Previous studies have shown that soil organic carbon (SOC) impacts the provision of edaphic ecosystem services, making it a key indicator of soil health under sustainable land-use management and for climate change resilience. However, the SOC sequestration processes during tropical forest succession remain unclear, particularly after land abandonment from agriculture practices.
In a study published in Journal of Ecology, researchers from Xishuangbanna Tropical Botanical Garden (XTBG) and Kunming Institute of Botany (KIB) tried to examine the effects of plant functional diversity, species diversity, phylogenetic diversity, tree above-ground biomass and environmental factors on SOC during forest succession after land abandonment from swidden agriculture.
The researchers used data from two large-scale surveys of 320 plots (of 1000？m2 each) and 1280 subplots (of 100？m2 each) covering a total landscape area of 20,000？ha in Southeast Asia. They measured SOC stocks during forest succession to infer sequestration via space-for-time substitution.
They found that functional trait diversity played an important role in determining SOC sequestration across successional trajectories. Plant trait composition was directly associated with carbon input and output from plants to soil and reflected the resource-use complementary within plant communities and its effect on biogeochemical cycles. Increases in SOC carbon storage were associated with indirect positive effects of species diversity and succession age via functional trait diversity, but phylogenetic diversity and above-ground biomass showed no significant relationship with SOC stock. Furthermore, the effects of soil properties and functional trait diversity on SOC carbon storage shifted across elevation.
"Our study helps to clarify the relationships among different components of plant biodiversity, environmental factors and soil carbon stocks across natural tropical forest succession, particularly after land abandonment from swidden agriculture," said Gbadamassi Dossa, one of the three corresponding authors.
The researchers suggested that, in the mosaic landscape of tropical region, a trait-based approach in restoration and afforestation management practices should be considered.
Contact
Gbadamassi G. O. Dossa Ph.D
Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan 666303, China
E-mail: dossa@xtbg.org.cn
First published: 07 June 2023
