Response ofTaxodium distichumto winter submergence in the water-level-fluctuating zone of the Three Gorges Reservoir region

Abstract

This study investigated the physiological and ecological processes of Taxodium distichum in the water-level-fluctuating zone (WLFZ) of the Three Gorges Reservoir (TGR). We determined the contents of non-structural carbohydrates (NSCs), N and P in the aboveground parts and root systems of T. distichum individuals that had experienced 3 yearly flooding cycles. These flooding cycles were driven by the operation of the reservoir in the Zhong County vegetation restoration demonstration area. This flooding inhibited the growth of T. distichum. The plant heights and canopy diameters of the flooded groups were significantly smaller than those of the control group. The flooding facilitated the synthesis of NSCs, and the soluble sugar content in the NSCs increased. The flooding inhibited the uptake of N and P, but the N/P ratios remained stable. The ratios of NSCs to N or P increased. T. distichum adapts well to submergence because of its regulation of NSC synthesis and storage, its balancing of the inputs of photosynthetic products to growth and storage, and its storage of material during exposure to maintain physiological activities during winter submergence and the energy sources required for growth during exposure. This study may provide a useful reference for use in vegetation reconstructions in areas with hydrological characteristics similar to those of the TGR. ARTICLE HISTORY

Responses of Ecological Stoichiometric Characteristics of Carbon, Nitrogen, and Phosphorus to Periodic Submergence in Mega-Reservoir: Growth of Taxodium distichum and Taxodium ascendens

“…The growth, photosynthetic response, physiological metabolism, and nutrient levels of T. distichum and T. ascendens under flooding stress have been evaluated using in situ and controlled garden experiments [4,10,12], which better explain the flooding tolerance mechanism of T. distichum and T. ascendens. However, under flooding stress conditions, many physiological processes related to plant C, N, and P can be constrained, such as C-sequestration, N-fixation, and nutrient mineralization.…”

Research Status and Trends of Taxodium distichum

“…Cluster 7, labeled "submergence" and "Three Gorges Reservoir," focused on the effects of long-term periodic flooding on photosynthesis and growth (Wang et al 2016). Cluster 8 was labeled "carbohydrates" and "saline flooding" and focused on the research on the physiological response to saline flooding and carbohydrates (Iwanaga et al 2011;Wang et al 2019). Cluster 9 was labeled "single nucleotide polymorphisms" and "caps" and focused on the research on T. distichum molecular mechanisms of genetic diversity and resistance (Duan et al 2020;Tsumura et al 1999).…”

“…Flooding inhibited the absorption of N and P and increased the ratio of nonstructural carbohydrates to N or P. T. distichum is well adapted to submerging because it balances growth through the regulation of nonstructural carbohydrate synthesis and storage (Nyman and Lindau 2016;Wang et al 2019). In general, C content showed leaves > branches > fine roots; the contents of N and P showed leaves > fine roots > branches.…”

“…T. distichum has been widely used in wetland parks, farmland forest networks, rural and urban greening, hydro-fluctuation belt, and swamps along rivers, playing vital roles in water and soil conservation (Conner and Inabinette 2005;Jing et al 2018;Wang et al 2019; Yunsheng and Wenmei 2018; Yunsheng and Yihui 2017). The roadside T.…”

Composition and distribution of vegetation in the water level fluctuating zone of the Lantsang cascade reservoir system using UAV multispectral imagery

“…Around the vegetation in the WLFZ, the related research is mainly focused on two aspects. One is from the aspects of plant physiology and ecology, including plant physiological characteristics, growth response, ventilatory tissue, photosynthetic response, antioxidant enzyme activity, non-structural carbohydrates and so on [10][11][12][13]. On the other hand, from the aspects of vegetation community composition, including flora, vegetation status, soil seed bank, species diversity, community structure, landscape pattern, spatial distribution, vegetation cover, succession trend and so on [14][15][16][17][18].…”