杨槐混交林生长及土壤酶与肥力的相互关系

以黄河三角洲滨海盐碱区１０年生杨树刺槐混交试验林为对象，着重研究了泰青杨刺槐混交林与相应纯林的生长状况、林分土壤养分指标和酶活性的差异，以及土壤养分与酶活性两类因子间的相关性。结果表明：①混交林中的杨树生长优于杨树纯林，总蓄积量大于杨树纯林。②混交林土壤各层次的ｐＨ值均低于纯林，而有机质等主要养分指标含量大多高于纯林。③混交林土壤微生物总量和脲酶等主要酶的活性普遍高于纯林。④多数养分指标与酶活性间的相关关系均达显著水平，研究从一个侧面揭示了杨树刺槐混交造林速生丰产的机理。

Research on Relations Between Growth Effect and Soil Enzyme Activities and Soil Nutrient Factors in Mixed Poplar and Black Locust Plantations

The paper took a 10-year-old mixed experimental plantation of poplar andblack locust in coastal saline-alkai area of the Yellow River Delta as an object of study,dis-cussed the differences of individual tree and stand’s growth,the differences of soil nutrientindexes and enzyme activities between the mixed and pure stands of Populus×xiaozhuanicaw.Y. Hsu et Liang cv.‘Balizhuangyang’and Robinia pseudoacacia,and the relationship be-tween the nutrient and enzymes. Results showed that:①Poplar in mixed stands grew betterthan those in pure poplar stands; total stocks of both types of mixed stands were larger thanthose of pure poplar stands. ②pH value of each layer of the soil profiles in mixed stands wasgenerally lower than the corresponding one in pure stands, whereas the concentrations of or-ganic matter and other nutrient indexes were higher in mixed stands. ③Soil microbialbiomass, urease and several other enzyme activities were significantly correlated with soil nu-trient indexes and among themselves,These conclusions may help partially interpret themechanism that mixed poplar locust plantations usually grows better than pure poplarstands.