Variation In Community Structure Research Articles

Effects of sugarcane-duck symbiosis on rhizobacterial community structure and interannual variability

Effects of sugarcane-duck symbiosis on rhizobacterial community structure and interannual variability

Variation in insect community structure between natural and constructed tidal marshes

Abstract Insects perform important ecological roles that influence ecosystem functions, including primary production and nutrient cycling. Likewise, wetland ecosystems perform important functions and provide numerous services, yet they are highly vulnerable to loss. Wetland restoration and construction can provide habitat for insects and other organisms and recover ecosystem functions. While the community structure of plants and non‐insect macroinvertebrates in restored and constructed wetlands often fails to recover to comparable levels of reference wetlands, less is known about the recovery of insect communities in restored wetlands. We aimed to determine if differences in biological structure (i.e., plant biomass and soil organic matter) between one reference and two constructed Juncus roemerianus‐dominated tidal marshes extend to their respective insect communities. We classified insect communities into taxonomic families and functional feeding groups in one reference marsh and two constructed marshes in Alabama, USA. Sampling methods included replicated pan trapping, line‐transect netting, floral observations and floral clippings. We also conducted light trapping at one site per marsh. All insect taxa and functional groups were identified monthly from April to October 2021 and analysed for taxon richness, abundance and H′ diversity. Floral density and herbivory scars on J. roemerianus shoots were also measured during flowering and peak growing seasons, respectively. While insect abundance and taxon richness were similar among sites, the reference marsh generally supported a more diverse insect community than the constructed marshes, although nocturnal flying insects were less diverse. Additionally, temporal shifts in community composition, based on relative abundances of insect taxa and functional feeding groups, differed among marshes, likely reflecting differences in habitats in the surrounding landscapes of each site. By comparing structural differences (i.e., taxonomic and functional) of insect communities in reference and constructed marshes, we can further understand the community composition of an understudied group of organisms, thereby informing restoration strategies to recover habitat and support the health of tidal marshes.

Effects of Water Level Fluctuations and Vegetation Restoration on Soil Prokaryotic Microbial Community Structure in the Riparian Zone of the Three Gorges Reservoir

Riparian zones are typical fragile and sensitive ecological areas. Fluctuations in water level are the main factor affecting the soil environment in these zones, and vegetation restoration is considered an important means of soil conservation there. However, the interactive effects of water level fluctuations and vegetation restoration on the soil microbial community structure in the reservoir riparian zone remain unclear. Therefore, we selected abandoned grassland and artificial forestland at different water level elevations as research objects in the riparian zone of the Three Gorges Reservoir. We used 16S rRNA high-throughput sequencing technology to explore the composition and diversity of soil prokaryotic microbial communities and investigated the main environmental factors driving the soil microbial community structure. The results showed that the α diversity of soil prokaryotes was the highest at the low water level of the riparian zone. The Pielou_e index, Shannon index, and Simpson index at the 163 m elevation were significantly higher than those at the 168 m elevation, and the Chao1 index and Shannon index were significantly higher than those at the 173 m elevation. However, no significant difference was found in the soil microbial community α diversity between abandoned grassland and artificial forestland. At the same time, water level fluctuations and vegetation restoration had significant effects on the community composition of soil prokaryotic microorganisms, and there were significant differences in biomarker categories in different study sites. Notably, the effects of vegetation restoration types on the soil prokaryotic microbial community structure were stronger than that of water level fluctuations. In addition, the results of hierarchical segmentation showed that soil pH was the main driving factor for the change in soil prokaryotic microbial community structure in the Three Gorges Reservoir. These results deepen our understanding of the variations in microbial community structure in the reservoir riparian zone and provide scientific reference for the restoration and reconstruction of the riparian zone ecosystem.

