川西亚高山川滇高山栎灌丛地被物与土壤持水性能

Water conservation capacity of ground cover and soils in the subalpine Quercus aquifolioides shrubs of western Sichuan,China

为进一步研究川西亚高山灌丛的水文特性,选取米亚罗林区川滇高山栎灌丛正向演替的4种类型和杜鹃灌丛(CK),测定林下地表枯落物、苔藓和土壤的持水能力以及探讨土壤持水能力的影响因素.结果表明:(1)地表枯落物积蓄量表现为川滇高山栎-陕甘花楸灌丛(QS)<杜鹃灌丛(CK)<川滇高山栎-华山松灌丛(QM)<川滇高山栎-云杉灌丛(QP)<川滇高山栎-粉背黄栌灌丛(QC);苔藓积蓄量为QC <QP <QM <CK;(2)枯落物最大持水量和有效拦蓄量分别为163.78-351.78 t/hm^2和17.69-79.65 t/hm^2,二者为CK> QP> QC> QM> QS;苔藓最大持水量和有效拦蓄量分别为12.48-1207.88 t/hm^2和5.24-741.07 t/hm^2,均为CK> QM> QP> QC;(3)土壤最大持水量为887.06-1373.19t/hm^2,表现为CK> QS> QP> QC> QM;(4)土壤非毛管持水量为221.25-576.23 t/hm^2,表现为CK> QP> QS>QM> QC.(5)综合水源涵养能力为CK> QP> QM> QS> QC.综合地被物持水和土壤持水,地被物层持水能力占综合持水量的21.30%.随川滇高山栎灌丛正向演替的发展,地被物调节水量的作用逐渐增加.因此,对其灌丛维护和经营管理中,应强化地被物的监管力度.

Soil water retention directly or indirectly affects forest ecosystem soil properties and the soil hydrological process.To study the hydrological characteristics of sub-alpine shrubs in Western Sichuan,Rhododendron simsii shrub(CK)and four Quercus aquifolioides shrubs under different succession stages were used as research objects.The water conservation function of different shrub litter,moss,and soil layers was analyzed via the cutting ring,drying,and indoor immersion methods.The results showed that(1)the surface litter accumulation of the different shrub types were ranked as Q.aquifolioides-Sorbus koehneana shrub(QS)<Rhododendron simsii shrub(CK)<Q.aquifolioides-Pinus massoniana shrub(QM)<Q.aquifolioides-Picea asperata shrub(QP)<Q.aquifolioides-Cotinus coggygria var.glaucophylla shrub(QC).The accumulation of moss was QC<QP<QM<CK.(2)The maximum water holding and effective storage capacities of the litters were 163.78-351.78 t/hm^2 and 17.69-79.65 t/hm^2,respectively,and both the orders of the indexes was CK>QP>QC>QM>QS.The maximum water holding and effective storage capacities of the moss were 12.48-1207.88 t/hm^2 and 5.24-741.07 t/hm^2,respectively,and in the order of CK>QM>QP>QC.(3)The maximum water holding capacity of the soil was 887.06-1373.19 t/hm^2,and the order was CK>QS>QP>QC>QM.(4)The non-capillary porosity of the soil was 221.25-576.23 t/hm^2,and the order was CK>QP>QS>QM>QC.The density,total porosity,and capillary porosity of QC and QM were generally higher than QP and QS.The order of the comprehensive water conservation functions for different shrub types was CK>QP>QM>QS>QC.When considering the combination of the water holding capacity of the ground covers and soils,the ground covers accounted for 21.30%of the total water holding capacity of the whole ecosystem.Moreover,the water regulating function of the ground covers increased with Q.aquifolioides shrub positive succession.These results suggest that the supervision of the ground covers should be strengthened during the maintenance and management projects of the Q.aquifolioides shrub.