Search

Trout-perch (Percopsis omiscomaycus) is an abundant, small-bodied, benthic fish species often found in deeper regions of large lake ecosystems. Historical evidence suggests that Trout-perch may participate in nearshore lake food webs by migrating from deep to shallow areas at night. However, little is known about Trout-perch ecology or their potential role in nearshore food webs. We used Trout-perch abundance estimates, diet analysis, and benthic invertebrate community surveys to (1) assess Trout-perch trophic ecology in Lake Champlain, USA/CAN, and (2) determine whether deepwater prey resources existed at sufficient densities to support Trout-perch populations or whether supplemental prey resources were required. Trout-perch showed variability in size and biomass across lake regions, but diet patterns were largely consistent across the lake, with > 50% of diets consisting of emergent insect larvae and oligochaetes. Results suggest that migrations into nearshore habitats may be required to sustain Lake Champlain's Trout-perch populations, and therefore, Trout-perch could function as conduits of allochthonous energy across distinct lake habitat boundaries. This study is one of only a few that have examined the trophic ecology of Trout-perch in deep lakes and fundamentally improves our understanding of energy flow and coupling between distinct lake food web compartments in large lakes. [ABSTRACT FROM AUTHOR]

Large grazers modify vegetated ecosystems and are increasingly viewed as keystone species in trophic rewilding schemes. Yet, as their ecosystem influences are context‐dependent, a crucial challenge is identifying where grazers sustain, versus undermine, important ecosystem properties and their resilience.Previous work in diverse European saltmarshes found that, despite changing plant and invertebrate community structure, grazers do not suppress below‐ground properties, including soil organic carbon (SOC). We hypothesised that, in contrast, eastern US saltmarshes would be sensitive to large grazers as extensive areas are dominated by a single grass, Spartina alterniflora. We predicted that grazers would reduce above‐ and below‐ground Spartina biomass, suppress invertebrate densities, shift soil texture and ultimately reduce SOC concentration.We tested our hypotheses using a replicated 51‐month large grazer (horse) exclusion experiment in Georgia, coupled with observations of 14 long‐term grazed sites, spanning ~1000 km of the eastern US coast.Grazer exclusion quickly led to increased Spartina height, cover and flowering, and increased snail density. Changes in vegetation structure were reflected in modified soil texture (reduced sand, increased clay) and elevated root biomass, yet we found no response of SOC. Large grazer exclusion also reduced drought‐associated vegetation die‐off.We also observed vegetation shifts in sites along the eastern US seaboard where grazing has occurred for hundreds of years. Unlike in the exclusion experiment, long‐term grazing was associated with reduced SOC. A structural equation model implicated grazing by revealing reduced stem height as a key driver of reduced soil organic carbon.Synthesis: These results illustrate the context dependency of large grazer impacts on ecosystem properties in coastal wetlands. In contrast to well‐studied European marshes, eastern US marshes are dominated and structured by a single foundational grass species resulting in vegetation and soil properties being more sensitive to grazing. Coastal systems characterised by a single foundation species might be inherently vulnerable to large grazers and lack resilience in the face of other disturbances, underlining that frameworks to explain and predict large grazer impacts must account for geographic variation in ecosystem structure. [ABSTRACT FROM AUTHOR]

Drought is an increasing risk to the biodiversity within rivers—ecosystems which are already impacted by human activities. However, the long‐term spatially replicated studies needed to generate understanding of how anthropogenic stressors alter ecological responses to drought are lacking.We studied aquatic invertebrate communities in 2500 samples collected from 179 sites on rivers emerging from England's chalk aquifer over three decades. We tested two sets of alternative hypotheses describing responses to and recovery from drought in interaction with human impacts affecting water quality, fine sediment, water temperature, channel morphology, flow and temporal change in land use. We summarized communities using taxa richness, an index indicating tolerance of anthropogenic degradation (average score per taxon, ASPT) and deviation from the average composition.Responses to drought were altered by interactions with human impacts. Poor water quality exacerbated drought‐driven reductions in taxa richness. Drought‐driven deviations from the average community composition were reduced and enhanced at sites impacted by flow augmentation (e.g. effluent releases) and flow reduction (e.g. abstraction), respectively.Human impacts altered post‐drought recovery. Increases in richness were lower at sites impacted by water abstraction and higher at sites with augmented flows, in particular as recovery trajectories extended beyond 3 years. ASPT recovered faster at sites that gained woodland compared to urban land, due to their greater recovery potential, that is, their lower drought‐driven minimum values and higher post‐drought maximum values.Synthesis and applications. We show that communities in river ecosystems exposed to human impacts—in particular poor water quality, altered flow volumes and land use change—are particularly vulnerable to drought. These results provide evidence that management actions taken to enhance water quality, regulate abstraction and restore riparian land use could promote ecological resilience to drought in groundwater‐dominated rivers such as globally rare chalk streams and other rivers of the Anthropocene, as they adapt to a future characterized by increasing climatic extremity. [ABSTRACT FROM AUTHOR]

Predators regulate communities through top‐down control in many ecosystems. Because most studies of top‐down control last less than a year and focus on only a subset of the community, they may miss predator effects that manifest at longer timescales or across whole food webs. In southeastern US salt marshes, short‐term and small‐scale experiments indicate that nektonic predators (e.g., blue crab, fish, terrapins) facilitate the foundational grass, Spartina alterniflora, by consuming herbivorous snails and crabs. To test both how nekton affect marsh processes when the entire animal community is present, and how prior results scale over time, we conducted a 3‐year nekton exclusion experiment in a Georgia salt marsh using replicated 19.6 m2 plots. Our nekton exclusions increased densities of plant‐grazing snails and juvenile deposit‐feeding fiddler crab and, in Year 2, reduced predation on tethered juvenile snails, indicating that nektonic predators control these key macroinvertebrates. However, in Year 3, densities of mesopredatory benthic mud crabs increased threefold in nekton exclusions, erasing the tethered snails' predation refuge. Nekton exclusion had no effect on Spartina biomass, likely because the observed mesopredator release suppressed grazing snail densities and elevated densities of fiddler crabs, whose burrowing alleviates soil stresses. Structural equation modeling supported the hypotheses that nektonic predators and mesopredators control invertebrate communities, with nektonic predators having stronger total effects on Spartina than mud crabs by controlling densities of species that both suppress (grazers) and facilitate (fiddler crabs) plant growth. These findings highlight that salt marshes can be resilient to multiyear reductions in nektonic predators if mesopredators are present and that multiple pathways of trophic control manifest in different ways over time to mediate community dynamics. These results highlight that larger scale and longer‐term experiments can illuminate community dynamics not previously understood, even in well‐studied ecosystems such as salt marshes. [ABSTRACT FROM AUTHOR]

