Bioinvasion of Tradescantia zebrina Heynh. (Commelinaceae) in uplands, State of Paraíba, Brazil

Abstract

The study of invader species and their consequences to the environment represents an important reinforcement to the knowledge of environmental preservation. This work aimed to evaluate the invasive aspects of Tradescantia zebrina Heynh., subsidizing information to their adequate management or control. The study area is compound by a Open Ombrophylous Forest in the Municipality of Areia, Paraíba State, Brazil. The evaluated variables were populational density, biomass, biometry, invasion velocity and impacts of species under resilience of native vegetation. The results found density of 627 +/- 16 individuals/m2, (mean +/- standard deviation), 25.9 +/- 68 cm length and 0.21 +/- 0.03 cm de diameter with positive relationship between both variables (r = 0.24; t = 2.4; p = 0.02) and biomass of 16.9 g (leaves), 10.6 g (stems) and 1.3 g (roots) for each 100 sampled individuals, being that in each m2, reached to have 18.8 +/- 5,1 g leaf biomass, 22.4 +/- 7.6 g stem biomass and 3.4 +/- 1.3 g root biomass. The population showed a rapid expansion occupying 0.30 +/- 0.09 m2 after seven days and 0.51 +/- 0.15 m2 in eighty four days. Parcels without the invader species (SE) showed expansive accumulation of individuals throughout the evaluation time, while in the parcels with the species (CE) the number of individuals exhibit few changes (p = 0.021 and H = 5.327). The results exhibit the biological invasion in the UFPB Campus II by T. zebrina, represents a threat to the local biodiversity due to its aggressive invasive behavior.