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Grassland Plant Diversity Loss May Cut Global CO2 Uptake 15% by 2050
A major study reports that loss of plant species diversity in grasslands reduces global CO2 uptake through photosynthesis by 15% by 2050. The study notes that strongly reduced plant diversity in some tropical grasslands could cut carbon absorption by up to 50% by mid-century.
Grassland Plant Diversity Loss and CO2 Uptake:
| Dimension | Key Details |
|---|---|
| Extreme regional cases | Strongly reduced plant diversity in tropical grasslands of Paraguay, India, and parts of sub-Saharan Africa reduces carbon absorption by up to 50% by mid-century. |
| Functional niche complementarity (components) | Biodiverse grasslands comprise deep-rooting and shallow-rooting species, C3 and C4 photosynthetic pathways, and nitrogen-fixing legumes. |
| Functional niche complementarity (effect) | This variety maximises water, nutrient, and solar radiation efficiency across varied microclimates, driving higher overall carbon sequestration rates. |
| Biodiversity as “insurance” | Diverse plant communities act as a buffer against weather shocks, such as severe droughts and heatwaves, by maintaining ecosystem-level photosynthesis. |
| Vulnerability of monocultures | Monocultures or species-poor pastures lack ecological redundancies, making them prone to structural productivity crashes during prolonged heatwaves or rainfall deficits. |
| Grassland types | Grasslands include meadows, steppes, savannas, and pastures. |
| Global coverage | Grasslands cover nearly 25% to 30% of the Earth's ice-free land surface. |
| Carbon storage pattern | Grasslands store most of their carbon underground in deep root networks and organic soil matter. |
| Forest comparison | Forests store carbon heavily in above-ground biomass that is vulnerable to wildfires. |
| India (Examples) | Tropical and semi-arid grasslands in developing nations include India’s Banni grasslands, Deccan thorn scrub savannas, and Terai-Duar inundation grasslands. |
| Drivers of degradation | Severe degradation occurs due to overgrazing, invasive alien species, and land-use conversion. |
| Invasive alien species | Invasive alien species include Prosopis juliflora and Lantana camara. |
| Livelihood implication | A drop in grassland primary productivity degrades forage quality for pastoralist communities, threatening rural livestock economies and food security. |
| Policy mandate | Converting natural open grassy ecosystems (OGEs) into monoculture tree plantations under carbon credit schemes destroys native plant diversity and worsens water security. |
| Restoration emphasis | Grassland restoration must prioritise re-establishing native multi-species plant diversity rather than merely expanding total green cover percentage. |