Simplification of agricultural environments is linked to declines in biodiversity. Improving the floral diversity within and around these areas may result in more robust and diverse ecosystems. We investigated how floral resource abundance, diversity, and species composition in a cranberry agricultural system correlated to the abundance and overall invertebrate diversity and to the abundance and diversity of specific invertebrate groups of agricultural importance (e.g. parasitoids, phytophagous taxa, pollinators and predators). This study focused on habitats immediately surrounding cranberry production and included grassy dikes under a managed system (‘dike’), and semi‐natural areas growing on the surrounding support land (‘semi‐natural’). Floral resource availability and diversity tended to be similar between habitats, while invertebrate richness, diversity and composition differed. As the availability of floral resources increased, invertebrate abundance increased but diversity decreased. Overall invertebrate community composition differed with the specific species and availability of floral resources. The habitat type and floral resource composition impacted some agriculturally important groups, as pollinator abundance was higher in the semi‐natural habitat, and parasitoid abundance varied with floral resource composition across both habitats. These results suggest that managing the structural and floral resource diversity associated with agroecosystems can help support local biodiversity. However, these systems may disproportionately benefit more common taxonomic groups. The difference in responses of individual taxonomic groups also highlights the potential tradeoffs of focusing on only a subset of biodiversity aspects. [ABSTRACT FROM AUTHOR]

The physical effects of climate warming have been well documented, but the biological responses are far less well known, especially at the ecosystem level and at large (intercontinental) scales. Global warming over the next century is generally predicted to reduce food web complexity, but this is rarely tested empirically due to the dearth of studies isolating the effects of temperature on complex natural food webs. To overcome this obstacle, we used 'natural experiments' across 14 streams in Iceland and Russia, with natural warming of up to 20°C above the coldest stream in each high‐latitude region, where anthropogenic warming is predicted to be especially rapid. Using biomass‐weighted stable isotope data, we found that community isotopic divergence (a universal, taxon‐free measure of trophic diversity) was consistently lower in warmer streams. We also found a clear shift towards greater assimilation of autochthonous carbon, which was driven by increasing dominance of herbivores but without a concomitant increase in algal stocks. Overall, our results support the prediction that higher temperatures will simplify high‐latitude freshwater ecosystems and provide the first mechanistic glimpses of how warming alters energy transfer through food webs at intercontinental scales. [ABSTRACT FROM AUTHOR]

Numerous and diverse groundwater habitats suitable for sustaining aquatic invertebrate communities exist across Australia. These habitats include enclosed subterranean aquifer systems, fractured rock, alluvial aquifers, perched aquifers, artesian springs, and spring-fed seeps and marshes. Crustaceans are a dominant member of these groundwater-associated invertebrate communities, and amphipods, both stygobiont and associated epigean species, are particularly diverse yet are still relatively poorly known. We review both the diversity and distributions of Australian amphipods associated with groundwater habitats, describing hotspots of diversity, providing notes on the unique Australian habitats, and examining the extraordinary species diversity and endemism of the Australian species. Our review highlights the significance of Australian groundwater ecosystems, their associated biodiversity, and the importance in considering these ecosystems in groundwater conservation management plans. [ABSTRACT FROM AUTHOR]

Simple Summary: The widespread use of broad-spectrum insecticides reduces the capabilities of ecological self-regulation of phytophages in agrocoenoses and in the adjacent natural territories. Those ecosystems suffer disruption of trophic relations that have been forming over long periods of time. At the same time, the numbers of non-target invertebrates affected by pesticides are declining. Pirimiphos-methyl is one of the cheapest, most effective, and widely used insecticides in the world. Its effect on invertebrate species is useful for agriculture; however, its effect on arthropods that improve soil fertility remains virtually unstudied. This article establishes that this insecticide can have a strong effect on some species useful for plant growing and a weak effect on others. As a result of such an effect of pirimiphos-methyl, the taxonomic structure of invertebrate communities in agrocenoses should change dramatically. The use of this insecticide in fields gives an advantage to species that are relatively more resistant to it and causes a faster disappearance of sensitive invertebrate species. The effects of pirimiphos-methyl have previously been assessed on blood-sucking insect species, pollinating insects, and target crop pest species. The sensitivity of non-target zoophagous and saprophage species to this insecticide remains largely unstudied. In laboratory conditions, we assessed the susceptibility of 43 species of invertebrates to pirimiphos-methyl. The most tolerant species to this insecticide were Pyrrhocoris apterus (LC50 measured over 60 mg/m2), Cylindroiulus truncorum, Pterostichus niger, Harpalus rufipes, Lithobius forficatus, and Carabus hortensis (LC50 ranged from 25 to 50 mg/m2). Average tolerance to pirimiphos-methyl was displayed by Ophonus rufibarbis, Teuchestes fossor, Silpha carinata, Badister sodalis, Rugilus rufipes, Phosphuga atrata, Porcellio laevis, Pterostichus oblongopunctatus, Aphodius foetens, Lasius fuliginosus, Oxypselaphus obscurus, Platydracus fulvipes, Myrmica ruginodis, Xantholinus tricolor, and Megaphyllum sp. (LC50 for those species ranged from 12 to 24 mg/m2). Higher sensitivity to this insecticide was seen for Amara nitida, Leistus ferrugineus, Harpalus xanthopus winkleri, Philonthus nitidus, Pterostichus melanarius, Harpalus latus, Limodromus assimilis, Philonthus decorus, Tachinus signatus, Ponera coarctata, Carabus convexus, Philonthus coprophilus, Philonthus laevicollis, Platydracus latebricola, Labia minor, and Carabus granulatus (LC50 for those species ranged from 6 to 12 mg/m2). The greatest sensitivity to pirimiphos-methyl was observed in Hister fenestus, Drusilla canaliculata, Bisnius fimetarius, Oxytelus sculptus, Lasius niger, and Lasius flavus (LC50 ranged from 0.4 to 6 mg/m2). We found a relationship between the parameters of bodies of invertebrates (the average body length and dry body mass) and sensitivity to pirimiphos-methyl. With an increase in body sizes of invertebrates, the tolerance to the insecticide increased (per each mm of body length, LC50 increased by 0.82 mg/m2 on average). We identified no relationship between the trophic specialization and sensitivity to the insecticide. [ABSTRACT FROM AUTHOR]

