Benthic Invertebrate Community Composition Research Articles

Local factors drive the richness, biomass and composition of benthic invertebrate communities in Neotropical reservoirs

Local factors drive the richness, biomass and composition of benthic invertebrate communities in Neotropical reservoirs

Functional Traits Drive the Changes in Diversity and Composition of Benthic Invertebrate Communities in Response to Hydrological Regulation

Of all the environmental elements that influence the biological communities of rivers, water flow characteristics are undoubtedly the most important. Unfortunately, natural hydrological characteristics are increasingly threatened by human activities, especially in alpine or high mountain areas where there are numerous hydropower plants. In this study, we analysed the impact of hydrological alterations on the macroinvertebrate community of a lowland river in NW Italy. Specifically, we analysed the macroinvertebrate communities of an unaffected site by comparing them with those of a site subject to hydrological alteration. We adopted an approach that is not only taxonomic but also functional, allowing us to study a component of biodiversity that is generally less known. Our results show that the flow-altered site hosted a benthic community with lower species and functional diversity than the control site. Interestingly, we also detected a number of significant differences between the summer and autumn samples. In particular, examination of community-weighted mean (CWM) trait values reveals significant variation in body size, voltinism, substrate, locomotion, feeding habits and other traits between sites and seasons. The integration of taxonomic and functional approaches provides a comprehensive understanding of how human-induced hydrological variations can affect aquatic biodiversity and ecological functions.

Habitat type strongly influences the structural benthic invertebrate community composition in a landscape characterized by ubiquitous, long-term agricultural stress

ABSTRACT The importance of small waterbodies for biodiversity and ecosystem processes has long been neglected in research and policy development. However, because of their heterogeneous characteristics and habitat structures, these waterbodies are biodiversity hotspots for various aquatic and terrestrial organisms, as previously shown for rotifers, aquatic birds, and amphibians. Knowledge of benthic invertebrate community structures in small waterbodies is scarce. Thus, we performed a comprehensive field study of these structures in an agricultural landscape in the northeastern German lowlands. We obtained a dataset containing biological (taxon abundances) and chemical (pesticide residue and nutrient concentration) data as well as data on environmental parameters (e.g., conductivity and habitat type) for 111 samples. The dataset was analyzed using generalized linear models, permutational multivariate analysis of variance, and partial redundancy analysis to understand the relationships among benthic invertebrate communities, agricultural stressors, and environmental parameters. The factor that best explained structural community composition was habitat type. Pesticide and nutrient concentrations were of minor importance in our analysis. Because of the ubiquitous and long-term occurrence of the agricultural stressors, the structural indices used in benthic invertebrate biomonitoring were not sufficiently sensitive to provide information on the main environmental variables that shape macroinvertebrate communities.

Responses by benthic invertebrate community composition to dissolved organic matter in lakes decline substantially above a threshold concentration

Abstract Dissolved organic matter (DOM), often measured as dissolved organic carbon (DOC), plays a fundamental role in influencing the structure and function of lake ecosystems. Due to the myriad ecosystem effects of DOM, widespread observations of long‐term increasing DOM concentrations have received much attention from ecologists. DOM positively influences primary production and consumer production at low concentrations due to the fertilising influence of bound nutrients. However, beyond a unimodal peak in production, a reduced light environment may result in a negative effect on production. This unimodal model has been largely developed and tested in lakes with low to moderate DOM concentrations (i.e., typically ≤10 mg/L DOC). To understand ecological responses in lakes across a larger range in DOM concentrations, we examined the response of benthic invertebrate communities in 148 Swedish lakes with DOM concentrations ranging between 0.67 and 32.77 mg/L DOC. We found that increasing DOM concentrations had a strong effect on invertebrate community composition below c. 10 mg/L. Across this range, abundances of individual taxa both increased and decreased, probably in response to environmental change induced by DOM. However, in lakes above this concentration, increasing DOM had minimal influence on community composition. As DOM concentrations continue to increase, faunal communities in lakes below this 10 mg/L DOC threshold are likely to undergo substantial change whereas those above this threshold are likely to be minimally impacted.

