紫色丘陵区坡坎生态系统资源组合特征

Ecological Condition Features of Terrace Slope Ecosystem in the Purple Hilly Area

为有效保护和合理开发紫色丘陵区坡坎生态系统,该文采用典型调查法对坡坎生态系统的光热、水土与植被等生境条件予以调查分析,综合评价其资源组合特征。结果表明紫色丘陵区不同地形部位的坡坎生态系统,其小气候、土壤及植被等资源特征不同。逆倾陡坡坡坎生态系统土壤理化性状较差,雨后径流水分易于泄去,植被类型较为单一;顺倾缓坡坡坎生态系统土壤养分含量高,雨后径流入渗快而易于保蓄,光热资源利用充分,对农田生态系统具有较好的温湿调节作用,植被组合结构完整,类型丰富;梯地边坡与田边地埂坡坎生态系统,受人为耕作影响大,土壤养分含量较高,能得到梯地、稻田连续的水分供应,可利用的光热资源充足,覆地植物种类多,鲜生物量大。

Terrace slope, referring to the side slope of terraces and the ridge of paddyfield, is one type of land resources in the Sichuan Basin of China that has favorable sunlight and heat but has a limited amount of water and soil. This paper investigated and evaluated the ecological condition features of the terrace slope ecosystem in the purple hill area by the method of typical investigation. Four typical terrace slope ecosystems derived from Peng Lai Zhen formation were selected and a comprehensive evaluation is provided: 1) the first one terrace slope ecosystem about 11.4 m in height represented a steep terrace slope with more dry and less side leached water supply; 2) the second one about 16.1 m in height represented a gentle terrace slope with side leached water supply and good cypress canopy; 3) the third one about 2.6 m in height represented a side slope of the dry land; 4) the fourth one only 1.8 m in height located at a lower site near the paddyfield. The results showed that the steep terrace slope ecosystem with less side leached water supply possessed the relatively inferior conditions including single plant cover and less soil fertility, especially when it was exploited runoff water losing and soil erosion were the shortcomings. On the other hand, the gentle terrace slope ecosystem, the side slope ecosystem of the paddyfield and the dry land with side leached water supply, possessed the favorable conditions to develop, including good sunlight and heat, plentiful plant cover, a certain amount of water and soil fertility to supply. Many useful techniques such as mulch and contour planting may be selected to improve terrace slope ecosystem conditions. It is worth studying how to comprehensively evaluate the terrace slope ecosystem and introduce new species of cash plant with conservation effects to utilize the terrace slope ecosystem.