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Ditches are widespread and common elements of the agricultural landscape. Although they can provide habitats for aquatic biodiversity, their ecosystem integrity and processes are generally limited or even unknown due to anthropogenic pressures and the paucity of studies on this type of aquatic ecosystem. This study aimed to enhance the knowledge on the biodiversity, ecosystem attributes and ecological status of agricultural ditches by analyzing the macroinvertebrate communities of six different ditches and those of the main river in the same area. While negligible differences in taxonomic richness were observed, macroinvertebrate community composition significantly varied among sites as a function of the heterogeneous habitat conditions. These compositional differences strongly affected the relative abundance of functional feeding groups among sites and their derived ecosystem attributes. Moreover, the ecological status assessment depicted different scenarios depending on the biomonitoring indices applied. By means of a multifaceted, but still poorly adopted, analysis of the macroinvertebrate community, ranging from the taxonomic and functional diversity to ecosystem attributes and biomonitoring indices, the results obtained in this study offer useful information on the ecology of agricultural ditches with potential insights to improving their management. [ABSTRACT FROM AUTHOR]

Rivers of tropical islands formed by volcanic eruptions experience unpredictable and heavy rainfall and are characterised by irregular topography. During the 2019 and 2020 low-water season, we investigated the responses of benthic macroinvertebrate assemblages to variations in local environmental conditions in four rivers located in areas of different rainfall intensity. We found that changes in local environmental conditions associated with lower rainfall intensity reduced abundance and taxonomic richness and modified taxonomic composition but did not impact the balance of functional feeding groups of macroinvertebrate communities amongst streams, except for piercer herbivores. Heterotrophy associated with substrate instability and autotrophy with a more stable substrate co-occurred in semi-arid climate rivers. In contrast, a change from heterotrophy upstream to autotrophy and substrate stability downstream was apparent in the two humid rivers studied. Surrogates of stream ecosystem function revealed a very low ratio of coarse to fine particulate organic matter related to the quasi-absence of shredders in these streams and suggested a low allochthonous input contribution, which could be the result of the 5% decline in forest cover over the two past decades. [ABSTRACT FROM AUTHOR]

Different measures of macroinvertebrate diversity (species diversity, functional diversity, phylogenetic diversity) and functional feeding groups (FFGs) are commonly used to assess the ecological status of large shallow lakes. In this study, biodiversity and FFGs in a large shallow lake, Lake Hongze, differed between littoral and pelagic habitats, with the spatial variability of littoral assemblages more correlated with nutrient concentrations, whilst pelagic assemblages were more associated with wave-induced disturbance (e.g., mean effective fetch). Species diversity was poorly correlated with measures of nutrient concentrations, whereas functional diversity, phylogenetic diversity, and functional feeding groups are promising indicators of nutrient concentrations. Lastly, our findings support the use of biodiversity and FFGs to disentangle the effects of nutrients and wave-induced disturbance on macroinvertebrate assemblages. Furthermore, monitoring both littoral and pelagic habitats in large shallow lakes is recommended to better understand and quantify ecosystem changes. [ABSTRACT FROM AUTHOR]

Urbanization is an inevitable process accompanying economic development. However, the rapid urbanization process is posing a threat to aquatic communities and causing disruptions to river ecosystems. In highly urbanized river ecosystems, the mechanisms of human activities on the functional feeding groups (FFGs) of macroinvertebrates remain unclear, hindering the restoration of river ecosystems. This study focuses on an urban stream called the Yangmei River in Guangzhou and investigates environmental factors and macroinvertebrates in August and November 2022 and February and May 2023. Variance analysis, principal component analysis, and hierarchical cluster analysis were employed to research the temporal and spatial characteristics of FFGs. Redundancy analysis was used to explore the environmental factors influencing FFGs. Finally, ecosystem attributes were calculated based on FFG data and ratios. The results indicate that gathering-collectors dominate in the Yangmei River, leading to a transition toward a heterotrophic river system. Simultaneously, the damaged material transportation function, weakened riparian function, and poor habitat stability all reveal the fact of partial functional degradation of the Yangmei River. This study provides valuable insights into the overall functionality of the Yangmei River and contributes theoretical support for the application of FFG methods in the ecological assessment of highly urbanized rivers. HIGHLIGHTS Gathering-collectors occupy a dominant position in functional feeding groups of macroinvertebrates.; Chemical characteristics act as limiting factors for macroinvertebrates.; River functions about material cycling, transport, and others are impaired.;

We aimed to understand how the environmental variability produced by water parameters, land use, and land cover in small streams affects aquatic hyphomycete and invertebrate assemblages associated with leaf litter. Land use and land cover were quantified in the drainage area of streams located in the subtropical portion of the Atlantic Forest. We incubated Nectandra megapotamica leaves in streams and, after 30 days, collected decomposing litter to analyze associated aquatic hyphomycetes and invertebrates. Dissolved oxygen was associated with the distribution of aquatic hyphomycetes. On the other hand, 4,068 aquatic invertebrates were found, assigned into five functional feeding groups (FFG). Native vegetation and water temperature were the variables responsible for structuring the invertebrate assemblages associated with detritus. Native vegetation, dissolved oxygen, and total dissolved nitrogen were responsible for the structuring of FFGs. Streams that showed high rates of agriculture and urbanization in the drainage area showed low leaf mass loss. Our study demonstrated that the presence of anthropic uses and reduced native vegetation in the drainage area affected the assemblages of aquatic hyphomycetes and shredders, which are key players in the process of leaf decomposition in streams. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Introduction: The Sanzenbacher Ranch deposit represents an early Permian plant assemblage in north-central Texas predominantly composed of pteridosperms, of which callipterids are dominant. This study investigates the interactions of a taxonomically broad range of plant hosts with insects, mites, and pathogens to assess the richness and frequency of damage. Methods: We used standard methods of the functional feeding group-damage type system and analyses graphically illustrated as nonmetric multidimensional scaling. Results: Of the total surface area represented, we quantified the fraction of the area herbivorized, providing a comparative perspective with regard to several similar studies of herbivory at nearby plant assemblages from the late Paleozoic. To assess insect herbivory, 1,361 plant specimens were analyzed, including fronds, leaves, reproductive structures, axes, and wood impressions. A total of 205 specimens presented one or more instances of insect herbivory (11.17%). Callipterid-peltasperms exhibited the highest number of interactions, with Autunia conferta, Rhachiphyllum schenkii, cf. Lodevia sp., cf. Comia sp., and an unidentified callipterid accounting for 49.34% of all interactions. Medullosans represented 10.53%, followed by lyginopterids with 8.55%. Forty-eight damage types (DTs) were recognized and classified into the nine functional feeding groups of hole feeding, margin feeding, surface feeding, piercing and sucking, oviposition, galling, seed predation, borings, and pathogens. Discussion: When compared to analogous late Paleozoic plant assemblages in Texas, Sanzenbacher Ranch exhibited almost all herbivore functional feeding groups, high richness of DTs, and low herbivory index of 0.26. This record shows high plant diversity in a seasonally dry environment that supports a trend of an early Permian increase in DT diversity in southwestern Euramerica. Sanzenbacher Ranch, different from other early Permian plant assemblages, sheds light on the dynamic ecological interactions of these ancient ecosystems. [ABSTRACT FROM AUTHOR]

Continuous wetland restoration initiatives in China are increasing, due to the global degradation of wetland ecosystems. However, monitoring of the restoration situation remains incomplete. In this study, we investigated the effects of wetland restoration on the macroinvertebrate taxonomic structure and feeding functional groups (FFGs) in the Naolihe National Nature Reserve (NNNR). Macroinvertebrate taxonomic diversity can be used to monitor wetlands, and we hypothesized that FFGs serve the same function. We calculated the diversity index, performed a non-metric multidimensional analysis based on macroinvertebrate taxonomics and FFGs, and subsequently, performed a t-test on the results. The results showed that macroinvertebrate diversity and FFGs analyses were in general agreement with taxonomic diversity, indicating that the macroinvertebrate community in the wetland with five years of fallow land was resembled that of the natural wetland. In contrast, the macroinvertebrate community in the wetland with two years of fallow differed significantly from that in the natural wetland. Additionally, the results of the ecosystem attributes based on biomass and FFGs showed that restored wetlands exhibited lower habitat stability than natural wetlands. Nutrients (NH4+-N, NO3−-N, and total phosphorus) explained the changes in macroinvertebrate FFGs in the restored wetlands to a greater extent than in the natural wetlands. The results of this study highlight the importance of macroinvertebrate FFGs in wetland monitoring, which supports the use of macroinvertebrate FFGs in the NNNR to monitor wetland restoration.

