下辽河平原杨树连栽对土壤养分、微生物生物量和酶活性的影响  

Effects of continuous planting poplar on the soil nutrient contents,microbial biomass,and enzyme activities in lower reaches of Liaohe River Plain,Northeast China

作　　者：蔡立佳[1,2] 徐永刚[1] 宇万太[1] 胡宝柱 吴亚西 

机构地区：[1]中国科学院沈阳应用生态研究所,沈阳110016 [2]中国科学院大学,北京100049 [3]新民市机械林场,辽宁新民110300

出　　处：《生态学杂志》2013年第2期337-343,共7页Chinese Journal of Ecology

基　　金：国家自然科学基金项目(31100465和31070547);国家科技部支撑计划项目(2012BAD05B01)资助

摘　　要：以下辽河平原地区农田和不同退耕年限杨树林(一代10年生林,二代6年生林,二代15年生林)为对象,开展了退耕还林对土壤养分含量、微生物生物量和酶活性的研究。结果表明:1)土壤退耕还林后,除pH表现出一直上升趋势外,大部分养分含量和微生物生物量均在退耕初期表现出下降趋势,但随着退耕年限延长又逐渐恢复并呈现升高趋势。2)土壤基础呼吸和土壤过氧化氢酶活性均表现为林地显著大于农田水平,而磷酸酶和脲酶表现出相反趋势;3)垂直方向上,除了pH表现为表层低于下层外,其他大部分指标均为表层高于下层。结果表明,退耕还林初期,土壤肥力呈下降态势,但随着退耕年限的延长有恢复的趋势。该研究可为中国东北地区退耕还林工程提供参考。Taking the farmland and the poplar （Populus x liaoningensis） plantation stands with different successive rotation durations （the first rotation of ten-year-old, the second rotation of six-year-old, and the second rotation of fifteen-year-old） in Jixie Forest Farm in Xinmin City, Liaoning of Northeast China as test objects, an investigation was made on the soil nutrient con- tents, microbial biomass, and enzyme activities, aimed to evaluate the effects of returning farm- land to forestland on the soil chemical and biological properties. After returning farmland to for- estland, and with the increasing stand age and successive rotation duration, the soil pH presented an increasing trend, whereas the soil nutrient contents and microbial biomass increased after an initial decrease. The soil basal respiration and catalase activity were significantly higher in poplar stands than in farmland, whereas the soil urease and neutral phosphatase activities were in oppo- site trend. The soil fertility indices except pH all decreased with increasing soil depth. All the results indicated that the soil fertility tended to be declined at the early stage of afforestation, but gradually increased with the increasing stand age and successive rotation duration. These findings could offer references for the returning farmland to forestland in Northeast China.

关 键 词：退耕还林 养分含量 酶活性 杨树林 

分 类 号：S714[农业科学—林学]