Biodiversity Conservation and Ecological Function Restoration in Freshwater Ecosystems

Editorial

06 February 2023

Editorial: Biodiversity conservation and ecological function restoration in freshwater ecosystems

Naicheng Wu

Min Zhang

Xiaodong Qu

and

Francisco Martinez-Capel

1,731 views

1 citations

Editors

Min Zhang

China Institute of Water Resources and Hydropower Research

Francisco Martinez-Capel

Universitat Politècnica de València

Xiaodong QU

China Institute of Water Resources and Hydropower Research

Naicheng Wu

Ningbo University

Impact

Original Research

11 October 2022

Environmental factors indirectly reduce phytoplankton community stability via functional diversity

Xiaoguang Zhang

, 2 more and

Lin Ye

Weekly dynamics of phytoplankton community stability (Bray–Curtis similarity) (A) and the components of Bray–Curtis similarity shown in panels (A,B) in the Xiangxi Bay of Three Gorges Reservoir (TGR).

The biodiversity-stability relationship is a fundamental subject of ecological research. Considerable evidence demonstrates that biodiversity can either increase or decrease stability. Most relevant research mainly focuses on grassland and forest ecosystems. The biodiversity-stability relationship in aquatic ecosystems and the underlying mechanisms remain poorly understood. To fill the gap, we conducted a year-long study on the phytoplankton of reservoir ecosystems in the Xiangxi Bay of Three Gorges Reservoir (TGR) to test the following hypotheses: (H1) phytoplankton species richness and functional diversity directly reduce phytoplankton community stability in reservoir ecosystems; (H2) nutrient enrichment and water temperature increasing directly reduce phytoplankton community stability; and (H3) nutrients and water temperature indirectly reduce phytoplankton community stability via biodiversity. The structural equation model (SEM) found that functional diversity (community-weighted means of traits and functional divergence) had significant negative correlations with phytoplankton community stability (p < 0.05), while the species diversity had no significant correlation with phytoplankton community stability (p > 0.05). This finding partially supported the hypothesis H1, which suggested that the functional diversity had a closer tie with stability than the species diversity. SEM did not find any direct effect of environmental factors on phytoplankton community stability, which rejected our hypothesis H2. Instead, SEM found that water temperature and phosphate decreased phytoplankton community stability by increasing the first principal component of the community-weighted means of traits (CWM_PC1), which supported hypothesis H3. Further analysis showed that the increased water temperature and phosphate concentration can promote “r-strategists” species (larger CWM_PC1), which are less resistant to environmental disturbances, therefore decreasing the phytoplankton community stability. Our study highlights the importance of functional diversity in maintaining the relationship between biodiversity and stability in the phytoplankton community, which may provide a mechanistic understanding of the biodiversity-stability relationships in aquatic ecosystems.

2,966 views

9 citations

The temporal distribution of fish number and body length in a full day. The distribution of body length of spawning fish was depicted by hour in a whole day.

Original Research

10 January 2023

Application of artificial spawning substrates to support lacustrine fish recruitment and fisheries enhancement in a Chinese lake

Kai Feng

, 6 more and

Qidong Wang

1,645 views

1 citations

Rank-abundance (total number of individuals captured) and occurrence frequency (percentage of sampling locations in which the species occurred) of the 45 species captured from the Datong and Xiaotong rivers. Fish species codes are shown in Table 1.

Original Research

26 September 2022

Spatio-temporal dynamics of fish assemblage in the Datong and Xiaotong rivers, karst tributaries in the upper Yangtze River drainage: Implications for ecological adaptation and conservation of fish in rivers

Peng Xiang

, 4 more and

Zhaobin Song

2,061 views

2 citations

Original Research

23 September 2022

Comparative transcriptomics analyses of chemosensory genes of antenna in male red swamp crayfish Procambarus clarkii

Zihao Zhou

, 5 more and

Jinlong Huang

2,318 views

3 citations

Locations of the sampling sites in the Laoguan River.

