Influence Of Light-felling On Undergrowth Hydrological Effects In Korean Pine Forests By "Planting Needles And Preserving Broad Leaves" In Xiaoxing’an Mountains Of China

In order to reveal the influence of "planting needles and preserving broad leaves " and light-felling on the understory hydrological effects in the process of restoring the climax vegetation broad-leaved Korean pine forest with temperate zone of Northeast China,and the accumulation of litter,water holding process of litter,and maximum holding water,maximum blocking,effective blocking amount of litter layers and hydrological effect of soil were simultaneously measured by using sample survey method and indoor immersion method in three forests(aspen-Korean pine forests,white birch-Korean pine forest,and Mongolian oak-Korean pine forest)under different light-felling intensity(control C-uncut and unplanted needles,low light-felling(L)-1/7,moderate light-felling(M)-1/5,and heavy light-felling(H)-1/4,intensity meaning upper layer accumulation)in Xiaoxing’an Mountains,to reveal the influence law and mechanism of light-felling on the hydrological effect of litter and soil in three forests.The results shown that:①The intensity of light-felling had different effects on the accumulation of litter(7.32 to 15.58 t·hm-2)in three forest types(L,M and H made it significantly enhance 24.3%～34.6%in the Mongolian oak-Korean pine forest,L and M made it enhance 15.3%～19.3%in aspen-Korean pine forest,and H made it enhance 27.1%in white birch-Korean pine forest);②The water holding capacity or water absorption rate of the undecomposed layer and the semi-decomposed layer of the litter were in accordance with the relationship between the soaking time:W=alnt+b(R2>0.908)or V=ktn(R2≥0.999),but all light-felling intensity treatments generally significantly increased its initial water holding capacity or water absorption rate(which of the undecomposed layer in aspen-Korean pine forest and Mongolia oak-Korean pine forest increased by 27.4%～39.5%;and those of the semi-decomposed layer in the three forest types(except H in aspen-Korean pine forests)increased by 35.3%～141.7%);③The intensity of light-felling(except H in aspen-Korean pine forests)made the the maximum water holding capacity(17.86～45.12t·hm-2),maximum interception capacity(16.10～34.19 t·hm-2)and effective interception capacity(13.42～27.42 t·hm-2)of litter in the three forest types increased significantly by 30.1%to 74.8%,27.4%to 83.6%and 26.7%to 86.0%,respectively;And changed the difference of the maximum or effective accumulations of litters between forest types;④The intensity of light-felling had different effects on the accumulation of soil physical properties,and there was no significant effect on Mongolia oak-Korean pine forest and aspen-Korean pine forest by different intensity of light-felling,but moderate light-felling treatment significantly increased the non-capillary porosity by 60.2%in the soil layer ranging from 20 cm to 40cm in white birch-Korean pine forest;And changed the difference of the maximum or effective accumulations of soil physical properties between forest types(C was aspen forest>Mongolian oak forest,L was similar to each other,M was aspen-Korean pine forest>Mongolian oak-Korean pine forest,H was white birch-Korean pine forest>aspen-Korean pine forest and Mongolian oak-Korean pine forest);⑤ The intensity of light-felling had different effects on the accumulation of effective water holding capacity of soil,and there was no significant effect on Mongolia oak-Korean pine forest and aspen-Korean pine forest of soil water storage capacity by different intensity of light-felling,but heavy light-felling treatment significantly reduced effective water holding capacity by 22.2%in 0～10cm soil layer in white birch-Korean pine forest,and moderate light-felling treatment significantly increased the effective water holding capacity by 60.2%in the soil layer ranging from 20 cm to 40cm in white birch-Korean pine forest;And changed the difference of the maximum or effective accumulations of soil water holding capacity between forest types.Light-felling significantly enhances the hydro-ecological function of litter layers in the medium-term broad-leaved Korean pine forests by "planting needles and preserving the broad leaves",and there was no significant effect on soil hydrological effect of each forest land,after comprehensive evaluation,the low,moderate,and heavy light-felling is best for the Mongolian oak-Korean pine forest,the aspen-Korean pine forest,and the white birch-Korean pine forest in turn in the practice of the subsequent secondary forest restoration to broad-leaved Korean pine forest.