Differences in archaeal diversity and potential ecological functions between saline and hypersaline lakes on Qinghai-Tibet Plateau were driven by multiple environmental and non-environmental factors beyond the salinity

BackgroundSaline lakes are home to various archaea that play special and crucial roles in the global biogeochemical cycle. The Qinghai-Tibet Plateau hosts a large number of lakes with diverse salinity ranging from 0.1 to over 400 g/L, harboring complex and diverse archaea. To the best of our knowledge, the formation mechanisms and potential ecological roles of archaea in Qinghai-Tibetan Plateau saline lakes remain largely unknown.ResultsUsing High-throughput Illumina sequencing, we uncovered the vastly distinct archaea communities between two typical saline lakes with significant salinity differences on the Qinghai Tibet Plateau (Qinghai saline lake and Chaka hypersaline lake) and suggested archaea played different important roles in methanogenesis-related and nitrate reduction-related functions of these two lakes, respectively. Rather than the individual effect of salinity, the composite effect of salinity with diverse environmental parameters (e.g., temperature, chlorophyll a, total nitrogen, and total phosphorus) dominated the explanation of the variations in archaeal community structure in different habitats. Based on the network analysis, we further found the correlations between dominant archaeal OTUs were tight but significantly different between the two habitats, implying that archaeal interactions may also largely determine the shape of archaeal communities.ConclusionThe present study improved our understanding of the structure and function of archaea in different saline lakes on the Qinghai-Tibet Plateau and provided a new perspective on the mechanisms underlying shaping their communities.

Understanding filamentous cyanobacteria and their adaptive niches in Lake Honghu, a shallow eutrophic lake

Freshwater lakes globally are witnessing an escalation in the frequency and intensity of cyanobacterial harmful blooms. However, underlying factors influencing the succession or coexistence of cyanobacteria, especially filamentous ones, remain poorly understood. Lake Honghu, a Ramsar Wetland of International Importance with degrading aquatic ecological quality, served as a case study to elucidate the intricate relationship between environmental changes and cyanobacterial dynamics. Our analysis revealed a significant increase in the dominance of filamentous cyanobacteria, marked by high spatiotemporal variability in community structure. This dominance of filamentous diazotrophic cyanobacteria is attributed to a decrease in the ratio of dissolved inorganic nitrogen to total phosphorus and their capacity to utilize organic phosphorus in phosphorus-deficient conditions. Species-specific density variations were linked to diverse environmental factors, with total nitrogen or total phosphorus concentration remaining as a crucial factor influencing dominant cyanobacterial density fluctuations. The dominance of low-temperature-tolerant Aphanizomenon and Pseudanabaena was evident in spring and winter, whereas Dolichospermum and Cylindrospermopsis, which prefer higher temperatures, thrived in summer and autumn. Additionally, non-algal turbidity and heterogeneity can potentially alter the competitive outcome among filamentous cyanobacteria or foster coexistence under conditions of elevated temperatures and nutrient limitation. This study predicts that filamentous cyanobacteria may spread and persist in lakes spanning a wide trophic range. Current findings enhance our comprehension of the dynamic responses exhibited by filamentous bloom-forming cyanobacteria in the face of environmental changes within shallow eutrophic lakes and provide valuable insights for lake managers involved in the remediation of degraded shallow lakes.

Effect of auxiliary materials on the formation of humic acid carbon and nitrogen and bacterial dynamics in kitchen waste composting

This study investigated the impacts of different types of auxiliary materials on the humification process and bacterial dynamics during kitchen waste composting. Five types of auxiliary materials, including sawdust (SD), garden waste (GW), aquatic plants (AP), rice straw (RS), and rice husk (RH), were compared. The relationship between humic acid carbon and nitrogen components as well as bacterial community was analyzed by structural equation model and redundancy analysis. The results dindicated that SD and RS exhibited better thermophilic stage duration, germination index, and organic fractions degradation than other groups, which had higher degree of polymerization and the humification index of kitchen waste composting. AP, SD and RS had higher total nitrogen (TN) content and ammonia nitrogen accumulation, and RS had more humic acid nitrogen in TN with more amino acids and polyphenols precursors compared to other groups. High-throughput sequencing indicated that sawdust affected the variation of community structure and bacterial genera associated with lignocellulose degradation more than others. Redundancy analysis showed that Pseudoxanthomonas helped to the NH4+-N conversion to humic acid nitrogen for TN preservation. Structural equation modelling suggested that the conversion and utilization efficiency of microbes directly influenced the accumulation of humic acid carbon and nitrogen based on the types of intermediate metabolites. This study highlighted the role of auxiliary materials on improving the humification process of rapid kitchen waste composting.

