气候变化领域集成服务门户(CCPortal): Dynamics of CO2 and H2O fluxes in Johnson grass in the U.S. Southern Great Plains

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DOI	10.1016/j.scitotenv.2020.140077
	Dynamics of CO2 and H2O fluxes in Johnson grass in the U.S. Southern Great Plains
	Wagle P.; Gowda P.H.; Billesbach D.P.; Northup B.K.; Torn M.S.; Neel J.P.S.; Biraud S.C.
发表日期	2020
ISSN	489697
卷号	739
英文摘要	Johnson grass (Sorghum halepense (L.) Pers.) is rapidly spreading throughout the continental United States (U.S.). Thus, determining magnitudes and seasonal dynamics of carbon dioxide (CO2) and water vapor (H2O) fluxes in Johnson grass is crucial to understand regional changes in hydrology and carbon balance. Using eddy covariance (EC), CO2 and H2O fluxes were measured from June 2017 to October 2019 over a rainfed Johnson grass field in central Oklahoma. Hay was harvested from late May to early July each year, with biomass yield ~7.5 t ha−1. Weekly averaged daily integrated net ecosystem CO2 exchange (NEE), gross primary production (GPP), and evapotranspiration (ET) reached −8.28 ± 0.76 g C m−2, 20.02 ± 1.62 g C m−2, and 5.42 ± 0.26 mm, respectively. Ecosystem water use efficiency (EWUE) and ecosystem light use efficiency (ELUE) ranged from 3.22 to 3.93 g C mm−1 ET and 0.34 to 0.41 g C mol−1 PAR (photosynthetically active radiation), respectively, during peak growths. Based on aggregated fluxes for each month over the three years (2017–2019), cumulative annual NEE was −434 ± 112 g C m−2, indicating a carbon gain by the Johnson grass field. Cumulative annual ET (858 ± 72 mm) was ~86% of the average annual rainfall (996 ± 100 mm). Results showed Johnson grass could be a carbon sink from May to September in the U.S. Southern Great Plains. Both NEE and ET did not decline up to air temperature (Ta) of ~33 °C and vapor pressure deficit (VPD) of ~2 kPa, suggesting optimum Ta of ≥33 °C and VPD of ≥2 kPa for the fluxes. Results indicated that Johnson grass might be well suited for dryland production in the region. Additionally, these findings provide initial baseline information on CO2 fluxes and ET for Johnson grass relative to other forage species in the region. © 2020
英文关键词	Ecosystem light use efficiency; Ecosystem water use efficiency; Eddy covariance; Evapotranspiration; Net ecosystem exchange
scopus关键词	Ecosystems; Efficiency; Water supply; Gross primary production; Light use efficiency; Net ecosystem co2 exchanges; Photosynthetically active radiation; Seasonal dynamics; Southern great plains; Vapor pressure deficit; Water use efficiency; Carbon dioxide; carbon dioxide; rain; carbon dioxide; biomass power; carbon balance; carbon dioxide; carbon emission; carbon flux; evapotranspiration; grass; seasonal variation; water vapor; air temperature; Article; biomass production; carbon balance; carbon dioxide transport; controlled study; covariance; environmental parameters; evapotranspiration; forage; harvest; hydrology; nonhuman; Oklahoma; photosynthetically active radiation; plant growth; plant water use; primary production (biomass); priority journal; seasonal variation; Sorghum halepense; vapor pressure; water flow; water vapor; ecosystem; season; sorghum; United States; Great Plains; Oklahoma [United States]; United States; Sorghum halepense; Carbon Dioxide; Ecosystem; Oklahoma; Seasons; Sorghum; United States
来源期刊	Science of the Total Environment
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/176773
作者单位	USDA, Agricultural Research Service, Grazinglands Research Laboratory, El Reno, OK 73036, United States; USDA, Agricultural Research Service, Southeast Area, Stoneville, MS 38776, United States; University of Nebraska-Lincoln, Department of Biological Systems Engineering, Lincoln, NE 68583, United States; Lawrence Berkeley National Laboratory, Earth Sciences Division, Berkeley, CA 94720, United States; Lawrence Berkeley National Laboratory, Climate and Ecosystem Sciences Division, Berkeley, CA 94720, United States
推荐引用方式 GB/T 7714	Wagle P.,Gowda P.H.,Billesbach D.P.,et al. Dynamics of CO2 and H2O fluxes in Johnson grass in the U.S. Southern Great Plains[J],2020,739.
APA	Wagle P..,Gowda P.H..,Billesbach D.P..,Northup B.K..,Torn M.S..,...&Biraud S.C..(2020).Dynamics of CO2 and H2O fluxes in Johnson grass in the U.S. Southern Great Plains.Science of the Total Environment,739.
MLA	Wagle P.,et al."Dynamics of CO2 and H2O fluxes in Johnson grass in the U.S. Southern Great Plains".Science of the Total Environment 739(2020).