The objective of this work was to determine the taxonomic structure and Functional Feeding Groups (FFGs) of benthic invertebrates and their roles in two different water turbidity scenarios in a floodplain lake in the Pantanal wetland (Sinhá Mariana Lake, Barão de Melgaço, state of Mato Grosso). We studied the benthic invertebrate fauna at 18 sampling sites in periods of high turbidity (HT) and low turbidity (LT) during high water (HW) and low water (LW). We hypothesize that the structure of Chironomidae assemblages (species and functional feeding groups) varies between sites in Sinhá Mariana Lake, and the density and diversity attributes of species in this family and their functional feeding groups are reduced under increased turbidity. Depth, water temperature, turbidity, pH, pCO₂, water color, and organic matter content of the sediment were analyzed in each sampling site. Chironomidae presented higher density and diversity in periods of high water (HW) in sites with low turbidity water (LT). The dominance increased in periods of low water (LW). The main FFGs were represented by collector-gatherers, while the smallest groups corresponded to shredder-herbivores (50% and 9% of the total abundance, respectively). Collector-gatherers (Aedokritus sp., Chironomus strenzkei, Goeldichironomus petiolicola, G. maculatus, Beardius phytophilus), predators (Ablabesmyia gr. annulata, Labrundinia sp. and Cryptochironomus brasiliensis) and shredder-herbivores (Asheum sp., Polypedilum sp., Polypedilum gr. fallax) predominated in high water (HW) periods. A change in the community structure from the HW to LW was evidenced, characterized by the substitution of collector-gatherers for collector-filterers. Notodiaptomus deitersi (Crustacea) was dominant in LW (dominance index = 10.9) and Aedokritus sp. (Insecta) in HW (dominance index = 5.4). Water turbidity and the hydrological cycle are important factors determining spatial and temporal patterns in communities, particularly changes in FFGs. Changes in turbidity in different sites and periods alter the structure of trophic communities and lead to questions about the main drivers of communities in Pantanal wetlands as areas of high ecological relevance for maintaining biodiversity.

This article is a Commentary on Xiao et al. (2024), 242: 2803–2816. [ABSTRACT FROM AUTHOR]

Floods are normal components of many river regimes and, as such, they exert a significant influence at the ecosystem level. In recent decades, however, climate change has increased the frequency and intensity of floods, with serious consequences for lotic biota, particularly benthic macroinvertebrates, due to their limited mobility and sensitivity to disturbance. The impact of floods varies according to different biological parameters including the characteristics of the macrobenthic communities (taxonomic composition, morphology, behaviour, and life history traits) on one hand and various nonbiological parameters such as flood intensity, artificialisation of the river bed, the presence of dams, and many other factors on the other. Understanding these dynamics is pivotal to improve the effective management and conservation of aquatic ecosystems in the context of current climate change. The aim of this short communication is to evaluate the impact of a catastrophic flood on the macroinvertebrate community of a low-order Appennine stream (NW Italy). This will provide data regarding the varying impacts on different taxa and the recovery pattern of this significant component of the ecosystem.

Ditches are widespread and common elements of the agricultural landscape. Although they can provide habitats for aquatic biodiversity, their ecosystem integrity and processes are generally limited or even unknown due to anthropogenic pressures and the paucity of studies on this type of aquatic ecosystem. This study aimed to enhance the knowledge on the biodiversity, ecosystem attributes and ecological status of agricultural ditches by analyzing the macroinvertebrate communities of six different ditches and those of the main river in the same area. While negligible differences in taxonomic richness were observed, macroinvertebrate community composition significantly varied among sites as a function of the heterogeneous habitat conditions. These compositional differences strongly affected the relative abundance of functional feeding groups among sites and their derived ecosystem attributes. Moreover, the ecological status assessment depicted different scenarios depending on the biomonitoring indices applied. By means of a multifaceted, but still poorly adopted, analysis of the macroinvertebrate community, ranging from the taxonomic and functional diversity to ecosystem attributes and biomonitoring indices, the results obtained in this study offer useful information on the ecology of agricultural ditches with potential insights to improving their management.

Plants and insects are the most diverse and ecologically important organisms in the terrestrial biosphere. Their interactions are also among the richest biotic relationships, and offer significant insights into the evolution of terrestrial ecosystem complexity through the geological record. This investigation of the late Rhaetian Xujiahe and the earliest Jurassic Zhenzhuchong floral assemblages provides the first data on foliar herbivory generated by terrestrial arthropods across the Triassic-Jurassic transition in the eastern Tethys (East Asia) region. The damage types from two fossil assemblages are collectively attributed to seven functional feeding and egg-laying categories (i.e., hole feeding, margin feeding, surface feeding, skeletonization, piercing and sucking, oviposition, and galling). Most feeding strategies are spread across the major plant groups and persist through the Triassic-Jurassic boundary, with the exception of skeletonization (a category of external foliage feeding), which was restricted to the latest Triassic within dipteridacean ferns. The survey reveals that the respective frequency and diversity of interactions between plants and insects prior to and following the end-Triassic mass extinction event are almost the same, despite a substantial turnover of floral components. This suggest that insect herbivores were largely able to transfer to alternative (but commonly related) plant groups during the dramatic floristic turnover and environmental changes at the end of the Triassic. Sporadic occurrences of foliar modifications, such as marginal cusps on pinnules of Pterophyllum and prominent ridges on the rachises of some ferns and bennettites are interpreted as adaptations for defense against insect herbivores. A few differences in taxonomic composition and herbivory representation between the latest Triassic Xujiahe flora and the earliest Jurassic Zhenzhuchong flora are more likely to be related to collection and preservational biases rather than reflecting palaeoecological changes. We encourage further investigations exploring the distribution of insect damage in fossil floras from other palaeolatitudinal zones and spanning other major extinction events to develop a better understanding of terrestrial ecosystem responses to major crises in Earth's history. [ABSTRACT FROM AUTHOR]

In fast-flowing streams, caddisfly larvae are responsible for processes that collectively determine the efficiency with which the detritivore community is able to decompose autochthonous and allochthonous detritus. This ecosystem function ensures high water quality and represents a precious service for resident rural communities. The analysis of δ13C and δ15N in eight caddisfly taxa from a mid-mountain stream evidenced a remarkable complementarity in their feeding preferences. An aquatic moth mimicking the caddis mode of life was also included in the survey and its feeding niche appeared to be in between the one of caddis taxa. Moderate niche overlap was interpreted in terms of low functional redundancy, implying that in case of a reduction in diversity, no taxon could be a perfect substitute for another, with a loss of functional efficiency. Low redundancy could be caused by niche segregation due to avoidance of competition/interference between taxa. The broad range of δ13C and δ15N described in this study warns against attributing single δ13C and δ15N to Trichoptera as a group, or even to single families. These results contribute to the still poorly known distribution of East African caddisflies and to the characterisation of feeding preferences of Afrotropical trichopteran larvae. [ABSTRACT FROM AUTHOR]

Tidal marsh insect communities are influenced by both salinity and aspects of vegetation texture (vegetation diversity, plant density, and architectural structure). These factors affect the abundances and intra‐ and interguild interactions of these insects and should result in broad‐scale variation in the distribution and ecological functioning of tidal marsh insect communities along these gradients. However, this assumption has not been tested within Gulf Coast marshes, and the insect communities and their ecological roles are not well known. This study identifies how family‐level insect biodiversity varies by salinity and which factors are most important in affecting the distribution of insect functional feeding groups within Louisiana's coastal marshes. Insect family diversity was found to decrease as salinity increased for several indices. Vegetation texture and the underlying salinity gradient were found to be important factors affecting the distribution of free‐living sucking, stem‐boring, parasitic, and filtering functional feeding groups. [ABSTRACT FROM AUTHOR]

