AQUATIC INVERTEBRATES RESPONSES TO WINTER FLOODING IN KAGA AND HIKONE CITY PADDY FIELD AREA, JAPAN

• Main Author: Budi Prasetyo, Didot
• Format: Theses
• Language: Indonesia
• Subjects: Ilmu hayati ; Biologi
• Online Access: https://digilib.itb.ac.id/gdl/view/36018
• Institution: Institut Teknologi Bandung

The modernization of irrigation system has reduced the number of fishes, invertebrates, and foraging birds in paddy fields. This indicates that water managements may have high influence on biological life in paddy fields ecosystem. Based on that, “winter flooding” method was introduced, as a promising new attempt to recover faunal biodiversity in paddy field area. To evaluate this new method, comparison between invertebrates community in winter-flooded and conventional paddy fields were studied in 2010. Physicochemical factors were measured and aquatic invertebrates were collected from 5 paddy field areas in Kaga City and Hikone City between April-June 2010. Body size and biomass were also measured and invertebrates were classified based on taxonomy, feeding group, and desiccation tolerance ability. Study sites in Kaga City consist of WF1 area (winter-flooded), WF2 area (winter-flooded) and Kaga area (conventional). In Hikone city, there were only 2 kinds of paddy field; WF3 (winter-flooded) and Hikone (conventional). Comparison was made between winter flooding and conventional paddy field within each City. Conventional paddy field was regarded as control site. The results showed that body size and biomass per taxon were not affected significantly (p>0.05) by winter flooding practice in both City. However, classification based on feeding group showed that biomass of predators were significantly higher in winter flooded “WF1” compared to other sites. In addition, if classified by desiccation tolerant ability, invertebrates that less tolerant against desiccation were more abundant (p<0.05) in winter flooded paddy fields in both Cities. In Kaga city, overall shannon diversity index were higher in “WF1” (3.0) and “WF2” (2.9), compared to conventional “Kaga” (2.7). However, in Hikone city index value were not different in “WF3” (2.7) and conventional “Hikone” (2.7). Similarity analysis using Jaccard index was clearly shown that winter flooding created a different faunal composition compared to conventional methods. Additionally, Canonical Correspondence Analysis showed that winter flooding practice was one of significant factors (p<0.05) that influenced invertebrates’ community both in Kaga and Hikone City paddy fields area.