Amphibians are among the most endangered taxa worldwide, but little is known about how their disappearance can alter the functioning and structure of freshwater ecosystems, where they live as larval stages. This is particularly true for urodeles, which often are key predators in these ecosystems. The fire salamander (Salamandra salamandra) is a common predator in European fresh waters, but the species is declining due to habitat loss and the infection by fungal pathogens. We studied the consequences of fire salamander loss from three montane streams, by comparing two key ecosystem processes (periphyton accrual and leaf litter decomposition) and the structure of three communities (periphytic algae, aquatic hyphomycetes and invertebrates) using stream enclosures with and without salamander larvae. Salamander loss did not cause changes in invertebrate abundance or community structure, except for one stream where abundance increased in the absence of salamander larvae. However, salamander loss led to lower periphyton accrual, changes in algal community structure and slower leaf litter decomposition, with no associated changes in fungal communities or microbial decomposition. The changes observed may have been caused by release of salamander predatory pressure on invertebrates, which could have promoted their grazing on periphyton, in contrast to their preference for leaf shredding in the presence of salamander. Our study demonstrates an important role of salamander larvae in montane streams through top‐down control of lower trophic levels and thus in regulating key stream ecosystem processes. Our results highlight the need for improving protection measures for amphibians to prevent these alterations on ecosystem structure and function. [ABSTRACT FROM AUTHOR]

Molecular techniques like metabarcoding, while promising for exploring diversity of communities, are often impeded by the lack of reference DNA sequences available for taxonomic annotation. Our study explores the benefits of combining targeted DNA barcoding and morphological taxonomy to improve metabarcoding efficiency, using beach meiofauna as a case study. Beaches are globally important ecosystems and are inhabited by meiofauna, microscopic animals living in the interstitial space between the sand grains, which play a key role in coastal biodiversity and ecosystem dynamics. However, research on meiofauna faces challenges due to limited taxonomic expertise and sparse sampling. We generated 775 new cytochrome c oxidase I DNA barcodes from meiofauna specimens collected along the Netherlands' west coast and combined them with the NCBI GenBank database. We analysed alpha and beta diversity in 561 metabarcoding samples from 24 North Sea beaches, a region extensively studied for meiofauna, using both the enriched reference database and the NCBI database without the additional reference barcodes. Our results show a 2.5‐fold increase in sequence annotation and a doubling of species‐level Operational Taxonomic Units (OTUs) identification when annotating the metabarcoding data with the enhanced database. Additionally, our analyses revealed a bell‐shaped curve of OTU richness across the intertidal zone, aligning more closely with morphological analysis patterns, and more defined community dissimilarity patterns between supralittoral and intertidal sites. Our research highlights the importance of expanding molecular reference databases and combining morphological taxonomy with molecular techniques for biodiversity assessments, ultimately improving our understanding of coastal ecosystems. [ABSTRACT FROM AUTHOR]

The widely observed negative scaling relationship between organism size and abundance is predicted to have a universal −0.75 scaling exponent across all life forms. However, factors influencing frequently observed deviations from this exponent, such as ecosystem succession and organism traits, remain poorly understood.We explore the dependence of size–density scaling on ecosystem succession and organism traits by analysing size–density relationships in trees and soil invertebrates across 183 temperate forest plots comprising urban secondary forests, urban old‐growth forests and non‐urban natural forests.Exponents of scaling relationships in urban tree and invertebrate communities progressively steepened with increasing restored (planted) forest stand age as small organisms increased in abundance. In contrast, non‐urban tree scaling relationships flattened during succession with exponents veering away from −0.75, whereas urban tree and invertebrate communities converged towards this prediction in later successional stages.Our results shed light on how the body size structure of tree and soil invertebrate communities spanning multiple trophic levels shift over successional time as the relative abundances of large versus small‐bodied organisms increase. This study emphasises the fundamental influence of organismal traits and ecosystem succession on scaling relationships of organism body size and abundance. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Coral reefs are among the most biodiverse ecosystems on Earth, largely due to the structural complexity created by corals. Coral habitat is crucial refuge for numerous small animals, and competition for habitat can structure populations if in short supply. Reefs in Hawai'i are largely dominated by the small branching coral Pocillopora meandrina, which supports diverse communities of fishes and invertebrates. Two species of nocturnal scorpionfishes, Sebastapistes coniorta and S. galactacma, are particularly common in P. meandrina, inhabiting the complex branching morphology of their host corals during the day and feeding in and around these corals at night. Surveys of scorpionfishes in 458 P. meandrina between 3 and 22 m deep along the south and west shores of O'ahu revealed inverse depth distributions over which these species occurred in P. meandrina. Sebastapistes coniorta almost exclusively occurred in coral colonies between 5 and 10 m deep, while S. galactacma were found across all depths surveyed, though were far more common and abundant in deeper coral colonies (15–20 m) below the range of S. coniorta. Further, measurements of host colony morphometrics revealed that these species appeared to use microhabitat in subtly different ways. The larger-bodied species, S. coniorta, was more commonly found in P. meandrina with wider spaces between branches, while the smaller-bodied species was negatively associated with wider branch spacing. These patterns indicate habitat partitioning between S. coniorta and S. galactacma at both the reef and colony scale, which may explain how these species are able to coexist on reefs in Hawai'i. [ABSTRACT FROM AUTHOR]

Aquatic invertebrate community composition was sampled over 10 months in ephemeral and permanent pools along the upper segment of an ephemeral stream in Central Texas. A total of 67 total taxa were documented during this study. The highest numbers of taxa by total count found during the study were Hyalella, Chironomidae, Physa, and Caenis with total counts ranging from 1957 to 7437 individuals. Taxa with total moderate counts ranging between 209 and 856 individuals were Oligochaeta, Helobdella, Corbicula, Cyclopoida, Planorbis, and Berosus. Twelve different functional feeding groups were observed with collector-gathers-shredder accounting for 29.1%. The Pollution Tolerance Level was highest from 6 to 9 and peaked at 8 for both permanent and ephemeral pools indicating poor water quality. Based on the Hilsenhoff Family Biotic Index (FBI), the FBI was estimated to 7.47 and 7.53 for permanent and ephemeral pools, respectively, indicating poor water quality high in organic matter. Ephemeroptera, Plecoptera, and Trichoptera (EPT) taxa were represented by 5.3 and 18.2% of the total counts in permanent and ephemeral pools, respectively. All other taxa, excluding EPT taxa, represented 94.7 and 81.8% of the total counts in permanent and ephemeral pools, respectively. Our results indicate the runoff from adjacent urban areas resulted in reduced water quality within the pools based on aquatic invertebrate taxa. With reduced protection of ephemeral streams under the 2023 Supreme Court WOTUS decision, water quality and biodiversity will continue to decline and impact perennial river water quality longitudinally during flow events. [ABSTRACT FROM AUTHOR]

