Controls on soil carbon dioxide and methane fluxes in a variety of taiga forest stands in interior Alaska
Controls on soil carbon dioxide and methane fluxes in a variety of taiga forest stands in interior Alaska
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DOI：
10.1007/s100210000025
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发表时间：
2000-05-01
期刊：
影响因子：
3.7
通讯作者：
Schimel, JP
中科院分区：
文献类型：
--
作者：
Gulledge, J;Schimel, JP
CO2和CH 2通量进行了监测，超过4年，在一系列的针叶林沿着塔纳纳河在阿拉斯加内陆。洪泛平原桤木和白色云杉网站和高地桦树/白杨和白色云杉网站进行了检查。每个站点都有控制，施肥，木屑修正地块;通量测量开始在第二个治疗年。CO2排放量随演替年龄的网站（桤木，桦树/白杨，和白色云杉，顺序继承），无论景观位置。虽然CO2通量与土壤温度呈指数关系，但CO2产量对水分的响应符合渐近模型。操作，只有氮肥对CO2通量的影响，减少在河漫滩的网站，但增加它在桦树/白杨网站的通量。景观位置是CH 4通量的最佳预测因子。两个高地站点以相似的速率消耗CH 4（约0.5 mg Cm（-2）d（-1）），而洪泛平原站点的消耗速率较低（0-0.3 mg Cm（-2）d（-1））。N施肥和锯末都抑制CH 4消耗在高地桦树/白杨和漫滩云杉网站，但不是在高地云杉网站。驱动CO2通量的生物过程是敏感的温度，湿度和植被，而CH 4通量主要是敏感的景观位置和生态地球化学扰动。因此，气候变化对针叶林土壤碳气体通量的影响将取决于土壤温度和湿度之间的关系，以及随之而来的土壤养分库和循环的变化。
CO2 and CH2 fluxes were monitored over 4 years in a range of taiga forests along the Tanana River in interior Alaska. Floodplain alder and white spruce sites and upland birch/aspen and white spruce sites were examined. Each site had control, fertilized, and sawdust amended plots; flux measurements began during the second treatment year. CO2 emissions decreased with successional age across the sites (alder, birch/aspen, and white spruce, in order of succession) regardless of landscape position. Although CO2 fluxes showed an exponential relationship with soil temperature, the response of CO2 production to moisture fit an asymptotic model. Of the manipulations, only N fertilization had an effect on CO2 flux, decreasing flux in the floodplain sites but increasing it in the birch/aspen site. Landscape position was the best predictor of CH4 flux The two upland sites consumed CH4 at similar rates (approximately 0.5 mg C m(-2) d(-1)), whereas the floodplain sites had lower consumption rates (0-0.3 mg C m(-2) d(-1)). N fertilization and sawdust both inhibited CH4 consumption in the upland birch/aspen and floodplain spruce sites but not in the upland spruce site. The biological processes driving CO2 fluxes were sensitive to temperature, moisture, and vegetation, whereas CH4 fluxes were sensitive primarily to landscape position and biogeochemical disturbances. Hence, climate change effects on C-gas flux in taiga forest soils will depend on the relationship between soil temperature and moisture and the concomitant changes in soil nutrient pools and cycles.