2006 Fiscal Year Final Research Report Summary
Evaluation and Conservation of Ecosystems throughout irrigational water networks
| Project/Area Number |
16380154
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Irrigation, drainage and rural engineering/Rural planning
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| Research Institution | Hirosaki University |
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Principal Investigator |
AZUMA Nobuyuki Hirosaki University, Faculty of Agriculture and Life Science, Associate professor (40262977)
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| Co-Investigator(Kenkyū-buntansha) |
IZUMI Mattashi Hirosaki University, Faculty of Agriculture and Life Science, 助教授 (60132007)
SAWARA Yuji Hirosaki University, Faculty of Science and Engineering, Associate professor (10113797)
NODA Kaori Hirosaki University, Faculty of Science and Engineering, Associate professor (10281198)
KOIZUMI Noriyuki Hirosaki University, Chef scientist (60301222)
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| Project Period (FY) |
2004 – 2006
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| Keywords | networks of cannel and river / water cannel for irrigation / farm pond / ecosystem / conservation |
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| Research Abstract |
Our objectives were making new evaluation systems for agricultural ecosystem. We carried out investigation and analysis of the macroscopic viewpoint in addition to microhabitat evaluation ever promoted. We set the large-scale research ground for making habitat evaluation for cannels and farm ponds in watershed of the Iwaki River.
Firstly, several scale units for investigation were set throughout this river basin as follows. (1) paddy field-small cannels, (2) farm pond, (3) river-the irrigation canal-drainage canal. The multivariate analyses were used for grouping of fish communities in each habitat and for analyzing of habitat preference of each fish species. As a result of the TWINSPAN analysis, it became clear to be formed fish community in each habitat with the position of the cannel in the Tsugaru plane. This result shows that cannel categories were important for the community structure rather than microhabitat physical dimension. Because these fish communities were consist with inhabitant member of flood plane, each species should has delicate different habitat preference in flood plane by nature. But, by the multiple regression analysis, it was shown that there was a preference in some species in microhabitat structure and similarly cannel category.
These results support our hypothesis and we must consider the factor of spatial scale for evaluation model.
Secondly, we evaluated the relationship between the farm pond structure and effect of invasive fish species, such as large-mouse bass. In most of the introduced pond, fish community structures were destroyed, but in some pond, several species survived with introduced invader. The follower ponds had rich vegetation area near the shore line and temporal hypoxia water body. Feature of these ponds are to have the lake bed in shelving bottom.
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