Simple Summary: High-altitude Andean streams are fragile ecosystems that require urgent actions such as bioassessment for proper environmental management. In the present study, we investigated the distribution and composition of the macroinvertebrate community in relation to the environmental variables in the Antisana river basin (Andean–Ecuadorian region). Macroinvertebrates were sampled at fifteen localities to predicate ecological condition which were expressed by the Biological Monitoring Working Party Colombia (BMWP-Col) index, the Andean Biotic Index (ABI) and the Andean–Amazon Biotic Index (AAMBI), and their main feeding traits as indicators of ecological functionality. Results show that dissolved oxygen saturation and total phosphorus, ammonia and conductivity contributed significantly to the composition of taxa and functional feeding groups (FFGs). Taxa and FFG diversity were most abundant at sites with the best ecological conditions. Shredders were, in general, dominant and especially abundant in the medium-high-quality sites. Predators were almost absent throughout the study, but they were collected from low-quality sites, showing greater tolerance to the presence of human disturbance. The BMWP-Col index seems to be the best fit for this ecosystem, showing a significant difference in FFG between the index classes compared to the other indices evaluated. The results of the present investigation may be regarded as a fundamental starting point and used in the future bioassessment works in other tropical Andean streams, especially where their resilience is threatened by poorly managed human activities. High-elevation tropical streams are under increasing threat from human activities and climate change. Specifically, Ecuadorian Andean streams require priority actions such as bioassessment (e.g., biodiversity and functional ecology of macroinvertebrates) in order to generate adequate environmental management policies. Therefore, we investigated the distribution and composition of the macroinvertebrate taxa and their functional feeding groups in relation to the environmental variables in the Antisana river basin (Andean–Ecuadorian Region). We sampled macroinvertebrates from 15 locations to assess ecological conditions (ECs), expressed as the Biological Monitoring Working Party Colombia (BMWP-Col) classes, the Andean Biotic Index (ABI) and the Andean–Amazon Biotic Index (AAMBI). Results indicate that dissolved oxygen saturation, elevation, nutrient concentration and conductivity contributed significantly to the composition of the taxa and functional feeding groups (FFGs). Taxa diversity and FFGs were more abundant in the best EC sites. Shredders (SH) were, overall, dominant and abundant at sites with medium-high ECs. Scrapers constituted the second most prevalent assemblage, exerting dominance at moderate ecological conditions (high altitude and high oxygen saturation). Collector–gathers (CGs) are less sensitive to contamination than the previous two groups but were equally abundant at medium-high EC sites. Collector–filterers (CFs) and parasites (PAs) were less abundant, although the presence of the former was slightly related to better environmental conditions. Predators (PRs) were almost absent throughout the study, but they were collected from poor EC sites. CGs, PAs and PRs showed more tolerance to the presence of human disturbances (e.g., hydraulic constructions or slope erosion). The BMWP-Col index seems to be the best fit for this ecosystem, showing a significant difference in FFG between the index classes, compared to the other indices evaluated. The results of this investigation may be regarded as a fundamental starting point and used in future bioassessment work in other similar ecosystems, particularly high-altitude tropical Ecuadorian streams. [ABSTRACT FROM AUTHOR]

IntroductionThe Sanzenbacher Ranch deposit represents an early Permian plant assemblage in north-central Texas predominantly composed of pteridosperms, of which callipterids are dominant. This study investigates the interactions of a taxonomically broad range of plant hosts with insects, mites, and pathogens to assess the richness and frequency of damage.MethodsWe used standard methods of the functional feeding group--damage type system and analyses graphically illustrated as nonmetric multidimensional scaling.ResultsOf the total surface area represented, we quantified the fraction of the area herbivorized, providing a comparative perspective with regard to several similar studies of herbivory at nearby plant assemblages from the late Paleozoic. To assess insect herbivory, 1,361 plant specimens were analyzed, including fronds, leaves, reproductive structures, axes, and wood impressions. A total of 205 specimens presented one or more instances of insect herbivory (11.17%). Callipterid-peltasperms exhibited the highest number of interactions, with Autunia conferta, Rhachiphyllum schenkii, cf. Lodevia sp., cf. Comia sp., and an unidentified callipterid accounting for 49.34% of all interactions. Medullosans represented 10.53%, followed by lyginopterids with 8.55%. Forty-eight damage types (DTs) were recognized and classified into the nine functional feeding groups of hole feeding, margin feeding, surface feeding, piercing and sucking, oviposition, galling, seed predation, borings, and pathogens.DiscussionWhen compared to analogous late Paleozoic plant assemblages in Texas, Sanzenbacher Ranch exhibited almost all herbivore functional feeding groups, high richness of DTs, and low herbivory index of 0.26. This record shows high plant diversity in a seasonally dry environment that supports a trend of an early Permian increase in DT diversity in southwestern Euramerica. Sanzenbacher Ranch, different from other early Permian plant assemblages, sheds light on the dynamic ecological interactions of these ancient ecosystems.

AbstractThe biotic integrity of streams is frequently compromised by anthropogenic disturbance; thus, it is important to study the potential mitigating effects of undisturbed riparian zones on streams within disturbed watersheds. In this study, two first-order northern Michigan streams located 1 km apart in adjacent agricultural watersheds, but with differing riparian land use, were compared to observe the effects of intact forest within the immediate 100 m stream corridor. Both streams had high specific conductance values associated with agricultural streams. The stream with a primarily forested riparian corridor, however, had greater canopy cover, faster stream velocity, greater coarse substrate, lower percentage of organic sediment, lower water temperatures, higher dissolved oxygen, higher taxonomic richness, higher relative biomass of shredders, lower relative biomass of gathering collectors, and more pollution intolerant taxa than the stream with a primarily agricultural corridor. Moreover, the benthic macroinvertebrate assemblages were highly distinct from each other, with the riparian forested stream dominated by aquatic insects like mayflies and caddisflies, and the agricultural stream by non-emergent isopods and amphipods. These results demonstrate the effects of a buffer zone on stream substrate composition, water physicochemistry, and benthic assemblages, and indicate the importance of preserving riparian zones within agricultural watersheds.

Plants and insects are the most diverse and ecologically important organisms in the terrestrial biosphere. Their interactions are also among the richest biotic relationships, and offer significant insights into the evolution of terrestrial ecosystem complexity through the geological record. This investigation of the late Rhaetian Xujiahe and the earliest Jurassic Zhenzhuchong floral assemblages provides the first data on foliar herbivory generated by terrestrial arthropods across the Triassic–Jurassic transition in the eastern Tethys (East Asia) region. The damage types from two fossil assemblages are collectively attributed to seven functional feeding and egg-laying categories (i.e., hole feeding, margin feeding, surface feeding, skeletonization, piercing and sucking, oviposition, and galling). Most feeding strategies are spread across the major plant groups and persist through the Triassic–Jurassic boundary, with the exception of skeletonization (a category of external foliage feeding), which was restricted to the latest Triassic within dipteridacean ferns. The survey reveals that the respective frequency and diversity of interactions between plants and insects prior to and following the end-Triassic mass extinction event are almost the same, despite a substantial turnover of floral components. This suggest that insect herbivores were largely able to transfer to alternative (but commonly related) plant groups during the dramatic floristic turnover and environmental changes at the end of the Triassic. Sporadic occurrences of foliar modifications, such as marginal cusps on pinnules of Pterophyllum and prominent ridges on the rachises of some ferns and bennettites are interpreted as adaptations for defense against insect herbivores. A few differences in taxonomic composition and herbivory representation between the latest Triassic Xujiahe flora and the earliest Jurassic Zhenzhuchong flora are more likely to be related to collection and preservational biases rather than reflecting palaeoecological changes. We encourage further investigations exploring the distribution of insect damage in fossil floras from other palaeolatitudinal zones and spanning other major extinction events to develop a better understanding of terrestrial ecosystem responses to major crises in Earth’s history.

