The Banni grasslands of Gujarat stretching over 2,300 square kilometers, are more than just a biodiversity hotspot they are proving to be one of India most effective carbon sinks. A new study has found that these saline tropical grasslands store an estimated 27.69 million tonnes of soil organic carbon, making them critical in the fight against climate change.
Unlike many arid and semi-arid savannas, the Banni region developed from inherently saline soils formed by riverine sand deposits over millennia. This unique soil texture dense and compact with silt and clay has long remained undisturbed, giving it an extraordinary capacity to lock away carbon.
Restoration Boosts Carbon Storage
The study, conducted over nine years with sampling in 2014, 2017, and 2023, compared different land use types across the grasslands. It found that community-restored areas known as vaadas had the highest soil organic carbon density, storing about 143 tonnes of carbon per hectare. Wetlands followed closely at 138.59 tonnes per hectare, while saline brushlands stored around 125.75 tonnes.
In contrast, sites dominated by Prosopis juliflor an invasive species introduced in the 1960s showed the lowest carbon storage, with just 105.56 tonnes per hectare. Prosopis now covers nearly half of the Banni grasslands, restricting the growth of native grasses and reducing soil carbon storage potential.
Since saline brushlands remain the most extensive land type, covering over 1.27 lakh hectares, they contributed the largest share to overall stocks, storing 16.03 million tonnes of carbon.
Grasslands vs. Tree Planting
Experts say the findings highlight the importance of protecting and restoring grasslands, which have often been dismissed as “unproductive” lands. “Planting more trees in tropical grasslands does not necessarily increase soil carbon,” the study notes, stressing that soil, not biomass, holds the majority of carbon in these landscapes.
Grasslands account for 55% of India’s total carbon stock, yet remain overlooked in domestic climate policies that mostly prioritize afforestation. Researchers argue that conserving undisturbed soil and scaling up community-led restoration in the Banni region could unlock its full carbon storage potential.
As threats from invasive species, climate variability, and salinity rise, scientists warn that protecting the Banni’s soil is crucial for long-term carbon sequestration. “Ensuring the soil is left undisturbed is the key to keeping carbon locked in,” said co-author Chetan Misher, a wildlife ecologist with the Wildlife Conservation Trust.