel du revenu provient des hévéas, complétés par des cultures vivrières et commerciales pendant les premières années. Les espèces prérennes qui se développent spontanément avec les hévéas fournissent des fruits et du bois, principalement pour l'autoconsommation. Le revenu tiré de ce système est inférieur à celui de plantations d'hévéa clonal entretenues. Il nécessite cependant moins d'investissements en intrants et en travail grâce au rôle protecteur de courvert forestier vis-à-vis des adventices herbacées et des mannifères prédateurs. Avec une structure et une diversité d'espèces comparable à celles d'une forêt secondaire, ce système fait partie des agroforêts complexes. Il a fourni depuis 1910 l'essentiel du revenu d'une population en croissance rapide tout en préservant un environnement forestier.Le revenu que tirent les paysans des forêts à hévéa est en déclin en raison de l'augmentation de la population. De nouvelles orientations de la recherche et du développement pourraient permettre d'améliorer la productivité de ce système. Le revenu tiré de la composante nonhévéa pourrait être augmenté grâce à une amélioration des transports et de la commercialisation. Le crédit à court terme et à petite échelle permettrait aux paysans d'adopter des variétés d'hévéa sélectionné et d'augmenter ainsi leurs revenus. La recherche devrait aider à mettre au point de nouvelles méthodes de gestion des hévéas sélectionnés, de type agroforestier, afin de réduire les coûts d'entretien. Les paysans purraient ainsi planter des hévéas hauts producteurs à moindres frais, et conserver partiellement la diversité économique et écologique du système actuel.

     

Streuobst: a traditional agroforestry system as a model for agroforestry development in temperate Europe

The development of agroforestry for industrialised countries can be furthered by an understanding of the history and present functioning of traditional systems. In temperate Europe, fruit trees were traditionally grown on agricultural land undersown with crops or managed grassland (Streuobst). The historical evolution of this agroforestry system has been driven by the interaction of technical progress, market development and intervention by public authorities. Streuobst reached its peak in the 1930s, but has since been in continuous decline due to the development of intensively managed dwarf-tree orchards. However, even today, it still occupies approximately one million hectares in 11European countries and has a strong impact on the European fruit market. The profitability of streuobst is relatively poor due to its low labour productivity, but it has advantageous ecological and socio-cultural features, particularly in terms of biological diversity and landscape aesthetics. Accordingly, it finds strong acceptance among the general public, such that subsidised eradication programs have been abandoned and, in a number of countries, streuobst is now supported by non-governmental organisations and by state conservation policies. Modern agroforestry in temperate, industrialised countries should be oriented towards the creation of similar ecological and socio-cultural benefits in order to receive public support as a land-use system. This revised version was published online in June 2006 with corrections to the Cover Date.     

Traditional agroforestry practices in Zimbabwe

Traditional agroforestry systems in the communal areas of Zimbabwe are described. There are systems centered on main fields, on home gardens, on homesites and on grazing areas. In the main fields, the major tree-related management practice is the conservation of preferred indigenous fruit trees. Fruit trees are also the focus of forestry activities around the gardens and the homesite; but here it is the planting of exotic species. In a localized area of Zimbabwe Acacia albida is important in fields. There is almost no use of tree fallows in Zimbabwe. Trees in grazing areas have numerous roles, but at present there is little knowledge about traditional management practices in these areas. In the development of agroforestry systems in Zimbabwe it is suggested that those systems designed to improve fodder production will make a significant contribution to farm productivity because of the importance of cattle in the farming system and the present fodder shortage. Interventions involving the planting of fruit trees are likely to be very successful, as there is much interest in such planting. Another area that needs to be developed is that of tree plantings to improve soil fertility.     

