Water Constraint is Limiting Global Gross Primary Productivity

Abstract

<p> </p><p>We use a light use efficiency model (LUE)  to describe gross primary productivity (GPP) from 1982 to 2016 using the GIMMS-3g FPAR record and NASA MERRA-2 reanalysis, and explore how GPP trends and anomalies can be explained using annual changes in temperature and hydrology. The GPP model uses optimum LUE (LUE<sub>opt</sub>) inferred from the global FLUXNET network and extrapolated using solar induced chlorophyll fluorescence observations. We find that increasing trends in GPP at mid to high latitudes over the 35-year study period are due to reduced cold temperature of plant growth constraints. Our results suggest a persistent and increasing negative carbon-climate feedback at mid to high latitudes. We also find an increasing atmospheric vapor pressure deficit trends over the tropics, which represents an emerging positive climate feedback that results in a negative trend in GPP after the early 2000s. We expect that further warming, increasing water constraints, and disturbance events will significantly reduce global ecosystem productivity.</p>

CO2 fertilization enhances vegetation productivity and reduces ecological drought in India

“…The reanalysis data for hydro-meteorological variables is obtained from ERA5 (Hersbach et al 2019;10.24381/cds.f17050d7). The GPP data is obtained from Oak Ridge National Laboratory Distributed Active Archive Center (ORNL DAAC) (Madani and Parazoo 2020). The reanalysis GPP is based on the Monteith light use efficiency (LUE) equation and was improved with optimized LUE values derived by FLUXNET tower sites.…”

“…The reanalysis GPP is based on the Monteith light use efficiency (LUE) equation and was improved with optimized LUE values derived by FLUXNET tower sites. The gridded reanalysis GPP is then derived using the optimized LUE, Global Inventory Modeling and Mapping Studies (GIMMS3g), canopy fraction of photosynthetically active radiation, and Modern-Era Retrospective analysis for Research and Applications, Version 2, (MERRA-2) meteorological information (Madani and Parazoo 2020).…”

Ignoring Plant Physiological Responses to Elevated CO2 Will Overestimate Terrestrial Vertebrate Biodiversity Loss Under Global Climate Change

“…All the data used in this study are publicly available from open-access databases. The input data for habitat suitability models training can be accessed from various sources: thickness of the permeable layers above bedrock (Pelletier et al, 2016), soil class (https://www.fao.org/soils-portal/data-hub/soil-classification/world-referencebase), soil texture (https://files.isric.org/soilgrids/), elevation (Jarvis et al, 2008), climate (Abatzoglou et al, 2018), gross primary production (Madani & Parazoo, 2020), leaf area index (Mao & Yan, 2019) and tree cover fraction . The species richness maps can be accessed from https://biodiversitymapping.org/index.php/download/, and simulated climate and vegetation data can be found at https:// esgf-node.llnl.gov/search/cmip6/.…”