Adaptative traits to fire in five forest species in a subxerophilous vegetation formation in the central rainforest of Peru

Abstract

Forest fires have become increasingly frequent and devastating, threatening the plant diversity of tropical forests; for this reason, it is essential to carefully identify and analyze the functional traits of different tree species that are particularly susceptible to the effects of these fires. In this context, the present study consisted of characterizing the functional traits related to fire adaptability in a subxerophytic plant formation of the Chanchamayo valley by measuring the branching (IDA), basic density (DB) and bark thickness (Ect) in five potentially fire­adapted species Curatella americana L., Astronium graveolens Jacq., Machaerium hirtum (Vell.) Stellfeld, Luehea paniculata Mart. and Physocalymma scaberrimum Pohl. The evaluations of the functional traits were taken in two different populations, one with evidence of burning and the other without evidence of burning. The results of the two populations were compared to analyze the influence of fire on the evaluated traits. The average values of IDA, DB and Ect in trees affected by burning were 2,662 m^­-1,  0,461 g/cm³ and 8,636 mm respectively and in unburned trees were 1,945 m^-­1, 0,467 g/cm³ and 5,150 mm respectively. Finally, it was found that a greater branching and bark thickness may imply an adaptation of the species to the burns to which they have been exposed; while the basic density in branches does not show any relationship with sufficient statistical evidence to demonstrate an influence of burning on the tree.