Journal Archives > BGjournal > Not just the forest, but the trees: Research on the conservation and sustainable use of forest genetic resources
Not just the forest, but the trees: Research on the conservation and sustainable use of forest genetic resources
Volume 5 Number 1 - January 2008
Laura Snook, Ehsan Dulloo, and Barbara Vinceti
Forests and their component species yield a vast array of products, from fruit and nuts for food to barks, leaves and resins for medicinal purposes and fibre for construction materials. Most forest products are harvested from wild populations; many are particularly important to poor people in rural communities in developing countries. Because forest genetic resources (FGR) consist of thousands of useful species, of which very few are domesticated, little is known about their biology, conservation, variation and potential. Furthermore, populations of many of these species are threatened by factors ranging from over-harvesting to land conversion and climate change. Bioversity International focuses on sustaining diversity, particularly intra-specific diversity, through research, capacity building, and advocacy in the policy arena. Since 1993, Bioversity has sought to address the challenges of conservation and enhanced use of the diversity of forest trees by generating information about intraspecific diversity of tree species, the benefits that this variation can confer on users, the threats to this diversity, and the range of approaches that can be applied to conserving and sustainably using forest tree diversity.
Understanding genetic diversity
A body of Bioversity’s research has focused on analyzing the spatial patterns of diversity in tree species of high local priority, including Swietenia macrophylla (mahogany) in Latin America, wild pistachio (Pistacia atlantica) in the Middle East, and rare Malaysian dipterocarps (Neobalanocarpus heimii and Shorea lumutensis). This understanding is being applied to the formulation of conservation strategies in situ, collection for ex situ conservation in botanical gardens, and domestication to increase availability through planting by users. A study of populations of Shorea lumutensis in Peninsular Malaysia elucidated the demography and molecular diversity of these trees and used these insights to define the most important areas for in situ conservation. This constituted one of the first attempts to combine ecological and genetic approaches to the conservation of a rare tree species and reveals how research findings can be translated into practical recommendations (Lee et al., 2006).
Impact of use on forest species
Thousands of tree products are harvested from wild populations growing on land with ill-defined tenure; these trees are often treated as open-access resources, which frequently leads to over-harvesting. Bioversity has carried out several studies assessing the impact of local use on the regeneration and thus the sustainability of local tree populations, including a study of Araucaria nut harvesting in Argentina and Brazil. Research focused on the development of multidisciplinary and participatory approaches for conserving Araucaria species and used modelling to reveal the interactions and threats resulting from the respective impacts of nut gathering by local communities, livestock grazing and browsing, and fragmentation of tree populations and inbreeding (Vinceti et al. 2004). The project enabled local communities to contribute to decision-making on policy, management and use of the resources (van Breugel et al., 2004).
Tropical forest tree seeds – a challenge for conservation and use
Despite the importance and value of indigenous tree species, there is little capacity in most countries to sustain them through planting. In part this is because of the difficulty of maintaining the viability of seeds of most tropical tree species. Most of these lack dormancy, germinating immediately. This makes even short-term storage and transport difficult, and means that maintaining seed samples in genebanks is not an option for thousands of useful tree species. In addition, most valuable fruit species cannot be conserved as seeds, either because they do not breed true or because their seeds (described as “recalcitrant”) cannot survive in the cold, dry storage environments used by genebanks for storing the seeds of cereals and other species. Bioversity organized and led a major research project co-sponsored by DANIDA’s Forest Seed Centre focused on overcoming the constraints to storing tropical tree seeds as a contribution to increasing the variety of high-value indigenous species available for planting. Standardized protocols were developed to test for desiccation tolerance and applied by national partners in 15 countries world-wide who screened approximately 60 tropical forest tree species to determine how to store their seeds in a viable state. Protocols for seed drying were developed and tested, and for more than half of the species including Prunus africana, two important dipterocarps and Vitellaria paradoxa, the shea butter tree, germination percentages in excess of 90% were obtained (Pritchard et al., 2004). Contrary to expectations, research revealed that 23 species could tolerate desiccation to less than 9% moisture content. Future work will focus on scaling-up the methods developed for seed handling in order to promote the development of seed-supply systems to increase the availability of highquality germplasm of indigenous species (Sacande et al., 2004)
Bamboo and rattan
Much of Bioversity’s research on nontimber forest products has focused on bamboo (a large grass) and rattan (a spiny climbing palm). It has been estimated that 1.5 billion people depend on these resources which, as well as being important for local use, also feed an export market worth $US 5 billion/yr, providing significant income to small-scale farmers. Bioversity carried out studies characterizing the diversity in situ of ten bamboo and rattan species, and evaluated their status. An analysis of major threats in China, Vietnam and the western Ghats of India revealed that over-harvesting threatened this diversity. As a safeguard, key material was collected and established in ex situ bamboo collections: 34 species in the botanic garden at Malaya University, Malaysia, 20 populations of Dendrocalamus asper in Bondowoso, East Java, Indonesia and 40 species of bamboo at Cau Hai, Vietnam. A collection was established in China to serve as a source of planting stocks for local communities. A study on the demographic status and genetic variation in populations of Calamus mannan, an economically valuable rattan, was also undertaken in Indonesia.