State of benthic invertebrate communities and water quality in the ponds of Noginsk district of Moscow region

Hydrochemical regime is one of the important factors affecting the species composition and the amount of benthic invertebrate communities in a water body. With heavy metal pollution and high eutrophication, the oligochaete index increases, the species diversity of benthic invertebrate communities decreases, and almost all representatives of the entomofauna disappear, with the exception of chironomids. Pollution with phosphates and ammonium nitrogen has an adverse effect on the development of benthic invertebrate communities. At present, the amount of available scientific data on the influence of hydrochemical factors on the development of benthic invertebrate communities in pond farms seems to be insufficient, the focus is on hydrological factors, and this suggests the relevance of new research in this area. The purpose of this study was to compare hydrochemical and temperature indicators with the quantitative and qualitative composition of benthic invertebrate communities in three ponds of Noginsk district of Moscow region in December 2022 - January 2023. The selection of hydrobiological materials and water samples for hydrochemical analysis was carried out in December 2022 - January 2023 in the ponds of Noginsk district of Moscow region in EPB RRIFF, a branch of the Federal State Budgetary Scientific Institution FRC RIAH named after L.K. Ernst. Pond № 1 has an area of 4,48 ha, pond № 2 has an area of 1,7 ha, pond № 3 has an area of 0,61 ha. The studies conducted in December 2022 - January 2023 showed the presence of correlation between water quality (the sum of hydrochemical indicators: concentration of ammonium and nitrate nitrogen, phosphates, total iron, general and carbonate hardness, total mineralization, as well as water temperature) and benthic invertebrate communities (qualitative and quantitative) development indicators. The best indicators of benthic invertebrate communities development were observed in the pond with the best water quality (from a fishery point of view), the worst ones were observed in the pond with the worst water quality (zoobenthos was not found in samples from this pond). In total, 6 taxones of benthic invertebrate communities were found in the studied ponds.

Восстановление макрозообентоса после дноуглубительных работ на озере Манжерокском (Республика Алтай)

Dredging is the activity of excavating soil and performing other soil operations in order to expand and increase the depth of water bodies. Under conditions of increased pollution, dredging operations may cause certain damage to aquatic ecosystems in general and to particular aquatic species. The changes in the composition and structure of benthic invertebrate communities have been studied in Lake Manzherokskoe in different periods: before dredging (2007), two weeks after the dredging has been started (2018), and 3 years after the dredging activities have been finished (2021). In 2021, there was an increase in species diversity and quantitative indicators of the development of benthic communities comparing to the period of dredging completion. Our data indicated the restoration of macrozoobenthos community in the lake to a certain extent. Later, this process may end in complete restoring with an increase in the water level in the lake and a significant decrease in the technogenic load on bottom communities.

Re-assessing the degradation of benthos beneficial use impairment in the Toronto and Region Area of Concern

Sediment quality of the Toronto and Region Area of Concern (AOC) waterfront was assessed using a weight of evidence approach following the Sediment Quality Triad, with the addition of contaminant bioaccumulation data, to determine current status following the 2013 re-designation of the “degradation of benthos” Beneficial Use Impairment as “no longer impaired.” Five stations within the AOC were sampled in 2015 and compared to lower Great Lakes nearshore reference areas (n = 22) selected based on similarity of sediment physicochemical properties. Sediment chemistry was comparable except for a localized instance of elevated perfluorinated compounds at one AOC site. Laboratory sediment toxicity bioassays indicated chronic toxicity associated with point sources to the AOC, corresponding to increased invertebrate body burdens measured in laboratory exposures. Diversity metrics and multivariate analysis showed that benthic invertebrate community composition present at the AOC sites was not significantly different from reference conditions of the lower Great Lakes. The weight of evidence from this study indicates benthic invertebrate communities continue to show effects of degraded sediment conditions at sites impacted by point sources. While the 2013 RAP decision was to re-designate the “degradation of benthos” BUI to “no longer impaired,” our results support the notion that life after AOC delisting must continue to prioritize monitoring efforts.

Do changes in temperature affect EU Water Framework Directive compliant assessment results of central European streams?

