蒙古栎林生态系统的水分循环与养分循环关系

STUDY ON RELATION BETWEEN WATER CYCLING AND NUTRIENT CYCLING IN OAK FOREST ECOSYS- TEM.

本文从群体水平上研究了蒙古栎林生态系统中的水分循环与养分循环的关系。结果表明,降雨是系统养分的重要输入。降雨对林冠的淋洗淋溶作用有助于养分的归还及缩短养分循环的途径。蒙古栎树干茎流量大,且其中含有的养分元素较多,从而使蒙古栎的根系能获得更多的水分与养分,有助于适应干旱、瘠薄的立地环境。径流是系统的水分输出,也是养分输出。蒙古栎林的下渗流约占整个径流的90％,且养分元素含量较低,从而有助于养分的积累。降雨在蒙古栎林内的分配格局不一,导致系统养分积累的明显差异。本文还探讨了干扰对养分循环与水分循环的影响。结果表明,采伐森林导致水分分配的变化,也使系统的养分发生亏损。只有把养分循环与水分循环结合起来,才能较完整地评价森林的生态功能。

The relation between water cycling and nutrient cycling was studied from, community level in the oak forest. The results showed that rainfall is a very important input of nutrient to ecosystem and the washing-leaching processes of canopy are very helpful for the return of nutrient to soil and shorting the route of nutrient cycling. As nutrient enriched stemflow is large in oak forest, the roots of oak can obtain lot of nutrient and water. This helps oak to adaptdry and meager soil. Runoff is an important output of nutrients and water to e-cosystem. Because infiltration flow with low nutrient content accounts for 90% of total runoff, nutrient can be accumulated. As rainfall passes through ecosystem. its distribution pattern is varied, which causes the difference of nutrient accumulation. The effects of human interference on nutrient cycling and water cycling were also studied. It shows that clear-cuting can cause hydrological changes and loss of nutrient. In order to estimate well the ecological function of forest, it is very necessary to combine water cycling with nutrient cyclung.