PARENT SESSION
Oral Session #49: Restoration Ecology. Presiding: J. Callaway.
Wednesday, August 8, 2001. 1:00 PM to 4:30 PM. Madison Ballroom D.
Expediting forest regeneration in tropical grasslands: distance and isolation from seed sources in plantations.
Zanne, Amy1, Chapman, Colin1,2, 1 2
ABSTRACT- As human populations increase, pressures for food and fuelwood have led to tropical deforestation. Because of increases in extent of degraded lands, facilitating their reforestation becomes increasingly important. One option for facilitating reforestation is to establish plantations of fast-growing non-invasive trees that ameliorate site conditions and allow indigenous trees to grow in their understories. To quantify effects of distance and isolation from seed sources on indigenous tree regeneration, we evaluated tree species richness and stem density in 4 pine plantations surrounded by natural forest within Kibale National Park, Uganda, and 1 isolated pine plantation surrounded by agriculture near Kibale. Tree regeneration in these plantations was compared to that in anthropogenic grassland similar to those upon which the plantations were established and natural forest. Tree species richness and stem density were negatively correlated with distance to plantation edge. The grassland had lower richness and density than the isolated plantation, which had lower richness and density than plantations within Kibale. These differences may be due to decreased seed dispersal across large distances or unfavorable habitats and greater disturbance in the isolated plantation and grassland than in plantations within Kibale. This study demonstrates that forest reestablishment can be faster if plantations are established than if grasslands are left to recover without management. However, differences within and among plantations can lead to very different communities with respect to species composition, richness, and density.
KEY WORDS: arrested succession, plantations , reforestation, tropical forests