The contribution of agroforestry systems to reducing farmers' dependence on the resources of adjacent national parks: a case study from Sumatra, Indonesia

There is much debate about the way conservation and development are best integrated to reduce the encroachment pressures of poor rural communities on the biodiversity resources of protected areas in the tropics. One frequently recommended instrument is to intensify farming systems in the adjacent areas, so as to decrease the need to harvest resources from national parks. This study examined this issue by analyzing the effects of different household land uses in villages near a national park on their propensity to harvest resources from the park. In the northern part of the Kerinci Seblat National Park (Sumatra Island, Indonesia) the park buffer zone is comprised largely of community or village forests and human settlements. The village forests were formerly managed as production forests and provided significant cash income to the village. They were converted into farmland, particularly to mixed-tree gardens or agroforests. Natural forest coverage has now declined to 10% of the former area within village forest land. We analyzed the characteristics of the mixed gardens and village forests, and their practical contribution to reducing farmers' dependence on the adjacent national park resources. Households with farms that were more diversified were found to have much less dependency on the national park resources. Households that farmed only wetland rice fields registered the highest value of forest products obtained from inside the park. Households that farmed only mixed gardens had an intermediate level of park resource extraction, while those that had farms composed of both components (i.e. wetland rice fields and mixed gardens) had a dramatically lower level of economic dependency on park resources than households in either of the other two categories.This revised version was published online in November 2005 with corrections to the Cover Date.     

The domestication and commercialization of indigenous trees in agroforestry for the alleviation of poverty

New initiatives in agroforestry are seeking to integrate into tropical farming systems indigenous trees whose products have traditionally been gathered from natural forests. This is being done in order to provide marketable products from farms that will generate cash for resource-poor rural and peri-urban households. This poverty-alleviating agroforestry strategy is at the same time linked to one in which perennial, biologically diverse and complex mature-stage agroecosystems are developed as sustainable alternatives to slash-and-burn agriculture. One important component of this approach is the domestication of the local tree species that have commercial potential in local, regional or even international markets. Because of the number of potential candidate species for domestication, one crucial first step is the identification of priority species and the formulation of a domestication strategy that is appropriate to the use, marketability and genetic potential of each species. For most of these hitherto wild species little or no formal research has been carried out to assess their food value, potential for genetic improvement or reproductive biology. To date their marketability can only be assessed by their position in the local rural and urban marketplaces, since few have attracted international commercial interest. To meet the objective of poverty alleviation, however, it is crucial that market expansion and creation are possible, hence for example it is important to determine which marketable traits are amenable to genetic improvement. While some traits that are relatively easy to identify do benefit the farmer, there are undoubtedly others that are important to the food, pharmaceutical or other industries that require more sophisticated evaluation. This paper presents the current thinking and strategies of ICRAF in this new area of work and draws on examples from our program. This revised version was published online in June 2006 with corrections to the Cover Date.     

People,trees and projects: a review of CARE's activities in West Africa

CARE, in collaboration with a range of government agencies, has been active for over 15 years in agriculture, agroforestry and natural resource management projects in West Africa. Many of these projects evolved from emergency food distribution activities during the drought years of the 1970s and 80s. A number of valuable lessons are now emerging, particularly in relation to agricultural and agroforestry activities in the Sahelo-Sudanian and Sahelian zones. In the context of CARE's orientation and capabilities as a non-governmental development agency, these lessons are used to construct a framework for prioritizing future agriculture and natural resource management activities in the region.     

Inorganic and organic soil phosphorus and sulfur pools in an Amazonian multistrata agroforestry system