Abstract Tidal marsh insect communities are influenced by both salinity and aspects of vegetation texture (vegetation diversity, plant density, and architectural structure). These factors affect the abundances and intra‐ and interguild interactions of these insects and should result in broad‐scale variation in the distribution and ecological functioning of tidal marsh insect communities along these gradients. However, this assumption has not been tested within Gulf Coast marshes, and the insect communities and their ecological roles are not well known. This study identifies how family‐level insect biodiversity varies by salinity and which factors are most important in affecting the distribution of insect functional feeding groups within Louisiana's coastal marshes. Insect family diversity was found to decrease as salinity increased for several indices. Vegetation texture and the underlying salinity gradient were found to be important factors affecting the distribution of free‐living sucking, stem‐boring, parasitic, and filtering functional feeding groups.

The objective of this work was to determine the taxonomic structure and Functional Feeding Groups (FFGs) of benthic invertebrates and their roles in two different water turbidity scenarios in a floodplain lake in the Pantanal wetland (Sinhá Mariana Lake, Barão de Melgaço, state of Mato Grosso). We studied the benthic invertebrate fauna at 18 sampling sites in periods of high turbidity (HT) and low turbidity (LT) during high water (HW) and low water (LW). We hypothesize that the structure of Chironomidae assemblages (species and functional feeding groups) varies between sites in Sinhá Mariana Lake, and the density and diversity attributes of species in this family and their functional feeding groups are reduced under increased turbidity. Depth, water temperature, turbidity, pH, pCO₂, water color, and organic matter content of the sediment were analyzed in each sampling site. Chironomidae presented higher density and diversity in periods of high water (HW) in sites with low turbidity water (LT). The dominance increased in periods of low water (LW). The main FFGs were represented by collector-gatherers, while the smallest groups corresponded to shredder-herbivores (50% and 9% of the total abundance, respectively). Collector-gatherers (Aedokritus sp., Chironomus strenzkei, Goeldichironomus petiolicola, G. maculatus, Beardius phytophilus), predators (Ablabesmyia gr. annulata, Labrundinia sp. and Cryptochironomus brasiliensis) and shredder-herbivores (Asheum sp., Polypedilum sp., Polypedilum gr. fallax) predominated in high water (HW) periods. A change in the community structure from the HW to LW was evidenced, characterized by the substitution of collector-gatherers for collector-filterers. Notodiaptomus deitersi (Crustacea) was dominant in LW (dominance index = 10.9) and Aedokritus sp. (Insecta) in HW (dominance index = 5.4). Water turbidity and the hydrological cycle are important factors determining spatial and temporal patterns in communities, particularly changes in FFGs. Changes in turbidity in different sites and periods alter the structure of trophic communities and lead to questions about the main drivers of communities in Pantanal wetlands as areas of high ecological relevance for maintaining biodiversity.

Freshwater mussels (Bivalvia: Unionidae) are often described as ecosystem engineers, with the capacity to alter abiotic habitats; this can facilitate certain macroinvertebrate taxa, increasing biodiversity and potentially altering community composition. Mussel species are often implicitly considered to be broad ecological equivalents, with similar impacts on abiotic environments and benthic communities. This assumption of redundancy is important in conservation approaches that aim to preserve ecosystem functioning, rather than species identity. We tested this assumption of equivalence in two species of subtropical freshwater mussels, Lamellidens marginalis and Parreysia caerulea, studying the associations between these mussel species and macroinvertebrate communities.We measured mussel density and abundance of macroinvertebrates, identified to family level, at 50 sites within Dhanmondi Lake, a heavily polluted sub‐tropical urban lake in Dhaka, Bangladesh. We investigated the associations of mussel density on different macroinvertebrate families, which we further classified into functional feeding groups (predators, scrapers, collectors and shredders).We found that densities of the two mussel species were negatively correlated in the 1–3‐m nearshore zone; average density of Lamellidens was 46.4 ± SE 3.6 individuals/0.25 m2, and average density of Parreysia was 6.4 ± SE 1.4 individuals/0.25 m2. In total, 2319 Lamellidens and 320 Parreysia specimens were recorded. Sites containing higher densities of Lamellidens had greater similarity in macroinvertebrate community composition, while there was no effect for Parreysia. Particular macroinvertebrate families and functional feeding groups were also associated with mussels; the majority of significant associations were with Lamellidens but not Parreysia. The clearest associations were with predators and scrapers, which increased in abundance with Lamellidens density.This provides support for a possible role for mussels in structuring freshwater invertebrate communities and emphasises the importance of species identity in these effects, with one possible keystone species (Lamellidens) largely accounting for mussel–invertebrate associations. While microhabitat variables (shading and sediment type) were poor predictors of abundance in any invertebrate taxa (including mussels), manipulative studies are needed to disentangle the direct effects of mussels from the role of overlapping habitat preference between mussels and other invertebrates.Our results highlight the importance of species identity in patterns of community composition, particularly for ecosystem engineer species. We also reinforce the need to test the assumption of ecological redundancy within communities. [ABSTRACT FROM AUTHOR]

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.

Increase in antibiotic resistance genes (ARGs) in freshwater ecosystems as a consequence of anthropogenic activities is a matter of public health concern. Although researchers have looked at ARG abundance and the factors affecting them in biofilms, water and sediment, the role of freshwater macroinvertebrate gut microbiomes in harbouring and disseminating ARGs is unknown. In the current study, we tested whether: (a) macroinvertebrate gut microbiomes serve as hotspots of ARGs in comparison to their immediate environment, (b) functional feeding groups (FFGs) impact ARG abundance in macroinvertebrate guts, (c) bacterial community composition and ARG abundance are correlated, and (d) macroinvertebrates can be potential vectors of ARGs.Macroinvertebrates, sediment and water samples were collected from seven different sites along northeastern Ohio (U.S.A.) streams and abundances of three ARGs (sulI, sulII and tetW) were determined. Bacterial community composition also was examined for respective microbiomes and a microcosm study was designed for testing hypothesis 4.In many cases, the gut microbiome had higher relative ARG abundance (sulI and sulII) at sites along Tinker's Creek compared to the surrounding substrate and water. ARG abundances along with taxonomic differences in bacterial community composition were different among the FFGs (ARG abundance higher in omnivores). Certain bacterial taxa were significantly correlated with one or more ARGs. We did not find that freshwater macroinvertebrates can serve as vectors of ARGs (from the microcosm study).Overall, our site‐based results suggest that freshwater macroinvertebrate guts may serve as reservoirs of ARGs, differences in ARG abundance among FFGs was possibly a result of differences in bacteria ingested and gut morphophysiological conditions.Because this study indicates that macroinvertebrate guts can be potential reservoirs of ARGs, future studies can be designed to understand the role of macroinvertebrates in dissemination of ARGs in freshwater ecosystems. [ABSTRACT FROM AUTHOR]

Macro-benthos is commonly considered an indicator for evaluating the health of an aquatic ecosystem. Earlier research from sub-tropical mangrove estuaries, however, has primarily relied on conventional taxonomic methods to determine the pattern of macro-benthos diversity. Therefore, this study aimed to describe the pattern of both taxonomic and functional groups of macro-benthos with respect to ecological variables in three separate seasons (pre-monsoon, monsoon, and post-monsoon) from a mangrove-dominated Pasur River estuary, Bangladesh. The findings revealed significant seasonal variations in the water and sediment parameters (p < 0.05). During the study period, 47 species belonging to 35 families of macro-benthos were identified. The pollution indicator species, Capitella capitata complex was found to be dominant. The highest density of macro-benthos was recorded in post-monsoon (545 ± 13.76 ind./m2) followed by pre-monsoon (214 ± 5.57 ind./m2) and monsoon (63 ± 2.27 ind./m2). Diversity indices, Shannon, and evenness also displayed a similar seasonal trend. This pattern may be explained by the more stable bottom and higher food availability during post-monsoon, and on the other side, by erosion and higher turbidity during monsoon. Analysis of similarity (ANOSIM) detected a significant difference in community assemblage among the seasons (R = 0.7222, p = 0.0005), whereas similarity percentage analysis (SIMPER) identified Dendronereis aestuarina as the most contributory species for the overall average dissimilarity. Six functional feeding groups (FFGs) were identified where gathering collectors (GC) had the highest total density (221.83 ind./m2) and relative abundance (26.97%). The community was shown to be shaped by the amount of sedimentary silt and dissolved oxygen in the water main, according to a canonical correspondence analysis (CCA) study, they were positively correlated with the abundance of Pristinella acuminata, Lumbrineris sp., Cossura coasta, C. capitata complex, Neritina violacea, Laccotrephes griseus, Hydrometra butleri, Gomphus sp. and Libellula sp. CCA analysis also revealed a significant positive influence of pH, NO3-N, PO4-P, and organic matter, whereas, sand particles of sediments were found to have a negative effect on FFGs. Overall, the study suggests that the estuary is moderately diverse with macro-benthos and their functional feeding groups and influenced by monsoon strongly. The present study on FFGs of macro-benthos in an estuarine river of Bangladesh will provide baseline information for further investigation of other estuaries. [ABSTRACT FROM AUTHOR]

