Wednesday, December 12, 2007
D0582

Distribution of Nasutitermes (Insecta: Isoptera) mounds in the Parupa region, Gran Sabana, Bolivar State, Venezuela

Carmen Andara, cvandara@cantv.net, Universidad de Carabobo, Departamento de Biología, Naguanagua. Estado Carabobo, Naguanagua, Carabobo, Venezuela and Solange Issa, sissa@usb.ve, Universidad Simon Bolivar, Departamento de Biología de Organismos, Apdo 89000, Caracas, Miranda, Venezuela.

Termites are important insects in the ecosystem due to their role as degraders of plant material. In Venezuela the genus Nasutitermes sp. build characteristic arboreal nests, notwithstanding in the Gran Sabana region the nests take the form of mounds above the ground level. The ecological influence of such nests on the soil composition and plant life, and has not been addressed before. Our objective here is to determine the spatial distribution of the nests of Nasutitermes cf. ephratae and its relation to the soil parameters and plant life characteristics. The study was performed in the Parupa region of the Gran Sabana in the Bolivar state, using two plots of 100 x 200 m and 50 x 100 m respectively, separated by 5 km. In each plot we determined the position of each nest measuring the linear distance between the nest and the closest edge of the plot. In order to take samples of soil and plant life, a grid was drawn on the plots with lines running every 50m parallel to the longest dimension of the plot, while perpendicular lines ran every 20m parallel to the shortest dimension of the plot. Using the VESPER software we performed a geostatistical analysis of the data, that showed little relation between the position of the nests and the plant life composition. The distribution also showed a poor correlation to the pH, carbon and phosphorous content. In contrast, we found that the nitrogen content is spatially associated with the nest localization.



Species 1: Isoptera Termitidae Nasutitermes