论文部分内容阅读
采用野外监测方法,研究了鄂东南低丘地区主要森林类型枫香林和马尾松林土壤异养呼吸、土壤温湿度的年动态;并通过室内试验研究了土壤呼吸随土壤深度的变化以及表层土壤(0～5 cm)异养呼吸的温湿度敏感性,建立了表层土壤异养呼吸的温湿度响应模型,探讨全球温暖化对该区土壤异养呼吸的潜在影响.结果表明:枫香林和马尾松林0～5 cm土壤呼吸速率分别是5～10 cm、10～15 cm层的2.39、2.62倍和2.01、2.94倍,说明土壤异养呼吸主要发生在土壤表层(0～5 cm);枫香林和马尾松林0～5 cm、5～10 cm及10～15 cm土壤的Q10分别是2.10、1.86、1.78和1.86、1.77、1.44;枫香林和马尾松林表层土壤呼吸对温度(T)的响应符合指数模型[R=αexp(βT)],对湿度(W)的响应符合二次函数模型(R=a+bW+cW2);0～5 cm土壤对温湿度双因子的响应符合lnR=a+bW+cW2+dT+eT2模型,且异养呼吸对湿度的响应具有温度依赖性,即在高温下敏感,低温下敏感性下降;应用表层土壤异养呼吸温湿度模型预测枫香林和马尾松林土壤异养呼吸年动态及总量,枫香林土壤异养呼吸量的模拟值比实测值略高,而马尾松林比较接近,说明该方法具有较好的应用价值.在全球温暖化的背景下,该地区马尾松林和枫香林的土壤呼吸会明显上升.
The field monitoring method was used to study the annual dynamics of soil heterotrophic respiration and soil temperature and humidity in the main forest types of Pinus hilly forest and Pinus massoniana in the hilly area of southeastern Hubei Province. The indoor soil respiration was studied with soil depth changes and the topsoil (0 ~ 5 cm) heterotrophic respiration, the establishment of a model of heterotrophical respiration of surface soil temperature and humidity response to explore the potential impact of global warming on soil heterotrophic respiration. The results showed that: Fenglin and Masson pine 0 The soil respiration rates of ~ 5 cm were 5 ~ 10 cm, 2.39 and 2.62 times and 2.01 and 2.94 times respectively in 10 ~ 15 cm layer, indicating that soil heterotrophic respiration mainly occurred in the soil surface (0 ~ 5 cm) The Q10 of 0-5 cm, 5-10 cm and 10-15 cm soil were 2.10, 1.86, 1.78 and 1.86, 1.77 and 1.44 respectively. The responses of surface soil respiration to temperature (T) in Pinus forest and Pinus massoniana forest conformed to exponential model [R = αexp (βT)]. The response to humidity (W) was in accordance with the quadratic function model (R = a + bW + cW2) cW2 + dT + eT2 model, and the response of heterotrophic respiration to humidity is temperature dependent, ie at Sensitive to temperature and decreased sensitivity at low temperature. Using surface temperature-hyperthermia model of heterotrophic respiration of soils to predict the annual dynamic of soil heterotrophic respiration and the total amount of soil respiration of Pinus massoniana and Pinus massoniana forest, the simulation values of soil heterotrophic respiration were slightly higher than the measured values , While the Pinus massoniana forest is closer, indicating that this method has a good application value.In the context of global warming, the soil respiration of Pinus massoniana and Maple Grove forest will obviously increase.