【摘要】 结合青藏高原地区黑土滩型退化高寒草甸改建成人工草地后恢复过程中植物群落组分的数量特征变化,基于中心差分法、相对误差热图、ODE算法等研究方法进行计算机模拟,对Lotka-Volterra种间竞争模型进行非线性化改进,建立了适于高寒草地人工恢复演替过程中的竞争效应预测模型,与经典的Lotka-Volterra种间竞争模型进行对比验证,实证了改进模型的可解性和准确性。并分析了改进的Lotka-Volterra模型的系统动力学行为,预测人工恢复植物群落各组分的竞争结局,判断人工草地恢复演替状况。结果表明:(1)随着恢复年限的增加,栽培植物(垂穗披碱草或草地早熟禾)与原生植物在经历一个激烈的竞争阶段后逐渐趋于动态平衡,表明人工种植的垂穗披碱草、草地早熟禾等本土植物,可以促进青藏高原地区"黑土滩"型退化高寒草甸的有效恢复;(2)综合各分组的恢复演替阶段特征,可食牧草、栽培植物和顶极植物均从第7年开始竞争力呈现明显下降的趋势,因此建议在对人工草地的恢复管理中,7—10年间进行适度的人为干预,如施肥、灭鼠害以及适当去除有毒有害杂草等;(3)综合各类植物的竞争演替预测情况,均从第20年左右开始逐渐趋于动态平衡。因此,根据该模型分析,从生态恢复的角度来看,"黑土滩"型退化草地进行人工恢复至少需要20年以上,才能获得较为稳定的植物群落。更多还原

【Abstract】 Combining the quantitative characteristic changes of plant community components in the restoration process of the "black soil patch" degraded alpine meadow in the Qinghai-Tibet Plateau after being converted into artificial grassland, computer simulations based on methods, such as the central difference method, relative error thermography, and ODE algorithm were conducted. A prediction model of competitive effects suitable for alpine meadow restoration succession was established through the nonlinear improvement of the Lotka-Volterra interspecific competition model. The model was compared with the classical Lotka-Volterra interspecific competition model, and the solvability and accuracy of the improved model were demonstrated. Furthermore, the dynamic behavior of the improved Lotka-Volterra model system was analyzed, the competitive outcome of the plant community components in the artificial restoration was predicted, and the restoration succession of the artificial grassland was judged. The results showed that:(1) With the increasing length of vegetation recovery, cultivated plants(Elymus nutans or Poa pratensis) and original plants will gradually tend to be dynamically balanced after undergoing a fierce competition phase. Accordingly, cultivated plants —— Elymus nutans or Poa pratensis can promote the effective restoration of the "black soil patch" degraded alpine meadow in the Qinghai-Tibet Plateau;(2) Synthesizing the characteristics of the restoration succession stage of each group, the competitiveness of edible forage, cultivated plants, and climax plants all showed an obvious downward trend since the 7 th year. In the restoration management of the artificial grassland, we recommend that moderate human interventions, such as fertilization, rodent control, poisonous and harmful weed removal be carried out in the next 7—10 years;(3) Analyzing the prediction results on competition succession of each group synthetically, all of tend to be dynamically balanced from the 20 th year. Consequently, according to the model, from the perspective of ecological restoration, it will take at least 20 years for the artificial restoration of the "black soil patch" degraded grassland to obtain a relatively stable plant community.更多还原