文档介绍：分类号 学校代码 10129
U D C 504 学号 2010204032
不同载畜率对荒漠草原春季冻融时期温室气体通量的影响
Effect of Stocking Rate on Greenhouse Gas Flux during Spring
Freeze-Thaw Cycles in a Desert Steppe
申请人:唐士明
学科门类:农学
学科专业:草业科学
研究方向:草地资源管理与生态
指导教师:王成杰教授
论文提交日期:二〇一三年六月
摘要
本试验于 2010 年和 2011 年春季冻融时期在内蒙古四子王旗短花针茅荒漠草原进
行,主要研究不同放牧强度处理下土壤-大气甲烷(CH4)和二氧化碳(CO2)通量的变
化,了解荒漠草原生态系统对全球气候变化的响应机制,为全球变化与土壤温室气体
排放/吸收提供理论依据。试验处理分为不放牧(UG),轻度(LG),中度(MG),
重度(HG)四种方式,采用随机区组设计,每个处理三个重复,共 12 个试验小区。
研究结果如下:
-大气 CH4 的吸收和 CO2 的排放(P<)。
-大气 CH4 的吸收和 CO2 的排放(P<)。土
壤-大气 CH4 的吸收和 CO2 的排放在不放牧和轻度放牧区没有显著性差异(P>),
但重度放牧显著的降低了土壤对 CH4 的吸收,增大了对 CO2 的释放。
-大气 CH4 的吸收和 CO2 的排放与土壤温度(5 cm)呈正相关。CH4 吸
收与土壤湿度(5 cm)呈负相关;CO2 的排放与土壤湿度没有显著关系。
关键词: 荒漠草原;载畜率;甲烷;二氧化碳;春季冻融
Effect of Stocking Rate on Greenhouse Gas Flux during Spring
Freeze-Thaw Cycles in a Desert Steppe
Abstract
The experiment was conducted at twelve grazing plots denoting four treatments defined
along a grazing gradient with three replications: non-grazing (0 sheep/ha, NG), light
grazing ( sheep/ha, LG), moderate grazing ( sheep/ha, MG) and heavy grazing
( sheep/ha, HG). Using an automatic cavity ring-down spectrophotometer, we
measured CH4 fluxes from March 1 to April 29 in 2010 and March 2 to April 27 in 2011.
The results were shown as follows:
CH4 uptake activity is affected by freeze-thaw cycles and stocking rates. CH4 uptake is
correlated with the moisture content and temperature of soil. MG and HG decreases CH4
uptake while LG exerts a considerable positive impact on CH4 uptake during spring
freeze-thaw cycles in the northern desert steppe in China.
The freezing-thawing induced emissions of CO2 were more significant in UG in this
study. Grazing decreased total CO2 emission during the freezing-thawing period. Soil CO2
efflux of among all areas correlated strongly with soil temperature. No correlation between
CO2 fluxes and so