Soil organic carbon characterization in a tropical ecosystem under different land uses using proximal soil sensing technique

Unregulated land-use conversion influences soil organic carbon (SOC) storage and sequestration causing fluctuations. As one of the most vulnerable regions to climate-change impact, Caribbean ecosystems require formulation of strong adaptation strategies to cope with the vagaries of climate change. Therefore, understanding SOC dynamics under land-use change is critical. With increasing popularity of proximal soil sensing (PSS), relating obtained signals to properties of interest, could offer time and cost-efficient procedures for characterizing properties. To our knowledge, no investigation has been conducted employing PSS using electromagnetic-induction (EMI) to characterize the spatial dynamics of SOC as a consequence of transitional land-use. Hence, our research broadens the evidence base for the characterization of SOC in island ecosystems. Apparent electrical conductivity (ECa) measured by a DUALEM-1S sensor was used to characterize SOC at 0-0.3 m under different land-uses. Spatial maps showed that EMI was suitable for distinguishing between natural and anthropogenic land-uses, with anthropogenic land-uses generally having higher and more variable ECa values (Quarry = 22.8-30.5 mS m(-1), Agriculture = 5.0-11.3 mS m(-1), Residential = 39.2-60.0 mS m(-1), Forest = 9.3-14.5 mS m(-1), Grass = 13.6-17.0 mS m(-1)). Natural land-uses had better soil quality indicating that SOC controls soil quality and varies in response to land-use.

Automated summary

Unregulated land-use conversion can have an impact on soil organic carbon storage and fluctuations in the region. Caribbean ecosystems, being one of the most vulnerable regions to climate change, require strong adaptation strategies to cope with the effects. Understanding the dynamics of soil organic carbon under land-use change is crucial in this context.