The impact of Sangju Qingjie Decoction on the pulmonary microbiota in the prevention and treatment of chronic obstructive pulmonary disease.

Exploring the effect of SJQJD on the pulmonary microbiota of chronic obstructive pulmonary disease (COPD) rats through 16S ribosomal RNA (rRNA) sequencing. A COPD rat model was constructed through smoking and lipopolysaccharide (LPS) stimulation, and the efficacy of SJQJD was evaluated by hematoxylin and eosin (H&E) staining and Enzyme-Linked Immunosorbnent Assay (ELISA). The alveolar lavage fluid of rats was subjected to 16S rRNA sequencing. The diversity of lung microbiota composition and community structure was analyzed and differential microbiota were screened. Additionally, machine learning algorithms were used for screening biomarkers of each group of the microbiota. SJQJD could improve lung structure and inflammatory response in COPD rats. 16s rRNA sequencing analysis showed that SJQJD could significantly improve the abundance and diversity of bacterial communities in COPD rats. Through differential analysis and machine learning methods, potential microbial biomarkers were identified as Mycoplasmataceae, Bacillaceae, and Lachnospiraceae. SJQJD could improve tissue morphology and local inflammatory response in COPD rats, and its effect may be related to improve pulmonary microbiota.

Zooplankton community structure and diel migration patterns vary over hours, days, and years in the pelagic and littoral zone of a eutrophic reservoir

Abstract Zooplankton play an integral role as indicators of water quality in freshwater ecosystems, but exhibit substantial variability in their density and community composition over space and time. This variability in zooplankton community structure may be driven by multiple factors, including taxon-specific migration behavior in response to environmental conditions. Many studies have highlighted substantial variability in zooplankton communities across spatial and temporal scales, but the relative importance of space vs. time in structuring zooplankton community dynamics is less understood. In this study, we quantified spatial (a littoral vs. a pelagic site) and temporal (hours to years) variability in zooplankton community structure in a eutrophic reservoir in southwestern Virginia, USA. We found that zooplankton community structure was more variable among sampling dates over 3 years than among sites or hours of the day, which was associated with differences in water temperature, chlorophyll a, and nutrient concentrations. Additionally, we observed high variability in zooplankton migration behavior, though a slightly greater magnitude of DHM vs. DVM during each sampling date, likely due to changing environmental conditions. Ultimately, our work underscores the need to continually integrate spatial and temporal monitoring to understand patterns of zooplankton community structure and behavior in freshwater ecosystems.

Plants attacked above-ground by leaf-mining flies change below-ground microbiota to enhance plant defense

Abstract Root-associated microbiomes play a crucial role in plant responses to biotic and abiotic stresses. Plants can recruit beneficial microbes to increase their stress-relieving ability. Above-ground insect herbivory is among the most detrimental stresses for plants, especially to crop production. However, few studies have explored how root-associated microbiomes respond to herbivores and influence plant-defense functions under herbivory stress. We investigate the changes and functional role of root-associated microbial communities under herbivory stress using leafminer (Liriomyza trifolii) and cowpea (Vigna unguiculata) as a focal system. We did this by using a combination of 16S ribosomal RNA gene profiling and metagenomic sequencing to test for differences in co-occurrence networks and functions between cowpea plants infested and noninfested with leafminers. The results demonstrated that leafminer infestation caused a shift in the rhizosphere microbiome, which was characterized by a significant variation in microbiome community structure and composition, the selection of hub microbes involved in nitrogen (N) metabolism, and functional enrichment related to N metabolism. Notably, nitrogen-fixing bacteria Bradyrhizobium species were actively recruited and selected to be hubs in the rhizosphere. Inoculation with Bradyrhizobium enhanced cowpea performance under leafminer stress and increased protease inhibitor levels to decrease leafminer fitness. Overall, our study characterized the changes of root-associated microbiota between leafminer-infested and noninfested cowpea plants and revealed the mechanisms underlying the rhizosphere microbiome shift that enhance plant performance and defense against herbivory. Our findings provide further support for the notion that plants recruit rhizosphere microbes to counteract aboveground insect herbivores.

