不同林地水土流失规律及其对林木生长的影响——以不同整地马尾松幼林地为例

Law of Water and Soil Loss and Its Influence on Tree Growth ——TakingPinus massoniana Young Forest Land with Different Ploughing Patterns as an Example

对桂东南不同整地马尾松幼林地的水、土、肥流失规律及林木生长量进行连续６年的定位观测研究表明：（１）不同整地马尾松幼林地的年平均水土流失量为：全垦（１３５４．８ｔ／ｈｍ２）＞带垦（１１４２．５ｔ／ｈｍ２）＞穴垦（１０９６．８ｔ／ｈｍ２）；年平均养分流失量为：全垦（１６６．１７ｋｇ／ｈｍ２）＞带垦（７６．２７ｋｇ／ｈｍ２）＞穴垦（３９．８２ｋｇ／ｈｍ２）。（２）不同整地水土流失量的季节动态，主要受降雨量的季节分配所制约，表现为：夏季＞春季＞秋季＞冬季，５～８月占全年流失总量的７８．２％～８２．７％。（３）不同整地的林木生长量，以全垦最好，穴垦次之，带垦最差；产出与投入的比值，则以穴垦最大（２．９９），全垦次之（２．５７），带垦最小（２．２４）。

In 1991～1996 year,the observation method of fixed position of runoff plots was used to study the loss amounts of soil and water, and its nutrient and tree growth of Pinus massoniana young forests of different ploughing in Guiping city of Guangxi. The results show:①Mean amounts of water and soil loss of Pinus massoniana young forest land with overall plough, band plough and cave plough is 1 354.8, 1 142.5,1 096.8t/hm 2.a respeetively. Mean amounts of nutrient loss of overall Ploughging, band ploughing and cave ploughing is 166.17, 76.27,39.82 kg/hm 2.a respectively. ②Seasonal dynamics of water and soil loss was mainly restricted by seasonal distribution of rainfall, summer>spring>autumn>winter, May to August is 78.2%～82.7% of yearly total losses.③Stocking of Pinus massoniana young forest(6 years) with overall plough, band plough and cave plough is 42.8,29.51,36.16 m 3/hm 2 respectively,the ratio of input and output is 2.57,2.24,2.99 respectively.