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Ecological Restoration in Costa Rica. Fred Loxsom Evolution and Diversity November 21, 2003. Sustainable Development Course Summer 2002 & Summer 2003. Renewable Energy. Biodiversity. Ecotourism. Service Learning. Sustainable Agriculture.
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Ecological Restoration in Costa Rica Fred Loxsom Evolution and Diversity November 21, 2003
Dry Tropical Forest • 500 years ago, 200,000 square miles from Central Mexico to Panama. • Profoundly threatened! Less than 2% remains. • Less than 0.1% of the original has conservation status. • More rare than tropical rain forest. • Pressure from logging, farming, ranching.
Characteristics • Pacific coastal lowlands • Tropical with prolonged dry season (5-8 months). • 40 – 80 inches rain. • In rain shadow of central mountain chain
Deciduous Forest • During the dry season 80% of the trees lose their leaves. • 23,000 species. • 65% of species in CR • Fewer plant and bird species than in rainforest • Variety of insects and mammals about the same
Vegetation • Low stature (30 m) • Semi-deciduous • Leguminosae family • Upper story - deciduous • Lower story – evergreens • Understory – thorny trees
Endangered Species • Many rare and endangered species live in the dry tropical forest, including an endangered species of spider monkey (Ateles geoffroyi) • Many endemic species
Deforestation • Unlike rainforest land, tropical dry forest is good agricultural land and is useful for ranching and farming (sugar cane, corn, and beans.)
Guanacaste Project • Using the remaining islands of dry tropical forest as seed sources, restore a large section of dry tropical forest • Involve local Ticos in the project so that they support it and profit from it.
Guanacaste Conservation Area • Starting in the mid 80s, Daniel Janzen, University of Penn., led an effort to establish a large park in Guanacaste. • Dry Tropical Forest would be restored in this park. • 120,000 terrestrial hectares (300,000 acres – ½ size of RI)
Reason #1 Dry season magnifies the differences between habitats and a large park provides a heterogeneous environment
Reason #2 Tapirs, jaguars, and mountain lions – need large area to maintain healthy breeding populations
Reason #3 Agricultural effects penetrate for 2 km into a natural area. Large area is needed to minimize these edge effects.
Reason #4 Many animals migrate to moist areas during dry season. A large preserve is needed to protect migration routes
Reason #5 Duplicate habitats are needed for ecotourism, scientific study, and conservation.
Reason #6 GCA is watershed providing drinking water and irrigation for communities. (Rio Sapoa’ & Rio Tempisque)
Restoration Plan • Control of Fires • Natural recolonization (low cost) • Managed restoration • Sustaining the forest
Fire • Used to clear land of trees • Set by ranchers • Provides habitat for exotic grasses
Jaragua grass • Hyparrhenia rufa • Exotic grass • Cattle graze on it. • Suppression of fire allows trees to dominate over exotic grasses.
Texas Grassland Restoration • In Texas, fire is used to maintain native grasses against the encroachment of cedar and exotic grasses
Natural Recolonization • Natural, wind dispersal of seeds can move a forest several hundred meters in 10 years. 25% of the 215 tree species in Santa Rosa NP are wind-dispersed and would be pioneers.
Natural Recolonization • Animal dispersers drop seeds in dung • Produces nuclear trees which produces habitat for seed dispersing animals. • Some seeds must pass through animals to germinate.
Managed Restoration • GCA plants 4000 – 9000 trees each year. • Usually native trees, but some experiments with non-natives as pioneers.
Sustaining the Forest • Low cost • $3,000,000 endowment • Local farmers as caretakers, guides, and fire fighters. • All employees are Costa Ricans. • With InBio, bioprospecting.
Success? • Restoring the distribution of plants and the diversity of animals to a degraded landscape will take 100 or more years. • Success will depend upon the value of this project to the people of Costa Rica.
Biology • Since trees that disperse seeds by wind will be the pioneers – entering cleared land, doesn’t this mean that the composition of the restored forest will be different from the original forest?
Biology • Can exotic plants (e.g. jaragua grass) ever be eliminated from the dry tropical forest? If it can’t be eliminated, can the forest really be regenerated?
Fire • Why does fire play such a different role in maintaining prairies in the US and destroying forest in Central America? • Is fire a part of the natural environment in both situations?
Social issues • Wouldn’t it be better to make the GCA a protected area and keep locals and tourists out of it? Isn’t that what we do in Yellowstone and other US National Parks?
Social issues • What is the proper role of foreigners in the conservation of Costa Rica’s natural resources? • Is it appropriate that Daniel Janzen played such a large role?
Ecotourism • What is ecotourism? • What role should ecotourism play in sustaining GCA?
Bioprospecting • GCA cooperates with InBio to do bioprospecting in the park. In turn, InBio will make deals with pharmaceutical firms to produce commercial products. Is this appropriate?