A variety of stormwater infrastructure such as constructed wetlands, rain gardens, vegetated drainage channels and retention ponds are primarily used for managing water runoff, but these environments can also foster biodiversity. Despite extensive literature about certain taxa (e.g., amphibians, aquatic macroinvertebrates, etc.) found in these human-made environments, the terrestrial plants and invertebrates present there remain understudied. Here, we compared alpha and beta diversity of plant and terrestrial invertebrate communities and assessed the influence of landscape characteristics on their composition in different types of urban stormwater basins and ponds. Plants and terrestrial invertebrates were identified in the main body (excluding the aquatic section) and on the banks of 54 basins and ponds (dry basins, wet basins with and without a water channel and retention ponds) in Quebec City and Trois-Rivières, in Eastern Canada. Results showed poor and homogenous plant and invertebrate communities in dry basins. Wet basins had the highest plant alpha diversity, with more facultative wetland species than the two other types. Wet basins with and without a water channel had similar plant and invertebrate composition, and wet basins and retention ponds were the most heterogeneous. Retention ponds (with permanent water) had distinct communities with fewer plant species than wet basins. The presence of natural areas around the infrastructure significantly influenced communities within a 2000 m and 500 m radius for plant and invertebrate communities, respectively. Wetland plant species were generally found in infrastructure close to natural areas, whereas tolerant and opportunist species were associated with disturbed environments. Our results suggest that enhancing diversity of the stormwater basins and ponds at the regional and local (microhabitat) scales has the potential to maximize diversity of plants and terrestrial invertebrates. [ABSTRACT FROM AUTHOR]

Estuaries support diverse fish and invertebrate communities, including resident species that rely on estuarine habitats year‐round and transient migratory species. The unique movement patterns of these animals connect habitats within and far beyond the estuary and are integrally linked to fisheries management objectives. With a focus on Chesapeake Bay, this study leveraged data from collaborative acoustic telemetry networks in the northwest Atlantic to assess habitat use and phenology of movements for seven species of fish (cownose rays, dusky sharks, smooth dogfish, alewife, striped bass, common carp, and blue catfish) and one invertebrate (horseshoe crabs). A total of 288 acoustically tagged individuals were detected >3.2 million times (6,743 to 2,095,717 detections per species) on receivers across ~20.5 degrees of latitude spanning the North American Atlantic seaboard from Florida, USA, to New Brunswick, Canada. Common metrics of movement and phenology grouped these species as resident (common carp, blue catfish, horseshoe crabs), primarily resident in estuaries (juvenile striped bass), and coastal migrant (cownose rays, dusky sharks, smooth dogfish, alewife); maximum distance traveled varied by three orders of magnitude among these species. Further analysis of phenology for coastal migrants elucidated the timing and duration of these species' use of Chesapeake Bay. Collectively, movements linked habitats within Chesapeake Bay and connected the estuary to coastal ecosystems both to the north (e.g., alewife) and south (e.g., cownose rays), creating networks of fisheries management jurisdictions that varied in complexity and identified opportunities for enhancement to current management or co‐management of some species. Our results elucidate the importance of estuaries to species with diverse movement behaviors, identify scales and pathways of habitat connectivity via animal movements, and highlight the utility of collaborative acoustic telemetry networks for quantifying movements relevant to both ecological research and fisheries management. [ABSTRACT FROM AUTHOR]

Alarm calls produced by basal prey have a well-known informative value. In multi-predator communities, mesopredators, when faced with top predators, may emit alarm calls that could inform basal prey about their lowered predation risk. To test this unexplored possibility, we conducted one field and one mesocosm experiment in which we simulated alarm and non-alarm calls from little owls (Athene noctua) as mesopredators and measured their effects on grasshoppers as prey of little owls but not of top predators. In the field experiment, we found that grasshopper species were significantly more abundant in patches where we simulated either the presence of scared little owls (alarm treatment) or no owls (control treatment) compared to patches where the presence of non-scared little owls (non-alarm treatment) was simulated. In the mesocosm experiment, locusts (Locusta migratoria) moved significantly more to exposed areas when we simulated the presence of scared little owls (alarm treatment) or of a granivorous bird (control treatment), while they moved to sheltered areas when we simulated the presence of non-scared owls (non-alarm treatment). These results show that prey could cue on predators' calls to assess their predation risk and make decisions, revealing unprecedented potential ecological consequences of alarm calls in invertebrate communities. [ABSTRACT FROM AUTHOR]

Invertebrates account for over 90% of all described species and provide crucial ecosystem services. Land clearing, including the removal of abiotic habitat features, threatens invertebrate biodiversity, making environmental restoration crucial for conservation. However, little is known about the effects of abiotic restoration compared to the restoration of biotic features. To determine if rock addition increased invertebrate biodiversity, we introduced 120 t of rocks to 10 sites across five grassland reserves in the Australian Capital Territory in a before‐after‐control‐impact design. We sampled invertebrates using pitfall traps before treatment in 2016 and after rock addition in 2019 (during record‐breaking drought). We recorded 29,164 individual invertebrates from 19 orders and undertook a functional trait‐based analysis of rock effects on the invertebrate community. No effects of rock addition were observed on the probability of occurrence, richness, diversity, community similarity, or abundance of any taxonomic or functional group. The abundance of snare‐building spiders and large ants was higher in the control plots at the end of the experiment. These abundance responses in 2019 did not differ from the control or treatment plots in 2016. Thus, some combination of drought and rock addition appears to have neutralized a positive temporal change that was evident without rocks. Despite a regionwide, replicated restoration effort and an extensive functional analysis of invertebrate communities, very little positive response to rock addition was recorded. Rock addition did not have a negative effect on grassland invertebrate biodiversity and may still be beneficial to the long‐term conservation and restoration of vertebrate and invertebrate communities. [ABSTRACT FROM AUTHOR]

Anthropogenic biodiversity loss can impair ecosystem functioning. Human activities are often managed with the aim of reversing biodiversity loss and its associated functional impacts. However, it is currently unknown whether biodiversity–ecosystem function (BEF) relationships observed during biodiversity recovery are the same as those observed during biodiversity loss. This will depend on how species extirpation and recolonisation sequences compare and how different species influence ecosystem functioning. Using data from a marine benthic invertebrate community, we modelled how bioturbation potential – a proxy for benthic ecosystem functioning – changes along biodiversity loss and recovery sequences governed by species' sensitivity to physical disturbance and recolonisation capability, respectively. BEF relationships for biodiversity loss and recovery were largely the same despite species extirpation and recolonisation sequences being different. This held true irrespective of whether populations were assumed to exhibit compensatory responses as species were removed or added. These findings suggest that the functional consequences of local biodiversity loss can be reversed by alleviating its drivers, as different species present at comparable levels of species richness during biodiversity loss and recovery phases have similar functional effects. Empirically verifying and determining the generality of our model‐based results are potential next steps for future research. [ABSTRACT FROM AUTHOR]

