A STUDY ON ECOLOGICAL CHARACTERISTICS OF SMALL IRRIGATION POND (DUM-BUNG) IN PADDY FIELD

摘要

The objectives of this study are to identify ecological characteristics of constructed smallirrigation pond (Dum-bung) and eco-corridor in paddy fi elds. The abundance of loach washigher in drainage canal than in irrigation pond at the early stage of midsummer drainage,because water fl ow was formed toward the drainage canal. As the paddy was drying, loachmoved to the pond during midsummer drainage period. Contrary to the general hypothesis,the marked loach was not found in holes in paddy fi eld. Loach caught in the pond ingestedmainly animal prey, and it's frequency of empty stomach was 10%. On the other hand, all loachcollected in the paddy fi eld showed empty stomach. It was apparent from the experiment thatloach are eating normally in the small irrigation ponds, while they are not eating properly inpaddy fi eld. It can be concluded that small irrigation ponds provide a shelter and prey to loachin the midsummer drainage period.