Thursday, August 9, 2007 - 10:10 AM

OOS 39-7: An ecological and economic comparison of living fence species and seedlings in tropical forest restoration

R. A. Zahawi, Organization for Tropical Studies and K. D. Holl, University of California-Santa Cruz.

Trees are usually planted as seedlings to restore tropical forests, whereas vegetative propagation has received little study.  We evaluated the ability of multiple tree species to establish vegetatively (stakes) at sites in northern Honduras (HN) and southern Costa Rica (CR).  We also quantified above- and below-ground biomass production of stakes and seedlings for Erythrina poeppigiana and Gliricidia sepium (CR) and evaluated the impact of initial stake diameter and height on crown development for Gliricidia (HN).  Lastly, we compared the economic, logistical, and ecological advantages of each planting methodology.  In HN, five of ten species (Erythrina berteroana, Erythrina fusca, Jatropha curcas, Gliricidia sepium, and Bursera simaruba) had high establishment success.  In CR, Erythrina poeppigiana and E. berteroana had the highest establishment success (>90%), and were among those species with the greatest canopy development.  Most other species had an establishment range between 40 and 70%.  Above- and below-ground biomass production was 7 to >50 times greater in stakes (65–125 g) than seedlings (2–15 g) for both species.  Gliricidia stakes with greater initial height and diameter developed larger crowns.  Stake roots were considerably more extensive, reaching lengths >6 m.  Our economic estimates suggest that seedlings are two to three times more expensive to establish than seedlings, although transporting stakes is more cumbersome, and fewer species can establish vegetatively.  Vegetative propagation could have broad application for forest restoration throughout tropical regions and may be an especially important method for rapid carbon storage.