BackgroundBenthic invertebrate communities are an integral and longstanding component of stream biomonitoring. However, multiple stressors driven by global change threaten benthic invertebrate communities. In particular, climate warming is expected to disrupt freshwater ecosystems. While an increasing number of studies have shown changes in benthic invertebrate community composition in response to climate warming, the effect on stream assessments has rarely been investigated. As several community composition metrics are also used in stream assessments, we predicted that climate warming would worsen stream assessment results. Therefore, we used a comprehensive data set of 2865 benthic invertebrate samples taken between 2000 and 2014 from small central European low mountain streams. We examined the effects of changes in temperature on common community and stream assessment metrics. We used 31 metrics covering composition, richness, tolerance and function of communities, of which many are used in various stream assessment schemes.ResultsAgainst our expectations, we identified a decreasing air temperature trend of − 0.18 °C over 15 years. This trend was accompanied by significant changes in community composition, for example, increases in species richness and decreases in the community temperature index (CTI). Further, we identified slight concomitant improvements of various globally used stream quality assessment metrics, such as a decreasing saprobic index and an increasing BMWP.ConclusionsWhile temperature increased by + 0.9 °C during the past 30 years (1985–2014), our 15-year study period (2000–2014) showed a decrease by − 0.18 °C. Therefore, we regard the concomitant improvement in several assessment metrics as a recovery from prior increasing temperatures. In turn, we assume that increases in water temperature will lead to opposite effects and therefore cause declining assessment results. Water managers should be aware of this linkage that in turn could provide a chance to mitigate the effects of global warming by, for example, planting trees along the rivers and the removal of artificial barriers to increase current velocity to minimize a warming effect.

黄河三角洲芦苇湿地底栖无脊椎动物与环境因子的关系研究——以石油开采区与淡水补给区为例

PDF HTML阅读 XML下载 导出引用 引用提醒 黄河三角洲芦苇湿地底栖无脊椎动物与环境因子的关系研究——以石油开采区与淡水补给区为例 DOI: 10.5846/stxb201901100087 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家重点研发计划项目（2017YFC0505901）；国家青年科学基金项目（41801084）；吉林省科技发展计划项目（20180101080JC）；中国博士后科学基金项目（194419） Composition of benthic invertebrate communities in reed (Phragmites australis) wetlands of the Yellow River Delta: Comparisons between oil exploitation and freshwater recharge areas Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:分别于2018年5月和8月对黄河三角洲芦苇湿地19（淡水补给区11处，石油开采区8处）处采样点的底栖无脊椎动物和水体理化指标进行调查采样，运用统计方法分析两个区域物种组成、优势种、多样性、群落结构以及与环境因子的关系。结果表明：两季共采集到底栖无脊椎动物54种，主要以水生昆虫、腹足纲和软甲纲为主，淡水补给区和石油开采区各类群组成差异明显。独立样本T检验表明淡水补给区和石油开采区水体理化指标间差异显著（P<0.05）。双因子方差分析显示，昆虫纲和腹足纲密度在两区域差异显著（P<0.05），软甲纲和腹足纲密度在季节上差异明显（P<0.05）。底栖无脊椎动物优势种共10种，淡水补给区指示物种8种，而石油开采区未发现有指示物种。聚类和非参数多维排序（nMDS）显示，底栖无脊椎动物群落结构相似性较低；RDA结果表明：淡水补给区底栖无脊椎动物群落结构主要受Cond，TDS，Sal，pH，Eh，HCO3-，SO42-等环境因子的影响。石油开采区底栖无脊椎动物群落结构影响较大的环境因子为HCO3-、NH4-N。 Abstract:The benthic invertebrates and environmental factors were sampled and analyzed in May and August, 2018 from 19 sites of reed wetlands (11 freshwater recharge areas and 8 oil exploitation areas) in the Yellow River Delta. Multivariate analysis methods were used to analyze the composition, dominant species, biodiversity, community of benthic invertebrate assemblages, as well as their relationships to the environmental factors. The results showed that 54 taxa collected by two samplings were mainly composed by Aquatic Insect, Gastropoda and Mollusca. There are obvious differences in composition of benthic invertebrates between freshwater recharge and oil exploitation area. Independent-Samples T Test showed that freshwater recharge area and oil exploitation area were significant different in environmental factors (P<0.05). Two-way ANOVA analysis showed that there were significant differences in insect and Gastropoda density between the two regions (P<0.05). The seasonal variations of Mollusca density and Gastropoda density were both significant (P<0.05). Ten species of benthic invertebrates were dominant in the study area. Eight species of benthic invertebrate were tested to be the indicator species in freshwater recharge area, but no indicator species were found in oil exploitation area. Cluster and nMDS analysis indicated the low similarity of the benthic invertebrate community between the freshwater recharge area and oil exploitation area. The RDA results showed that the community structure of benthic invertebrates in freshwater recharge area was mainly affected by Cond, TDS, Sal, pH, Eh, HCO3-, SO42- and the influential environmental factor in oil exploitation areas were HCO3-and NH4-N. 参考文献 相似文献 引证文献

Bioassessment of a Northwest Florida Estuary Using Benthic Macroinvertebrates.

