元谋干热河谷人工林地的水分输入与土壤水分研究*
Study on Input of Water Regime and soil Water Content in the Plantation of the Yuanmou Dry and Hot River Valley
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摘要: 通过1992年3月~1994年5月对赤桉一山毛豆人工幼林地的观测,在雨季降水平均481mm,比多年平均值少17%的条件下,林木未出现萎蔫和死亡,全年土壤平均含水量在11%以上,在最干的3~5月份,土壤水分也能满足林木存活;水分输入后被林冠截留部分约占总降水量的10%,地表流失量仅占3%左右,大部分水分渗入土壤。在无任何地下水补给,天然降水作为唯一水分来源的情况下,干热河谷地区的营林和植被恢复应采取以获取最大的水分输入为主的整地、造林措施。Abstract: Through two year's observation, it was found out that no trees ever withered or died in the young Eucapytus manldnlensis×Tophroria candida plantation when the mean precipitation was 17% less than that of the normal years. Even if in the driest season from March to May,soil water content could meet the need of the young trees, In terms of water input loss, the loss of crown-intercepting water amounts to 10% of the total precipitation,while surface run-off only 3%. In the dry and hot river valley areas where there is no subterranean water available and rainfall is the only water source,afforestation and plant vegetation recovery should aim at obtaining the most water input.