Soil aggregates are an important component of soil and a special organic-inorganic complex. It is an important method of soil carbon sequestration, having positive effects on stabilizing productivity and coping with climate change. This paper, by taking the soil of Pinus massoniana forests of different ages as the object, researched the soil aggregates' distribution characteristics and carbon sequestration mechanism. The results show that for the 20-year-old Pinus massoniana forest, the content of soil aggregates decreases with the decrease of aggregates' particle size in different soil depths; for the 60-year-old Pinus massoniana forest, the overall percentage content of soil aggregates is similar to that of the 40-year-old Pinus massoniana forests in terms of distribution, but has some differences in the value. The percentage of aggregates with a particle size of 2.00 mm changes significantly, from approximately 16.00% to more than 20.00% (except for the 60-80 cm soil layer). The soil aggregates with different particle sizes are mainly dominated by aggregates with a particle size of 10.00 mm, followed by aggregates with a particle size of 2.00 mm. The new organic matter in Pinus massoniana forests promotes the formation of coarse aggregates, and the particulate organic matter in coarse aggregates helps the formation of fine aggregates. The coarse aggregates can physically protect the newly added organic carbon in Pinus massoniana forests, but the protection has a saturation limit. With increasing forest age, the saturated limit of coarse aggregates would be broken under the combined action of internal and external forces, and fine aggregates would then be released. The research results will provide theoretical and methodological support for the study of aggregates' organic carbon and promote the sustainable development of forest soil carbon sequestration and emission reduction technology.
HE, HZ; ZHANG, ZM; LI, DY; ZHOU, W; ZHOU, YC
SOIL AGGREGATES, DISTRIBUTION CHARACTERISTICS AND ORGANIC CARBON PROTECTION MECHANISM OF PINUS MASSONIANA FORESTS OF DIFFERENT AGES
Pakistan Journal Of Botany