The influences of deer overbrowsing on nutrient cycling in forest ecosystems : Preliminary study of streamwater chemistry
- Other Title
- シカの食害が森林生態系の物質循環に与える影響 : 渓流水質の予備調査から
- シカ ノ ショクガイ ガ シンリン セイタイケイ ノ ブッシツ ジュンカン ニ アタエル エイキョウ ケイリュウ スイシツ ノ ヨビ チョウサ カラ
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Currently, the decrease of forest understorey by Japanese deer overbrowsing is widely reported in Japan. In order to clarify the influences of the understorey disturbances by deer on nutrient cycling in forest ecosystem, we examined streamwater chemistry in the U watershed, where deer exclusion fence was installed over all, and in the unfenced K watershed. One outlet and four sub-catchments within each watershed were used. The wide variability of streamwater chemistry was observed among sub-catchments of both watersheds, while no significant difference was detected between both outlets. This indicates that by using not only outlets, but also the small sub-catchments within the watersheds in our study sites, we can evaluate the spatial heterogeneity of streamwater chemistry, so the effects of spatio-temporally heterogeneous and gradual recovery of understorey vegetations after deer exclusion can be expectedly comprehended in more details. The results also indicate that throughout one year since the fence installation, there has been no effect of deer exclusion on streamwater chemistry yet. Continuous observation is needed to clarify the effects of deer overbrowsing on forest ecosystem functioning and the definite impacts of atmospheric depositions to nutrient cycling in our study sites, where the watershed design is convenient for clearly demonstrating them.
- Forest Research, Kyoto
Forest Research, Kyoto 77 77-87, 2008-12-26