Comparative evaluation of Cassia siamea and Albizia lebbeck for their potential to recover carbon and nutrient stocks in a chronosequence post-mining site

Nature of the tree species used for revegetation of post-mining land affects the soil carbon and nutrient stocks. This study was aimed at a comparative evaluation of Cassia siamea and Albizia lebbeck for their potential to increase the carbon and nutrient stocks in mined land. Soil and plant samples were collected from chronosequence (3-16 years) sites and evaluated for biomass stock, soil C, nutrient contents, microbial biomass, and dehydrogenase activity. The increase in tree height, diameter at breast height, and biomass weight with age was observed to be higher in C. siamea than A. lebbeck. Biomass carbon stock increased from 0.97 Mg ha(-1) to 54.81 Mg ha(-1) for C. siamea and from 0.60 Mg ha(-1) to 48.96 Mg ha(-1) for A. lebbeck for 3-16-year old sites. Soil dehydrogenase activity and microbial biomass C were higher in C. siamea (32.5-102 mu g TPF g(-1) 24 h(-1), 116-416 mg kg(-1)) compared to A. lebbeck (24.6-88.2 mu g TPF g(-1) 24 h(-1), 92-377 mg kg(-1)). In C. siamea, soil carbon stock increased from 6.61 to 24.04 Mg ha(-1) and in A. lebbeck from 6.10 to 21.43 Mg ha(-1) along the chronosequence. Overall, there was 3.5-fold increase in soil carbon stock, 5.5 and 2.5-fold increase in soil available N and available P stock, and a 30-fold increase in the available K stock along the age gradient of reclaimed mine soil. Reclamation time played a major role in increasing the soil C and nutrient stocks, where C. siamea performed comparatively better than A. lebbeck.

Automated summary

The nature of tree species used for revegetation of post-mining land can affect soil carbon and nutrient stocks. This study compared Cassia siamea and Albizia lebbeck for their potential to increase carbon and nutrient stocks in mined land. Results showed that Cassia siamea performed better in increasing soil carbon and nutrient stocks than Albizia lebbeck, with significant differences observed in biomass carbon stock, soil dehydrogenase activity, and microbial biomass. Overall, reclamation time played a major role in increasing soil carbon and nutrient stocks, and Cassia siamea showed superior performance compared to Albizia lebbeck.