In the central Amazon basin, the effects of secondary vegetation and primary forest on inorganic and organic P and S pools were compared with those of different fruit and timber tree species in a multistrata agroforestry system. The soils (Xanthic Ferralsols) were low in readily available P and S. Fertilizer applications increased the less accessible nutrient pools more than the plant available pools. For example, dilute-acid extractable P increased substantially (from 2 to 76 mg P kg⁻¹), whereas Mehlich P (plant available) increased less (from 3 to 19 mg P kg⁻¹). In contrast, the recalcitrant soil P pools, such as the residual P, did not increase on the short term, but only after more than six years following application. The proportion of less available ester-sulfate S was significantly higher in fertilized sites than in unfertilized sites, in contrast to soluble inorganic sulfate S or carbon-bonded S. The marked increase of successively available soil P and S pools through fertilization was advantageous with respect to the long-term effect of nutrient applications. Soil nutrient availability was not only related to the amount of nutrients applied but was also influenced by tree species. Nutrient return by litterfall and litter quality played an important role in soil P and S dynamics. Incorporation of applied nutrients into successively available organic nutrient pools will decrease potential P fixation and S losses by leaching and increase long-term nutrient availability. Therefore, tree species with rapid above-ground nutrient cycling and high quality litter (such as annato [Bixa orellana] and peach palm [Bactris gasipaes]) should constitute the majority of crops in multistrata agroforestry systems on infertile soils to ensure adequate medium to long term availability of P and S. This revised version was published online in June 2006 with corrections to the Cover Date.     

Ecological factors affecting durian production in the forest gardens of West Kalimantan,Indonesia

Whereas a natural ecosystem is stochastically created by mechanism of natural selection, an agroecosystem is systematically fashioned by farmers in response to specificperceived ecological and economic constraints. In this paper, I employ a geographical information systems (GIS) based analysis to examine the beliefs of forest garden owners in West Kalimantan, Indonesia, regarding ecological factors involved in maximizing durian fruit (Durio zibethinus) production. Factors that I tested included individual tree characteristics (age, size, color), microsite factors (on or off ridge, near stream, slope, proximity to rock outcrops, in dry or swampy site), species associations (with other types of trees, spacing to nearest large tree), and the overall position of the garden (on flat land or hill, distance to natural forest). I first conclude that respondents generally had accurate perceptions as to how ecological factors influence durian production. I then briefly discuss how the findings of this study could be used to improve existing and future durian gardens. Finally, I discuss the potential for studying slow-growing agroforestry systems using cross-sectional data collected from plots owned and managed by individual house-holds through the use of a GIS and statistical control.In spite of the high specific richness of the gardens' vegetation ... the place of each plant is carefully chosen, and often corresponds to its ecological niche in the natural forest. Enauiries have shown that people have a certain ecological knowledge in individual care towardseach plant that is in contradicion to the mass treatment of cultivated crops in monoculture.-G.Michon (1983, p.19)     

Farmers' perspectives on slash-and-burn as a land clearing method for small-scale rubber producers in Sepunggur, Jambi Province, Sumatra, Indonesia

On September 10, 1997, Indonesian President Soeharto renewed a ban on the practice of burning forests to clear land. At that moment a thick haze caused by land-clearing related fires in Kalimantan and Sumatra, Indonesia, blanketed large parts of Indonesia, Malaysia, Singapore, Brunei, the Philippines and Thailand. These fires, aggravated by the El Niño weather pattern and described as the worst in Southeast Asian history, renewed a long-term debate on slash-and-burn (S&B) as a method of land clearing.

Acceptable alternatives to S&B should address both the problems and the benefits of the use of fire. In depth knowledge and a clear diagnosis of the problems that rise with S&B and its alternatives are needed. A social/economic/agronomic survey was therefore conducted among 37 small-scale rubber producers in Sepunggur, Jambi Province, Sumatra, Indonesia. Our objectives were to: (1) characterize S&B techniques; (2) characterize farmers' perspectives on land clearing methods related to agronomic/economic factors (soil fertility, plant growth, production); and (3) evaluate alternatives to S&B that would be acceptable to individual farmers at present and in the near future. Small rubber producers (average farm size ≈5 ha) were selected because rubber gardens are the major land use type in this area, small producers are the main contributors, and most of the forest that is presently converted for agricultural use is being planted with rubber seedings.

