Rainfall Effects on the Distribution and Abundance of Conspicuous Termite Nests in Ecosystems of the Brazilian Northeast

<p>More than 25% of termite species inhabiting tropical forests of South America build conspicuous nests. Their nests are<br> remarkable components of the ecosystems composition and influence the biodiversity of a wide variety of organisms from<br> functional groups other than termites. Thus, the evaluation of abundance and distribution of nests may represent an <br> additional tool in the analysis of habitat quality in tropical forests. The density and volume of conspicuous nests <br> were estimated in an east-west direction along Paraiba state, in order to assess the variation of these factors among<br> the studied areas. The study was carried out in eight areas of the Atlantic Forest domain (including humid highland <br> forests – "Brejos de Altitude") and Caatinga. The density of nests was estimated from six plots (65 x 20 m) randomly <br> established. In these plots, all nests with volume > 2,0 liters were analyzed. There was significative variation among <br> areas in relation to nest density (F=2,4; P=0,03) and volume (F=2,45; P=0,03). Nests had a greater density in Caatinga<br> areas. The highest density value in this area was represented mainly by \textit{Constrictotermes cyphergaster}, species with strong performance in nutrient cycling in the areas of this domain. There was a negative and significant relationship<br> between the species composition and the rainfall of the areas (r=-0,71; P=0,04; N=8). The results indicate an influence<br> of environmental variables, such as rainfall, in nest density and distribution, and in the population size of termites <br> throughout the studied gradient. Financial support: CNPq, CAPES <br>