The role of environmental gradients and microclimates in structuring communities and functional groups of lizards in a rainforest-savanna transition area.

Environmental heterogeneity poses a significant influence on the functional characteristics of species and communities at local scales. Environmental transition zones, such as at the savanna-forest borders, can act as regions of ecological tension when subjected to sharp variations in the microclimate. For ectothermic organisms, such as lizards, environmental temperatures directly influence physiological capabilities, and some species use different thermoregulation strategies that produce varied responses to local climatic conditions, which in turn affect species occurrence and community dynamics. In the context of global warming, these various strategies confer different types of vulnerability as well as risks of extinction. To assess the vulnerability of a species and understand the relationships between environmental variations, thermal tolerance of a species and community structure, lizard communities in forest-savanna transition areas of two national parks in the southwestern Amazon were sampled and their thermal functional traits were characterized. Then, we investigated how community structure and functional thermal variation were shaped by two environmental predictors (i.e., microclimates estimated locally and vegetation structure estimated from remote sensing). It was found that the community structure was more strongly predicted by the canopy surface reflectance values obtained via remote sensing than by microclimate variables. Environmental temperatures were not the most important factor affecting the occurrence of species, and the variations in ecothermal traits demonstrated a pattern within the taxonomic hierarchy at the family level. This pattern may indicate a tendency for evolutionary history to indirectly influence these functional features. Considering the estimates of the thermal tolerance range and warming tolerance, thermoconformer lizards are likely to be more vulnerable and at greater risk of extinction due to global warming than thermoregulators. The latter, more associated with open environments, seem to take advantage of their lower vulnerability and occur in both habitat types across the transition, potentially out-competing and further increasing the risk of extinction and vulnerability of forest-adapted thermoconformer lizards in these transitional areas.

Distinct orchid mycorrhizal fungal communities among co-occurring Vanilla species in Costa Rica: root substrate and population-based segregation.

Despite being the second largest family of flowering plants, orchids represent community structure variation in plant-microbial associations, contributes to niche partitioning in metacommunity assemblages. Yet, mycorrhizal communities and interactions remain unknown for orchids that are highly specialized or even obligated in their associations with their mycorrhizal partners. In this study, we sought to compare orchid mycorrhizal fungal (OMF) communities of three co-occurring hemiepiphytic Vanilla species (V. hartii, V. pompona, and V. trigonocarpa) in tropical forests of Costa Rica by addressing the identity of their OMF communities across species, root types, and populations, using high-throughput sequencing. Sequencing the nuclear ribosomal internal transcribed spacer (nrITS) yielded 299 fungal Operational Taxonomic Units (OTUs) from 193 root samples. We showed distinct segregation in the putative OMF (pOMF) communities of the three coexisting Vanilla hosts. We also found that mycorrhizal communities associated with the rare V. hartii varied among populations. Furthermore, we identified Tulasnellaceae and Ceratobasidiaceae as dominant pOMF families in terrestrial roots of the three Vanilla species. In contrast, the epiphytic roots were mainly dominated by OTUs belonging to the Atractiellales and Serendipitaceae. Furthermore, the pOMF communities differed significantly across populations of the widespread V. trigonocarpa and showed patterns of distance decay in similarity. This is the first report of different pOMF communities detected in roots of wild co-occurring Vanilla species using high-throughput sequencing, which provides evidence that three coexisting Vanilla species and their root types exhibited pOMF niche partitioning, and that the rare and widespread Vanilla hosts displayed diverse mycorrhizal preferences.

Spatial and diel variations of bacterioplankton and pico-nanoeukaryote communities and potential biotic interactions during macroalgal blooms

We investigated spatial heterogeneity and diel variations in bacterioplankton and pico-nanoeukaryote communities, and potential biotic interactions at the extinction stage of the Ulva prolifera bloom in the Jiaozhou Bay, Yellow Sea. It was found that the presence of Ulva canopies significantly promoted the cell abundance of heterotrophic bacteria, raised evenness, and altered the community structure of bacterioplankton. A diel pattern was solely significant for pico-nanoeukaryote community structure. >50 % of variation in the heterotrophic bacterial abundance was accounted for by the ratio of Bacteroidota to Firmicutes, and dissolved organic nitrogen effectively explained the variations in cell abundances of phytoplankton populations. The factors representing biotic interactions frequently contributed substantially more than environmental factors in explaining the variations in diversity and community structure of both bacterioplankton and pico-nanoeukaryotes. There were higher proportions of eukaryotic pathogens compared to other marine systems, suggesting a higher ecological risk associated with the Ulva blooms.

