Complementarity and taxonomic difference estimates and priority analysis for an insight into tettigoniid (Orthoptera: Tettigoniidae) diversity in Chennai, Tamil Nadu (India).

Abstract

We explored the diversity of tettigoniids in four habitats in Chennai, India, namely forestlands, wastelands, grasslands, and arable lands. The number of species and the number of individuals observed during a sampling period of 24 months were recorded. Seventeen species of tettigoniids belonging to 5 subfamilies of Tettigoniidae were encountered, with 9 species belonging to the subfamily Phaneropterinae. Root weights were provided to assess differences between the species and priority analysis was carried out to assess site selection for conservation augmentation. Results indicate that the forestlands were the most diverse habitat, with the wastelands serving as a complementary site. Fisher's diversity and Shannon's index also gave high values of the forestlands. Several species richness estimators were calculated to assess the number of additional species that one could expect had sampling been more intense. The Michaelis-Menten model and the Coleman curve indicated an early asymptote for the grasslands, wastelands, and arable lands in contrast to the coverage based estimators ACE and ICE for these habitats. However, all the species richness estimators fitted well for the forestlands. Estimates of diversity showed that the forestlands, grasslands, and wasteland were similar in species composition, but different in species abundance and that the wastelands complemented the forestlands in the species richness attribute.

Keywords

Complementarity, Priority analysis, Tettigoniidae, Biodiversity, Species conservation.