Impact of disturbance on forest structure and tree species composition in a tropical dry forest of South Ecuador
Tropical dry forests (TDFs) are often degraded and fragmented through human impact, which is also the case in Southern Ecuador, where land-use pressure is high. In this context we studied tree species composition and forest structure in a protected and adjacent disturbed TDF at altitudes between 560 – 1,080 m asl. Fabaceae and Malvaceae were identified as most important tree families in both forest types. The disturbed forest displayed lower tree species richness than the protected forest, and the gap in species richness between the two forest types increased with increasing altitude. Twenty species of the protected forest were not recorded in the disturbed forest, four of them endemic species. The disturbed site was further characterized by a lower number of stems but with larger diameters, in comparison to the protected forest. The majority of the most abundant tree species in the disturbed forest had rather low wood densities, but also the combination of high wood density with browsing tolerance and high resprouting capacity was encountered, and seems to be advantageous for getting established in such sites. Whereas certain tree species showed a good representation in the disturbed forest, some endemic species with rather low abundance (e.g. Simira ecuadorensis, Prockia crucis) should receive more attention through conservation efforts.