Abstract
Beyond natural factors, overgrazing is emerging as a critical threat to grassland ecosystems, potentially driving degradation and unsustainable resource utilization. Grassland carrying capacity refers to the maximum number of livestock that can be sustained by available grassland biomass. Accurately assessing its sustainability is critically important, yet challenging without considering long-term trends, especially at the continental scale. Here, we develop a grassland carrying capacity alert index to assess its utilization risk, reflecting whether grassland ecosystems are currently sustainable. Using data from 2001 to 2020, we assess spatiotemporal changes in grassland carrying capacity across Africa. Our results show that increases in aboveground biomass do not keep pace with growing livestock feed demand. Moreover, the utilization level of grassland resources remains highly uneven across the continent. Approximately 51.02% of African grasslands are under high pressure, with livestock numbers exceeding carrying capacity, primarily in northern Africa. In contrast, 26.53% of grasslands, mainly in southern Africa, remain underutilized over the long term. Shifting livestock development focus to Southern Africa, complemented by cross-regional cooperation to utilize southern pastures for alleviating northern overgrazing, may balance economic growth with grassland sustainability across the continent.
Data availability
The livestock data for Africa countries from FAOSTAT database (https://www.fao.org/faostat/). The Gridded Livestock of the World dataset is available on the FAO Livestock Systems website (http://www.fao.org/livestock-systems/global-distributions/en/). NPP data for African countries are derived from the MOD17A3HGF dataset, which can be downloaded from the LAADS DAAC website (https://ladsweb.modaps.eosdis.nasa.gov/). The EAR5 dataset used for daily meteorological data can be downloaded from the ECMWF website (https://cds-beta.climate.copernicus.eu/datasets). PDSI and VPD data were extracted from the TerraClimate dataset, available for download at Climatology Lab(https://www.climatologylab.org/terraclimate.html). The percent tree cover uses the MOD44B VCF dataset, which is available at LP DAAC. The topographic data were derived from the Geomorpho90m dataset, which was published by Amatulli et al. and is publicly available on the OpenTopography website (https://portal.opentopography.org/datasets)77. Source data are provided with this paper.
Code availability
The code for estimating aboveground biomass of African grasslands is hosted on Google Earth Engine (https://code.earthengine.google.com/fd12ba602cd5eb1b85c90a9c8f95b278). Custom MATLAB scripts for analyzing trends in African grassland AGB using the Theil–Sen estimator and Mann‒Kendall method are provided in the Figshare database (https://doi.org/10.6084/m9.figshare.28590758).
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Acknowledgements
This research was financially supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (XDA19030202); Key Program of Natural Science Foundation of Henan Province, China (252300421288); the Key Program of the Joint Fund of the National Natural Science Foundation of China (U21A2014); the Major Special Project of High Resolution Earth Observation System (80-Y50G19-9001-22/23) and Henan Province Science and Technology Research Project (252102320235). We are grateful to all organizations that share data.
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X.Z., YS.L., and S.Y. designed research, performed research, analyzed data, wrote the paper; N.Y. and W.Z. designed research, analyzed data, and revised the manuscript; Y.L., M.C., and Y.C. discussed the results and revised the manuscript; X.Y., C.Z., and Y.J. performed research and analyzed data.
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Yu, S., Zhang, X., Liu, Y. et al. Assessment of African grassland sustainability for livestock use by constructing a carrying capacity alert index.
Nat Commun (2025). https://doi.org/10.1038/s41467-025-68084-7
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DOI: https://doi.org/10.1038/s41467-025-68084-7
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