scholarly journals Estimation of net carbon exchange using eddy covariance CO2flux observations and a stochastic model

2008 ◽  
Vol 113 (D3) ◽  
Author(s):  
Vanessa J. Stauch ◽  
Andrew J. Jarvis ◽  
Karsten Schulz
Keyword(s):  
Stochastic Model ◽  
Eddy Covariance ◽  
Carbon Exchange ◽  
Net Carbon Exchange

scholarly journals Combining eddy covariance measurements with process-based modelling to enhance understanding of carbon exchange rates of dairy pastures

2020 ◽  
Vol 745 ◽  
pp. 140917 ◽  
Author(s):  
Miko U.F. Kirschbaum ◽  
Nicolas J.B. Puche ◽  
Donna L. Giltrap ◽  
Lìyǐn L. Liáng ◽  
Abad Chabbi
Keyword(s):  
Exchange Rates ◽  
Eddy Covariance ◽  
Carbon Exchange ◽  
Eddy Covariance Measurements

scholarly journals Net ecosystem carbon exchange of a dry temperate eucalypt forest

2017 ◽  
Vol 14 (16) ◽  
pp. 3781-3800 ◽  
Author(s):  
Nina Hinko-Najera ◽  
Peter Isaac ◽  
Jason Beringer ◽  
Eva van Gorsel ◽  
Cacilia Ewenz ◽  
...  
Keyword(s):  
Eddy Covariance ◽  
Air Temperature ◽  
Carbon Exchange ◽  
Night Time ◽  
Annual Variability ◽  
Eucalypt Forest ◽  
Ecosystem Carbon ◽  
Environmental Controls ◽  
Net Ecosystem Carbon Exchange ◽  
Ecosystem Carbon Exchange

Abstract. Forest ecosystems play a crucial role in the global carbon cycle by sequestering a considerable fraction of anthropogenic CO2, thereby contributing to climate change mitigation. However, there is a gap in our understanding about the carbon dynamics of eucalypt (broadleaf evergreen) forests in temperate climates, which might differ from temperate evergreen coniferous or deciduous broadleaved forests given their fundamental differences in physiology, phenology and growth dynamics. To address this gap we undertook a 3-year study (2010–2012) of eddy covariance measurements in a dry temperate eucalypt forest in southeastern Australia. We determined the annual net carbon balance and investigated the temporal (seasonal and inter-annual) variability in and environmental controls of net ecosystem carbon exchange (NEE), gross primary productivity (GPP) and ecosystem respiration (ER). The forest was a large and constant carbon sink throughout the study period, even in winter, with an overall mean NEE of −1234 ± 109 (SE) g C m−2 yr−1. Estimated annual ER was similar for 2010 and 2011 but decreased in 2012 ranging from 1603 to 1346 g C m−2 yr−1, whereas GPP showed no significant inter-annual variability, with a mean annual estimate of 2728 ± 39 g C m−2 yr−1. All ecosystem carbon fluxes had a pronounced seasonality, with GPP being greatest during spring and summer and ER being highest during summer, whereas peaks in NEE occurred in early spring and again in summer. High NEE in spring was likely caused by a delayed increase in ER due to low temperatures. A strong seasonal pattern in environmental controls of daytime and night-time NEE was revealed. Daytime NEE was equally explained by incoming solar radiation and air temperature, whereas air temperature was the main environmental driver of night-time NEE. The forest experienced unusual above-average annual rainfall during the first 2 years of this 3-year period so that soil water content remained relatively high and the forest was not water limited. Our results show the potential of temperate eucalypt forests to sequester large amounts of carbon when not water limited. However, further studies using bottom-up approaches are needed to validate measurements from the eddy covariance flux tower and to account for a possible underestimation in ER due to advection fluxes.

Carbon allocation and translocation in chlorsulfuron-treated canola (Brassica napus)

Weed Science ◽  
1997 ◽  
Vol 45 (4) ◽  
pp. 466-469 ◽  
Author(s):  
Songmun Kim ◽  
William H. Vanden Born
Keyword(s):  
Brassica Napus ◽  
Carbon Fixation ◽  
No Reduction ◽  
Carbon Allocation ◽  
Starch Content ◽  
Carbon Exchange ◽  
Net Carbon Exchange

Our objective was to determine if the chlorsulfuron-induced reduction in assimilate export from leaves can be attributed to a shortage of carbohydrates. Treated canola leaves showed no reduction in carbon fixation or carbohydrate production during the first 24 h, but they exuded only 17 to 27% of the amount of sucrose exuded by corresponding control leaves. Exposure of the leaves to higher concentrations of CO2(500 vs. 350 μl L−1) resulted in greater net carbon exchange and higher starch content, but failed to overcome the reduction in sucrose export, presumably because of increased carbon allocation to starch.

scholarly journals An Interannual Comparative Study on Ecosystem Carbon Exchange Characteristics in the Dinghushan Biosphere Reserve, a Dominant Subtropical Evergreen Forest Ecosystem

2021 ◽  
Vol 12 ◽  
Author(s):  
Brian Njoroge ◽  
Yuelin Li ◽  
Shimin Wei ◽  
Ze Meng ◽  
Shizhong Liu ◽  
...  
Keyword(s):  
Carbon Sequestration ◽  
Eddy Covariance ◽  
Forest Ecosystem ◽  
Climatic Factors ◽  
Carbon Sink ◽  
Biosphere Reserve ◽  
Carbon Exchange ◽  
Eddy Covariance Technique ◽  
Ecosystem Carbon ◽  
Ecosystem Carbon Exchange

Compared with other forest systems, research interest in the potential for a stronger ecosystem carbon sequestration of evergreen forests throughout subtropical China has greatly increased. The eddy covariance technique is widely employed to determine accurate forest-atmosphere carbon dioxide (CO2) flux, which is subsequently used to determine forest ecosystem carbon exchange characteristics. The Dinghushan Biosphere Reserve, a subtropical monsoon evergreen broad-leaved forest, is a suitable study area due to its warm and humid climate (compared with other regions within the same latitude), consequently playing a role in the carbon cycle in the region. For this study, we hypothesized that the forest land in this region generally acts as a carbon sink, and that its carbon sequestration capacity increases over time despite the influence of climatic factors. Here, we compared net CO2 flux data derived from the eddy covariance technique over an 8-year study window. Additionally, we ascertained the effects of various environmental factors on net CO2 flux, while also using the Michaelis–Menten model and a physiologically based process model to track and report on ecosystem carbon exchange characteristics. We observed seasonal trends in daily ecosystem flux, indicative of sensitivity to climatic factors, such as air temperature, precipitation, and sunlight. The carbon sequestration capacity of the region exhibited seasonal variability, increasing from October to March (−264 g C m−2 year−1, i.e., 48.4%) while weakening from April to September (−150 g C m−2 year−1, i.e., 40.4%) on average. The net ecosystem exchange (NEE) rate varied from −518 to −211 g C m−2 year−1; ecosystem respiration (Re) varied from 1,142 to 899 g C m−2 year−1; and gross primary production (GPP) varied from 1,552 to 1,254 g C m−2 year−1. This study found that even though the Dinghushan Biosphere Reserve generally acts as a carbon sink, its carbon sequestration capacity did not increase significantly throughout the study period. The techniques (models) used in this study are suitable for application in other ecosystems globally, which can aid in their management and conservation. Finally, the Dinghushan Biosphere Reserve is both an exemplary and a model forest system useful in exploring CO2 absorption and sequestration from the atmosphere.

Sign in / Sign up

Export Citation Format

Share Document