Climate change impacts
In the Daisetsuzan National Park, Kamikawa-gun, Hokkaido, there has been a decrease in wetland flower population (flowering plants clustered in alpine wetlands) in the Goshikigahara area in the last few years, and an expansion of Sasa kurilensis (Chishimazasa). One of the reasons for the disappearance of the Anemone narcissiflora var. sachalinensis (Ezonohakusan-ichige), a common species of wetland flower, is thought to be dry soil caused by earlier snow thaws. In addition, early thaws accelerate the expansion of Sasa kurilensis and its transpiration itself further increases soil dryness.
Adaptation activity
Sasa grass-harvesting trials have been in progress since 2008, as a way to protect alpine vegetation biodiversity. For this trial a test area with dense Sasa growth was demarcated, and all grass in the test area was cut at ground level ground (fig.). This process of reaping new growth Sasa is repeated once a year.
Outputs / Expected benefits
The number of alpine plants in the test area was negligible after the first Sasa removal, but more than ten species have appeared after five years, and vegetation coverage has greatly improved. Conventional ecosystem conservation in nature parks has primarily focused on eliminating human-induced impacts as much as possible. However, the results of this study demonstrate that the decline in alpine vegetation could be restored by intentional Sasa removal. The effectiveness of anthropogenic countermeasures for ecosystem change and biodiversity loss caused by climate change was confirmed.
Fig. Sasa cutting trial in Goshikigahara (Left) Before cutting (Middle) 1 year after cutting (Right) 5 years after cutting.
(Source: Yuka Kawai, Gaku Kudo, "Changes in Alpine plant distribution in the Daisetsuzan National Park and Impacts on Biodiversity")
