Land use and environmental factors influencing soil surface CO2 flux and microbial biomass in natural and managed ecosystems in southern Wisconsin
Land use and environmental factors influencing soil surface CO2 flux and microbial biomass in natural and managed ecosystems in southern Wisconsin
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DOI：
10.1016/s0038-0717(98)00041-8
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发表时间：
1998-10
影响因子：
9.7
通讯作者：
Rota Wagai;K. Brye;S. Gower;J. Norman;L. Bundy
中科院分区：
文献类型：
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作者：
Rota Wagai;K. Brye;S. Gower;J. Norman;L. Bundy
威斯康星州南部和美国中西部的许多原生草原已经被传统的耕作(凿犁)和免耕玉米农业生态系统所取代。然而，关于土地利用变化对生态系统结构和功能的影响的知识是不完整的。土壤表面CO2通量是碳从陆地生态系统向大气的主要转移，并且在不同植被类型之间差异很大。我们测量了耕作和免耕玉米农业生态系统和一个恢复的草原生态系统的土壤表层CO2通量和微生物生物量，考察了各种环境因素对这些生态系统土壤表层CO2通量的影响，并估算了自然生态系统和管理生态系统的土壤表层CO2通量。春季，草原和常规耕作玉米的土壤表层CO2通量显著大于免耕玉米，从7月到10月初，草原的土壤表层CO2通量显著大于耕作和免耕玉米，而在秋末和冬季，这三个生态系统的土壤表层CO2通量基本相同。3个生态系统的土壤表层CO2通量与10 cm土温呈正相关(R2=0.43~0.60，P<；0.001)，与土壤水分的相关性较弱。利用一个由10 cm土壤温度估算土壤表层CO2通量的经验模型，我们估算了耕作、免耕玉米和恢复草地生态系统的年土壤表层CO2通量分别为508和719(g cm−2y−1)，表明土地利用方式对土壤表层CO2通量有显著影响。
Many of the native prairies in southern Wisconsin, and the midwestern United States in general, have been replaced by conventional till (chisel plow) and no-tillage corn agroecosystems. However, knowledge of the influence of land use change on the structure and function of ecosystems is incomplete. Soil surface CO2flux is a major transfer of carbon from terrestrial ecosystems to the atmosphere and varies greatly among vegetation types. We measured soil surface CO2flux and microbial biomass in tilled and no-till corn agroecosystems and a restored prairie ecosystem, examined the influence of various environmental factors on soil surface CO2flux in these ecosystems, and estimated annual soil surface CO2flux for the natural and managed ecosystems. Soil surface CO2flux is significantly greater for prairie and conventional tilled corn than for no-till corn in the spring, greater for prairie than tilled and no-till corn from July to early October, and is similar for all three ecosystems in the late fall and winter. Soil surface CO2flux is positively correlated to soil temperature at 10cm for all three ecosystems (r2=0.43–0.60, P<0.001), but is only weakly correlated to soil moisture. Using an empirical model to estimate soil surface CO2flux from 10cm soil temperatures, we estimate annual soil surface CO2fluxes of 508, 535 and 719 (g Cm−2y−1) for the tilled and no-till corn and restored prairie ecosystems, respectively, demonstrating that land use practices significantly affect soil surface CO2flux.