The involvement of trait-based approaches is crucial for understanding spatial patterns, energy flow and matter transfer in running water systems, which requires consistent knowledge of the functional structures of aquatic communities, with the advantage of combining physical properties and behavioral mechanisms of food acquisition rather than the taxonomic group. The present study indicated how functional feeding groups may be used as a proxy for classical taxonomic evaluation, as well as the potential interest in incorporating them as indicators of anthropogenic stressors. The composition and abundance of the functional feeding groups of aquatic insects were examined from September 2021 to August 2022 along the Western Rif Region. Benthic samples were collected from nine sampling points in the studied area using a Surber sampler with a mesh size of 500 µm and a diameter of 20*20 cm. The stations included in this work were chosen for their accessibility as well as their position on the hydrographic systems. The abundance of sampled aquatic organisms in the whole study area revealed 5,342 individuals belonging to 60 families and seven orders of aquatic insects, classified into five feeding functional groups. In terms of abundance, Collectorgatherers (Ephemeroptera and Diptera) were the most abundant trophic group at most of the sites, with a proportion of 38.47%. Predators (Coleoptera, Hemiptera and Odonata) were the second group at all sites, followed by Collector-filters, accounting for 39.53%, 28.14% and 22.37% respectively, while Scarpers and Shredders had the lowest representation across all sites with 4.16%. The high number of registered Collectors could be related to their ability to feed on a diverse range of food items compared to the remaining trophic guilds. According to the Canonical Correspondence Analysis results, physicochemical (i.e. T, pH, BOD, Cl- and NO -) and hydromorphological (i.e. current velocity and depth) variables were amongst the key predictors of shaping the functional structure of aquatic biota during this investigation. It is highly recommended to carry out suitable measures to largely attenuate anthropogenic pressures in order to preserve the integrity of freshwater bodies and their biota. [ABSTRACT FROM AUTHOR]

Abstract Secondary production is the formation of heterotrophic biomass across time, which integrates several important ecological processes that affect the life of organisms, populations, communities and ecosystems, but its study has poor developed in South America. The objectives of this work were to describe the diversity of benthic macroinvertebrate assemblages in terms of abundance and biomass, and to quantify their secondary production for the first time in Andean rivers. A quantitative sampling scheme was implemented, using a Surber sampler, in three forested streams. Physical-chemical variables, nutrients, organic matter and chlorophyll were measured also. The macroinvertebrates were separated and identified mostly at the species level. Each taxon was assigned to a functional feeding group. Secondary production was estimated for 38 taxa, mostly Diptera, Trichoptera, Coleoptera, and Ephemeroptera. The annual production varied from 3769 to 13916 mg dry mass m-2 y-1. Most abundant taxa were also those with higher production, dominated by Ephemeroptera (Baetidae), Trichoptera (Hydropsychidae) and Diptera (Chironomidae and Simuliidae). Density, biomass, and production of collectors and predators were much higher than the other feeding groups. We expect that our results will be useful to evaluate the effects on stream functioning produced by global warming and other anthropogenic disturbances in our region.

Despite their potential as indicators of water quality and their key role in river ecosystems, Chironomidae is still poorly studied in Neotropical rivers. This lack of knowledge is especially relevant for rivers subjected to intense human activities, such as many rivers in Mexico. The aim of this investigation is to contribute to the knowledge of the midges of the Pesquería River (Mexico) along its main courses and relate the composition and abundance to river health. Thirty samples were collected during two different periods (August 2015 and February 2016) using a D-frame and kick sampling. Thirty-five taxa were found in total, with four taxa found in more than 50% of the sites and 19 only found once. Midges accounted for more than 50% of the total macroinvertebrate abundance. Chironomus gr. plumosus, Rheotanytarsus spp. and Cricotopus gr. bicinctus were the most abundant species. Collector-gatherers dominated in August (71% of individuals), whereas collector-filterers dominated in February (43,2%). The major factor explaining the midge distribution and abundance is pollution, while the structure of riparian area does not explain much of the midge richness. This is most likely related to the organic pollution coming from untreated or poorly treated sewage in the city of Monterrey and its surroundings. Three main sectors are distinguished along the river: i) the upper part section with higher biodiversity and presence of intolerant taxa; ii) the middle sewage polluted area with the presence of large red midges very tolerant to pollution (Chironomus, Dicrotendipes); iii) the lower section in the agricultural zone where the community is dominated by red, small midges (Rheotanytarsus). Overall, our study shows that Chironomidae can be useful as better indicators of water quality when genera or species levels are used instead of family or subfamily, as is usually found in most papers on river pollution.

The Ramsar-accredited Makuleke Wetlands are located in the Makuleke Concession in the northern Pafuri region of the Kruger National Park in South Africa. The Pafuri area holds up to 75% of Kruger National Park’s total biodiversity, emphasising the Makuleke Wetlands’ international environmental importance. The Makuleke Wetlands are composed of the floodplains of the Luvuvhu and Limpopo rivers, with an estimated 31 wetlands present within the floodplains. Ten floodplain wetlands were assessed in the Makuleke region, eight of which are fed by the Limpopo River and the other two from the Luvuvhu River. Water and aquatic invertebrate communities were sampled at each site during surveys in April and September 2015 to provide baseline information on the aquatic biota of this Ramsar site. Multivariate data analytical techniques were used to assess the role of season and water quality in structuring the aquatic invertebrate communities of the wetlands. Macroinvertebrate functional feeding group ratios were also calculated as an indication of wetland ecosystem structure and function. Aquatic invertebrate diversity was some of the highest recorded for wetlands in South Africa, indicating the important role these habitats play in supporting high biodiversity in the Makuleke region. Worryingly, one of the most prolific invasive molluscan species, Tarebia granifera, was present in the wetlands and is a significant threat to native biodiversity of this conservation area. Community characteristics and ecosystem structure and function of the aquatic invertebrates further indicated that the Makuleke Wetland habitats were of good quality and provided a sufficient stable substrate for all aquatic invertebrates. Functionally, the system was characterised as reliant on heterotrophic inputs as autotrophic sources are limited. This is the first study of its kind for the region and lays the groundwork for future ecosystem studies on these important wetlands in the second-largest floodplain of South Africa.

The identification of functional feeding traits in aquatic macroinvertebrates often requires a morphology-based identification of species, which is important for trait-based methods of biological assessment. The extent of functional homogenization is compared along scales of impairment, where trait-based information is used as an input in models that examine degradation pathways. However, trait-based information is not always readily available for all groups of aquatic insects, especially for species diverse families, such as chironomids (Diptera: Chironomidae). Taxonomic challenges and ambiguous traits complicate the use of chironomid larvae in trait-based bioassessment. Here, we examine the use of geometric morphometric analysis (GMA), deep learning (Convolutional Neural Networks), and computer vision (deep CNN) applied to the mouthparts (mandibles) of chironomid larvae as a proxy for identifying the relationship between the functional morphology and food acquisition behaviour. We determined the variability in morphology of mandibles for 23 taxa of chironomid larvae from different genera, subfamilies, and their Functional Feeding Group (FFG). Analysis using GMA showed that the five different FFGs examined had different mandibular traits that significantly varied in shape and size. A deep CNN model was then built that was able to classify the 23 taxa into their respective FFG automatically with 92.31 % accuracy. A gradient-weighted Class Activation Mapping (Grad-CAM) algorithm found that the most important part of mandibles for classification were the gula and mandibular joint. We introduced three additional species to the deep CNN models to test whether automatic classification would directly and automatically identify traits of the specimens independently from taxonomic identification. The deep CNN process avoids issues surrounding both taxonomic identification and previous knowledge of a specific taxon’s feeding trait, and in all cases the model classified taxa correctly based on their mandibular traits. The use of deep learning approaches could substantially enhance the use of trait-based approaches and increase the reliability and use of chironomids in bioassessment.

