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以北亚热带红壤丘陵区林地、茶园、菜地为对象,采用静态箱-气相色谱法,对3种土地利用方式下CH4通量进行了研究,同时测定了土壤温度、含水量和无机氮含量。旨在探索不同土地利用方式下CH4“源”和“汇”的功能,对评估不同土地利用方式对全球气候变化的贡献具有重要意义。结果表明,不同土地利用方式下土壤甲烷平均通量有显著差异,分别为:林地-15.44μg·m-2·h-1,茶园-1.49μg·m-2·h-1,菜地7.11μg·m-2·h-1;菜地土壤甲烷平均通量最高,茶园其次,林地最低,CH4年累积通量分别为0.52、-0.31和-1.46 kg·hm-2,菜地土壤以排放CH4为主,而茶园和林地土壤是CH4的汇。茶园和菜地土壤CH4通量呈一定的季节性变化,春、秋季CH4通量较高。林地CH4吸收通量与土壤湿度呈显著的负相关关系(P<0.05),且当土壤湿度(WFPS)高于70%时,林地土壤才以排放CH4为主;而茶园和菜地土壤CH4吸收通量与土壤含水量无显著相关关系。土壤CH4通量与土壤温度之间未呈显著的相关关系。不同土地利用方式下土壤CH4排放通量与铵态氮含量呈显著的负相关关系(P<0.05),而与硝态氮含量未呈显著的相关性。
In the northern subtropical hilly red soil region, the woodland, tea plantations and vegetable fields were studied. The CH4 flux under three land use patterns was studied by static box-gas chromatography. The soil temperature, water content and inorganic nitrogen content were also determined. The aim is to explore the function of CH4 “source ” and “sink ” under different land use patterns, which is of great significance for assessing the contribution of different land use patterns to global climate change. The results showed that there were significant differences in average methane fluxes under different land use types, which were: -15.44μg · m-2 · h-1 in forest land, -1.49μg · m-2 · h-1 in tea plantation, 7.11μg · M-2 · h-1. The average flux of methane in vegetable soil was the highest, followed by tea plantation and the lowest in forest land. The annual cumulative CH4 flux was 0.52, -0.31 and -1.46 kg · hm-2, Dominated, while tea plantations and woodland soil is a sink of CH4. The fluxes of CH4 in tea plantation and vegetable field showed seasonal changes, and CH4 fluxes were higher in spring and autumn. There was a significant negative correlation between soil CH4 flux and soil moisture (P <0.05), and when soil moisture (WFPS) was higher than 70%, CH4 was the main emission in woodland; CH4 uptake in tea plantation and vegetable field There was no significant correlation between flux and soil water content. There was no significant correlation between soil CH4 flux and soil temperature. There was a significant negative correlation between soil CH4 flux and ammonium nitrogen (P <0.05) and no significant correlation with nitrate nitrogen content under different land use patterns.