Carbon pools in the agroforestry landscapes of the Western Ghats biodiversity hotspot of Kerala, India

Abstract

As global climate discussions increasingly emphasize nature-based solutions and results-based payments, studying carbon pools within agroforestry systems in world’s biodiversity hotspots is of paramount importance. The present study quantifies the carbon stocks in different crop-based agroforestry systems in the Kerala region of the Western Ghats biodiversity hotspot, India. A total of 116 sample plots were randomly established, and standard methods were employed to estimate the carbon in aboveground biomass, belowground biomass, deadwood, litter, and soil organic matter. The result shows an average above-ground carbon of 115.49 Mg/ha across various agroforestry systems, with the highest observed in cardamom-based systems (143.60 Mg/ha), followed by coffee (136.98 Mg/ha), rubber (82.62 Mg/ha), homegardens (79.36 Mg/ha), and tea plantations (43.60 Mg/ha). The average soil organic carbon across all systems was 34.68 Mg/ha, with cardamom-based systems showing the highest and rubber-based systems the lowest. The ecosystem carbon stock, which combines all the carbon pools ranged from 34.79 to 558.51 Mg/ha with an average of 190.59 ± 122.77 Mg/ha. The study found significant differences in ecosystem carbon stocks between mixed and mono-trees species agroforestry systems (p < 0.001). The study highlights the importance of agroforestry systems in the Western Ghats biodiversity hotspot for carbon sequestration and climate change mitigation and contributes to the implementation of the Paris Agreement, the REDD + framework, and reporting under the UNFCCC.