Ground Beetle (Carabid) Biodiversity Research
In a three-year study involving saltcedar-free, saltcedar-infested and burned habitats in a riparian area at Lake Meredith, TX, the number of carabid species collected, diversity indices and indicator species varied significantly among habitats. A three-year average of 15, 14, and 24 carabid species were collected from the saltcedar-free, saltcedar-infested and burned sites, respectively. Values for species richness, Shannon’s and Simpson’s diversity indices, and evenness index for pooled data collected from 2005-2007 were higher at the burned site followed by the saltcedar-free site and the saltcedar-infested site. Within-year parameters across the three sites generally followed the pooled data results with some variation. Nonmetric multidimensional scaling analyses clearly indicated groups of carabid species preferred specific habitats. Five species in the burned area had indicator species percentage values greater than 50 % (Agonum punctiforme, Agonum texanum, Brachinus alternans, Harpalus pensylvanicus, and Poecilus chalcites). In the saltcedar-infested and saltcedar-free habitats only one species in each habitat had indicator species percentage values that exceeded 50 % – Calathus opaculus and Cicindela punctulata punctulata, respectively.
This research illustrated that carabid species diversity, richness, and abundance varies significantly in small diversified riparian habitats where saltcedar is present. Pooled data for three years of sampling revealed that the burned site had the highest species richness and diversity (both Shannon’s and Simpson’s indices) followed in most cases by the saltcedar-free area and the saltcedar-infested area. Analyses of the data resulted in four or five carabid species that were consistently shown to be indicator species in the burned area. Over the course of the research, the burned area seems to have quickly returned to a “native” state in regard to carabid parameters. Results of the saltcedar-infested site and the saltcedar-free sites analyses pointed to one strong indicator species in each habitat.
We believe that the results presented here illustrate how carabid species composition can vary in a rather small geographic area containing three distinct habitats. Confirmation of area- or region-wide indicator species in these habitats would require replication of the habitat types over a much larger area.
A manuscript of these results has been submitted as a paper to Environmental Entomology, and is currently in review.
Carabid Beetles as Indicators of Variation in Riparian
Carabid Photo List