Hydrological gradients and functional diversity of plants drive ecosystem processes in Poyang Lake wetland

Abstract

Functional trait approaches have greatly improved the mechanistic understanding of the impacts of biodiversity in ecosystem. We evaluated how hydrological gradients (i.e., soil water content and elevation) affected the taxonomic diversity, functional identity, and functional diversity and assessed how changes in these measures of diversity ultimately drove variations in above‐ground biomass (AGB). Results showed that a combination of hydrological gradients and functional trait composition (i.e., the community weighted means, the single‐trait functional diversity and the multiple‐trait functional diversity) better explained variations (40.8%) of AGB. No significant relationships between taxonomic diversity and AGB were observed. The dominant species became taller with thicker stem, and co‐occurring species showed greater divergent distribution of stem diameter towards higher soil water content. As elevation increased, the dominant plant had thinner leaves with later onset of flowering and longer flowering duration, and co‐occurring species showed less divergent distribution of lamina thickness and leaf dry‐mass content. Our results highlighted that the positive biodiversity–ecosystem functioning relations were largely attributed to the co‐operations of selection and complementary effects, as evidences showed that the dominant trait values (i.e., community weighted mean of shoot height) and trait diversity (i.e., functional evenness) improved biomass production of wetland plants.

Human activities uncouple the cascading effects of hydrological gradients on plant diversity and ecosystem functions in the Lake Dongting wetland

“…Soil moisture was estimated five times at each plot using a WET sensor. In each plot, we randomly sampled ten 1 × 1 m 2 quadrats and identified visually the relative abundance of each species in each quadrat according to seven cover classes (1: 0% < 0.1%; 2: 0.1%–0.9%; 3: 1%–5%; 4: 6%–25%; 5: 26%–50%; 6: 51%–75%; 7: 76%–100%) (Fu et al, 2015; Fu et al, 2018). The samples were dried for 48 h (60°C) and then weighed.…”

“…For each species, we measured at least 30 intact individuals for each of six key functional traits: specific leaf area, leaf dry mass content, lamina thickness, shoot height, stem diameter and stem dry mass content, and collected data for the other five traits: life history (annual or perennial), tuber or rhizome (present or absent), growth form (erect or rosette), mean Julian flowering date and flowering duration, from regional floras (Fu et al, 2014). Details of the trait measurements are described in our previous study (Fu et al, 2014; Fu et al, 2015; Fu et al, 2018). The mean values of functional traits for each species are shown in Table S1.…”

A biodiversity evaluation framework for restoration of aquatic macrophyte communities in shallow lakes driven by hydrological process management

“…A study of a forest community showed that taxonomic indices did not account for functional differences among species, and therefore could not fully represent the variations of species traits and species diversity within and among communities (Kraft, Valencia, & Ackerly, 2008). Other studies showed that accounting for functional diversity can reveal problems between ecosystems and communities, including the patterns and drivers of biodiversity, community assembly, diversity–ecosystem functional relationships, ecological restoration, and conservation (Arthaud, Vallod, Robin, & Bornette, 2012; H. Fu, Lou, et al, 2018; X. Liu & Wang, 2018; Santos, Cianciaruso, & De Marco Jr., 2016; Swenson et al, 2012). Furthermore, biodiversity effects on ecosystem functions, such as production and nutrient cycling, are much stronger when this diversity is based on functional traits than when it is based only on taxonomic diversity (Cadotte, Carscadden, & Mirotchnick, 2011; Flynn, Mirotchnick, Jain, Palmer, & Naeem, 2011).…”

“…It can be quantified as taxonomic diversity (based on the species that are present) (Gagic et al, 2015; Magurran, 2004) and functional diversity (based on the functional groups, which represent groups of species that perform a similar ecological role) (Mason, Mouillot, Lee, & Wilson, 2005; Mouillot, Villeger, Scherer‐Lorenzen, & Mason, 2011). Macrophyte alpha diversity is driven by local‐scale variation in environmental characteristics (H. Fu, Lou, et al, 2018; X. Liu & Wang, 2018; Stefanidis & Papastergiadou, 2019). Beta diversity refers to the differences of species composition among communities, and relates to environmental gradients or patterns (Whittaker, 1960).…”

The effects of flooding regimes and soil nutrients on lakeshore plant diversity in a pristine lake and a human managed lake in subtropical China

“…Historically, nearly all these floodplain lakes could freely connect with the Yangtze River, but most of these natural river to lake connections were cut off in the late twentieth century by sluices to avoid flooding and to maintain irrigation (Zhang et al 2015;Yuan et al 2019). Interestingly, scientists have intensively studied the structure and determining factors of the lakeshore plant communities in the few pristine lakes in the MLYP, such as Poyang Lake and Dongting Lake (Chen et al 2015;Xu et al 2015;Duan et al 2018;Fu et al 2018;Hu et al 2018;Lan et al 2019), but few studies have investigated the formation mechanisms of lakeshore plant communities in the human managed lakes representing the majority of lakes in the MLYP (Zhao et al 2012;Zhang et al 2014bZhang et al , 2015.…”