摘要:为进一步探究林下植被和凋落物管理对我国寒温带森林生长季土壤CH₄通量的影响，采用静态箱-气相色谱法对大兴安岭北部4种林型（白桦林、山杨林、樟子松林和兴安落叶松林）4种处理（自然状态、去除凋落物、去除林下植被以及去除林下植被和凋落物）的土壤CH₄通量排放特征进行观测研究。结果表明：该地区森林生长季土壤均表现为CH₄的汇，4种林型不同处理后土壤CH₄通量表现为单峰变化趋势，吸收峰值出现在7月或8月。自然状态4种林型土壤CH₄平均吸收通量表现为白桦林（-79.23±14.92）μg m^-2 h^-1>山杨林（-64.27±9.60）μg m^-2 h^-1>樟子松林（-62.54±15.48）μg m^-2 h^-1>兴安落叶松林（-48.73±12.26）μg m^-2 h^-1，兴安落叶松土壤CH₄平均吸收通量显著小于其他三种林型（P<0.05）。相比于自然状态，4种林型在去除凋落物后土壤CH₄吸收通量提高了2.12%-12.15%，但变化幅度均没有达到显著水平（P>0.05）。去除林下植被后4种林型CH₄吸收通量提高了0.84%-20.55%，且只有山杨林吸收增加达到显著水平（P<0.05）。同时去除林下植被和凋落物后，对白桦林和樟子松土壤CH₄通量影响不显著（P>0.05），但对山杨林和兴安落叶松林影响显著（P<0.05）。总之，去除凋落物或林下植被均会提高土壤对CH₄吸收，去除林下植被对土壤CH₄通量的影响要大于去除凋落物的影响，但不同林型不同处理之间还存在差异。



Abstract:In order to explore the impacts of understory vegetation and litter management on soil CH₄ flux of cold temperate zone forest during the growth season, the characteristics of soil CH₄ flux emission under different treatments were analyzed and studied, which provides a scientific basis and theoretical reference for the management of the forest ecosystem in the Greater Xing'an Mountains in China. The static chamber-gas chromatography was used to analyze the characteristics of soil CH₄ flux emission in four forest types (Betula platyphylla forest, Populus davidiana forest, Pinus sylvestris var. mongolica forest, and Larix gmelini forest) with 4 kinds of treatments (natural state, removal of litter, removal of understory vegetation, and removal of understory vegetation and litter). The results showed that the soil of the four forest types all appeared as CH₄ sinks in this area during growth season. The soil methane showed a single-peak change trend in the four forest types with different treatments, and the absorption peak appeared in July and August. In the natural state, the average soil CH₄ absorption flux of the four forest types showed the trend of Betula platyphylla forest (-79.23±14.92) μg m^-2 h^-1> Populus davidiana forest (-64.27±9.60) μg m^-2 h^-1> Pinus sylvestris var. mongolica forest (-62.54±15.48) μg m^-2 h^-1> Larix gmelini forest (-48.73±12.26) μg m^-2 h^-1. The average absorption flux of soil CH₄ in Larix gmelini forest was significantly smaller than the other three forest types (P<0.05). Compared with the natural state, the soil CH₄ absorption flux increased by 2.12%-12.15% after the removal of litter in the four forest types, but the change range did not reach a significant level (P>0.05). After removing the understory vegetation, the CH₄ absorption flux of the four forest types increased by 0.84%-20.55%, of which only the Populus davidiana forest showed a significant (P<0.05) increase in the soil CH₄ absorption flux. The removal of understory vegetation and litter had no significant effects on the soil CH₄ flux of Betula platyphylla forest and Pinus sylvestris var. mongolica forest (P>0.05), but had significant effects on Populus davidiana forest and Larix gmelini forest (P<0.05). In short, the removal of litter and understory vegetation both increased the soil's absorption of CH₄. The removal of understory vegetation had a greater impact on soil CH₄ flux than the removal of litter, but there were still differences between different forest types and different treatments. Therefore, a scientific and reasonable forest management method is the prerequisite for regulating the absorption of CH₄ by forest soil in this area and the ecological environment protection.





PDF全文下载地址:

https://www.ecologica.cn/stxb/article/pdf/stxb202012203232