北京东灵山两种温带森林根际和非根际土壤酶活性、温度敏感性及矢量特征的季节动态

以北京东灵山两种主要植被类型——白桦(Betula platyphylla)林和辽东栎(Quercus wutaishanica)林土壤为研究对象, 于2017年春季(5 月)、夏季(7 月)、秋季(9 月)和冬季(12 月)分别采集根际与非根际土壤, 测定土壤理化性质、微生物生物量、植物根叶功能性状、3种水解酶(BG, NAG 和 AP)及两种氧化酶(POX和PER)的活性及其温度敏感性和矢量特征。结果表明, 白桦林和辽东栎林土壤胞外酶活性、温度敏感性和矢量角度均存在显著的季节变化趋势, 且水解酶活性及温度敏感性的变化趋势与氧化酶相反; 根际土壤与非根际土壤中胞外酶活性、温度敏感性及矢量特征存在差异, 但季节变化趋势相同。温度是土壤胞外酶活性温度敏感性及矢量特征季节动态的重要驱动因素, 土壤 pH、土壤养分含量、植物叶片养分含量及细根生物量、细根密度对土壤胞外酶活性、温度敏感性及矢量特征有显著影响。

Seasonal Dynamics of Activities,Temperature Sensitivities and VectorCharacteristics of Extracellular Enzymes in Rhizosphere and Bulk Soils of Two Temperate Forests in Mt. Dongling,Beijing

Taking Betula platyphylla forest and Quercus wutaishanica forest, two main vegetation types in Mt. Dongling, Beijing as study object, we sampled paired rhizosphere and bulk soils in spring (May), summer (July), autumn (September) and winter (December) in 2017, and measured soil physiochemical properties, microbial biomass, functional traits of plant leaves and fine roots, activities of three hydrolases (BG, NAG, AP) and two oxidases (POX, PER) as well as their temperature sensitivities and vector characteristics. The results showed that EEA, Q₁₀ and vector angle of soil in both forests had significant seasonal variation trends, and the seasonal variation trends of hydrolase activity and temperature sensitivity were opposite to those of oxidase. EEA, Q₁₀ and vector characteristics of rhizosphere soil and bulk soil were different, but their seasonal variation trends were similar. Temperature was an important driving factor of the seasonal dynamics of soil EEA, Q₁₀, and vector characteristics. Soil pH, soil nutrient content, leaf nutrient content, fine root biomass and fine root density showed significant effects on soil EEA, Q₁₀, and vector characteristics.