Data from: Evidence of trait shifts in response to forest disturbance in Taiwanese Carabus masuzoi (Coleoptera: Carabidae)

Shifts of functional traits are important because phenotypic responses of
species to environmental changes caused by natural and anthropogenic
disturbances are fundamental in determining the risk of population
extinction. This study tested the effect of forest thinning on the body
shape and male genital size of an endemic ground beetle species Carabus
masuzoi (Imura and Satô 1989) (Coleoptera, Carabidae) in cypress
plantations started approximately 30 years ago in central Taiwan. The
beetles were sampled and compared from (1) natural broadleaf forest, (2)
non-thinned cypress plantation, and (3) 45% thinned cypress plantation.
Female prothorax length from the non-thinned plantation was significantly
greater than that of the natural forest, and the 45% thinned plantation
had a higher frequency of the small (S-type) and a lower frequency of the
large (L-type) male genitalia than in the natural forest. The results
indicated that, within a short ecological time frame, the prothorax shapes
and male genital sizes of C. masuzoi populations might respond to changes
induced by different forest types and forest thinning, respectively. We
hypothesized that the difference in thoracic shape was related to
locomotory ability in forest understories, whereas the changes in male
genital sizes might have been a result of different levels of
intraspecific sexual selection, random effects of population
fluctuations/dispersal or pleiotropy.