Geographic isolation is a factor that is known to affect species composition and diversity in marine systems. In this study, we tested the effects of geographic isolation on invertebrate fauna living among the belt-forming foundation species Fucus vesiculosus in the northern Baltic Sea. Sampling was carried out on reefs with varying levels of isolation (0.5, 1 and 2 km) in July 2021 in the Åland islands (between 59.96°N 20.24°E and 59.75°N 20.84°E). The total number of taxa, abundance, Shannon-Wiener index, Pielou's evenness and biomass were calculated and the effects of isolation were tested using generalised linear models. Multivariate methods were used to analyse differences in the invertebrate community composition. Although the number of taxa and Shannon´s diversity index did not vary along the isolation gradient, the total abundance of fauna decreased with increasing isolation. In addition, some taxa-specific patterns were observed, e.g. the abundance of insect larvae decreased with isolation while isopods were more numerous in the most isolated locations. As diversity and the number of taxa were similar regardless of isolation, shallow Fucus vesiculosus belts likely act as important biodiversity refuges and potential stepping-stones for invertebrates in remote outer archipelago areas. In a changing climate, these kinds of refuges aiding species dispersal are likely to be even more important, and should be considered in conservation planning. [ABSTRACT FROM AUTHOR]

Aquatic macrophytes serve as shelter and a direct source of food for invertebrates, in addition to indirectly providing items such as algae, detritus, and microorganisms. Thus, aquatic macrophytes act as habitat structuring elements, requiring a distinction between habitat complexity (physical formations such as fractal dimensions, density and biomass) and habitat heterogeneity (diversity of these structures). Here we explore the effects of habitat complexity and habitat heterogeneity on the invertebrate community.We collected macrophytes and invertebrates from 28 sampling sites along a 13.7‐km stretch of the Baía River in Brazil, and examined specific groups (insects, microcrustaceans, and other invertebrates). Environmental variables in the sites were also measured. We aimed to explore the effects of habitat complexity (measured by macrophyte biomass) and habitat heterogeneity (evaluated through macrophyte functional diversity) on the richness and abundance of invertebrates.We found that overall invertebrate richness was positively influenced solely by habitat heterogeneity. For invertebrate abundance, intermediate habitat complexity had more invertebrates, while habitat heterogeneity had a positive impact. Environmental variables influenced only the abundance. For specific groups, insect richness was positively influenced by habitat heterogeneity, while insect abundance decreased with high complexity and increased with high heterogeneity. Microcrustacean abundance was positively influenced by habitat complexity. Richness and abundance of other invertebrates was positively influenced by habitat heterogeneity.Invertebrates prefer macrophyte stands with intermediate complexity and high heterogeneity. Abundance is linked to structural complexity and heterogeneity, while species richness is more strongly associated with heterogeneity. Furthermore, the impact of these factors varies among invertebrate groups.These findings emphasise the importance of integrating a broad range of metrics, such as macrophyte biomass and functional diversity, to gain a thorough understanding of invertebrate community dynamics in future studies. Additionally, our study demonstrates that preserving macrophyte stands with high heterogeneity significantly enhances the diversity of associated invertebrate species. [ABSTRACT FROM AUTHOR]

Small Shallow Lakes and ponds (SSLs) provide numerous ecosystem services and harbour unique biodiversity. They are very vulnerable to human disturbances and play a central role in ecosystem functioning. In this study, we aimed to disentangle the role of environmental variables in the composition and richness of invertebrate communities using datasets collected from 143 French SSLs with minimal impact from human activities. The SSLs were sampled across four climatic ecoregions, encompassing various geologies and elevations. A hierarchical classification revealed a clear separation into two groups: (1) highland waterbodies and (2) lowland waterbodies. The main environmental variables identified by the db-RDA were elevation associated with climate, and the presence of fish, along with interrelated variables such as SSLs morphology. Generalised additive models GAMs that combined diversity and composition indices or taxonomic richness with determinant environmental variables demonstrated that (1) elevation, mesohabitat complexity and the presence of exotic crayfish strongly influenced the structure, richness, and composition of macroinvertebrate communities, and (2) the presence of fish had a significant impact only on community composition (e.g., reducing the relative richness of typical pond-swimmer taxa). Furthermore, even though connectivity with other waterbodies influenced the macroinvertebrate communities, its impact appeared to be less significant than elevation, climate, and local variables such as the presence of predators (fish or crayfish). [ABSTRACT FROM AUTHOR]

Disturbances are drivers of ecosystem function and play important roles in shaping ecological communities. Prescribed fire and grazing disturbances are common management tools in restored and remnant grasslands. The effects of these management actions on plant communities and on vegetation-dwelling invertebrates are generally well studied. However, less is known about their effects on ground-dwelling invertebrates, which can contribute to important ecosystem processes like herbivory, predation, and decomposition. We examined bison grazing and prescribed fire effects on abundance, diversity, and community composition of ground-dwelling invertebrate groups in restored tallgrass prairies using pitfall trap samples. Surprisingly, invertebrate Shannon diversity decreased when bison were present and was unaffected by fire or the fire–bison interaction. Bison, and to a lesser extent fire, also shifted community composition, increasing abundance of ground, rove, and dung beetles, as well as orthopterans and spiders. Prescribed fire generally increased beetles but caused declines in several ecologically diverse invertebrate groups, including harvestmen and true bugs, although these reduced abundances did not lead to differences in overall diversity. Bison presence may amplify the abundances of dominant groups, such as ground and dung beetles and orthopterans, that outcompete other invertebrates and reduce diversity. Implications for insect conservation: Prescribed fire and grazing by bison change ground-dwelling invertebrate community composition, but bison presence did not reduce the abundance of most taxonomic groups. Fire may have short-term negative impacts on some invertebrate groups that promote desirable invertebrate-driven ecosystem processes, but these effects are likely short-lived, and the resulting environmental mosaic under bison and fire management could support biodiversity over the long-term. [ABSTRACT FROM AUTHOR]

This article explores the topic of large-scale dam removal and its impact on ecosystems. It emphasizes the importance of rivers in supporting biodiversity and ecosystem services. The article highlights the need for more research and monitoring efforts to understand the outcomes of dam removal projects, as most studies have focused on smaller structures. The research presented in the article covers various aspects of dam removal, including ecology, water quality, fish populations, terrestrial ecology, and the social and economic aspects of restoration. The article concludes by acknowledging the complexity of dam removal and the need for further research to fully understand the long-term effects of restoration efforts. [Extracted from the article]

