Soil-atmospheric exchange of CO2, CH4, and N2O in three subtropical forest ecosystems in southern China
Soil-atmospheric exchange of CO2, CH4, and N2O in three subtropical forest ecosystems in southern China
复制标题
中国南方三个亚热带森林生态系统土壤-大气CO2、CH4和N2O交换
DOI：
10.1111/j.1365-2486.2006.01109.x
复制
发表时间：
2006-03-01
影响因子：
11.6
通讯作者：
Zhou, CY
中科院分区：
文献类型：
--
作者：
Tang, XL;Liu, SG;Zhou, CY
北回归线附近森林中土壤-大气温室气体(以下简称温室气体)交换的大小、时间和空间模式仍然高度不确定。为了改进实际估算，对中国南部鼎湖山自然保护区三个演替阶段的亚热带森林的土壤-大气CO2、CH4和N2O通量进行了测量。DNR林地土壤表现为N2O源和CH4汇。年平均CO2、N2O和CH4通量分别为7.7+/-4.6 mg CO2-C ha(-1)yr(-1)、3.2+/-1.2 kg N2O-N ha(-1)yr(-1)和3.4+/-0.9 kg CH4-C ha(-1)yr(-1)。2003年4月至9月(湿热季节)气候温暖潮湿，2003年10月至2004年3月(凉干季节)气候变得凉爽干燥。土壤CO2排放的季节性与季节气候格局一致，湿热季节CO2排放速率高，凉干季节CO2排放速率低。相反，CH4和N2O通量的季节格局不明显，尽管CH4吸收速率在凉干季节较高，N2O排放速率通常在湿热季节较高。在这三个地点测得的温室气体通量随演替的进行有明显的增加趋势。如果这一趋势在区域尺度上具有代表性，根据预测的林龄结构变化，未来中国南部的CO2、N2O排放和CH4吸收可能会增加。清除地表凋落物使三种森林的土壤CO2排放减少了17-44%，但对CH4吸收和N2O排放没有显着影响。这表明微生物对CH4的吸收和N2O的产生主要与矿质土壤有关，而不是在表层凋落物中。
The magnitude, temporal, and spatial patterns of soil-atmospheric greenhouse gas (hereafter referred to as GHG) exchanges in forests near the Tropic of Cancer are still highly uncertain. To contribute towards an improvement of actual estimates, soil-atmospheric CO2, CH4, and N2O fluxes were measured in three successional subtropical forests at the Dinghushan Nature Reserve (hereafter referred to as DNR) in southern China. Soils in DNR forests behaved as N2O sources and CH4 sinks. Annual mean CO2, N2O, and CH4 fluxes (mean +/- SD) were 7.7 +/- 4.6 Mg CO2-C ha(-1) yr(-1), 3.2 +/- 1.2 kg N2O-N ha(-1) yr(-1), and 3.4 +/- 0.9 kg CH4-C ha(-1) yr(-1), respectively. The climate was warm and wet from April through September 2003 (the hot-humid season) and became cool and dry from October 2003 through March 2004 (the cool-dry season). The seasonality of soil CO2 emission coincided with the seasonal climate pattern, with high CO2 emission rates in the hot-humid season and low rates in the cool-dry season. In contrast, seasonal patterns of CH4 and N2O fluxes were not clear, although higher CH4 uptake rates were often observed in the cool-dry season and higher N2O emission rates were often observed in the hot-humid season. GHG fluxes measured at these three sites showed a clear increasing trend with the progressive succession. If this trend is representative at the regional scale, CO2 and N2O emissions and CH4 uptake in southern China may increase in the future in light of the projected change in forest age structure. Removal of surface litter reduced soil CO2 effluxes by 17-44% in the three forests but had no significant effect on CH4 absorption and N2O emission rates. This suggests that microbial CH4 uptake and N2O production was mainly related to the mineral soil rather than in the surface litter layer.