云锦杜鹃林根际微生物及其生化特性的研究

通过对不同林型云锦杜鹃根际土壤和非根际土的养分状况、微生物区系、生化作用强度和酶活性等研究 ,结果显示 ,土壤细菌功能群与土壤养分和土壤酶活性有密切的联系 ,在光照和通气条件好的归云洞种群 ,云锦杜鹃的根际效应明显。在黄经洞和永字亭种群 ,由于植被盖度高 ,土壤空隙度低 ,土壤接触酶和过氧化物酶活性低 ,根际对土壤毒素转化能力弱及土壤腐殖质化过程缓慢 ;加上真菌和放线菌数量多 ,指示了土壤性质的恶化。因此 ,修剪上层树种和清理箬竹等可以阻止云锦杜鹃的衰退

SOIL MICROBES AND BIOCHEMISTRY OF RHIZOSPHERIC AND NON-RHIZOSPHERIC SOIL IN RHODODENDRON FORTUNEI FOREST IN TIANTAI MOUNTAINS

Soil nutrient status, microflora and their biochemical activities and enzyme activity in the rhizospheric soil and non-rhizospheric soil under Rhododendron fortunei in 3 different types of forests were investigated. The results showed that the number of soil bacteria functional colonies were closely related to soil nutrients and soil enzyme activities. Under good sunlight and aeration , the rhizospheric effect was significant in the Guiyundong Rhododendron fortunei community (R/S value) as compared with that of the other two. However, because of high vegetation coverage and low soil porosity, the activities of catalase and peroxidase were low, the soil capacity of transforming toxin was weak and the process of humification was slow in rhizosphere of the Rhododendron fortunei communities in Huangjingdong and Yongziting. Besides the populations of fungi and actinomyces in the soil increased significantly. These are clear indicators of degradation of the soil properties. All the results indicate that degeneration of Rhododendron fortunei could be prevented by pruning canopies of the surroundings arboreal trees and cleaning out Indocalamus latifolius.