Original Research

20 September 2022

The combined effects of land use and seasonal environmental factors on stream food web structure

Yang Wang

, 2 more and

Quanfa Zhang

1,588 views

3 citations

Original Research

25 July 2022

Genetic structure of wild rice Zizania latifolia in an expansive heterogeneous landscape along a latitudinal gradient

Godfrey Kinyori Wagutu

, 4 more and

Yuanyuan Chen

Global aquatic habitats are undergoing rapid degradation and fragmentation as a result of climate change and changes in land use. Understanding the genetic variability and adaptive potential of aquatic plant species is thus important for conservation purposes. In this study, we investigated the genetic diversity and structure of the extant natural populations of Zizania latifolia from five river basins in China based on 46 microsatellite markers. We tested isolation by environment (IBE), isolation by resistance (IBR), and isolation by distance (IBD) patterns using a reciprocal causal model (RCM). Furthermore, we elucidated the impact of the environment on Z. latifolia genetic diversity using generalized linear models (GLMs) and spatially explicit mixed models. Low genetic diversity (H_E = 0.125–0.433) and high genetic differentiation (F_ST = 0.641, Ø_pt = 0.654) were found. Higher historical gene flow (M_H = 0.212–2.354) than contemporary gene flow (M_C = 0.0112–0.0247) and significant bottlenecks in almost all populations were identified, highlighting the negative impact of wetland fragmentation. The IBE model was exclusively supported for all populations and in three river basins. The IBD and IBR models were supported in one river basin each. The maximum temperature of the warmest month and precipitation seasonality were the plausible environmental parameters responsible for the observed pattern of genetic diversity. Local adaptation signatures were found, with nine loci identified as outliers, four of which were gene-linked and associated with environmental variables. Based on these findings, IBE is more important than IBD and IBR in shaping the genetic structure of Z. latifolia.

3,173 views

7 citations

Global distribution of the 54 sites of coniferous leaf-litter decomposition in streams and rivers. There were 541 and 428 records of coniferous leaf-litter breakdown rates expressed as per day and per degree day, respectively. The colors of circles represent the number of records of leaf-litter breakdown rates (including per day and per degree day) at each site.

Original Research

25 July 2022

Global patterns and drivers of coniferous leaf-litter decomposition in streams and rivers

Hongyong Xiang

, 3 more and

Haijun Yang

3,494 views

2 citations

Original Research

22 July 2022

Longitudinal Variations in Physiochemical Conditions and Their Consequent Effect on Phytoplankton Functional Diversity Within a Subtropical System of Cascade Reservoirs

Henglun Shen

, 2 more and

Lu Tan

Spatial variation of environmental variables in the cascade reservoirs (A) TN, SiO2-Si and TP; (B) WT and DO; (C) Zeu, Zmix and Zeu: Zmix.

The social and environmental impacts of large dams are quantifiable and have been well documented, while small dams have often been presumed to be less environmentally damaging than large dams. The purpose of this study was to analyze longitudinal gradients in environmental, hydrodynamic variables and their impact on phytoplankton function, within a cascade of four reservoirs (XuanMiaoGuan, XMG; TianFuMiao, TFM; XiBeiKou, XBK; ShangJiaHe, SJH) and one reservoir bay (Huangbohe Bay, HBH), located from upstream to downstream in the Huangbo River, Hubei Province, China. Our results showed that water temperature, total nitrogen, and soluble silicate increased along the cascade reservoir system, while the concentration of dissolved oxygen and total phosphorus decreased. We identified 16 phytoplankton functional groups, and the predominant groups, including D (Synedra and Stephanodiscus hantzschii), E (Dinobryon divergens), Lo (Dinoflagellate: Peridinium bipes and Peridiniopsis), X2 (Chroomona), and Y (Cryptomonas), changed longitudinally from up to down in the cascade reservoirs. The number of dominant functional groups increased along the longitudinal gradient, indicating that the function of the phytoplankton community was more stable. Functional group D was the dominant phytoplankton functional group among the four reservoirs, and Lo group was dominant except SJH. The phytoplankton functional groups in the HBH have been completely changed due to the backwater jacking of the main stream of the Yangtze River. Euphotic depth, suspended solids, and nutrients were apparently the key factors driving variations in phytoplankton functional groups among the reservoirs. Notably, the patterns we observed were not all consistent with the cascading reservoir continuum concept (CRCC) that typically characterizes large rivers. Thus, our findings contribute to the further theoretical development of the CRCC, which may not apply widely to all cascade systems.

