Response of the termite community (Blattodea: Isoptera) to the regeneration time of Brazilian Savanna (Cerrado) areas in Itirapina, São Paulo
The present study aims to use termites (Insecta: Blattodea) to understand how the regeneration of the Cerrado (Brazilian Savanna) occurs in areas used for Pinus plantations and left to regenerate after felling. These insects have a set of characteristics that define them as bioindicators. Termites were sampled in 15 areas, three of them being savanna and the other 12 consisting of plantations of two Pinus species, (P. elliotti and P. caribea hondurensis) both intact and with different cutting dates, so as to include areas with older cuts (7 to 9 years) and others with more recent cuts (1 to 2 years). In each area, 10 plots of 5 m² (2.0 m x 2.5 m) were sampled, distributed in two transects containing five plots at least 10 m apart. Each plot was examined by a collector for 30 minutes. Analyses of alpha and beta diversity (comparing richness, abundance and composition), proportion of feeding groups, and calculation of the IndVal of species were performed. Our prediction that termite diversity would be higher in the preserved cerrado areas, followed by areas where Pinus cutting had occurred for a longer period of time, and finally Pinus plantations, was corroborated by the results. Humivorous termite feeding groups were the most diverse and abundant in the preserved areas and much less diverse in areas affected by recent human disturbance (1 to 2 years) left for regeneration. In plots and areas with longer regeneration time (7 to 9 years) the abundance and diversity of this group and intermediates was moderately decreased. In degraded areas these groups gave way to xylophages such as Heterotermes tenuis. Although environmental variables such as soil and altitude did not explain satisfactorily the variation of distribution by time classes this study confirms that the termite community can be used as bioindicator for studies on the regeneration of degraded environments.