The recent increase in the frequency of extreme weather events and declining soil biodiversity in global agricultural ecosystems make it crucial to assess the daily dynamics of soil communities in fields. To elucidate the daily dynamics of ground-dwelling invertebrate communities, their communities were monitored temporally using infrared camera traps in field farmland during and following an extremely high-temperature (EHT) event in summer 2022 in Ningbo City, China. Nine taxa and 1,147 individuals of the ground-dwelling invertebrate community were photographed in the 176,256 images. There were no significant differences in the taxonomic richness and abundance of the total ground-dwelling invertebrate communities during and following the EHT event. The abundance of ants was significantly decreased following the EHT event, whereas the abundance of other taxa was not. Significantly daily dynamics and obvious differences between each day in taxonomic richness, abundance of ground-dwelling invertebrate community, and abundance of each taxon were not observed during and following the EHT event. The results of this study showed that the daily dynamics of richness and abundance of the ground-dwelling invertebrate community and the abundance of each taxon were not significant during and following the EHT event. Overall, this study provides a useful monitoring method to observe the daily dynamics of ground-dwelling invertebrates in field farmlands and suggests that the daily dynamics of soil fauna communities should be further studied when assessing the effects of climate change on soil biodiversity. [ABSTRACT FROM AUTHOR]

Restoring and monitoring soil biodiversity has never been more important. Ecoacoustics is emerging as a promising tool to detect and monitor soil biodiversity and was recently effective in a temperate forest context. However, there is a need to investigate the efficacy of soil ecoacoustics in other ecosystems and bioregions. Here, we applied ecoacoustics tools and indices (Acoustic Complexity Index, Bioacoustic Index, Normalised Difference Soundscape Index) to measure soil biodiversity in an Australian grassy woodland restoration chronosequence, spanning three age classes. We collected n = 240 soil acoustic samples from two cleared plots (continuously cleared through active management), two woodland plots undergoing restoration (revegetated 14–15 years ago) and two plots of remnant vegetation over 5 days in Mount Bold, South Australia. We used a below‐ground sampling device and sound attenuation chamber to record soil invertebrate communities, which were also manually counted. We found that acoustic complexity and diversity were significantly higher in revegetated and remnant plots than in cleared plots, both in‐situ and in sound attenuation chambers. The acoustic complexity and diversity also significantly associated with soil invertebrate abundance and richness. Synthesis and applications. Our results provide new support that ecoacoustics can help monitor soil biodiversity in different forest restoration contexts, including in UK temperate and Australian grassy woodlands. This technology holds promise in addressing the global need for effective soil biodiversity monitoring methods and protecting our planet's most diverse ecosystems. [ABSTRACT FROM AUTHOR]

Intense disturbances such as hurricanes may drastically affect ecosystems, producing both acute and long-term changes along coastlines. By disrupting human activities (e.g., fishing), hurricanes can provide an opportunity to quantify the effects of these activities on coastal ecosystems. We performed predator-exclusion experiments on oyster reefs in 2016, one-year before a category-4 hurricane ("Harvey") and again in 2018 one-year post-hurricane where the storm made landfall. Additionally, we examined 8 years (2011–2018) of fisheries-independent data to gauge how fishing pressure and fish populations were affected by the storm in three locations that varied in storm impacts. In the month following Hurricane Harvey, fishing effort dropped by 90% in the area with wind and flooding damage, and predatory fish species commonly targeted by anglers were 300% more abundant than the year prior to the hurricane. The locations without damage to fishing infrastructure did not experience declines in fishing pressure or changes in fish abundance, regardless of flooding disturbance. Reef fish and invertebrate communities directly affected by the storm were significantly different after the hurricane and were ~ 30% more diverse. With low fishing pressure, sportfish CPUE were 1.7–6.9 × higher immediately after the hurricane. Intermediate consumers, such as crabs that prey on oysters, were 45% less abundant and 10% smaller. These results indicate that hurricanes can temporarily disrupt human-ecosystem linkages and reconstitute top-down control by sportfish in estuarine food webs. Disturbance events that interrupt or weaken those interactions may yield indirect ecological benefits and provide insights into the effects of human activities on food webs. [ABSTRACT FROM AUTHOR]

Irruptive or boom-and-bust population dynamics, also known as 'outbreaks', are an important phenomenon that has been noted in biological invasions at least since Charles Elton's classic book was published in 1958. Community-level consequences of irruptive dynamics are poorly documented and invasive species provide excellent systems for their study. African Jewelfish (Rubricatochromis letourneuxi, "jewelfish") are omnivores that demonstrate opportunistic carnivory, first reported in Florida in the 1960s and in Everglades National Park (ENP) in 2000. Twelve years after invasion in ENP, jewelfish underwent a 25-fold increase in density in one year. By 2016, jewelfish represented 25–50% of fish biomass. Using a 43-year fish community dataset at two sites (1978–2021), and a 25-year dataset of fish and invertebrate communities from the same drainage (1996–2021), with additional spatial coverage, we quantified differences in fish and invertebrate communities during different phases of invasion. During jewelfish boom, abundant, native cyprinodontiform fishes decreased in density and drove changes in community structure as measured by similarity of relativized abundance. Density of two species declined by > 70%, while four declined by 50–62%. Following the jewelfish bust, some species recovered to pre-boom densities while others did not. Diversity of recovery times produced altered community structure that lagged for at least four years after the jewelfish population declined. Community structure is an index of ecological functions such as resilience, productivity, and species interaction webs; therefore, these results demonstrate that irruptive population dynamics can alter ecological functions of ecosystems mediated by community structure for years following that population's decline. [ABSTRACT FROM AUTHOR]

Background and aims: Knowledge regarding the interactive effects of soil invertebrates and microbes on litter decomposition is limited. We aimed to reveal the interaction between soil invertebrates and microbes, and the mechanism underlying the effects of them on litter decomposition. Methods: Foliar litter of German oak (Quercus acutissima Carruth.) and China cedar (Cryptomeria sinensis Miquel.) were enclosed in the nylon bags with two different mesh sizes and incubated on the floor in a rainy zone of western China, respectively. Then retrieved at four critical periods each year in two years. The mass loss, invertebrates, and microbial community in the litterbags were measured. Results: The invertebrate abundances in both litter species were higher in the first year than in the second year, and that in German oak litter was higher than that in China cedar litter at most periods. Meanwhile, German oak litter decomposed faster than China cedar litter, and significantly higher decomposition rates occurred in the micro and early rainy seasons. Furthermore, soil invertebrate exclusion made the decomposition rates of German oak and China cedar litter decrease by 14.45% and 26.45%, respectively. Additionally, the interactive effects between invertebrates and microbes on litter decomposition varied greatly with litter quality and critical periods. The interactive effects between soil invertebrates and microbial communities dominated litter mass loss in the first decomposition year, but the gram-positive bacteria became the dominant decomposers in the second decomposition year. Conclusion: These results provided a holistic decomposition view, highlighting how invertebrates and microbes act in synergy to degrade litter. [ABSTRACT FROM AUTHOR]

