The role of invasive pine on changes of plant composition and functional traits in a coastal dune ecosystem

In this article we investigate how invasion by Pinus taeda L. alters plant community composition and functional traits in sand dunes. In invaded psammophilous vegetation in southern Brazil, we randomly selected 15 P. taeda individuals and measured their age based on the number of growth rings. For each tree, we sampled 1m2 quadrats beneath and 2m away of its crown. In each quadrat, we assessed non-graminoid plant composition and performed a multivariate analysis of variance. Data on species’ functional traits were scaled up to community level, and their variations were compared to tree age by linear regression. Species’ composition and functional traits under P. taeda crown were different from control plots. Tree age affected the presence of thorns, potential height, and functional diversity. P. taeda individuals likely change the micro-habitat beneath their crowns, thereby benefiting species with some traits and increasing functional diversity of plants that are not characteristic of open dune communities.