کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
8863724 | 1620289 | 2018 | 9 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Variability in carbon dioxide fluxes among six winter wheat paddocks managed under different tillage and grazing practices
ترجمه فارسی عنوان
تغییرات در جریان های دی اکسید کربن در شش گندم زمستانه تحت عملکردهای مختلف شخم زدن و حیوانات تحت کنترل قرار گرفت
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
علوم زمین و سیارات
علم هواشناسی
چکیده انگلیسی
Carbon dioxide (CO2) fluxes from six winter wheat (Triticum aestivum L.) paddocks (grain only, graze-grain, and graze-out) managed under conventional till (CT) and no-till (NT) systems were synthesized for the 2016-2017 growing season to compare the magnitudes and seasonal dynamics of CO2 fluxes and to investigate among-site variability of CO2 fluxes. Large variations in CO2 fluxes were observed among paddocks. Maximum daily (7-day averages) net ecosystem CO2 exchange (NEE) ranged from â3.39 to â8.68â¯gâ¯C mâ2, gross primary production (GPP) ranged from 7.33 to 16.92â¯gâ¯C mâ2, and ecosystem respiration (ER) ranged from 5.85 to 9.98â¯gâ¯C mâ2. Seasonal sums of NEE ranged from â137 to â542â¯gâ¯C mâ2. Optimum photosynthetically active radiation (PAR), air temperature (Ta), and vapor pressure deficit (VPD) for NEE were approximately 1700â¯Î¼molâ¯mâ2 sâ1, 22â¯Â°C, and 1.25â¯kPa, respectively. Across-site analysis showed percent of canopy cover (Canopy%) was strongly correlated with NEE (R2â¯=â¯0.76) and ecosystem light use efficiency (ELUE, R2â¯=â¯0.76). Integration of PAR with leaf area index (LAI) and integration of Ta with dry biomass weight (DW) explained 81% and 74% of variations in GPP and ER, respectively. Remotely-sensed enhanced vegetation index (EVI) explained 66% and normalized difference vegetation index (NDVI) explained 69% of the variations in NEE. Integration of PAR with NDVI or EVI explained â¼80% of variations in GPP, while NDVIâ¯Ãâ¯Ta explained 58% of variations in ER. Results illustrated that differences in wheat canopies related to paddock management, as indicated by differences in DW, LAI, Canopy%, NDVI, and EVI, must be accounted for explaining among-site variability of CO2 fluxes. Long-term measurements from our clustered and paired eddy covariance towers will provide insights into the effects of tillage and different grazing practices on CO2 dynamics in winter wheat.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Atmospheric Environment - Volume 185, July 2018, Pages 100-108
Journal: Atmospheric Environment - Volume 185, July 2018, Pages 100-108
نویسندگان
Pradeep Wagle, Prasanna H. Gowda, Brian K. Northup, Kenneth E. Turner, James P.S. Neel, Priyanka Manjunatha, Yuting Zhou,