Program in Tropical Foristry

The challenges that tropical forestry faces in the 21st century are very well known. In the early 1990s, the total area of deforested and degraded tropical land surpassed the area of mature tropical forests due to unsustainable forestry, illegal logging, overgrazing and agriculture. Similar trends persist in the current century. Tropical forestry is confronted with the task of finding strategies to alleviate pressure on remaining forests and techniques to enhance forest regeneration and restore abandoned lands, using productive alternatives that can be attractive to local communities. In addition, sustainable forestry in tropical countries must be supported by adequate policies to promote and maintain specific activities at local and regional scales.

Program Mission

The mission of the Program in Tropical Forestry is to promote collaborative research in sustainable forestry, the conservation of biological diversity and forest environmental services, and the restoration of degraded tropical ecosystems to alleviate pressure on remaining forests and provide economic and environmental benefits for local communities. The Program in Tropical Forestry seeks to expand and share the work of Yale faculty, students and staff by conducting research, offering relevant courses, seminars and workshops, and promoting cooperation among faculty and students from Yale FES and collaborating institutions worldwide.

The Program in Tropical Forestry works with local communities and institutions from developing countries to promote sustainable land use practices that facilitate the conservation of biological diversity and natural resources. At the local level, the Program aims to increase the technical skills of individuals in order to benefit communities and conserve natural resources.

Core Activities

Conservation of Native Tree Species
Research is ongoing on the rescue, propagation, conservation and use of highly endangered species and populations of forest trees in Central America in collaboration with colleagues from CATIE (Tropical Agriculture Research and Higher Education Center, Costa Rica).

Plantation Silviculture
We are studying the silviculture and environmental services of mixed and pure plantations of native species for sustainable development in rural areas of the humid tropics (Costa Rica, Nicaragua, Honduras).

Biodiversity
Strategies are being developed for the recovery of biodiversity in degraded ecosystems through natural regeneration in mixed and pure plantations of native species in humid tropical lowlands (Costa Rica).

Education Exchange
Faculty at the Yale School of Forestry and Environmental Studies teach courses in tropical forestry, agroforestry, tropical ecology and silviculture. Forum and roundtable discussions in this arena are part of the program’s information outreach.

Core Activities

It is becoming widely accepted that the conservation of biodiversity has to take place in managed landscapes as well as in protected areas. In many regions of the tropical world, the landscape consists of a complex mosaic of forest patches, pastures and agricultural fields and is heavily influenced by human activity. Any efforts to conserve biodiversity within this managed landscape must be compatible with local livelihood needs and offer sustainable and economically attractive alternatives to local farmers. Strategies that provide various ecosystem services and fulfill local human needs, in addition to promoting the conservation of biodiversity, will have a higher chance of success.

In many tropical countries, large portions of natural forests have been cleared for agriculture and grazing, yet the productivity of cleared lands is often short-lived. Forest regeneration on abandoned pasturelands is desirable to restore soil fertility, reduce erosion, reduce fire hazard, and restore biological productivity. However, on abandoned lands in advanced stages of degradation, native forests often cannot regenerate naturally. Selective planting and management of woody species can jump-start successional processes to restore native forests.

The existence of tree species in the tropics is under threat mainly because of irrational use and the absence of effective policies that could guarantee their sustainable management. Several tree species may have medicinal, ornamental or timber values yet to be discovered. The rescue and protection of forest species can be achieved by developing strategies for propagation and conservation and the promotion of plantations and agroforestry systems involving these species.

Research Agenda of the Program in Tropical Forestry

In Costa Rica, we are continuing long term research on the role of native tree species in plantations and agroforestry ecosystems in reclaiming degraded areas with species of economic value. Recently we have developed allometric equations to estimate standing biomass of plantations as a non-destructive method to determine biomass and carbon sequestration. We are currently testing our allometric models and using them to estimate carbon sequestration in experimental plantations as well as in farmers’ land. In addition, we are measuring seed rain, seed dispersal and animal activity in mixed and pure plantations with native species to estimate the value of plantations in recovering biodiversity in degraded pasture landscapes.

In Misiones, NE Argentina, in collaboration with the School of Forest Science of the University of Misiones (UNAM), with whom we have a Memorandum of Understanding, we are following up on several experimental settings that we started in the early 1990s, consisting of pure and mixed plantations with native timber species on degraded land; enrichment experiments in degraded forests, also using native trees of economic value; and native trees in agroforestry combinations with commercial crops. The objectives of the present project are to continue the long-term follow up of the already established experimental settings, as well as to plant trees in local municipalities, as part of community forestry projects for obtaining tree products and improving local environmental conditions. This year we will be presenting some of our results at the 9^th. North American Agrofrestry Conference (12-15 June 2005, Rochester, Minnesota).

In Santiago del Estero, the Chaco region of Argentina in collaboration with the National University of Santiago del Estero, we are conducting collaborative research on agrosilvopastoral systems and dry forest restoration.

In Mexico, in collaboration with the National University of Hidalgo, we are conducting an evaluation of forest ecosystem degradation in several regions and selecting tree species for restoration.