Growth rings, anatomy, and response to forest management of the liana Dalbergia frutescens (Leguminosae) in an Atlantic Rainforest remnant

Abstract

Summary Lianas, or woody climbers, are an important component of many tropical forests with fast growth responses to both natural environmental variations and human disturbances. Still, studies on their growth rate are rare to nonexistent. We sampled 22 specimens of Dalbergia frutescens , a liana that produces annual semi-porous growth rings in a secondary Atlantic Rainforest fragment in the megacity of São Paulo, Brazil. This forest fragment went through an intensive management of an exotic and invasive palm species, Archontophoenix cunninghamiana , that resulted in the removal of ca. 14 000 individuals in 2011 and 2012. We assessed the impacts of this management program on the growth of D. frutescens by measuring the tree-ring area in cross sections. Their ages ranged from 6 to 23 years old, and all samples had confluent rings. The occurrence of the confluent rings was not associated with any particular year, indicating that their formation is an intrinsic characteristic of this species. Despite the confluent rings, we successfully built a tree-ring basal area increment chronology spanning from 1995 to 2018. A piecewise regression indicated a growth release in 2014, right after the management of the palm trees. This study demonstrates the potential of tree-ring analysis in lianas as a valuable tool for detecting significant environmental changes and understanding the responses of lianas to natural and anthropogenic disturbances. These findings contribute to the broader understanding of tropical forest dynamics and the role of lianas in tracking ecological changes over time.