This study aimed to determine the impact of horticultural land use on the taxonomic composition and the composition of functional feeding groups of freshwater macroinvertebrate assemblages in lowland streams. Three streams running through intensively cultivated plots were compared to three less impacted streams, two of which run through a UNESCO Biosphere Reserve. Nutrient and pesticide measured concentrations, as well as the macroinvertebrate assemblages associated with aquatic vegetation, were analyzed in each stream. These concentrations were higher at the horticultural streams, negatively correlated to the richness, density, and diversity of the macroinvertebrate assemblages, leading to a dominance of tolerant families. The trophic structure of the macroinvertebrates assemblages was dominated by collector-gatherers in the horticultural streams, while all functional feeding groups were more equally distributed in less impacted streams. We concluded that horticulture reduces biodiversity and changes the trophic structure of the macroinvertebrate assemblage, eventually affecting stream functions. Mitigation measures are required to preserve the structure and function of these ecosystems. [ABSTRACT FROM AUTHOR]

Despite their potential as indicators of water quality and their key role in river ecosystems, Chironomidae is still poorly studied in Neotropical rivers. This lack of knowledge is especially relevant for rivers subjected to intense human activities, such as many rivers in Mexico. The aim of this investigation is to contribute to the knowledge of the midges of the Pesquería River (Mexico) along its main courses and relate the composition and abundance to river health. Thirty samples were collected during two different periods (August 2015 and February 2016) using a D-frame and kick sampling. Thirty-five taxa were found in total, with four taxa found in more than 50% of the sites and 19 only found once. Midges accounted for more than 50% of the total macroinvertebrate abundance. Chironomus gr. plumosus, Rheotanytarsus spp. and Cricotopus gr. bicinctus were the most abundant species. Collector-gatherers dominated in August (71% of individuals), whereas collector-filterers dominated in February (43,2%). The major factor explaining the midge distribution and abundance is pollution, while the structure of riparian area does not explain much of the midge richness. This is most likely related to the organic pollution coming from untreated or poorly treated sewage in the city of Monterrey and its surroundings. Three main sectors are distinguished along the river: i) the upper part section with higher biodiversity and presence of intolerant taxa; ii) the middle sewage polluted area with the presence of large red midges very tolerant to pollution (Chironomus, Dicrotendipes); iii) the lower section in the agricultural zone where the community is dominated by red, small midges (Rheotanytarsus). Overall, our study shows that Chironomidae can be useful as better indicators of water quality when genera or species levels are used instead of family or subfamily, as is usually found in most papers on river pollution. [ABSTRACT FROM AUTHOR]

The use of the functional feeding group–damage type system for analyzing arthropod and pathogen interactions with plants has transformed our understanding of herbivory in fossil plant assemblages by providing data, analyses, and interpretation of the local, regional, and global patterns of a 420-Myr history. The early fossil record can be used to answer major questions about the oldest evidence for herbivory, the early emergence of herbivore associations on land plants, and later expansion on seed plants. The subsequent effects of the Permian–Triassic ecological crisis on herbivore diversity, the resulting formation of biologically diverse herbivore communities on gymnosperms, and major shifts in herbivory ensuing from initial angiosperm diversification are additional issues that need to be addressed. Studies ofherbivory resulting from more recent transient spikes and longer-term climate trends provide important data that are applied to current global change and include herbivore community responses to latitude, altitude, and habitat. Ongoing paleoecological themes remaining to be addressed include the antiquity of modern interactions, differential herbivory between ferns and angiosperms, and origins of modern tropical forests. The expansion of databases that include a multitude of specimens; improvements in sampling strategies; development of new analytical methods; and, importantly, the ability to address conceptually stimulating ecological and evolutionary questions have provided new impetus in this rapidly advancing field. [ABSTRACT FROM AUTHOR]

The present study provides data on the trophic structure of the benthic macroinvertebrate communities in mountainous and semi-mountainous small streams and river sections belonging to Mesta, Struma and Vardar River catchments from 7th Ecoregion. The benthic macroinvertebrates were assigned to seven Functional Feeding Groups. We analyzed their trophic structure and the dynamics in different seasons. The level of similarity between the sampling localities was analyzed in the context of both the river typology and the water catchment. A comparison between the two trophic indices was conducted in order to analyze the advantages of the application of these indices for assessment of the ecological status at the studied sites. We found that the trophic structure of the benthic macroinvertebrate communities in ostensibly typologically similar river sections differs at the undisturbed vs the impacted sampled sites. To a large extent, these differences were also determined by the presence of anthropogenic influence that resulted in the predominance of deposit feeders amplifying on higher disturbance on some of the studied rivers. Long-term negative pressure has led to changes in microhabitats that affect the structure and functioning of the aquatic ecosystem by transformation of the trophic structure of the macrozoobenthos. [ABSTRACT FROM AUTHOR]

We examined the distribution patterns of Ephemeroptera, Plecoptera, and Trichoptera functional feeding groups (EPT FFGs) in five streams that drain semi-urban landscapes in the Tsitsa River catchment, Eastern Cape Province of South Africa. We undertook macroinvertebrate and physicochemical analysis over four seasons between 2016 and 2017 at eight sites in three land-use categories (Sites 1, 2 and 3), representing an in-creasing gradient of semi-urban pollution. Five EPT FFGs (shredders, grazers/scrapers, predators, collector-gatherers and collector-filterers) were fuzzy coded and analyzed using RLQ-R (environmental characteristics of samples), L (taxa distribution across samples) and Q (species traits) and fourth-corner analyses. Physicochemical variables, including phosphate-phosphorus, total inorganic nitrogen and temperature, were the most influential variables that significantly influenced the distribution patterns of EPT FFGs in the Tsitsa River. RLQ and the fourth-corner model revealed varying responses of FFGs to semi-urban pollution. Of the five FFGs, collectors were the most abundant EPT FFGs in the study area, exhibiting disparate responses to disturbances, with collector-gatherers associated with impacted sites and significantly associated with phosphate-phosphorus. On the other hand, collector-filterers decreased with increasing semi-urban disturbance and exhibited a significant negative association with phosphate-phosphorus, total inorganic nitrogen and temperature. Overall, this study provides further insights into the environmental factors that influence the distribution patterns of FFGs in Afrotropical streams and the potential use of FFGs as indicators of anthropogenic pollution in tropical streams and rivers. [ABSTRACT FROM AUTHOR]

High-elevation tropical streams are under increasing threat from human activities and climate change. Specifically, Ecuadorian Andean streams require priority actions such as bioassessment (e.g., biodiversity and functional ecology of macroinvertebrates) in order to generate adequate environmental management policies. Therefore, we investigated the distribution and composition of the macroinvertebrate taxa and their functional feeding groups in relation to the environmental variables in the Antisana river basin (Andean–Ecuadorian Region). We sampled macroinvertebrates from 15 locations to assess ecological conditions (ECs), expressed as the Biological Monitoring Working Party Colombia (BMWP-Col) classes, the Andean Biotic Index (ABI) and the Andean–Amazon Biotic Index (AAMBI). Results indicate that dissolved oxygen saturation, elevation, nutrient concentration and conductivity contributed significantly to the composition of the taxa and functional feeding groups (FFGs). Taxa diversity and FFGs were more abundant in the best EC sites. Shredders (SH) were, overall, dominant and abundant at sites with medium-high ECs. Scrapers constituted the second most prevalent assemblage, exerting dominance at moderate ecological conditions (high altitude and high oxygen saturation). Collector–gathers (CGs) are less sensitive to contamination than the previous two groups but were equally abundant at medium-high EC sites. Collector–filterers (CFs) and parasites (PAs) were less abundant, although the presence of the former was slightly related to better environmental conditions. Predators (PRs) were almost absent throughout the study, but they were collected from poor EC sites. CGs, PAs and PRs showed more tolerance to the presence of human disturbances (e.g., hydraulic constructions or slope erosion). The BMWP-Col index seems to be the best fit for this ecosystem, showing a significant difference in FFG between the index classes, compared to the other indices evaluated. The results of this investigation may be regarded as a fundamental starting point and used in future bioassessment work in other similar ecosystems, particularly high-altitude tropical Ecuadorian streams.

