D3252: Mean individual biomass of ground beetles (Carabidae) and forest age

Carabid beetles were collected from 28 Piedmont North Carolina sites representing approximately 0, 10, 50 and 90 year old forests. For the 36 most common species ( n min =4, n max >400 beetles) individuals that had previously been stored in ethanol were oven dried at 40 degrees C and their dry weight recorded. Mean individual biomass was recorded for each species. Regression of natural log MIB showed a positive relationship with natural log forest age (p < 0.001) for the combined data set of 36 species. When the data were sorted into subsets based on the presence of wings in adults (macropterous) or their absence (brachopterous), representing 19 species and 17 species respectively, the regressions were also positive (p< 0.001 for both). Although wet weight rather than dry weight was used, the regression equation for European carabid beetles is ln y = -8.509 + (2.555) ln x (Schwerk and Szyszo 2011), while the equation for the 36 American sites is ln y = -4.293 (2.900) ln x. Although the y intercepts differ between the European and American data, as would be expected given the use of wet versus dry weights, the slopes are remarkably similar, indicating a positive relationship between MIB and forest age on at least two continents. Reference: Schwerk, A. and J. Szyszko, 2011.Models of succession in degraded areas based on carabid beetles (Coleoptera, Carabidae). Zoo Keys 100:319-322.