Internationally vulnerable Korean water deer (Hydropotes inermis argyropus) can act as an ecological filter by endozoochory

Abstract

Seeds dispersed by endozoochory by large herbivores are disseminated over long distances, which has potential impacts on vegetation dynamics within a region. The Korean water deer (Hydropotes inermis argyropus) is a dominant deer species in South Korea, but is considered a vulnerable species internationally. In the present study, we aimed to elucidate the role of Korean water deer in seed dispersal in lowland areas where land-use change is occurring. We assessed seasonal differences in seed dispersal in Korean water deer, and the traits of seeds dispersed in this manner. We identified species dispersed by controlled germination using Korean water deer fecal samples from the Civilian Control Zone adjacent to the Demilitarized Zone between South and North Korea, a mixed lowland habitat of forest and open area. A total of 208 fecal pellet groups were collected throughout the year from April 2017 to March 2018. We found a total of 35 plant species from the deer feces. More seeds and species were dispersed in fall, the main seeding period in South Korea. Dispersed plant species were mainly forbs that were specific to lowland areas and had medium (1–2 mm) seeds with no specific dispersal adaptations. Our results suggest that Korean water deer preferentially disperse particular plant species. They disperse disproportionately more graminoids, species from open areas, shorter than 2 mm, with no special adaptation, and specifically without fleshy/edible fruits, which may result in ecological filtering. We conclude that Korean water deer, as an endozoochorous seed dispersal vector in the lowland of South Korea, can affect plant populations and communities in the region.