What determines the seedling viability of different tree species in raccoon dog latrines?

Abstract

Numerous studies have evaluated the qualitative and quantitative effectiveness of several animal species in each phase of the endozoochory. For the “seed germination and growth” phase, the ideal method of evaluation is to track the germination and seedling growth of seeds where they were dispersed by animals, but few studies have done so. Furthermore, because these studies were limited to measurements such as the seedling density and seedling growth over time or comparison with surrounding areas, survival rates, and factors specific to seedling mortality are unclear. This study aimed to qualitatively evaluate the effectiveness of one of the main seed dispersers in temperate forest ecosystems in Asia, raccoon dogs (Nyctereutes procyonoides), in the seed germination and growth phase. Seedlings of four tree species germinated in their latrines: Ginkgo biloba, Diospyros kaki, Aphananthe aspera, and Celtis sinensis. It was previously thought that most seeds in latrines germinated but died off quickly through competition within seedlings. However, this study has verified that in specific environmental conditions, seedlings of these four species live for at least one year after germination. In particular, G. biloba has a large seed size, and its survival rate of 85% could indicate that the raccoon dog latrines are suitable for its dispersal. These results demonstrate the effectiveness of seed dispersal raccoon dogs in the seed germination and growth phase.