PS 21-6: The palatability of dominant herbs to the Taiwan field vole (Microtus kikuchii) in alpine meadows in central Taiwan
Han-chih Ho and Yu-Teh K. Lin. National Taiwan University
Differential palatability of plants accounts for selective herbivory by small mammalian herbivores, and could alter plant species composition and diversity in various ecosystems. The endemic Taiwan Field Vole (Microtus kikuchii) is the dominant herbivore in the alpine meadows in central Taiwan. We hypothesize that the Taiwan field voles consume plants according to their abundance in the field. We performed feeding trials in local laboratory at Ho-huan mountains (3088m in altitude) to determine the palatability of 10 dominant plants in mountain meadows to voles, during summer (July) and fall (November). Fresh aboveground plant material were provided to 10 male and 10 female voles in random order over 10 consecutive days, one twelve-hour trial per day per vole. Palatability was measured as the amount of plant material consumed by voles during trials. The abundance of plant species was measured as the percent cover of each species in sample plots in the mountain meadows where voles where captured. The results showed that palatability ranks were not significantly different from cover ranks except Veratrum formosanum in July trial, which was consumed more than expected. The pattern was the same between male and female voles. The results indicated that the Taiwan field voles consumed plants according to their abundance in the mountain meadows, and suggested that vole herbivory would have little effects on the diversity and composition of alpine meadow vegetation.