Prioritizing Underutilized Tree Species for Domestication in Smallholder Systems of West Java Budi H. Narendra1,* - James M. Roshetko2 - Hesti L. Tata3 - Elok Mulyoutami4
This paper provides an overview of a tree species prioritization study of underutilized tree species in a participatory tree domestication program for smallholders in Indonesia. The study was conducted in three villages of Nanggung sub-district, Bogor district via farmer surveys, focus group discussion, SWOT analysis and evaluation of markets and germplasm sources. Five priority species were identified: Manglietia glauca, Parkia speciosa, Durio zibethinus, Gmelina arborea and Sandoricum koetjape. These species are promising components of agroforestry systems to enhance smallholder livelihoods and can grow under the low management conditions common in smallholder systems. They represent indigenous and exotic tree types that produce timber, fruit or spices within the domestication continuum. Furthering the domestication and utilization of these species requires the identification and dissemination of available germplasm sources, the dissemination of high-quality germplasm and the development of farmer-friendly propagation and tree management practices. Also, as with most smallholder systems, the marketing practices for the products of these five species require improvement, starting with the production of reliable quantities of high quality tree products.
Keywords: Species prioritization - Germplasm sources - Propagation - Tree management
Introduction Tropical rainforests of the Indo−Malayan region are endowed with a plethora of plant genetic resources that provide valuable and marketable timber, medicines, fruit and other products. There are more than 100,000 tree species worldwide (BGCI 2007) but only 10,000 species have been described in detail (Reeb 1998). Of the more than 4,000 tree species in Indonesia, less than 10% has been investigated in relation to their wood properties and utilization (Martawijaya et al 2005). Smallholders and forest industries tend to utilize only a few timber species, including Paraserienthes falcataria, Tectona grandis, Acacia mangium, Dalbergia latifolia and Swietenia macrophylla. These species share the following characteristics: commonly available germplasm, ease in propagation and management, current market demand, known wood properties and promotion by government, non-government and development organizations. Other tree species are less understood or underutilized. Lesser known tree species are generally neglected or overlooked because they have not been exploited commercially, there is a lack of information regarding their use and little, if any, research has been conducted on them. They occur in the wild or are grown as scattered trees in tree garden systems. They are a source of useful genes for related crop species and hold promise for economic development (Normah 2003). Underutilized plant species are those currently of minor importance in terms of production, consumption (food or medicine) and utilization, and are not yet fully exploited in terms of contribution to market or household economies (Aboagye et al. 2007). In this study, the status of underutilized species focuses on the specific conditions of the study area, because in other locations the same species might be commonly or intensively utilized.
Tree domestication is accelerated anthropogenic evolution that brings species into wider cultivation through a farmer-driven or market-led process. The objective is to enhance tree performance in terms of improved tree products or environmental services as well as increasing species awareness and market orientation (Roshetko and Evans 1999; Simons and Leakey 2004). Tree domestication is an iterative process that involves species selection, production, management and adoption of desirable germplasm, to product marketing (Figure 1). Some activities may be bypassed or occur in parallel during the domestication process. The progress may also flow back to earlier steps in the continuum as interest in or the economic value of a species develops further (Roshetko and Evans 1999).
Fig. 1 Tree domestication continuum (Roshetko and Evans 1999)
Participatory tree domestication with farmers is a viable strategy to enhance livelihoods, address food security and promote sustainable environmental management (Akinnifesi et al. 2008; Tchoundjeu et al. 2010; Leakey et al. 2012). Farmers’ active participation in tree domestication will increase efficiency and improve the applicability of results because they are best able to identify tree characteristics that will satisfy their needs and apply indigenous knowledge to guide tree management. In agroforestry, where systems and practitioners are highly heterogeneous, the choice of tree species is much more complex compared to classical plantation forestry. The farmers employ many distinct tree species, but little scientific information is available on them.