2,144 views

8 citations

Beta- diversity visualized using non-metric multidimensional scaling (NMDS) based on BPUE data in 2018 (left plots) and 2019 (right plots) with Bray-Curtis dissimilarity distances of community compositions for the wf-eDNA assay and traditional sampling methods in Klíčava, Římov and Žlutice reservoirs. NMDS plots on rank order using Bray-Curtis distances were used to evaluate relationships based on intersample variation in estimated fish community composition between sampling methods. Plot ellipses represent the 95% confidence regions for the group clusters. Traditional sampling methods are abbreviated as follows: DE = day electrofishing, NE = night electrofishing, SBG = standard benthic gillnets, SPG = standard pelagic gillnets, LBG = large mesh-size benthic gillnets, LPG = large mesh-size pelagic gillnets, NAS = night-time adult seining, DFS = day-time fry seining, NFS= night-time fry seining, FT = fry trawl and wf-eDNA = eDNA from water targeting fish.

Original Research

01 July 2022

Amin Golpour

, 13 more and

Petr Blabolil

4,605 views

13 citations

Methods

23 June 2022

Harmonizing and Searching Macroinvertebrate Trait Information in Alpine Streams: Method and Application–A Case Study in the Three Parallel Rivers Region, China

Sicheng Ao

, 3 more and

Qinghua Cai

2,010 views

8 citations

Original Research

15 July 2022

Drivers of Spatiotemporal Eukaryote Plankton Distribution in a Trans-Basin Water Transfer Canal in China

Yuying Li

, 7 more and

Xuemei Han

1,964 views

6 citations

Original Research

06 May 2022

Biogeography of Micro-Eukaryotic Communities in Sediment of Thermokarst Lakes Are Jointly Controlled by Spatial, Climatic, and Physicochemical Factors Across the Qinghai-Tibet Plateau

Ze Ren

, 2 more and

Cheng Zhang

2,051 views

4 citations

Original Research

03 June 2022

Genetic Diversity and Population Differentiation of Chinese Lizard Gudgeon (Saurogobio dabryi) in the Upper Yangtze River

Hongyan Liu

, 6 more and

Ming Xia

2,191 views

2 citations

Original Research

14 July 2022

Quantitative relationship between cladocera and cyanobacteria: A study based on field survey

Daikui Li

, 6 more and

Jiawen Wang

1,513 views

0 citations

Small run-of-river dams within the Xiangxi River watershed (B) in the People’s Republic (P. R.) of China (A) and sketch map of sampling sites (C). SHP, small hydropower station; letters in (B) are names of SHPs. The figure was modified from Wang et al. (2022).

Original Research

29 April 2022

Small Run-of-River Dams Affect Taxonomic and Functional β-Diversity, Community Assembly Process of Benthic Diatoms

Yixia Wang

, 3 more and

Qinghua Cai

Being increasingly constructed worldwide, dams are a main driver of flow regime change and biodiversity decline. Although small run-of-river dams have exceeded the number of large dams, their impacts on taxonomic and functional β-diversity as well as community assembly process of aquatic organisms have been largely neglected. Ninety sites within twenty three small run-of-river dams in the Xiangxi River were selected, and the hydrological and physicochemical variables for each site were measured. We analyzed the traits and β-diversity of benthic diatoms, and explored the key driving mechanism of benthic diatom community assembly. Our results indicated that the construction of small run-of-river dams could affect the β-diversity of benthic diatoms and the mechanism of community assembly. Specifically, we found that small run-of-river dams could change the relative contribution of nestedness components to the trait-based β-diversity of benthic diatoms, but generally the taxonomy-based β-diversity was relatively higher than the trait-based β-diversity. Furthermore, the community assembly process of benthic diatoms was also affected. In areas affected directly by small run-of-river dams, dispersal assembly was the key mechanism for community assembly. Compared to unregulated habitats, the dispersal assembly process between the impacted and the unregulated habitats has been enhanced. We advocate that this study can be expanded to other organisms (such as macroinvertebrates, phytoplankton, fish) in future to fully understand impacts of small run-of-river dams on biodiversity from a multi-trophic level aspect. Based on our results, we suggest that maintaining genetic and ecological connectivity based on an effective impact assessment in dry seasons is a potential solution to mitigate the impacts of such dams, as key to adaptive management and sustainability.

2,414 views

12 citations

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