摘要
以黄土高原水蚀风蚀交错区神木县六道沟小流域为研究区,采用动态密闭气室法对植物生长季节(2007年5～10月)5种土地利用方式的土壤呼吸速率进行了测定,并结合水热因子,对不同土地利用方式间土壤呼吸速率的差异性以及其和温度、含水量之间的关系进行了分析。结果表明:5种土地利用类型土壤呼吸速率季节性变化均呈现单峰型曲线,与气温变化趋势一致,其7、8月份土壤呼吸速率均显著高于其它月份(P<0.05);生长季节土壤CO2平均释放速率顺序为:长芒草地>苜蓿地>柠条地>农地>沙柳地,草地在生长前期和旺盛期土壤呼吸强度均显著高于农地和灌木林地;除沙柳地和苜蓿地以外,在土壤呼吸与所有温度指标的关系中,与10cm深度的土壤温度相关性最好,且除沙柳地外,其它4种土地利用类型均与之达到显著相关;农地土壤呼吸对温度的响应最敏感(Q10值为2.20),除沙柳地(Q10值为1.48)外,其它4种土地利用类型Q10值均在2.0左右,接近于全球Q10的平均水平;通过Van’t Hoff模型估算,2007年植物整个生长季节(5～10月份),5种土地利用类型土壤呼吸量从高到低依次为:苜蓿地259gC·m-2,长芒草地236gC·m-2,柠条地226gC·m-2,农地170gC·m-2,沙柳地94gC·m-2;水分对农地和沙柳地的土壤呼吸影响不大;长芒草地、柠条地和苜蓿地土壤呼吸的双变量模型关系显著(P<0.05),比相应的单变量模型更好地解释了土壤呼吸变异。
Soil respiration rates under five land use patterns in the water-wind erosion crisscross region of the Loess Plateau were measured by the closed-chamber IRGA method during the growing season of 2007. Differences in soil respiration under the five land use patterns and the relationships between soil respiration and soil temperature and soil water contents were analyzed. The results showed that seasonal changes of soil respiration presented single peak curves, and that of air temperature followed a similar trend, which had the highest values in July and August. The order of average soil respiration rates under the land use types during the growing seasons was： bunge needlegrass land 〉 alfalfa land 〉 Korshinsk Peashrub land 〉 cropland 〉 sand willow land. The soil respiration rate of the grassland was significantly higher than that of the crop and shrub lands. Except for sand willow and alfalfa lands, soil respiration rates were better correlated with soil temperature at 10 cm depth than with other temperature indexes. According to Qxo values （temperature sensitive index）, soil respiration under cropland was the most sensitive to temperature （Q10 = 2.20） and Q10 of the other land use patterns, except for sand willow land, were around 2.0, which is close to the global average Q10 value. Estimating the soil respiration flux using the Van＇t Hoff model gave CO2 effluxes from alfalfa land, bunge needlegrass land, Korshinsk Peashrub land, crop land, and sand willow land, during the growth period, of 259 gC·m^-2 236 gC· m^-2 226 gC· m^-2, 170 gC· m^-2 and 94 gC·m^-2, respectively. Soil moisture did not significantly affect soil respiration under crop and sand willow lands. A two-variable （soil temperature and soil moisture） soil respiration mode/best explained the variance of soil respiration under alfalfa land, bunge needlegrass land, and Korshinsk Peashrub land.
出处
《生态学报》
CAS
CSCD
北大核心
2008年第11期5428-5436,共9页
Acta Ecologica Sinica
基金
国家自然科学基金资助项目(90502006,40601041)
中国科学院西部之光资助项目(2005YB01)~~
关键词
水蚀风蚀交错带
土壤呼吸速率
季节变化
土地利用
土壤温度
土壤含水量
water wind erosion crisscross region
soil respiration rate
seasonal changes
land use pattern
soil temperature
soil moisture
