Abstract:

In order to monitor the impacts of afforestation methods on soil and water losses, one control plot (on the unafforested land) and one or two afforested land plots were established in each of runoff sites during 1991 ~ 1995 in Kuandian and Qingyuan county, Liaoning Province.Annual changes of water, soil and nutrient loss and the relations between loss and the method used for planting and tending were analyzed based on the data record.The results showed that only slight runoff occurred in the afforested land for the first three years and the maximum amount of solid loss was about 196.94t/hm²·a, which was less than the standard loss of 200t/hm²·a in the rock soil of North China and black soil of east-north China according to the National Standard for Grading Soil Erosion issued in 1996.It was further identified that heavey runoff occurred from July to August in Qingyuan runoff plots and amounted to 89.4 %of runoff and 61.7 % of the times of runoff in the whole year.Because the occurrence of runoff was closely related to site character, site preperation and tending method, reducing or enlarging the size of holes and changing the tending time or method could lead to further reduce soil and water losses.

Key words: Larix kaempferi(Lamb.) Carr., Young tree, Runoff plot, Runoff, Soil and water losses