不同立地侧柏林下植被与水源涵养能力的关系

Study of the Relationship between Underground Vegetation Biomass and Site Water Conservation of Platycladus orientalis Plantation in Different Site Condition

森林林下植被是森林生态系统的重要组成部分,林下土壤和枯落物是森林保持水土、涵养水源的主体,同时,林下植被的生长可以指示林地涵养水源的能力。设置了3种立地类型12块侧柏人工林样地,研究了林下植被生物量及其与林地土壤和枯落物涵养水源能力的关系。结果表明,不同立地条件林下植被生物量差异显著,其中阴坡厚土立地下灌草生物量最大(6671.66kg/hm2),阳坡厚土次之(6099.70kg/hm2),阳坡薄土最小(4998.73kg/hm2);不同立地条件土壤特征差异显著,阳坡薄土平均土壤容重最小(1.267g/cm3),平均非毛管孔隙度最大(13.766%),阳坡厚土情况与之相反;阳坡薄土立地条件土壤持水量最大,枯落物持水量最小,阴坡厚土居中,阳坡厚土与之相反;林下植被可以指示侧柏人工林林地水源涵养能力,林下植被生物量越大说明其林地水源涵养能力越弱,决定系数r2=0.99。

3 site types and 12 plots Platycladus orientalis plantation wereset for researching the relationship between underground vegetation biomass and the ability of water conservation of soil and litter levels. The results showed that： 1） biomass of underground vegetation has significant differences in different site type, shady slope and thick soil has the largest biomass of shrub and grass （6 671.66 kg/hm^2） than the sunny slope and thick soil （6 099.70 kg/hm^2）and the sunny slope and thin soil has the minimum biomass（4 998.73 kg/hm^2）; 2） soil condition also has significant differences in these sites, average soil bulk density of the sunny slope and thin soil site was the minimum（1.267g/cm^3） and the average non-capillary porosity was maximum （13.766%）, the shady slope and thin soil has the opposed side; 3） the largest amount of water conservation was in sunny slope and thin soil hut the litter has the lowest water conservation, shady slope and thick soil was the medium and sunny slope and thick soil has the opposed side;4） the growth condition of underground vegetation could indicate the ability of site water conservation, well growth condition indicated that the ability of water conservation of the site was worse and the correlation index equaled to 0.99.