Increasing income and nutrition through research on fruit trees
Bioversity has been particularly interested in fruit trees, which contribute not only to income generation, but also to the nutrition of rural people. Major efforts have been carried out in Asia to evaluate the diversity of priority regional fruits, among them Citrus, and mango, including not only domesticated varieties, but also their wild relatives, which can be crossed with them to yield improved fruit characteristics and enhanced resistance to pests, diseases, drought or flooding. Fruit tree species have also been a major focus of Bioversity’s work in Sub-Saharan Africa, where expert consultations and networks of collaborators from across Africa have been organized to define research needs and assess the conservation status of priority species, including many specifically suited to semi-arid environments. Because they are deep-rooted, trees integrated into agricultural systems are particularly important in areas vulnerable to drought and crop failure. Zizyphus mauritania is one of those in which intraspecific diversity has been tapped to produce larger-fruited varieties that are grafted onto local root stocks on farmers’ fields in the Sahel to increase incomes, address nutritional deficiencies, and contribute to adaptation to climate change. In Syria, molecular characterization (using AFLP) and ecogeograhic studies of Pistachio (Pistacia vera) in the Middle East were carried out to determine the extent of genetic diversity and its characteristics. The study allowed the identification of 25 female pistachio varieties, some of which were described for the first time (Ibrahim-Basha et al., 2007).
Strengthening collaboration through regional partnerships
Bioversity carries out research in partnership with collaborators in countries around the world. This yields multiple benefits, including facilitating multi-location comparative research, providing for integrated capacity building and increasing the likelihood of uptake and implementation of research results by local and regional stakeholders. During the past five years, collaborative relationships have been forged among experts in forest genetic resources through Bioversity’s sponsorship of regional Forest Genetic Resources (FGR) networks. These have been modelled on the European Forest Genetic Resources Network (EUFORGEN), a successful self-funded partnership among European countries for research, conservation and use of forest resources, which is carrying out cutting edge research on the evolution of genetic diversity among forest trees and associated organisms, linking different disciplines (ecology, genetics, genomic, and evolutionary). One of the main objectives is to identify genes of adaptive significance in the face of global change, in model species of trees (Pinus, Populus and Quercus), phytophagous insects and mycorrhizal fungi (www.evoltree.eu).
The Sub-Saharan African Forest Genetic Resources Network (SAFORGEN) was established in 1998 to support research by facilitating capacity-building and collaboration around important FGR issues, and to identify conservation and use options worthy of study and dissemination in resource-poor areas. SAFORGEN members are currently carrying out a study across 10 countries extending from West to East Africa, including Madagascar, to evaluate the genetic diversity among populations of Prunus africana, and the corresponding chemical diversity among their barks, of which the medicinal properties are used to treat prostate disease. The results will provide the foundation for developing strategies for domestication of these trees through planting to provide income to local farmers; and for the conservation of populations, both in situ and ex situ. Since 2003, the Asia Pacific Forest Genetic Resources Programme (APFORGEN; www.apforgen.org) has been facilitating collaborative research and information sharing on FGR among partners from 14 countries in Asia and Oceania. In 2006, an informal collaborative platform on FGR, LAFORGEN, was established in Latin America, the region with the world’s highest tropical forest area – and the highest proportion of global deforestation. Representatives from national and international research institutions in nine countries participated in a workshop to exchange information, define priority species and develop thematic research priorities: conservation of genetic diversity in threatened native forest species; the impact of use of native forest species on their genetic diversity; domestication and tree breeding; and storage and exchange systems for tree germplasm.
Increasing the critical mass of research on forest genetic resources
To increase the critical mass of researchers in the arena of forest genetic resources and the recognition among other key stakeholders of the issues associated with the conservation and utilization of genetic diversity of forest species, Bioversity carries out capacity building activities linked to our research, as well as providing training courses, and sponsoring several fellowships. For example, the DANIDAfunded Bioversity project on tropical forest tree seeds supported researchers in 18 institutions to conduct high-quality research on optimal seed-handling and storage of recalcitrant tree seeds for local species. Young researchers from Southeast Asia were trained by Bioversity in the collection and identification of bamboo, while the APFORGEN network has provided training on the use of molecular markers. With Austrian support, Bioversity has offered a short course on Forest Genetic Resources Conservation and Use, carried out most recently in Kuala Lumpur, Malaysia in 2006 and Tashkent, Uzbekistan in 2007. Other capacitybuilding activities have included a regional training course on in vitro and cryopreservation techniques for conservation in New Delhi, India. Bioversity is currently producing a training module on the conservation and sustainable use of FGR, integrating insights from a range of case studies. Bioversity’s Abdou Salam Ouedraogo Fellowship, Vavilov-Frankel Fellowship, and Austrian-funded Forest Genetic Resources Fellowships have provided opportunities for young developing country researchers to carry out research in collaboration with scientists in advanced research institutes on FGR topics including the impacts of domestication on Uapaca kirkiana; strategies for enhancing the conservation and use of Melia volkensii; genetic diversity and geneflow in Fagus orientalis; genetic variability and sustainable utilization of Blighia sapinda; and the application of molecular and ethnobotanical tools to the development of conservation and domestication strategies for diversity in baobab (Adansonia digitata), an important source of food, fibre and resins in traditional agroforestry systems in West Africa (Assogbadjo et al. in press).
The world’s forest genetic resources are both threatened and underutilized. Research is crucial to understanding and addressing these threats, and to developing effective strategies for conservation and sustainable use. Bioversity International and our partners around the world seek to contribute to this process, and to support other actors who must play key roles in the implementation of these strategies, among them botanic gardens, Ministries of Forestry and of the Environment, local communities and international conservation organizations. The challenges are great, but so are the benefits to be obtained by tapping into the great diversity of forest trees.
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