Both catchment geology and land use surrounding a stream will affect the degree of fine sediment deposition from erosion and its consequent impacts on stream macroinvertebrate communities. While geology and land use have been shown to impact stream communities individually, their interaction has received less attention.We investigated the interaction between geology and land use on stream macroinvertebrate communities in the Tairāwhiti Region, New Zealand. The region has streams that drain harder sandstones and softer shales and mudstones, the latter having some of the highest erosion rates in the world. Macroinvertebrates were sampled each year between 2016 and 2018 at 80 sites in exotic forest, indigenous forest and pasture streams that drained hard or soft geology catchments.Conductivity in pasture and exotic forest streams was nearly twice as high as in indigenous forest streams and higher in soft than hard sediment streams. Deposited sediment cover was greater in soft than hard sediment streams, and greater in pasture and exotic forest streams than in indigenous forest streams. Periphyton cover did not differ between land uses but was higher in soft sediment streams.Ecological health was higher in the indigenous forest sites, intermediate in exotic forest sites and lowest in pasture streams. Biological indices were also higher within each land use in streams draining hard than soft sediment streams. Invertebrate communities appear to be determined primarily by the amount of deposited fine sediment and conductivity, both of which are higher in soft than in hard bottom streams, and in exotic forest and pasture streams.Synthesis and applications: Our results illustrate a complex and strong interaction between geology and land use and the consequent impact on stream macroinvertebrate communities. The combination of soft bottom streams with pasture or exotic forest land use is more detrimental than in similar hard bottom streams. Therefore, regulations for the management of any given land use need to be much stricter in catchments dominated by soft sediment geology. [ABSTRACT FROM AUTHOR]

Changing nutrient concentrations and introduction of non-native species affect the energy and nutrient fluxes in aquatic ecosystems. As a response, invertebrate communities could be altered, and 'novel' trophic communities could develop. Lake Constance (Europe) experienced pronounced nutrient variation caused by cultural eutrophication (prior 1980s) and oligotrophication (post-1980) and experienced many neobiota invasions. We used archived samples to investigate the impact of oligotrophication and invasive species on carbon and nitrogen isotope signatures of littoral macroinvertebrates during spring and autumn periods from 2000 to 2015 and of littoral fish species in 2018. Isotopic signatures of invertebrate and fish species were in the same range and showed similar seasonal differences and clear patterns in respect to littoral vs pelagic food sources and trophic level. Oligotrophication did not strongly alter isotopic values and only δ15N values of invertebrates declined weakly with oligotrophication. In contrast, interannual variability of stable isotope signatures was related to abundances of the invasive Dreissena polymorpha suggesting interannual differences in the importance of benthic-pelagic coupling due to Dreissena pseudofaeces for the nutrition of littoral invertebrates. This study illustrates how stored samples can be used to detect the importance of oligotrophication and benthic-pelagic coupling on the stable isotope signatures of a benthic community. [ABSTRACT FROM AUTHOR]

Sulfidic caves support diverse and abundant subterranean communities, including numerous endemic species and complex food webs, though the full extent of species diversity and resource utilization in these ecosystems remains largely unexplored. This paper presents the results of biological surveys conducted from 2023 to 2024 in Sulfur Cave, located in the Vromoner Canyon on the Greek–Albanian border, focusing on microbial, vertebrate, and invertebrate communities and investigating the structure of the subterranean food web. The microbial communities from the different biofilms are dominated by chemosynthetic sulfur-oxidizing microorganisms, specifically filamentous bacteria such as Thiotrix and Beggiatoa. Two species of fish, an eel (Anguilla sp.) and a Cyprinid (Alburnoides sp.), and six bat species from three families (Rhinolophidae, Miniopteridae, and Vespertilionidae) were documented. The invertebrate fauna includes five aquatic species, 25 terrestrial species, and four amphibiotic species. Among these, eight species are endemic, and seven species exhibit troglomorphic traits. Stable isotope analysis showed light carbon and nitrogen values for the terrestrial and aquatic invertebrates, suggesting that subterranean communities rely on food produced in situ by chemoautotrophic microorganisms. Our results identified cave areas of significant biological relevance and provided reference data to inform conservation actions aimed at preserving the biodiversity of this sulfidic cave. [ABSTRACT FROM AUTHOR]

Terrestrial invertebrates are highly important for the decomposition of dung from large mammals. Mammal dung has been present in many of Earth's ecosystems for millions of years, enabling the evolution of a broad diversity of dung‐associated invertebrates that process various components of the dung. Today, large herbivorous mammals are increasingly introduced to ecosystems with the aim of restoring the ecological functions formerly provided by their extinct counterparts. However, we still know little about the ecosystem functions and nutrient flows in these rewilded ecosystems, including the dynamics of dung decomposition. In fact, the succession of insect communities in dung is an area of limited research attention also outside a rewilding context.In this study, we use environmental DNA metabarcoding of dung from rewilded Galloway cattle in an experimental set‐up to investigate invertebrate communities and functional dynamics over a time span of 53 days, starting from the time of deposition.We find a strong signal of successional change in community composition, including for the species that are directly dependent on dung as a resource. While several of these species were detected consistently across the sampling period, others appeared confined to either early or late successional stages. We believe that this is indicative of evolutionary adaptation to a highly dynamic resource, with species showing niche partitioning on a temporal scale. However, our results show consistently high species diversity within the functional groups that are directly dependent on dung.Our findings of such redundancy suggest functional stability of the dung‐associated invertebrate community, with several species ready to fill vacant niches if other species disappear. Importantly, this might also buffer the ecosystem functions related to dung decomposition against environmental change. Interestingly, alpha diversity peaked after approximately 20–25 days in both meadow and pasture habitats, and did not decrease substantially during the experimental period, probably due to preservation of eDNA in the dung after the disappearance of visiting invertebrates, and from detection of tissue remains and cryptic life stages. [ABSTRACT FROM AUTHOR]