Farmers generally start slashing in March and burn in the month of August. Burning takes place in two steps: broadcast burn followed by pile-and-burn. The five advantages of using fire as mentioned by the farmers were: (1) burning creates space (51%); (2) ash acts as a fertilizer (23%); (3) burning improves soil structure enabling faster establishment of seedlings (15%); (4) burning reduces weed/tree competition (5%); and (5) burning reduces the occurrence of pests/diseases (3%).

Alternatives to S&B should be economically acceptable. Mulching does not provide an alternative to any of the benefits of burning. Slash-and-remove-wood addresses only the first advantage and requires a tremendous effort in labor. If forced to accept either alternative, farmers expect a reduction in income due to difficulties in establishing new rubber gardens, reductions in yield, and an increase in labor costs.

At present, small quantities of wood with economic value are sold on the local market. Slash-sell-and-burn is an alternative that could maintain the advantages of using fire while supplying the farmer with extra income and the initiative to remove and not burn the trees. Even though forest is rapidly being converted to rubber gardens, land clearing will remain in practice to rejuvenate the old rubber gardens or to convert them to other land use systems. By selling rubberwood, farmers could cover costs of land clearing and earn enough to cover some of the costs of buying higher-yielding clones for rubber planting. This alternative has benefits similar to using fire and could significantly reduce pollution problems, but a change in local trade regulations and taxes is required for its successful adoption.     

The potential of agroforestry to increase primary production in the Sahelian and Sudanian zones of West Africa

The article presents a critical evaluation of agroforestry systems as regards their potential to increase primary production in the Sahelian and Sudanian zones of West Africa. The suggestion that trees would always and everywhere be profitable for the region will be counterproductive, the basis for disappointments and a waste of money. One has to consider carefully which properties of woody species could serve which objective, where and under what circumstances.Primary production is limited by water availability in the north Sahelian zone only, elsewhere in the region nutrient availability is critical. Woody species influence the water balance via rainfall interception, the influence on evapotranspiration and the influence on water infiltration. The ultimate result for grasslands and crops depends upon local conditions; positive effects of windbreaks should be particularly attributed to protection against mechanical stress. Processes that influence nutrient availability under trees are those acting via redistribution, those reducing nutrient losses and those increasing soil fertility. Of the latter processes, serious limitations exist in the region concerned: nitrogen fixation is limited by phosphorus shortage mainly and deep rooting is very limited and so is possible uptake of minerals from deep soil layers.The positive influence from woody species on soil fertility and primary production varies with average annual rainfall and soil type; its importance increases more than proportionally with rainfall going south. This positive influence is basically linked to the redistribution of nutrients and water, the internal nutrient cycling and the related enlarged plant-litter-soil nutrient cycle. Taking advantage of its effects is difficult and risks further depletion of soil fertility. Moreover, since woody species generally compete with the herb layer, it will be difficult to develop agroforestry in such a way that the positive influences are not overridden by negative ones. The potential to increase nutrient availability by agroforestry systems is limited and windbreaks are more beneficial under conditions which are rare in the region.More research is needed to determine under which conditions introduction of woody species may be beneficial.

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Le potentiel de l'agroforesterie pour augmenter la production primaire dans les zones sahélienne et soudanienne de l'Afrique de l'Quest