Biochar pH reduction using elemental sulfur and biological activation using compost or vermicompost

This study aimed to improve biochar’s quality for arid land applications by using elemental sulfur as a pH reducer agent co-applied with compost or vermicompost as biological activators. Biochar pH was decreased by the addition of elemental sulfur, with the highest reduction from 8.1 to 7.2 occurring when co-amended with vermicompost. Elemental sulfur increased the water-soluble concentrations of calcium, magnesium, and many other elements, and stimulated substrate-induced respiration, especially when co-amended with vermicompost. The bacterial diversity community structure were significantly affected by all treatments. The Shannon index significantly increased in response to compost and sulfur treatments, while the vermicompost treatments showed higher microbial evenness and equitability diversity indices. Multivariate analyses indicated that elemental sulfur oxidation was associated with specific sulfur-oxidizing bacterial clusters. Integrating biochar with sulfur and (vermi)compost was found to be a promising sustainable technology for managing excessive biochar alkalinity, increasing its fertility and potential for application in aridlands.

A study on spatio-temporal variations in physicochemical parameters and ciliate community structure of three freshwater bodies from Delhi, India

A study on spatio-temporal variations in physicochemical parameters and ciliate community structure of three freshwater bodies from Delhi, India

Coexistence Perspectives: Exploring the impact of landscape features on aesthetic and recreational values in urban parks

Urban parks play a crucial role in providing social services and promoting the health and well-being of residents. They serve not only as primary aesthetic spaces for urban residents but also as crucial venues for recreational activities. Exploring strategies for constructing urban parks that integrate landscape aesthetics and recreational value is essential. This approach will contribute to enhancing the quality of urban parks to meet the genuine needs of urban residents. However, there is currently limited attention given to related research. Based on this, the study focuses on Jinshan Park in Fuzhou City, Fujian Province, China, to investigate the relationship between landscape features and the coexistence of landscape aesthetics and recreation values of urban parks. The research employed field observations and questionnaire surveys to assess the landscape aesthetic and recreational values of urban parks and explore their coexistence. Additionally, semantic segmentation and other methods were introduced to quantify landscape features. Linear regression analysis was then applied to further examine the impact of landscape features on the landscape aesthetic and recreational values in urban parks, as well as their coexistence. The results revealed: (1) The landscape aesthetics of Jinshan Park is moderate, and the pattern of recreational activities in the park follows a sequence of passing‐by behaviors > static behaviors > dynamic behaviors, with the primary user demographic being middle-aged and elderly individuals. The coexistence of landscape aesthetics and recreational values in Jinshan Park needs to be improved. In comparison, the degree of coexistence between aesthetics and passing‐by behavior is relatively high. (2) The landscape aesthetics of urban parks are influenced by natural elements, with green view index playing a more crucial role. Recreational behaviors are jointly influenced by spatial, natural, construction, and facility elements. Concerning different types of behaviors, spatial elements have a significant impact on public static and dynamic behaviors, followed by natural elements and facility elements. Passing‐by behaviors are most influenced by construction elements, followed by spatial elements and facility elements. (3) The coexistence of landscape aesthetics and static behavior is facilitated by the presence of more water, an appropriately green view index, and a diverse plant community structure. Improving sky openness and green view index can effectively promote the coexistence of aesthetics with dynamic behavior. The coexistence of aesthetics and passing‐by behaviors is influenced by sky openness, garden architecture, and service facilities. This study provides a scientific theoretical foundation and a model reference to guide the construction of urban parks that integrate both aesthetic and recreational values.

