黔中喀斯特植被恢复过程中水土保持功能变化初步研究

THE PRIMARY STUDY ON THE CHANGES OF WATER AND SOIL CONSERVATION FUNCTION IN THE KARST VEGETATION RESTORATION PROCESS IN THE MID-AREA OF GUIZHOU

以'空间代替时间'的方法,在黔中退化喀斯特植被区,选择不同植被恢复阶段地段建立径流场进行野外测定,结合室内实验分析,对试验区植被恢复过程中的0～15cm和15～30cm土壤物理性质、土壤持水性及土壤抗蚀性能进行了分析研究.结果表明:退化植被恢复过程中,植被对土壤物理性质的改良作用明显,相同土层深度,土壤容重为草本群落阶段＞灌丛灌木阶段＞乔林阶段,孔隙度为乔林阶段＞灌丛灌木阶段＞草本群落阶段;土壤自然含水量呈规律性变化:乔林阶段和灌丛阶段自然含水量与草坡阶段之比,0～15cm土层中分别是1.39和1.07,15～30cm土层中分别是1.30、1.04;土壤蓄水能力提高,非毛管持水率为乔林阶段＞灌丛阶段＞草坡阶段;土壤保土能力提高,相同土层深度、相同时段内,土粒的崩解速度为草坡阶段＞灌丛阶段＞乔林阶段.因此,退化植被恢复可显著提高其蓄水保土功能.

By the investigation way of time replacement by space , In degraded Karst vegetation area of the middle area of Guizhou province, the typical plots in different vegetation restoration stages were selected , and the water flow fields were built ,in which could be taken field research. A series of indexes on soil physical properties amelioration, soil water content property and erosion-resistant were tested and analyzed . The result showed that the impact for vegetation to ameliorate soil physical properties was evidence. Soil volume weight was as follows as herbaceous stage> scrub-shrub and shrub-tree stage> forest stage. Soil porosity was forest stage> scrub-shrub and shrub-tree stage> herbaceous stage; Soil natural moisture became disciplinarian changes: In 0~15cm layer, the ratio between forest stage and herbaceous stage was 1.39 , the ratio between scrub-shrub and shrub-tree stage and herbaceous stage was 1.07; In 0~15cm layer, the ratio was 1.30 and 1.04 respectively. Soil water conservation ability was improved. non-capillary water content was forest stage> scrub-shrub and shrub-tree stage> herbaceous stage; The ability of soil conservation was improved too. In the same layer and period, soil collapse velocity was herbaceous stage> scrub-shrub and shrub-tree stage> forest stage. Therefore, with the restoration process of the degraded vegetation , the water and soil conservation function was obviously improved