江汉平原杨树林下土壤酶及微生物的年动态变化

Annual Dynamic Changes of Soil Enzyme and Microorganism under Poplars Forests in Jianghan Plain

在江汉平原选择有代表性的5-6龄的杨树林林地11块,并以林外土壤为参照,研究林下土壤酶（蔗糖酶、脲酶、蛋白酶、中性磷酸酶、过氧化氢酶、多酚氧化酶）活性和3大类微生物（真菌、细菌、放线菌）数量的年度动态变化。结果表明,林内与林外土壤酶及微生物的时间变化格局基本一致,林内土壤不同微生物数量和酶活性的变化反映了杨树凋落物数量变化的年节律性;在3个不同月份中,林下土壤大多数肥力特征指标均高于林外;从一年的观察数据来看,栽培杨树可在一定程度上提高林地土壤肥力,不会导致林下土壤肥力的恶化;在微碱性土壤上杨树对土壤肥力的正面作用比酸性土壤更好。

This paper studied the annual dynamic change of soil enzyme characters on 5 or 6-year-old poplars forests at 11 sites of Jianghan Plain,comparing with the neighbor fields outside of the forests.The soil enzyme characters included invertase,urease,protease,phosphatase,catalase,and polyphenol oxidase activity,and fungi,bacterium,and actinomycete number per gram soil.Field investigation and experimental results showed that the time change patterns of the soil enzyme and microorganism characters of inside and outside of poplar forest were similar.The number changes of different microorganisms and the enzyme activity changes of different soil reflected the annual rhythm of litter quantity under poplars forest.The majority of soil fertility characters of poplar forest were always higher than the soils outside of forest in three seasons.These result showed that poplar planting could improve soil fertility and would not make negative effect on next agricultural corps.Poplar grew better on alkalescent soil rather than on acid soil.