Global Ecology and Conservation (Sep 2022)
Response of leaf functional traits to precipitation change: A case study from tropical woody tree
Abstract
Precipitation change is one of the most important forms of current global climate change, which will significantly influence the plant growth and development. Although numerous experiments have been conducted to investigate the effects of precipitation regulation on the plant growth and ecosystem process, the response of leaf functional traits of tropical woody species to the precipitation change is still poorly understood. In this study, three treatments, including delayed wet season (DW), wetter wet season (WW) and control check (CK), were established to examine the responses of leaf functional traits, including morphological traits, photosynthetic pigments, and non-structural carbohydrates (NSC) of the dominant woody tree, Symplocos chunii, to the simulated precipitation change in a secondary tropical forest of southern China. Our results showed that the specific leaf area (SLA), photosynthetic pigments, and NSC contents exhibited distinctly seasonal variations (P < 0.05), but the simulated precipitation changes did not alter the leaf morphological traits (leaf length, width, or area) of S. chunii after six-year treatment. The leaf total chlorophyll contents increased observably by 83.9% in DW, and the chlorophyll b was increased by 181.5% compared to CK (P < 0.05), while WW markedly reduced chlorophyll b content but remarkably increased carotenoid content (P < 0.05). However, DW significantly reduced NSC contents in both dry and wet seasons. In contract, WW treatment significantly reduced leaf soluble sugar content only in the early stage of wet season, but after that, the WW did not alter the leaf soluble sugar and starch contents, even with the approach of dry season. These indicated that the precipitation change would alter the leaf photosynthetic rates thus influence the carbon assimilation, further regulate the allocation and transformation pattern of leaf NSC contents in tropical woody trees. The results suggest that the tropical woody trees may adapt to the frequent precipitation change via regulating the allocation and transformation of non-structural carbohydrates.
