知床 Shiretoko (Japan)
Disentangling the community assembly process is crucial for understanding the structure of biodiversity and how communities will behave in future. The biodiversity change by deer overabundance is one of the biggest problems in Japan. Even in the UNESCO World Natural Heritage Site, Shiretoko (located in northern island of Japan) also has problems with deer overabundance. To clarify the mechanisms biodiversity change by deer herbivory, I examined the local community assembly processes at both deer over- and no-grazed area by using plant functional traits.
日光 Nikko (Japan)
Evidence of the indirect effects of increasing global deer populations on other trophic levels is increasing.
However, it remains unknown if excluding deer alters ecosystem functional relationships. In Nikko National Park, a deer-proof fence was constructed in 1997 to protect the vegetation from deer grazing. Here, we measured soil properties, the understory plant community, and the traits of the dominant understory plant, Sasa palmata, both inside and outside a deer exclosure fence to gain an understanding of the general relations among the abiotic and biotic (including insect herbivory) properties of the ecosystem and to see if these relationships were altered due to deer exclosure.
Generally, the plant community assembly process become more deterministic (explained by niches) as the environmental condition becomes more severe.
Our study sire, Whapmagoostui-Kuujjuarapik (W-K) is located at the south end of the tundra in Canada (55°16’50” N, 77°45’10” W). On the characteristic topograph terrain in this site "parabolic dunes", in addition to the arctic harsh climate, extremely strong wind have prevented the vegetation growth. And there are only patchy dwarf vegetation for a long time. In this site, we assessed the variation of the importance of deterministic processes among these patches.
Pond Inlet- Bylot Island (Canada)
Greater snow geese have profound effects on plant community and ecosystem cycling via intense herbivory and a large number of feces, especially in the low-productivity arctic wetlands. But the knowledge of long-term disappearance effects is limited.
Here, by comparing 50 years-long geese disappearing site (Pond Inlet: Inuit village) to the geese exclosure and fertilization experiments (16 years) at the geese overabundance site (Bylot Island: National Park), I assessed the effect of extremely long-term geese existence/disappearance on the arctic ecosystem from the aspects of plant community and nutrient cycling.