Anaerobic mono-digestion and co-digestion of food waste and mixed sewage sludge: A comparative analysis of metabolic patterns and taxonomic profiles

This study systematically compares the anaerobic mono-digestion and co-digestion of food waste (FW) and sewage sludge to understand the effects of feedstock composition on biogas yield and microbial community structure. The results showed that FW mono-digestion is optimal for methane production, achieving a peak yield of 377.25 ± 29.55 mL/g volatile solids fed (VSfed) but also generated significant quantities of hydrogen (151.59 ± 1.35 mL H2/g VS) during initial hydrolysis and acidogenesis phases. In contrast, waste-activated sludge (WAS) mono-digestion results in significantly lower methane yields (206.63 ± 1.18 mL/g VSfed). However, co-digesting FW with WAS enhances process stability, reducing the lag phase duration, albeit with an 8 % decrease in methane production relative to the theoretical potential. Further, it was observed when WAS was co-digested with primary sludge (PS), leading to a 34 % increase in methane yield compared to WAS mono-digestion. Soluble protein breakdown was highly efficient in WAS and PS treatments, exceeding 80 %, while FW treatments achieved less than 14 % degradation. Taxonomic analysis revealed a dominance of Firmicutes, specifically Clostridium sensu stricto 1, in FW reactors, whereas WAS and PS reactors supported a more diverse microbial community structure. Enzyme analysis indicated an upward trend in cellulase activity in WAS and PS reactors over time. These insights emphasize the importance of selecting appropriate feedstock combinations to enhance methane production, offering a pathway to more efficient anaerobic digestion processes and improved biogas recovery from organic waste.

Variations and Interseasonal Changes in the Gut Microbial Communities of Seven Wild Fish Species in a Natural Lake with Limited Water Exchange during the Closed Fishing Season.

The gut microbiota of fish is crucial for their growth, development, nutrient uptake, physiological balance, and disease resistance. Yet our knowledge of these microbial communities in wild fish populations in their natural ecosystems is insufficient. This study systematically examined the gut microbial communities of seven wild fish species in Chaohu Lake, a fishing-restricted area with minimal water turnover, across four seasons. We found significant variations in gut microbial community structures among species. Additionally, we observed significant seasonal and regional variations in the gut microbial communities. The Chaohu Lake fish gut microbial communities were predominantly composed of the phyla Firmicutes, Proteobacteria(Gamma), Proteobacteria(Alpha), Actinobacteriota, and Cyanobacteria. At the genus level, Aeromonas, Cetobacterium, Clostridium sensu stricto 1, Romboutsia, and Pseudomonas emerged as the most prevalent. A co-occurrence network analysis revealed that C. auratus, C. carpio, and C. brachygnathus possessed more complex and robust gut microbial networks than H. molitrix, C. alburnus, C. ectenes taihuensis, and A. nobilis. Certain microbial groups, such as Clostridium sensu stricto 1, Romboutsia, and Pseudomonas, were both dominant and keystone in the fish gut microbial network. Our study offers a new approach for studying the wild fish gut microbiota in natural, controlled environments. It offers an in-depth understanding of gut microbial communities in wild fish living in stable, limited water exchange natural environments.

Physicochemical Variation of Water, Diversity, and Bacterial Community Structure in Post-coal Mining Ponds of Different Ages in Samarinda, East Kalimantan, Indonesia

<p>This study aims to determine physicochemical variation of water, diversity, and community structure of bacteria at post-coal mining ponds of various ages located in Samarinda, East Kalimantan, Indonesia. Bacteria species were identified using a metagenomic approach on the Next-Generation Sequencing (NGS) nanopore platform and analyzed using the QIIME2 pipeline. The result showed that ponds aged > 20 years old had better water quality compared to others < 5 years old. In addition, ponds > 20 years old had lower conductivity values (0,21-0,40 mS/cm), water temperature (29,1-30,1oC), and sulfur content (2,35-6,44 mg/L), as well as higher pH (6,57-7,61) and abundance of sulfur-oxidizing bacteria (SOB) (217-364 CFU/mL). Based on the results, ponds < 5 years old had water quality characterized by higher conductivity (0,27-1,29 mS/cm), water temperature (30,1-31,4 oC), and sulfur content (6,56-15,03 mg/L), lower pH (2,93-3,72), and abundance of SOB (0-38 CFU/mL). Diversity and structure of bacteria community showed that the Operational Taxonomic Unit (OTU) in post-coal mining ponds > 20 years old was 3819 compared to 2027 in those < 5 years old. Bacteria community in post-coal mining ponds > 20 years old consisted of 11 phyla and 45 classes, while those < 5 years old had 9 phyla and 38 classes. Moreover, the relative abundance of families, genera, and species at ponds > 20 years old was also higher. The high water quality, diversity, and community structure of bacteria at ponds > 20 years old showed the successful remediation of ponds water by SOB.</p>