Benthic invertebrate community composition was surveyed across the salinity gradient of the Pensacola Bay Estuary in Florida during summer 2016. Macrofauna densities ranged from 1000 to 9300 individuals m-2 , with highest densities occurring at the upper estuary and the lowest in the mid- and lower estuary. Taxonomic richness and Shannon diversity were lowest in the upper estuary and increased along the salinity gradient. Small-bodied, near-surface infaunal polychaete species (e.g., Mediomastus ambiseta and Paraprionospio alata) dominated the macrofaunal community in fine sediment areas. We calculated the Gulf of Mexico Benthic Index of Biological Integrity for each site and compared the index scores with those from Environmental Monitoring and Assessment Program - Estuaries, an earlier benthic assessment model. Condition evaluations by the different models did not match across all sites in this study; however, scores consistently indicated that most sites were at or near degraded levels, implying that Pensacola Bay represents a marginal habitat for a "healthy" benthic macrofauna community. This study provided new information about the benthic communities and sediments in the Pensacola Bay estuary. Integr Environ Assess Manag 2020;16:245-256. Published 2019. This article is a US Government work and is in the public domain in the USA.

Freshwater release into estuarine wetlands changes the structure of benthic invertebrate assemblages: A case study from the Yellow River Delta

Freshwater releases to wetlands degraded by excessive soil salinity in estuarine areas have been widely used to restore vegetation and maintain biodiversity of the wetland ecosystems. However, freshwater release also alters the physical and chemical properties of the water body, having a profound impact on the ecology of restored wetland ecosystems. In this study, physical and chemical parameters of water quality were compared between restored and non-restored tidal wetlands after 10 years of freshwater release in the Yellow River estuary. In addition, benthic invertebrates were used as bioindicators to reveal the effects of freshwater release on estuarine wetland ecology. The results showed that there was a significant difference in salinity between restored and non-restored wetlands (P < 0.05), which led to differences in the composition of benthic invertebrate communities (ANOSIM P < 0.001). The primary components of benthic invertebrate community were insects in restored wetlands, and in non-restored tidal wetlands the primary components were annelids, crustaceans, and gastropods. More long-term monitoring research of the impacts of freshwater introduction on degraded estuarine wetland ecosystems is needed to fully assess consequences.

Effects of hydropeaking on benthic invertebrate community composition in two central Norwegian rivers

AbstractHydropower regulations can have dramatic impacts on river ecological communities. The operation of hydropower stations is related to power demands, but their releases in the receiving water body causes sudden changes in flow, which in turn affect the biota. The effects of such flow variations on benthic invertebrates is not fully understood. Here, we studied the effects of duration and intensity of hydropeaking on benthic invertebrates in two rivers over a 3.5‐year period. We used both quantitative (Surber) and semiquantitative (kick samples) sampling methods to compare the ramping zone with the permanently water covered zone downstream of the hydropower plant, and with corresponding unaffected upstream areas. The ramping zone had a different invertebrate community composition and lower benthic density than other areas, especially after hydropeaking. Mayflies and chironomids were most negatively affected by hydropeaking and oligochaetes largely unaffected. Chironomids and the mayfly Baetis rhodani were able to recolonize the ramping zone and almost reach densities similar to deeper areas within 48 days following hydropeaking. The relative abundance of filter feeders tended to increase and gatherers/collectors tended to decrease from the ramping zone towards the deep, permanently water covered areas. In corresponding areas upstream of the power plant, the relative abundance of different functional feeding groups was the same in the mid‐channel and shore sites. Our study shows that hydropeaking has clear impacts on the functional structure of benthic invertebrates below the power plants. The ecological impact of hydropeaking on invertebrate communities should thus be taken into account, for example, by reducing the amplitude and duration of flow fluctuations.

