|| 要旨トップ | 目次 |
|日本生態学会第59回全国大会 (2012年3月，大津) 講演要旨
一般講演（ポスター発表） P3-280A (Poster presentation)
Deterioration of water chemistry including eutrophication is considered to be one of principal pressures that cause biodiversity loss of irrigation ponds. Clarifying the driving factors of eutrophication is required to prevent biodiversity loss. Hydrological and chemical budgets of irrigation ponds depend strongly on sources of pond water. Therefore, the factors of eutrophication are suspected to be different in response to water sources. The relationships between water chemistry and environmental factors including pond physical characteristics and catchment land-use were statistically analyzed with respect to each water-source type for 50 ponds. Ponds were divided into three types based on the inflow conditions (type-A, directly-inflow; type-B, indirectly-inflow, and type-C, no-inflow) of irrigation water from a large canal (Aichi Canal). Partial correlation coefficients between water chemistry and environmental variables were compared between different water-source types. As a result, nutrients concentrations were negatively correlated with the percentage of paddy field area for type-A ponds. For type-B and C ponds, nutrients concentrations were positively related to the percentage of agricultural area except for paddy field. These suggest the effects of land-use on pond water chemistry differ depending on water-source type.