Density data for Lake Erie benthic invertebrate assemblages from 1930 to 2019.

Benthic invertebrates are important trophic links in food webs and useful bioindicators of environmental conditions, but long-term benthic organism abundance data across broad geographic areas are rare and historic datasets are often not readily accessible. This dataset provides densities of benthic macroinvertebrates collected from 1930 to 2019 during surveys in Lake Erie, a Laurentian Great Lake. The surveys were funded by the governments of the United States and Canada to investigate the status and changes in the benthic community. From the total of 21 lake-wide and basin-wide benthic surveys conducted in Lake Erie from 1929 to 2019, we were able to acquire data for 17 surveys, including species-level data for 10 surveys and data by higher taxonomic groups for seven surveys. Our amassed Lake Erie dataset includes data from 11 surveys (including five with species-level data) conducted in the western basin in 1930-2019, seven surveys (six with species-level data) in the central basin, and eight surveys (seven with species-level data) in the eastern basin (1973-2019). This Lake Erie dataset represents the most extensive temporal dataset of benthic invertebrates available for any of the Laurentian Great Lakes. Benthic samples were collected using Ponar or Shipek bottom dredges and taxa densities were calculated as individuals per square meter using the area of the dredge. Density data are provided for taxa in the Annelida, Arthropoda, Mollusca, Cnidaria, Nemertea, and Platyhelminthes phyla. Current taxonomy was used for most groups but, in a few cases, older taxonomic names were used for consistency with historical data. Analysis of this dataset indicates that eutrophication, water quality improvement, and dreissenid introduction were the major drivers of changes in the benthic community in the western basin, while hypoxia was a major factor in the central basin, and dreissenid introduction was the most important driver in the eastern basin. Considering the rarity of high taxonomic resolution long-term benthic data for lake ecosystems, this dataset could be useful to explore broader aspects of ecological theory, including effects of eutrophication, hypoxia, invasive species, and other factors on community organization, phylogenetic and functional diversity, and spatial and temporal scales of variation in community structure. In addition, the dataset could be useful for studies on individual species, including abundance and distribution, species co-occurrence, and how the patterns of dominance and rarity change over space and time. Use of this dataset for academic or educational purposes is encouraged as long as this data paper is properly cited.

Thirty years of change: Assessing the dynamics of fish communities in Daya Bay, a semi-enclosed coastal ecosystem of the South China sea

Daya Bay is a semi-enclosed bay in the South China Sea which is a coastal ecosystem with significant ecological and economic value that is subjected to a variety of anthropogenic disturbances. However, long-term variation in fish community structure in this Bay remains uncertain. In this study, we aimed to explore the changing characteristics of fish species composition and community structure in Daya Bay during the past 30 years using data from 1989 to 2021 from bottom trawl surveys and historical literature data. As of now, a total of 544 species of fish have been identified in the Bay, belonging to 24 orders and 125 families. The structure of the fish community in the bay has changed over time. Firstly, there has been a clear decrease in the number of species and biomass of large fish. Secondly, the number of fish constituent orders and families has decreased. Moreover, both the average taxonomic distinctness and variation in taxonomic distinctness decreased from 1989 to 2021. Thirdly, there is low similarity among fishes at different time phases and distinct changes in the composition of dominant species. Present results indicate that the fish community structure in Daya Bay has tended to reflect a decline in diversity, shifts in composition, and shrinking of fish body size in the past 30 years. This study improves our understanding of fish species composition and its drivers over time in Daya Bay, providing important knowledge to support the protection and restoration of this ecosystem and the important ecosystem services it provides.