Tree Plantations in Saline Environments: Ecosystem Services, Carbon Sequestration and Climate Change Mitigation

Abstract

Nearly one billion hectares of arid and semiarid areas of the world are salt-affected and remain barren due to salinity or water scarcity. These lands can be utilized by adopting appropriate planting techniques and integrating trees with tolerant crops, forage grasses, oil-yielding crops, and aromatic and medicinal plants. Biosaline agroforestry provides various ecosystem services such as the improved soil fertility, carbon sequestration, and biomass production. Provisioning services relating to biomass production have been fairly well studied in different biosaline agroforestry. Tree plantations and agroforestry enrich the soil in organic matter and exert a considerable ameliorative effect on soil properties. The soil microbial biomass serves as a useful indicator of soil improvement under salt stress. Arbuscular mycorrhizal fungi colonized the roots of grasses in silvopastoral systems on saline and sodic soils, the dominant AM fungal species being Glomus and Acaulospora. By integrating trees with the naturally occurring grassland systems on highly sodic soils, the soil organic carbon content increased from 5.3 Mg ha−1 (in sole grass) to 13.6, 10.9, and 14.2 Mg ha−1, when Dalbergia sissoo, Acacia nilotica, and Prosopis juliflora trees were introduced with grass. The soils of biosaline agroforestry could store 25.9–99.3 Mg CO2 ha−1 in surface 0.3 m soil. Maintaining the stores and sink of carbon in agroforestry could play a key role in climate change mitigation as well as help in adapting to changing environmental conditions.