Long-term Influence of Deforestation on Tree Species Composition and Litter Dynamics of a Tropical Rain Forest in Puerto Rico

XIAOMING ZOU, CAROL P. ZUCCA, ROBERT B. WAIDE and WILLIAM H. McDOWELL

ABSTRACT: Understanding the long-term impact of deforestation on ecosystem structure and function of tropical forests may aid in designing future conservation programs to preserve biodiversity and sustain ecosystem productivity. We examined forest structure, tree species composition, litterfall rate, and leaf litter decomposition in a mid-successional forest (MSF) and an adjacent mature tabonuco forest (MTF) in the Luquillo Experimental Forest of Puerto Rico. Whereas the MTF site received limited human disturbance, the MSF site had been cleared for timber production by the beginning of this century and was abandoned after hurricanes struck the Luquillo Mountains in the 1920s and 1930s. We found that the MSF was dominated by successional tree species 50 yrs after secondary succession, and did not differ in tree basal area and litterfall rate from the MTF. Leaf decomposition rate in the MSF was higher than in the MTF, but this difference was small. Our results show that deforestation has long-term (>50 years) influence on tree species composition and that leaf decomposition processes in secondary forest is relatively faster than recovery of tree species composition.

Key words: forest recovery; litterfall; leaf decomposition; secondary forest; Tabonuco forest.