We examined the distribution patterns of Ephemeroptera, Plecoptera, and Trichoptera functional feeding groups (EPT FFGs) in five streams that drain semi-urban landscapes in the Tsitsa River catchment, Eastern Cape Province of South Africa. We undertook macroinvertebrate and physicochemical analysis over four seasons between 2016 and 2017 at eight sites in three land-use categories (Sites 1, 2 and 3), representing an increasing gradient of semi-urban pollution. Five EPT FFGs (shredders, grazers/scrapers, predators, collector-gatherers and collector-filterers) were fuzzy coded and analyzed using RLQ-R (environmental characteristics of samples), L (taxa distribution across samples) and Q (species traits) and fourth-corner analyses. Physicochemical variables, including phosphate-phosphorus, total inorganic nitrogen and temperature, were the most influential variables that significantly influenced the distribution patterns of EPT FFGs in the Tsitsa River. RLQ and the fourth-corner model revealed varying responses of FFGs to semi-urban pollution. Of the five FFGs, collectors were the most abundant EPT FFGs in the study area, exhibiting disparate responses to disturbances, with collector-gatherers associated with impacted sites and significantly associated with phosphate-phosphorus. On the other hand, collector-filterers decreased with increasing semi-urban disturbance and exhibited a significant negative association with phosphate-phosphorus, total inorganic nitrogen and temperature. Overall, this study provides further insights into the environmental factors that influence the distribution patterns of FFGs in Afrotropical streams and the potential use of FFGs as indicators of anthropogenic pollution in tropical streams and rivers.

Introduced organisms are seen as one of the greatest threats to resource sustainability worldwide, and aquatic macroinvertebrates are regarded as good indicators of the health of water resources. To explore these two perspectives, the responses of macroinvertebrate faunas to native and introduced fishes in three headwater tributaries of the Keiskamma River system, South Africa, were examined by comparing potential indicator communities in reaches considered to be fishless, reaches invaded by introduced salmonid species, and reaches containing native fishes. Patterns in the macroinvertebrate faunal assemblage data were driven strongly by season and flow rate, and less strongly by the presence of insectivorous fishes and biotope availability, a finding in parallel with several similar studies from the region. This affirms that aquatic macroinvertebrate faunas are responsive indicators of both environmental and biotic factors and leaves room for further studies to resolve the effects of non-native fish in the Keiskamma River system and other similar systems from South Africa.

Macro-benthos is commonly considered an indicator for evaluating the health of an aquatic ecosystem. Earlier research from sub-tropical mangrove estuaries, however, has primarily relied on conventional taxonomic methods to determine the pattern of macro-benthos diversity. Therefore, this study aimed to describe the pattern of both taxonomic and functional groups of macro-benthos with respect to ecological variables in three separate seasons (pre-monsoon, monsoon, and post-monsoon) from a mangrove-dominated Pasur River estuary, Bangladesh. The findings revealed significant seasonal variations in the water and sediment parameters (p < 0.05). During the study period, 47 species belonging to 35 families of macro-benthos were identified. The pollution indicator species, Capitella capitata complex was found to be dominant. The highest density of macro-benthos was recorded in post-monsoon (545 ± 13.76 ind./m2) followed by pre-monsoon (214 ± 5.57 ind./m2) and monsoon (63 ± 2.27 ind./m2). Diversity indices, Shannon, and evenness also displayed a similar seasonal trend. This pattern may be explained by the more stable bottom and higher food availability during post-monsoon, and on the other side, by erosion and higher turbidity during monsoon. Analysis of similarity (ANOSIM) detected a significant difference in community assemblage among the seasons (R = 0.7222, p = 0.0005), whereas similarity percentage analysis (SIMPER) identified Dendronereis aestuarina as the most contributory species for the overall average dissimilarity. Six functional feeding groups (FFGs) were identified where gathering collectors (GC) had the highest total density (221.83 ind./m2) and relative abundance (26.97%). The community was shown to be shaped by the amount of sedimentary silt and dissolved oxygen in the water main, according to a canonical correspondence analysis (CCA) study, they were positively correlated with the abundance of Pristinella acuminata, Lumbrineris sp., Cossura coasta, C. capitata complex, Neritina violacea, Laccotrephes griseus, Hydrometra butleri, Gomphus sp. and Libellula sp. CCA analysis also revealed a significant positive influence of pH, NO3-N, PO4-P, and organic matter, whereas, sand particles of sediments were found to have a negative effect on FFGs. Overall, the study suggests that the estuary is moderately diverse with macro-benthos and their functional feeding groups and influenced by monsoon strongly. The present study on FFGs of macro-benthos in an estuarine river of Bangladesh will provide baseline information for further investigation of other estuaries.

The aim of this study was to investigate the effects of agricultural land use and periods of hydrological variability on the environmental variables, as well as macrophyte and macroinvertebrate assemblages in lowland riverine wetlands. As a case study, we compared two periurban wetlands with intensive agricultural land use against two others with extensive livestock, considered references for the region during a normal and a dry flow period. Nutrient concentrations were significantly higher in agricultural riverine wetlands (total phosphorus and total nitrogen 30% higher). These wetlands exhibited higher relative coverage of floating anchored macrophytes and the absence of submerged vegetation. They showed significantly lower taxonomic richness and 40% lower density of macroinvertebrates, and a higher relative abundance of scrapers and predators. Wetlands of both land uses had a lower total density of macroinvertebrates and a higher abundance of tolerant desiccation taxa in the dry period. Particular differences between land uses, such as lower dissolved oxygen concentrations and lower macroinvertebrate diversity in agricultural wetlands, were found during the dry period. These findings indicate that the differences between land uses seemed to increase during the aforementioned period. Further studies in riverine wetlands of both land uses must be carried on to generalize the results found. Despite this limitation, this study provides evidence of the effects of the surrounding landscape and hydrologic periods in the environmental characteristics, as well as the macrophyte and macroinvertebrate assemblages of the riverine wetlands studied. [ABSTRACT FROM AUTHOR]

We evaluated the ecological integrity of Andean Patagonia urban streams by assessing changes in leaf litter decomposition rates and benthic invertebrate assemblage colonizing litter. Urban streams had higher nutrient concentrations and temperatures, and lower flow variability than cold-temperate oligotrophic Patagonia Andes streams. Leaf litter decomposition was faster in urban streams (50% higher than reference streams) mainly attributable to microbial decomposition; urban effect size in fine mesh (FM) bags was two-fold than in reference streams in coincidence with high nutrient concentrations and temperatures. Leaf litter decomposition had a similar effect in coarse mesh (CM) and FM bags, suggesting that invertebrate detritivore feeding activity was poor in urban streams. This was apparent when the effect of temperature on litter decay in CM bags was removed and urban effect size was nil. Invertebrates showed 71.5% dissimilarity between stream types, with higher tolerant species dominating urban streams. Functional feeding groups strongly varied between urban and reference streams over time, with shredders being the most contributing group in reference streams, and collector-gatherers, scrapers, and shredders contributing to urban streams. Our results highlight the avail of including functional studies to understanding the effect of human alterations on small streams complementing the analysis of ecosystem structure. [ABSTRACT FROM AUTHOR]