Benthic Invertebrate Community Composition and Sediment Properties in Barnegat Bay, New Jersey, 1965−2014

ABSTRACT Taghon, G.L.; Ramey, P.A.; Fuller, C.M.; Petrecca, R.F.; Grassle, J.P., and Belton, T.J., 2017. Benthic invertebrate community composition and sediment properties in Barnegat Bay, New Jersey, 1965−2014. In: Buchanan, G.A.; Belton, T.J., and Paudel, B. (eds.), A Comprehensive Assessment of Barnegat Bay–Little Egg Harbor, New Jersey. Extended time series of estuarine benthic community composition and the chemical and physical properties of sediment are necessary for distinguishing natural variation from possible anthropogenic influences, such as eutrophication. In July 2012, 2013, and 2014, 97 stations, randomly located throughout the Barnegat Bay–Little Egg Harbor estuary, were sampled. Benthic invertebrates were abundant, and the community was, in general, highly diverse. Although there was considerable spatial variability in sediment-particle sizes throughout the estuary, overall the total organic carbon content of the sediments was low (<1%). Comparable historical data from 1965–2010 are spotty...

Application of regional flow‐ecology relationships to inform watershed management decisions: Application of the ELOHA framework in the San Diego River watershed, California, USA

AbstractRelationships between changes in streamflow and changes in biological condition are important considerations for water resources management decisions. The Ecological Limits of Hydrologic Alteration (ELOHA) framework offers a way to protect stream health by managing flow conditions. We demonstrate application of a regionally derived ELOHA framework to inform stakeholder defined management challenges in the San Diego River Watershed in southern California, USA—a large semi‐urbanized watershed that is undergoing land use changes. Using previously defined flow‐ecology relationships based on benthic invertebrate community composition, we: (1) assess how future land use changes will affect flow conditions and impact biological endpoints in the watershed; (2) demonstrate how flow–ecology relationships can be used to prioritize regions of the watershed into various flow management classes that can inform future planning decisions; and (3) evaluate how two future management decisions (specifically, modification of reservoir operations and implementation of low impact development strategies to reduce stormwater runoff) will affect in‐stream flow conditions in the watershed. Our study shows a successful transition of regionally derived flow targets to inform local decisions at a catchment or watershed scale, thereby avoiding the need to develop local flow–ecology relationships for every stream of interest (as would be required by other instream flow methods). Case studies are a critical bridge between the science of flow‐ecology and real‐world implementation, and this work illuminates an example of how to navigate technical and management challenges and provide road maps for broader applications by including local stakeholders in defining, interpreting, and implementing products of flow‐ecology analyses.

Impact of Al-Rasheed Power Plant Effluents on Biodiversity of Benthic Fauna in Tigris River, Southern Baghdad

Quantitative and qualitative composition of benthic invertebrate communities was studied during the period from January to December2012 at four stations that were selected on the Tigris River at Baghdad Province. One of the stations S2 located near Al-Rasheed Power Plant (RPP) to represent the ecological features of the plant site, whereas other stations, S1 were located at the upstream of the RPP as a control station to investigate the ecological characters of the Tigris River. Moreover, the two other stations S3 and S4 were located down to the impact of RPP to reflect the possible effects of the plant on the ecology of the river by comparison with the control stations. The present study recorded 44 taxa belong to 4 order which are: 11 taxa belonged to Annelida(Oligochaeta) which recorded the highest percentage73% of the total number of benthic invertebrates, 18 taxa belong to Arthropoda with 9%, 11 taxa belonging to Mollusca with 13%, 4 taxa belong to Nematoda with 5%, monthly density ranged 325 – 64987 Ind. /m2 at all stations. Generally the result of biodiversity indicators shows the negative effect of thermal effluent of RPP on benthic invertebrate community at S2.

