Carbon exchange of a dryland cotton field and its relationship with PlanetScope remote sensing data
Autor: | Ronnie W. Schnell, Dorothy Menefee, Jason B. West, Nithya Rajan, Muthukumar V. Bagavathiannan, Song Cui |
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Rok vydání: | 2020 |
Předmět: |
0106 biological sciences
Atmospheric Science Global and Planetary Change 010504 meteorology & atmospheric sciences Eddy covariance Carbon sink Growing season Primary production chemistry.chemical_element Forestry 01 natural sciences Normalized Difference Vegetation Index chemistry Environmental science Precipitation Ecosystem respiration Agronomy and Crop Science Carbon 010606 plant biology & botany 0105 earth and related environmental sciences Remote sensing |
Zdroj: | Agricultural and Forest Meteorology. 294:108130 |
ISSN: | 0168-1923 |
Popis: | Agricultural systems experience numerous management-associated events during the growing season that can significantly influence seasonal and annual carbon balances. Measurements of carbon fluxes from agricultural fields using micrometeorological techniques such as eddy covariance can improve our understanding of management and weather-driven changes in carbon budgets. In-situ carbon flux data are also valuable in developing remote sensing-based models for extrapolation of biome-specific carbon budgets to higher spatial scales. In this study, net ecosystem carbon dioxide exchange (NEE) was continuously measured for two years (2017 and 2018) from a cotton (Gossypium hirsutum) field in College Station, Texas, USA. The measured NEE was partitioned into assimilatory (Gross Primary Production, GPP) and respiratory (Ecosystem respiration, Reco) fluxes. There were substantial differences in carbon fluxes between the two years, which were driven by variations in meteorological conditions and growth of weeds. Due to dry conditions, growing season carbon uptake in 2018 was reduced (883 g C m−2) compared to 2017 (947 g C m−2). While the growing season of 2018 was dry, the post-harvest off-season was remarkably wet with nearly 68% of the annual precipitation occurring after harvest (848 mm). This favored aggressive growth of weeds, resulting in substantial off-season carbon uptake in 2018 (374 g C m−2 in 2018 compared to 100 g C m−2 in 2017). Overall, the site was a net carbon source (175 g C m−2) in 2017, whereas it was a slight carbon sink (-5 g C m−2) in 2018. A significant correlation was found between satellite-derived normalized difference vegetation index (NDVI) and GPP (R2 0.78 in 2017 and 0.72 in 2018). Given that correlation, it would be possible to broaden these results to the wider region by estimating GPP with satellite data. |
Databáze: | OpenAIRE |
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