In the past, researchers determined species priority based on their own interests, and views on species importance were probably the most important criteria (Franzel et al 1996). Tree species selection, an iterative process of tree domestication, should be based on farmers’ preferences, market demand or potential, germplasm availability and environmental suitability. Farmers should also determine the tree characteristics to be improved. Selection of fruit trees, for example, might be determined by fruit characteristics, tree growth, morphology and insect resistance (Simons 1996). Two common constraints for smallholders are lack of high quality planting material and the absence of well-functioning germplasm supply systems, Access to the germplasm can be improved via participatory domestication, training in germplasm management and introduction of more productive germplasm. Access to tree product markets can be enhanced by identifying new opportunities, sensitizing consumers, increasing value-chain transparency and providing training and credit for growers (Dawson et al. 2011).
In West Java, the traditional tree farming system called dudukuhan is divided into four types: (i) timber, (ii) mixed fruit−timber−banana−annual crops, (iii) mixed fruit−timber and (iv) fallow (Manurung et al. 2008). Dudukuhans, like other tree farming systems in developing countries, are not managed intensively. Fertilizer application, weeding, thinning and pruning are usually conducted only when trees are intercropped with annual or seasonal crops. Harvesting products is often the most common management practice. As a result, the quality and quantity of products might be far below the systems’ potential (Holding-Anyonge and Roshetko 2003; Michon 2005; Roshetko et al. 2007).
Dudukuhan systems in West Java are dominated by the timber species Maesopsis eminii (22.1%) and Paraserianthes falcataria(14.4%)and by banana varieties (Musa spp.26.8%). Diverse species account for the remainder of the systems, including Artocarpus heterophyllus (4.0%), Archidendron pauciflorum (3.6%), Nephelium lappaceum (3.3%), Mangifera odorata (1.7%), Parkia speciosa (2.2%), Sandoricum koetjape (1.6%) and Durio zibethinus (1.5%),but they only make minor contributions to farmers’ livelihoods (Manurung et al. 2005). Manurung et al. (2008) theorized that dudukuhan productivity can be enhanced by improving farmers’ management skills and developing tree polycultures based on four or five potential species through a tree domestication program.
This study identified underutilized tree species in West Java where further domestication could enhance the productivity of smallholder livelihood systems governed by agroforestry. The study commenced in December 2010 and ran until March 2011, involving farmer surveys, focus group discussions, market and germplasm surveys; SWOT (strengths, weaknesses, opportunities and threats) analysis and literature review. Data evaluation targeted recommendations for a participatory tree domestication program of dudukuhan systems. This paper reports the results of species selection, farmers’ knowledge about the species, as well as availability of germplasm sources. Species selection intentionally included diverse tree types (both indigenous and exotic), those that produce timber, fruit or other products and others at various points on the domestication continuum.
Research Method The study was conducted in Nanggung sub-district, Bogor district, West Java province. Nanggung is within easy reach of two cities (Bogor and Jakarta). Nanggung farmers are primarily smallholders with access to less than 1 ha of land. They have limited access to professional technical assistance and poor market linkages, particularly to lucrative urban and regional markets in Bogor and Jakarta (Roshetko et al. 2004a). Nanggung consists of 10 villages encompassing 11,000 km2 and elevation ranges from 400−1,800 m (Fig. 2). Average landholding per household is 0.75 ha, of which 0.5 ha is given over to dudukuhan. Agricultural (31.2%) and off-farm activities (61.5%), remittances and miscellaneous earnings (7.3%) are income sources (Budidarsono et al.2006).
Fig. 2 Map of the study area
Farmer surveys were conducted in Cisarua, Curug Bitung and Parakan Muncang villages, selected purposively as representative of the sub-district and their watershed position (upstream, mid-stream and downstream). Thirty households (10 in each village) were selected on the basis that tree species supported their livelihoods significantly. Data were collected through personal semi-structured interviews. Subjects included: tree species in the dudukuhan systems; farmer preferences of tree species for domestication; knowledge and steps in tree management practices; commercial value and market chains for each species as well as quality and availability of germplasm sources. Farmers were asked to consider less-familiar or less-utilized species that may have high economic potential, including species that have been exploited but need improvement for greater revenue.
