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根据海南儋州地区不同树龄PR107无性系橡胶人工林生态系统养分循环规律,应用系统动力学原理,构建了土壤、胶树和凋落物层3个分室之间的养分循环分室模型及其微分方程组,并测定了各分室中氮素(N)现存量、流通量和流通率。结果表明:1)土壤、胶树、凋落物层中氮素现存量的平均值分别为3069.61kg/(hm2.a),580.22 kg/(hm2.a),62.94 kg/(hm2.a),随着树龄的增加(4~24a),土壤中氮素现存量变化为先减少后增加,胶树、凋落物中氮素贮存量则呈逐年增加的趋势;2)土壤、胶树、凋落物分室之间氮素流通量变化规律为吸收量、归还量、分解量都随树龄增加而逐渐增大,而胶乳中氮素流失量在24a有所下降;3)氮素在土壤、胶树与凋落物层各分室之间的流通率大小各不相同,4~24a胶树的吸收系数为0.0640~0.1588,并随树龄增加呈指数递增的趋势,归还系数、分解系数、流失系数的平均值分别为0.1335,0.6621,0.0279。此外,本文所建分室模型可以实现对橡胶林生态系统养分动态的精确模拟和预测,并可望用于指导人工施肥。
According to the nutrient cycling rules of ecosystem of PR107 clonal plantations with different ages in Pizhou district, Hainan, the nutrient cycling compartment model and its differential equations between soil, gum tree and litter layer were established based on the principles of system dynamics. , And measured the nitrogen (N) in each compartment of the existing stock, liquidity and circulation rate. The results showed as follows: 1) The average nitrogen contents of soil, gum tree and litter layer were 3069.61kg / (hm2.a), 580.22kg / (hm2.a), 62.94kg / (hm2.a) With the increase of tree age (4 ~ 24 years), the change of nitrogen in the soil decreased first and then increased, while the storage of nitrogen in plastic tree and litter increased year by year; 2) The soil, gum tree, litter The variation of nitrogen fluxes in different compartments was the absorption, the return and the amount of decomposition increased with the increase of tree age, while the amount of nitrogen loss in latex decreased at 24a. 3) The litter circulation rate varied from room to room, and the absorption coefficient of 4 ~ 24a gum tree was 0.0640 ~ 0.1588 and increased exponentially with the increase of tree age. The average of the return coefficient, decomposition factor and loss coefficient were 0.1335, 0.6621, 0.0279. In addition, the compartment model built in this paper can accurately simulate and predict the nutrient dynamics of the rubber plantation ecosystem, and is expected to be used to guide the artificial fertilization.