Résúme Une évaluation critique de l'agroforesterie est présentée, en ce qui concerne la possibilité d'augmenter la production primaire dans les zones sahélienne et soudanienne de l'Afrique de l'Quest. La supposition que dans cette région des arbres seraient toujours et partout avantageux, n'est pas productive, mais plutôt une cause de déceptions et un gaspillage de ressources. Il faut se demander quelles propriétés des espéces ligneuses pourraient servir quels objectifs, oú et sous quelles conditions.Seulement dans zoneone nord-sahélienne la production primaire est limitée par la disponibilité en eau; ailleurs c'est la disponsibilité des éléments nutritifs qui est la plus déterminante. Des espéces ligneuses influencent le bilan d'eau par l'interception de la pluie, par des modifications de l'evapotranspiration, et par une amélioration de l'infiltration d'eau. La conséquence pour les pâturages et les cultures dépend des conditions locales; les avantages de brise-vents dépendront notamment de la protection contre le stress mécanique. Des processus influençant la disponibilité des éléments nutritifs souls les arbres sont ceux agissant par la redistribution, par la diminution des pertes et par l'augmentation de la fertilité. Les derniers processus ont des limitations sérieuses dans la zone: la fixation d'azote est surtout limitée par le manque de phosphore et l'enracinemment profond paraît limité et ainsi la possibilité de profiter d'une disponibilité éventuelle de minéraux en profondeur.L'influence positive des espéces ligneuses sur la fertilité du sol et la production primaire varie avec la pluviosité annuelle et le type de sol; son importance accroît plus que proportionnelle avec la pluviosité vers le sud. Cet influence positive est liée à la redistribution des éléments nutritifs et de l'eau, au recyclage interne des éléments nutritifs et le cycle agrandi y en être la conséquence, de ces éléments en plante-litière-sol. Pour profiter de ses effets est difficile et on risque l'épuisement supplémentaire des éléments nutritifs. En plus, suite à la concurrence entre les espéces ligneuses et la strate herbacée, c'est difficile à développer l'agroforesterie d'une telle façon que les avantages ne seront pas surpassés par les inconvéniences. Des brise-vents sont avantageux sous des conditions qui sont rares dans la zone.Plus de recherche est nécessaire pour déterminer les conditions sous lesquelles l'introduction des espéces ligneuses peut être profitable.

     

Fruitcrops in the cashew-coconut system of Kenya: their use,management and agroforestry potential

The cashew-coconut system in the Coast Province of Kenya was appraised to determine the efficacy and adoption potential of a fruitcrop based agroforestry intervention designed to increase the productivity of the system. Fruitcrops on farmers plots ranged between 16–22 species. They featured mainly as understorey trees in cashew-coconut plots and upper storey of foodcrop plots. Fruit tree management was generally poor.Between 67–100% of farmers interviewed were interested in planting more fruit trees on their farms. Envisaged cash generation was a major reason for their interest. Preferred species were generally adapted exotics. Preference was in the order ofMangifera indica, Citrus sinensis, C. reticulata > Cocos nucifera, Anacardium occidentalis, Carica papaya > Passiflora edulis var. flavicarpa,Ananas comosus, Syzygium cumini, Citrus limon, Musa sapientum, Persea americana > Musa paradisiaca, Citrus aurantifolia Annona spp. Locational differences existed in exact order of preference within the groupings. Constraints to fruit production included lack of improved fruit tree seedlings, low proficiency in fruit seedling production, transportation, no capital for initial investment, damage by wild animals, prolonged dry spells, and frequent die back of fruit trees. Based on its high adoption potential, a fruitcrop based agroforestry intervention is recommended for increasing the productivity of the cashew-coconut system of Kenya.Possible agroforestry technologies in which fruitcrops could feature are discussed.     

Community Dependency on Forest Resources in West Java,Indonesia

Abstract

Policies aimed at the exclusion of local communities from forest management are inappropriate, especially in a densely populated area with a low level of land ownership. Here we demonstrate that termination of the Tumpang Sari program, which allowed local communities access to areas for controlled cultivation in several parts of the state forest area in West Java, Indonesia, did not cease illegal cultivation of the forestland. Moreover, illegal cultivation continues to be conducted by many people. This has created not only a land degradation problem but also has affected other forest resource users, the fuelwood collectors and the dairy cattle farmers. Therefore, the re-involvement of local communities in better forest management is required to avoid further environmental degradation as well as enhance poverty alleviation programs.     