Focus Group Discussion
Results from the farmer surveys were shared among 9 farmers from the 3 villages in a focus group discussion held in Parakan Muncang village. Each village was represented by 3 household heads. The objective was to determine 5 priority species for further domestication in the context of market and domestication potential. A list of preferred species identified during the surveys was displayed. The farmers were encouraged to consider diverse species types: indigenous and exotic, those that provide various products, those with potential to be improved and those with potential markets. They were also told that candidate species could be within the domestication continuum, but further improvement of the species used in smallholder systems was still possible. Farmers discussed the preferred species and selected 5 priority species.
The 5 priority species were evaluated by the research team using weighted SWOT scoring analysis adapted from Flavel and Williams (1996). Strengths and weaknesses (species characteristics influencing the selection of species) were identified based on respondents’ knowledge of the tree species to be domesticated. The same process was used to identify opportunities and threats (external factors influencing the selection of species). Each SWOT category was weighted based on importance against other categories out of a total score of 1.0. Each individual strength, weakness, opportunity and threat was also given a score, a percentage value out of a maximum of 100%, to indicate its level of importance. Final scores for each species in each category were calculated by multiplying the score by the weighting attributed to the relevant category to produce a weighted importance level for that category. The priority species were compared by checking each species coordinate (x=a-b; y=c-d).
Market and Germplasm Surveys
Market and germplasm surveys were conducted to identify the commercial value and markets of selected species, as well as possible germplasm sources. Sixteen traders were interviewed: 3 handled timber products, 4 fruits, 3 spices, 5 both fruits and spices, and 1 all types. Information collected in this interview included the cost of tree products, market linkages, traders, origin of goods, and product prices at each step along the market chain. Information regarding the availability of germplasm sources of each species was collected from farmers, staff of the Halimun Salak National Park, the Forestry Research and Development Agency (FORDA) and from a review of the directory of tree seed suppliers in Indonesia (complied by Roshetko et al. 2003). Subsequently, all potential germplasm sources near Nanggung were visited to obtain information from landowners or institutional staff. Sources included farms, plantations, forests and commercial seed suppliers.
Results A total of 44 tree species were identified for domestication. including fruit tree species (38.6%), timber species (47.7%) and spice species (13.6%). Respondents identified 45,767 woody trees on their farms, 3.9% being fruit trees, 90.3% timber trees and 5.9% spice trees. Although timber species represented less than half of the total species, they accounted for 90% of the trees on the farms. As seen in Table 1, Curug Bitung has the greatest species diversity, total number of trees and tree density, while Cisarua has the lowest number for most categories. The number of trees per household ranged from 50 in Parakan Muncang to 9,680 in Curug Bitung.
Table 1 Tree density and tree species in each study area
Study area (ha)
Tree density (trees/ha) a
Number of tree species b
Number of trees
Most trees owned
Least trees owned
Average trees owned
a. Total tree number of 10 respondents divided by total land area of those respondents.
b. This includes all woody trees.
All respondents cultivated Paraserianthes falcataria, which accounts for 46.0% of total trees. Maesopsis eminii was the second most common species, cultivated by 90% of respondents and accounting for 28.6% of the total (Table 2). Common fruit tree species in dudukuhans were Garcinia mangostana (39.6% of all fruit tree), Artocarpus heterophyllus (27.8%) and Durio zibethinus (7.7%), while common spice species were Coffea robusta(74.4% of all spice trees), Parkia speciosa (10.9%)and Archidendron pauciflorum (9.2%).
Table 2 Species composition in each village
Lamtoro/Leucaena/ Leucaena leucocephala (Lam.) de Wit
Timber tree density (trees/ha)
a Species were selected for further domestication by farmers during discussions.
Farmers primarily used fruit and spice tree products for household consumption, with small quantities sold in local markets or to local traders. The farmers prioritized 27 tree species (Table 3), which included fruit, spice and timber tree species. Trees in the dudukuhans originated from either natural regeneration or from planting. Wealthy farmers usually purchased seedlings from a supplier, while most farmers transplanted wildlings. Some farmers produced limited numbers of seedlings for themselves, primarily fruit and spice species, in small backyard nurseries.