Quantification of net ecosystem carbon exchange (NEE) between the atmosphere and vegetation is of great importance for regional and global studies of carbon balance. The eddy covariance technique can quantify carbon budgets and the effects of environmental controls for many forest types across the continent but it only provides integrated CO2 flux measurements within tower footprints and need to be scaled up to large areas in combination with remote sensing observations. In this study we compare a multiple-linear regression (MR) model which relates enhanced vegetation index and land surface temperature derived from the moderate resolution imaging spectroradiometer (MODIS), and photosynthetically active radiation with the site-level NEE, for estimating carbon flux exchange between the ecosystem and the environment at the deciduous-dominated Harvard Forest to three other methods proposed in the literature. Six years (2001-2006) of eddy covariance and MODIS data are used and results show that the MR model has the best performance for both training (2001-2004, R (2) = 0.84, RMSE = 1.33 g Cm(-2) day(-1)) and validation (2005-2006, R (2) = 0.76, RMSE = 1.54 g Cm(-2) day(-1)) datasets comparing to the other ones. It provides the potential to estimate carbon flux exchange across different ecosystems at various time intervals for scaling up plot-level NEE of CO2 to large spatial areas.

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4839024PMC
http://dx.doi.org/10.1186/s40064-016-2134-4DOI Listing

Publication Analysis

Top Keywords

eddy covariance
12
net ecosystem
8
ecosystem carbon
8
carbon exchange
8
covariance modis
8
modis data
8
carbon flux
8
flux exchange
8
carbon
6
comparison net
4

Similar Publications

Vegetation Types Shift Physiological and Phenological Controls on Carbon Sink Strength in a Coastal Zone.

Glob Chang Biol

January 2025

Key Laboratory of Coastal Zone Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, Shandong, China.

The carbon sink function performed by the different vegetation types along the environmental gradient in coastal zones plays a vital role in mitigating climate change. However, inadequate understanding of its spatiotemporal variations across different vegetation types and associated regulatory mechanisms hampers determining its potential shifts in a changing climate. Here, we present long-term (2011-2022) eddy covariance measurements of the net ecosystem exchange (NEE) of CO at three sites with different vegetation types (tidal wetland, nontidal wetland, and cropland) in a coastal zone to examine the role of vegetation type on annual carbon sink strength.

View Article and Find Full Text PDF

The partitioning of photosynthate among various forest carbon pools is a key process regulating long-term carbon sequestration, with allocation to aboveground woody biomass carbon (AGBC) in particular playing an outsized role in the global carbon cycle due to its slow residence time. However, directly estimating the fraction of gross primary productivity (GPP) that goes to AGBC has historically been difficult and time-consuming, leaving us with persistent uncertainties. We used an extensive dataset of tree-ring chronologies co-located at flux towers to assess the coupling between AGBC and GPP, calculate the fraction of fixed carbon that is allocated to AGBC, and understand the drivers of variability in this fraction.

View Article and Find Full Text PDF

A new proliferation of optical instruments that can be attached to towers over or within ecosystems, or 'proximal' remote sensing, enables a comprehensive characterization of terrestrial ecosystem structure, function, and fluxes of energy, water, and carbon. Proximal remote sensing can bridge the gap between individual plants, site-level eddy-covariance fluxes, and airborne and spaceborne remote sensing by providing continuous data at a high-spatiotemporal resolution. Here, we review recent advances in proximal remote sensing for improving our mechanistic understanding of plant and ecosystem processes, model development, and validation of current and upcoming satellite missions.

View Article and Find Full Text PDF

Enhancing evapotranspiration estimates in composite terrain through the integration of satellite remote sensing and eddy covariance measurements.

Sci Total Environ

January 2025

Department of Biological and Agricultural Engineering, University of California, Davis, CA, USA; Department of Land, Air, and Water Resources, University of California, Davis, CA, USA. Electronic address:

Accurate evaluation of water resource systems is essential for informed planning and decision-making. Evapotranspiration (ET), a key component of water resource management, is often estimated using remote sensing techniques; however, such estimates can be subject to significant uncertainties under certain conditions. In this study, we present a novel approach to improving the accuracy of ET estimates in composite terrains.

View Article and Find Full Text PDF

Dual controls of vapour pressure deficit and soil moisture on photosynthesis in a restored temperate bog.

Sci Total Environ

January 2025

Institute of Ecology and Earth Sciences, University of Tartu, Vanemuise Street. 46, 51003 Tartu, Estonia. Electronic address:

Despite only covering ~3 % of the land mass, peatlands store more carbon (C) per unit area than any other ecosystem. This is due to the discrepancy between C fixed by the plants (Gross primary productivity (GPP)) and decomposition. However, this C is vulnerable to frequent, severe droughts and changes in the peatland microclimate.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!