| Summary: | 碩士 === 國立中興大學 === 水土保持學系 === 93 === Sixteen landslide, vegetation treatment, and agriculture areas were selected for investigation of accommodate effect of vegetation and soil properties on earthworm population. Metaphire posthuma and Eisenia foetida were selected as experimental material to understand the two earthworm species effect on seed germination, soil properties, and soil erodibility.
The result indicated that earthworms’ group size is often related to food sufficiency. There are more abundant earthworm population living at those areas with high vegetation cover, abundant litter mulching, plant’s diversity, multiple vegetation cover layers, high organic matter content, and neutral pH. Furthermore, gravel content in soil is an important limiting factor for earthworm population. If there are high gravel content in soil, earthworm population will be limited.
Both Metaphire posthuma and Eisenia foetida can improve plant seeds’ germination, especially for significant Metaphire posthuma. However, seeds may also be ingested and pulled into deep soil by Metaphire posthuma. Actually, seeds will die if they have been injured by digestion or can’t break through deep soil cover.
Metaphire posthuma and Eisenia foetida both can promote soil water holding capacity, soil structure, and soil porosity. But both have no effect on soil pH and reduce organic matter content. Furthermore, Eisenia foetida can promote infiltration, and reduce soil erosion. But Metaphire posthuma’s ability of promote infiltration are not significant, and result in soil erosion increased due to higher initial soil moisture.
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