香溪河水生昆虫功能性状及功能多样性空间格局

PDF HTML阅读 XML下载 导出引用 引用提醒 香溪河水生昆虫功能性状及功能多样性空间格局 DOI: 10.5846/stxb201510292183 作者: 作者单位: 枣庄学院生命科学学院,中国科学院水生生物研究所,中国科学院水生生物研究所 作者简介: 通讯作者: 中图分类号: 基金项目: 国家水体污染控制与治理科技重大专项（2012ZX07501002-007）；枣庄学院国家自然科学基金预研项目（2014YY03） Spatial distribution patterns of trait composition and functional diversity of aquatic insects in the Xiangxi River system Author: Affiliation: College of Life Sciences,Zaozhuang University,Institute of Hydrobiology, Chinese Academy of Sciences,Institute of Hydrobiology, Chinese Academy of Sciences Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:近年来，生物多样性研究已从群落物种多样性拓展至功能多样性层面，使用功能性状表征功能组成及功能多样性是当前底栖动物生态学研究的热点之一。物种功能性状对环境变化敏感，对群落和种群沿环境梯度的演替具有许多潜在的指示作用。为了解香溪河水系水生昆虫功能性状空间分布格局及环境因子对功能多样性的影响，于2005年12月及2006年1月、2月对该水系的香溪河、九冲河、高岚河、古夫河4条河流的水生昆虫进行了调查，并对理化指标进行了测定；参考相关文献资料，本研究选择化性、漂移性、游泳能力、吸附能力、形状、个体大小、流态偏好、温度偏好、生活型、营养习性等10个功能性状纳入分析。研究结果发现，香溪河水系共鉴定水生昆虫127种，四节蜉（Baetis sp.）、高翔蜉（Epeorus sp.）、短尾石蝇（Nemoura sp.）为区域优势分类单元，相对丰度分别为38.6%、9.1%、6.7%；4条河流间优势物种组成差异较大。10个功能性状中相对丰度最高的等级性状分别为1世代/a（Volt2）、高漂移率（Drft3）、无游泳能力（Swim1）、无吸附能力（Atch1）、流线型（Shpe1）、小型个体（Size1）、沉积/侵蚀流态兼好型（Rheo2）、广温型（Ther2）、附着型（Habi4）、收集者（Trop1）；单因素方差分析及独立样本T检验表明，化性、附着能力、大小、流速偏好、温度偏好、漂移性、生活型、营养习性等性状级别间差异显著，而游泳能力、形状性状等级间无显著差异。对10个功能性状的33个等级性状在4条河流间相对丰度的差异性进行研究，结果发现，Volt1、Drft2、Swim2、Atch1、Atch2、Size3、Rheo1、Ther3、Habi2、Habi3、Trop3、Trop5等12个等级性状相对丰度在4条河流间差异显著。功能性状多样性、树状图功能多样性用来描述4条河流功能多样性，结果表明，功能性状多样性指数均值在古夫河、高岚河、九冲河、香溪河分别为2.8、3.2、6.9和5.4；树状图功能多样性指数均值在分别为4.8、5.7、11.1、8.8。功能冗余度均值在4条河流分别为 2.9、3.4、4.6、3.9。运用逐步回归分析功能多样性、功能冗余度与环境参数的关系，结果表明，功能性状多样性指数受总氮、水深影响显著；树状图功能多样性指数受总氮、水深、流速影响显著；功能冗余度指数受硝态氮、溶解氧、二氧化硅影响显著。 Abstract:Recently, biodiversity research has expanded from community species diversity to functional diversity. The use of species traits to characterize the functional composition of benthic invertebrate communities has become well established in ecological literature. This approach could potentially predict changes of both species and communities along environmental gradients in terms of traits that are sensitive to local environmental changes. With the aim of understanding the influence of environmental factors on the spatial distribution patterns of trait composition and functional diversity of aquatic insects, macroinvertebrates were surveyed at 12 sites along 4 rivers (i.e., Xiangxi, Jiuchong, Gaolan, and Gufu Rivers) in the Xiangxi River system during a period of low flow (from December 2005 to February 2006). Simultaneously, water samples were collected at each site and transported to the laboratory, where the concentrations of 6 parameters (TN, TP, NO2-N, NO3-N, NH4-N, and PO4-P) were determined. Other physical and chemical parameters were measured in the field. Based on published datasets and expert opinion, we compiled information on 10 biological and ecological traits of aquatic insects including voltinism, occurrence in drift, swimming ability, attachment, shape, size at maturity, rheophily, thermal preference, habit, and trophic habit. A total of 127 taxa were collected; Baetis sp., Epeorus sp., Nemoura sp. were the dominant taxa, with relative abundances of 38.6, 9.1, and 6.7% respectively; the dominant taxa compositions were significantly different among the 4 rivers (P <0.05). One-way ANOVA and independent samples T test were performed to compare the traits which showed that the proportion of Volt1 (univoltine), Drft2 (common occurrence in drift), Swim2 (weak swimming ability), Atch1 (none of attachment), Atch2 (some of attachment), Size3 (large size at maturity), Rheo1 (depositional rheophily only), Ther3 (warm eurythermal), Habi2 (climber), Habi3 (sprawl), Trop3 (herbivore), Trop5 (shredder) were significantly different among the 4 rivers (P <0.05). Modified functional attribute diversity and functional diversity based on a dendrogram were calculated to characterize functional diversity in the Xiangxi River system, and the results showed that the Jiuchong River had the highest modified functional attribute diversity (6.9), followed by the Xiangxi (5.4), Gaolan (3.2), and Gufu (2.8) Rivers; functional diversity based on a dendrogram and functional redundancy index also showed the same pattern. One-way ANOVA analysis showed that these 2 functional diversity indices all showed Jiuchong River > Xiangxi River > Gaolan, Gufu Rivers; and the functional redundancy index showed Jiuchong River ≥ Xiangxi River ≥ Gaolan River ≥ Gufu River. Finally, a stepwise regression analysis was conducted to exam the relationship between functional indices and physicochemical parameters. The results showed that modified functional attribute diversity was significantly impacted by total nitrogen, and water depth; whereas functional diversity based on a dendrogram was impacted by total nitrogen, water depth, and flow velocity; and functional redundancy was affected by nitrate-N, dissolved oxygen, and silicon dioxide. 参考文献 相似文献 引证文献

