Tree mortality and vine proliferation following a wildfire in a subhumid tropical forest in eastern Bolivia

lIn 1994, 1 x 10(6) ha of subhumid forest in eastern Bolivia burned in an uncontrolled wildfire; the objective of this study was to measure tree and liana mortality a year after this fire. About 60% of 500 trees sampled were either killed or damaged by the fire, Proportionally more small trees (74% of trees >2 m tall but <5 cm dbh) were killed than large trees (27% of 10-40 cm, 16% of trees greater than or equal to 40 cm dbh), and mortality varied with species. Basal cambial damage was found on 30-40% of living trees greater than or equal to 10 cm dbh. About 75% of liana stems (1-8 cm dbh) were killed; 15% of thr dead liana stems resprouted from the base. In lianas, basal resprouting of killed stems was independent of diameter class, whereas in trees smaller stems were more likely to resprout than larger stems. The proliferation of herbaceous vines plus lianas <1 cm dbh (mean density 21 000 ha(-1)) in the burned forest may impede tree regeneration and supply fine fuels capable of supporting frequent fires. Although anthropogenic and natural fires have probably played important roles in the development of tropical subhumid forests, the amount of damage and mortality observed in this study suggest that, in forests managed for timber production, fire-protection practices are warranted to reduce forest susceptibility to wildfire. (C) 1999 Elsevier Science B.V. All rights reserved.