造林對921地震崩塌地土壤性質與土壤水之影響

The Effects of Reforestation on Soil Characteristics and Soil Water to Landslide Area Crumbled by the 921 Earthquake

本試驗在921地震後的九九峰和烏石坑二處崩塌地，分別選擇崩塌後未實施造林者、崩塌後實施造林者，及未受地震干擾的天然林（九九峰崩塌地）和人工杉木林（烏石坑崩塌地）等三種情況作為樣區。在樣區內收集土壤興土壤水評估崩塌地造林，其土壤之化育情形，以為造林利益得失之參考依據。結果顯示，崩塌地土壤質地屬砂質壤土或壤質砂土，含水量相當低，礦質化和硝化作用遠不如天然林和人工林。造林初期並未顯現出土壤化育的差異，土壤養分流失嚴重，如何確保養分保存在此造林地是很重要的，崩塌地迅速恢復植群的被覆與生長應是涵養養分與水分的良好作業方法。 To investigate the influence of reforestation on soil characteristics and weathering rate to landslide areaed by the 921 earthquake, we collected soil and soil solution from three sites, reforestation in landslide areas, landslide areas, and undamaged areas in the Joujou mountain and Wushihkeng Watershed sites. The soil texture was sandy loams or loamy sands and soil moisture was very low in the both landslide areas. Additionally, mineralization and nitrification rates measured in the landslide areas were far lower than those measured in the undamaged areas (nature stand and China-fir plantation). The primary reforestation didn't show any effects on soil characteristics and weathering rates, but lost much soil nutrients from these landslide areas, therefore, it's very important to have the retention of soil nutrients in these areas. This study reveals the potential for using practices of reforestation to conserve soil nutrient and moisture and minimize landslides.

To investigate the influence of reforestation on soil characteristics and weathering rate to landslide areaed by the 921 earthquake, we collected soil and soil solution from three sites, reforestation in landslide areas, landslide areas, and undamaged areas in the Joujou mountain and Wushihkeng Watershed sites. The soil texture was sandy loams or loamy sands and soil moisture was very low in the both landslide areas. Additionally, mineralization and nitrification rates measured in the landslide areas were far lower than those measured in the undamaged areas (nature stand and China-fir plantation). The primary reforestation didn't show any effects on soil characteristics and weathering rates, but lost much soil nutrients from these landslide areas, therefore, it's very important to have the retention of soil nutrients in these areas. This study reveals the potential for using practices of reforestation to conserve soil nutrient and moisture and minimize landslides.