Water conservation function of litter and soil layer under main forest types in Xinglong Mountain of Gansu

Taken the litter and soil layer under six main forests(Picea wilosonii,P.wilosonii and Betula platyphlla,Populus davidiana and B.platyphlla,Cotonester multiglorus and Rosa xanthina shrubs,Larix principis-rupprechtii and Pinus tabulaeformis)in Xinglong Mountain of Gansu province as research objects.The water conservation function of the different forests were studied in 2010.The results showed that:(1)The accumulation amount of litters was 13.40-46.32 t/hm2 among six forests,the amount of P.tabulaeformis forest was 2.71 times larger than that of P.davidiana and B.platyphlla forest;the maximum water-holding capacity of litters varied from 39.38 t/hm2 to 85.91 t/hm2.Water-holding capacity of P.tabulaeformis forest was the biggest whereas P.davidiana and B.platyphlla forest was the least.(2)The bulk density of forest soil in Xinglong Mountain were augmenting with the increment of soil depth,whereas the capillary porosity,total porosity,maximum water-storage and non-capillary water-storage were all decreasing with the increment of soil depth;non-capillary water-storage of 0-60 cm soil layer was 413.38-771.71 t/hm2 among six forests.Non-capillary water-storage of P.wilosonii and B.platyphlla forest was the biggest whereas L.principis-rupprechtii forest was the least.(3)Total water-storage of six forest types was P.wilsonii and B.platyphlla forest(849.76 t/hm2)P.wilsonii forest(778.48 t/hm2)P.davidiana and B.platyphlla forest(623.24 t/hm2)P.tabulaeformis forest(504.80 t/hm2)L.principis-rupprechtii forest(492.02 t/hm2)C.multiglorus and R.xanthina shrubs(462.26 t/hm2),the amount of P.wilsonii and B.platyphlla forest was 1.84 times larger than that of C.multiglorus and R.xanthina shrubs.The water conservation function of natural forest firstly increase then decrease with the development of positive forest succession.