Multiple stressor effects on stream health in the Lake Simcoe Watershed

The Lake Simcoe Watershed (LSW) is an important natural resource, supporting varied agricultural, recreational, and tourism activities for millions of people. Historically, major alterations to land uses have occurred throughout the watershed, resulting in increases of nutrients and contaminants, and alteration of hydrological and thermal regimes. The combination of these stressors has the potential to elicit greater impacts on ecosystem health than any one stressor in isolation, yet no studies have examined their effects on stream health and aquatic biota in the LSW. In this study, we quantified the impacts of multiple stressors on indices of biotic integrity, as well as assessments of benthic invertebrate and fish community composition from 2004 to 2012. Using a suite of multivariate analyses, we examined stressors across three categories of environmental variables: water quality, temperature, and hydrology. Water quality explained the largest amount of variation in stream health and biological community composition, followed by water temperature and hydrological variables, respectively. Total phosphorus, dissolved oxygen, and iron concentrations, as well as the 7-day low flow and the mean summer temperature, were identified as predictors of both fish and benthic invertebrate variance. Multiple stressor interactions were detected for fish communities, although these interactions were of lower relative importance than for individual stressors. In contrast, no significant stressor interactions were found to influence benthic invertebrate communities. Overall, our results reinforce the importance of ecosystem monitoring, and the need to consider the influence of multiple aspects of ecosystem function, when examining the health of aquatic systems.

Distribution and Composition of Benthic-Invertebrate Community at Fish Floating Cages in Tigris River Before Al- Kut Barrier/ Wasit Province, Iraq

Distribution and Composition of Benthic-Invertebrate Community at Fish Floating Cages in Tigris River Before Al- Kut Barrier/ Wasit Province, Iraq

Seamount biodiversity: high variability both within and between seamounts in the Ross Sea region of Antarctica

Seamounts in the Ross Sea were surveyed during the New Zealand IPY-CAML research voyage in 2008. Admiralty seamount, and seamounts of the Scott Island Seamount chain (Scott Island, Scott A, Scott B, Scott South) were sampled to examine variability in benthic faunal communities of seamounts. Multivariate analysis of video and still image data showed that benthic community composition was highly variable both within and between seamounts. The distribution patterns of benthic communities varied considerably, with very high densities of certain taxa in some places, sparse fauna in many others, and highly patchy distributions for others. Dissimilarities between seamounts were influenced by differences in population densities of taxa, the proportions of transects in which taxa were present, and by taxa being restricted to only one seamount or group of seamounts. Scott Island seamount was less similar to the others, despite the greater distances between Admiralty and Scott A and B seamounts. The observed variability in community composition was mainly associated with differences in depth, chlorophyll concentration, and seabed rugosity. Results support an earlier hypothesis that the location of seamounts relative to the Ross Sea gyre could be an important factor determining the composition and abundance of benthic invertebrate communities.

Ecology of a Chalk Aquifer: Composition of Benthic, Hyporheic, and Phreatic Invertebrate Communities in Relation to Changing Environmental Conditions

Groundwater is recognised as an important resource for drinking water, agriculture, and industry, but it also plays an essential role in supporting the functioning of freshwater ecosystems and providing habitat for a number of rare species. However, despite its importance, groundwater ecology often receives little attention in environmental legislation or research. This study aims to improve our understanding of the organisms living in groundwater-dependent habitats and the influence of environmental conditions on their distribution.