Urban aquatic ecosystems are important sources of fresh water for multiple uses, but often receive a point or diffuse anthropic contamination. Benthic and zooplankton invertebrates are sensitive to water quality, being good indicators of ecosystem health. In this study, the composition and structure of benthic and zooplankton communities and environmental variables were analyzed seasonally in six urban wetlands of Santa Fe City (Argentina). We present the effect of water quality on both communities as bioindicators of ecological conditions, using different community attributes, functional feeding groups, and biotic indices. For the benthic community, the Macroinvertebrate Index for Pampean Rivers (IMRP) and the Benthic Community Index (BCI) were selected. For the zooplankton community, abundance of rotifers/abundance of total zooplankters, microcrustaceans/total zooplankters, cladocerans/total zooplankters, and macrozooplankton/microzooplankton ratios were applied. A functional feeding groups (FFGs) classification, adapted from the literature, is proposed for zooplankters. The urban wetlands showed a gradient from the most to the least disturbed sites. Some benthic and zooplankton species were identified as excellent bioindicators of pollution, and the FFGs and biotic indices revealed the ecological condition of each urban wetland. The present study contributes to the enhancement of management practices in urban landscapes aiming to maintain ecosystem services in sustainable cities. [ABSTRACT FROM AUTHOR]

The various human activities along the Steelpoort River in South Africa are causing changes in water quality and affecting the distribution of macroinvertebrate functional feeding groups (FFG). The objectives of this study were to assess the spatial and temporal distribution of FFG of macroinvertebrates and to determine if the community structure corresponds to the River Continuum Concept (RCC). The distribution of the FFG varied significantly among sites and the variation was related to the different characteristics of the sites. The collector-gatherers were the most abundant functional feeding group at Site 1, collector-filterers were the most dominant group at Site 4 and Site 5, predators were the most dominant group at Site 2, Site 3 and Site 6. Shredders were least represented at all sites of the river. Seasonally, the collector-gatherers were dominant in winter, collector-filterers were dominant in spring and predators were the dominant group in autumn and summer. The study showed that the distribution of FFG was not in conformity to the RCC. The results suggest that land use changes in the catchment is affecting the FFG distribution pattern. It is therefore important that policies governing land use changes should take into account the impact on the macroinvertebrate community. [ABSTRACT FROM AUTHOR]

Afforestation is a primary response to the loss and degradation of mangroves worldwide. The successful restoration of mangrove ecosystems is in part indicated by the rebuilding of macrobenthic community. However, the community dynamic of benthic macrofauna after mangrove afforestation was poorly known. Here, three quarterly surveys (2006–2007, 2014–2015, 2019–2020) of the benthic macrofauna and sediment grain size were conducted in a mix-planted mangrove stand (Kandelia obovata + Sonneratia apetala) in Xiamen Tong’an Bay, China. Our results showed that the community structure of benthic macrofauna differed significantly after mangrove afforestation. These differences were accompanied by the declines in the species number, abundance, biomass, and diversity (H’), as well as the fining of sediments. We also found that the epifauna and infauna exhibited different adaptabilities to mangrove vegetation. Additionally, shifts in the composition of the functional feeding groups were observed, indicating the modification of trophic structure after mangrove afforestation. We recommend that future mangrove afforestation programs call for a guide to coordinate habitats for different taxa. [ABSTRACT FROM AUTHOR]

Continuous wetland restoration initiatives in China are increasing, due to the global degradation of wetland ecosystems. However, monitoring of the restoration situation remains incomplete. In this study, we investigated the effects of wetland restoration on the macroinvertebrate taxonomic structure and feeding functional groups (FFGs) in the Naolihe National Nature Reserve (NNNR). Macroinvertebrate taxonomic diversity can be used to monitor wetlands, and we hypothesized that FFGs serve the same function. We calculated the diversity index, performed a non-metric multidimensional analysis based on macroinvertebrate taxonomics and FFGs, and subsequently, performed a t -test on the results. The results showed that macroinvertebrate diversity and FFGs analyses were in general agreement with taxonomic diversity, indicating that the macroinvertebrate community in the wetland with five years of fallow land was resembled that of the natural wetland. In contrast, the macroinvertebrate community in the wetland with two years of fallow differed significantly from that in the natural wetland. Additionally, the results of the ecosystem attributes based on biomass and FFGs showed that restored wetlands exhibited lower habitat stability than natural wetlands. Nutrients (NH 4 + -N, NO 3 - -N, and total phosphorus) explained the changes in macroinvertebrate FFGs in the restored wetlands to a greater extent than in the natural wetlands. The results of this study highlight the importance of macroinvertebrate FFGs in wetland monitoring, which supports the use of macroinvertebrate FFGs in the NNNR to monitor wetland restoration., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors.)

The present study provides data on the trophic structure of the benthic macroinvertebrate communities in mountainous and semi-mountainous small streams and river sections belonging to Mesta, Struma and Vardar River catchments from 7th Ecoregion. The benthic macroinvertebrates were assigned to seven Functional Feeding Groups. We analyzed their trophic structure and the dynamics in different seasons. The level of similarity between the sampling localities was analyzed in the context of both the river typology and the water catchment. A comparison between the two trophic indices was conducted in order to analyze the advantages of the application of these indices for assessment of the ecological status at the studied sites. We found that the trophic structure of the benthic macroinvertebrate communities in ostensibly typologically similar river sections differs at the undisturbed vs the impacted sampled sites. To a large extent, these differences were also determined by the presence of anthropogenic influence that resulted in the predominance of deposit feeders amplifying on higher disturbance on some of the studied rivers. Long-term negative pressure has led to changes in microhabitats that affect the structure and functioning of the aquatic ecosystem by transformation of the trophic structure of the macrozoobenthos.

Abstract: Aim The maintenance and condition of riparian vegetation are important factors for conserving headwater streams and their species diversity. Thus, variations in the width of a riparian zone can have dramatic effects in the structure and functioning of the adjacent freshwater ecosystem. In this study, we aimed to determine if increased riparian zone width changed the benthic assemblages’ structure (diversity, taxonomic and functional composition) in headwater streams. Methods We tested two predictions: (1) increased riparian zone width will change the diversity and taxonomic composition of benthic macroinvertebrate assemblages because narrow riparian zones do not buffer the anthropogenic impacts from the surrounding landscape; (2) wider riparian zones will change benthic macroinvertebrate assemblages’ functional structure, due to changes to energetic input and quality. To test the first prediction, we assessed the benthic macroinvertebrate assemblages’ taxonomic composition, richness and Shannon-Wiener diversity index. To test the second prediction, we assessed functional feeding groups (FFG) and metrics based on their proportion. Results Our results showed that our first prediction was not corroborated, because taxonomic structure and diversity did not show significant variation with increased riparian zone width. Our second prediction was partially corroborated, because there were significant alterations in the functional structure of benthic macroinvertebrate assemblages between the narrowest riparian zone width (30 m) and the others two (50 and 100 m). Conclusions Our results suggest that, contrary to the Brazilian Federal Law 12651/2012, 30-m wide riparian zones are insufficient to protect headwater stream ecosystem functioning.

One of Costa Rica’s driest areas is the province of Guanacaste, in the Pacific Northwest, with almost no rain during the dry season from November to April. Due to this marked seasonality, the area is covered by dry tropical deciduous forest, considered the most threatened and least known tropical ecosystem in this area. This study analyzes and characterizes the assemblages of aquatic macroinvertebrates in water bodies within the Tempisque basin. Biological water quality was measured using the BMWP′-CR index. Macroinvertebrate assemblages were analyzed using abundance, richness, and functional feeding group approaches (FFG). Partial least square (PLS) analyses were performed, and the relationships between environmental factors and macroinvertebrate assemblages are also discussed. Macroinvertebrate assemblages were dominated numerically by mayflies, caddisflies, flies, and beetles. The BWMP′-CR index showed varying biological water quality, ranging from “very bad” to “excellent,” depending on rainfall and site management. Results suggest that tropical Mesoamerican rivers contradict the “river continuum concept” because predators and scrapers displace shredders in numbers. On the other hand, the study area shows a notable high richness of the Coleoptera genera. The class Rhynchocoela (Nemertea) is reported for the first time in Central America. The results indicate that the dry forest river ecosystem shows staggering biodiversity despite the surrounding agricultural land use, probably because of their older origin concerning tropical rain forests in Central America.