Implementing on-farm agroforestry research: lessons learned in Talamanca,Costa Rica

The rapid appraisal and farmer selection procedures, preceding the establishment of over fifty agroforestry research trials on farms in Talamanca, Costa Rica are described. The highest probability of success and impact of these long-term collaborative trials is obtained by selecting innovative, experienced, motivated and locally respected farmers. The methodological lessons learned from implementing three types of researcher managed trials (shade-cacao; black pepper on living support posts; timber production in boundary lines) are discussed. The importance of fitting farmer selection criteria to project objectives, experimental designs to on-farm limitations, and project goals to farmers' goals, are emphasized.     

陆良县森林及森林生态资源管理与保护的思考

依据自然社会概况、森林资源概况分析了陆良县森林资源特点、森林资源管理现状及森林资源管理中面临的困难,对今后一段时期森林资源管理进行了思考,提出了相应的对策和措施,对林地和湿地专琐保护面临的问题进行了探讨,思索如何更好地保护森林及森林生态资源。     

Combination of cacao with other plantation crops: an agroforestry system in Southeast Bahia,Brazil

Brazil accounts for about 20% of the world production of cocoa, and about 95% of cocoa produced in Brazil is from the southeastern part of Bahia State. Traditionally, cacao is grown in monoculture (though under the shade of various other species). But various crop combinations involving cacao have recently been undertaken by the farmers with encouragement from Brazilian government.As a part of the crop diversification programme in the traditional cacao growing areas and their surroundings, extensive areas are being planted to other plantation crops, mainly clove and rubber and, to some extent, coconut too. Crop combinations have been adopted in some of these new plantings and cacao is an important component of most of such combinations. Whereas several other crops are combined with clove trees, cacao is usually the only species grown with mature rubber trees. Young rubber trees are, however, interplanted with a number of other species. Productive coconut areas are found mostly in sandy soils along the coast so that there is little intercropping. However, scattered farms are found where coconuts are underplanted with guarana, black pepper, cacao, cashew, etc. as done commonly in other parts of Northeast Brazil.     

Growth of four tree species managed as hedgerows in response to liming on an acid soil in West Sumatra,Indonesia

A hedgerow intercropping study was conducted for 7 years in West Sumatra, Indonesia on an acid and highly Al-saturated soil to determine growth and yield responses of tree hedgerows and upland rice and cowpea intercrops. Three tree species,Paraserianthes falcataria, Calliandra calothyrsus, andGliricidia sepium and a no-tree control were planted at three lime rates with low annual fertilizer inputs of 20 kg P and 50 kg K ha^–1.Paraserianthes andCalliandra grew vigorously, whileGliricidia grew poorly and was replaced after four years withFlemingia macrophylla. After four years,Paraserianthes yields declined due to tree mortality, probably due to intensive pruning.Calliandra andFlemingia were well adapted to intensive pruning (4 to 6 times per year). Gliricidia growth was especially limited by low soil Ca availability and high soil acid saturation.Calliandra andFlemingia yields increased with liming only in the last several years of the study whileParaserianthes did not respond to lime. The species can be tentatively ranked in response to lime as:Gliricidia > Calliandra > Flemingia > Paraserianthes.     

Rural participatory buffer zone management in northeastern Thailand

The past protected area management system which emphasized the ownership and control of forest by the state and overlooked the interaction between human and resources has failed because the annual rate of deforestation in Thailand is still as high as 2.6%. This paper aims to introduce a new approach to protected area management that would involve local people in the process. A case of buffer zone management through collaborative efforts is examined here. The project is located at the southeastern corner of the buffer zone of Phu Kheio Wildlife Sanctuary, Northeastern Thailand. Participatory Rural Appraisal (PRA) techniques including secondary data study, physical survey, participatory meeting, and semi-structured interviewing were employed in data gathering. The results discussed here suggest that there is a chance to create a better understanding among rural people of the importance of afforestation and nature conservation that will lead to a better management of resources in the future.     

田园镇森林资源经营措施研究

分析了田园镇森林资源的现状,从公益林补偿与工程建设等方面探讨了阻碍发展的因素,阐述了田园镇森林资源发展的有利条件,从科学规划、经营管理、资金投入、经济产品等方面提出了经营措施。