The theory of habitat heterogeneity, which treats one of the global drivers of biodiversity, is valid for several taxonomic groups and distinct ecosystems, including subterranean environments. However, knowledge about the factors that influence the structure of subterranean communities remains limited, especially in Neotropical regions. We sought to understand the main drivers of invertebrate species richness and composition. For that, we compared the substrate elements of twilight and deep-cave zones and their associated invertebrate communities. Variations in habitat heterogeneity were significantly related to richness in the deep cave zone, but had no effect on the fauna associated with the twilight zone. The local heterogeneity enhanced the richness in the deep cave zone due to the increase in the number of available habitats and the effect on decreasing niche overlap. For communities' composition, the geographic distribution of caves explained the similarity between the twilight zone of different caves. Therefore, nearby caves have a more similar fauna in the entrance regions but conversely, exhibit a higher dissimilarity between communities associated with the deep-cave zone. This study highlights the influence of local habitat heterogeneity on the invertebrate communities associated with different zones of the cave. [ABSTRACT FROM AUTHOR]

Wetlands in the Oil Sands Region of Alberta are vulnerable to direct and indirect effects of human development including land disturbance, hydrologic alteration, and addition of contaminants. Nineteen wetlands in the Athabasca Oil Sands Region were monitored over a five-year period to evaluate differences in water quality and benthic invertebrate composition between sites near to and further afield from surface mining operations. Concentrations of dissolved sulphate, dissolved iron, total dibenzothiophenes and specific conductance were significantly higher in wetlands near to surface mining operations. In addition, beta diversity of wetland invertebrates was higher in wetlands further afield of the industrial centre. Drivers of benthic assemblage differences among sites include specific conductance and pH. Conductance was positively correlated with Caenidae (Ephemeroptera) abundance and pH was negatively correlated with abundance of Naididae (Annelida). [ABSTRACT FROM AUTHOR]

Thoughtfully managed hydroperiods in natural and artificial wetlands could potentially provide a combination of desirable flood control services and high ecological functions. To explore how managed freshwater wetlands typical of the Houston, Texas area would respond to different hydrological regimes that might occur if wetlands were drained in anticipation of a heavy rain that did not materialize, we conducted a mesocosm experiment with six flooding depths and seven drought durations, followed by seven months of recovery. We found that the speed in which mesocosms dried out was a function of initial water depth, with mesocosms initially set with greater water depths (30 cm) taking ~ 38 days to dry out versus zero days for wetlands that were completely drained. Individual plant species (14 species planted; 8 species common at the end of the recovery period) were affected by drought length, flooding depth, or their interaction, although details of these responses varied among the species. The composition of the plant community at the end of the drought period was strongly affected by drought length, and the effect of the drought length treatment persisted through seven months of post-drought recovery, with the 80- and 160-day drought treatments diverging most strongly from shorter drought treatments. Above- and below-ground biomass of plants was not affected by the treatments, but above-ground dead biomass (litter) decreased with increasing drought length. Densities of mosquito larvae, snails and tadpoles were temporally variable, and were affected more during the treatment period and early in recovery than after a disturbance event late in recovery. Our results indicate that managed wetlands in southeast Texas would be quite resilient to dry periods of up to 40 days in duration, especially if water was not completely drained at the beginning of the drought. In addition, many species would persist in managed wetlands even with droughts of up to 160 days. This indicates considerable potential for managing the hydroperiods of artificial detention ponds by retaining water longer to increase ecological function, with little to no loss of flood control services, and for managing the hydroperiods of natural wetlands by draining them in advance of anticipated rains to increase flood control services, with little to no loss of ecological function. [ABSTRACT FROM AUTHOR]

Changes in the existence of mangroves will have an impact on changes in food webs in their respective areas. The purpose of this study was to determine the food source of the macrozoobenthos community within the Lubuk Damar mangrove ecosystem. Stable isotopes, carbon and nitrogen were used to describe the food sources for macrozoobenthos in the mangrove ecosystem of the Lubuk Damar Ecosystem, Aceh Tamiang, Indonesia. The stable isotope analysis of 13C and 15N was carried out using Isotopic-Ratio Mass Spectrometry. Potential food sources at the study site based on stable isotope ratios ranged between –29.08‰ to –20.66‰ (δ13C) and 4.07‰ to 5.63‰ (δ15N); macrozoobenthos –25.00‰ to –14.76‰ (δ13C) and 5.59‰ to 7.73‰ (δ15N). The potential food sources tested at the study site consisted of seven sources, but not all food sources in the ecosystem were consumed by the invertebrate community. This study shows that mangrove leaf litter serves as a food source for some invertebrates, such as the bivalves, gastropods, polychaetes, sipunculans, brachiopods and crustaceans. The results of this study evidence that the examined mangrove ecosystem has a function as a provider of food sources in the surrounding waters, therefore its existence is very important supporting diversity of coastal waters. [ABSTRACT FROM AUTHOR]

Water turbidity alters prey detectability and prey selection by a predator. In dimorphic mesopredators, the effect of water turbidity on foraging success may be sex specific, primarily due to sex differences in reproductive allotment, body size and vulnerability to predation. To experimentally test the effect of turbidity on prey consumption with respect to sex, we used turquoise killifish (Nothobranchius furzeri), a small fish from ephemeral savanna pools in southeast Africa that vary widely in turbidity. Large males possess conspicuous nuptial coloration while females are smaller and drab. Vision is assumed to be a fundamental sense for turquoise killifish, despite often living in very turbid water. As mesopredators, killifish regulate the invertebrate community in ephemeral pools. We tested the consumption of bloodworms (benthic and red‐coloured) and glassworms (pelagic and transparent) under clear (<1NTU) and turbid (320 NTU) water conditions. We found that turquoise killifish maintained their overall foraging success irrespective of turbidity. In both the clear and turbid water, the females consumed three times more food than males relative to their body mass. This likely stems from the females' high nutritional demands due to daily reproduction. It also suggests that females are not risk‐aversive in clear water despite their smaller size. Water turbidity affected the type of prey consumed by turquoise killifish and demonstrated its potential to affect the community structure of invertebrate species in ephemeral pools. [ABSTRACT FROM AUTHOR]

The ice stored in caves is a widespread yet neglected cryospheric component. The cold-adapted biodiversity of ice caves has received very little attention from research, despite the potential abundance of endemic troglobiotic and cryophilic species and their consequent sensitivity to the changing climate. In this study, we investigated the invertebrate diversity of two ice caves in Northeastern Italy (Bus delle Taccole and Caverna del Sieson, Veneto Region). During 2022 and 2023, we sampled, using pitfall traps, the invertebrates dwelling at different locations in each cave: the shaft base, an intermediate hall, and the cave bottom. At each cave location, we also collected ice samples, on which we measured the stable isotopes of oxygen and hydrogen (δ18O, δ2H), and monitored the air temperature with data-loggers. The two caves had different invertebrate communities, both dominated by a combination of troglobiotic and cryophilic taxa. Despite a low taxonomic richness, which was higher at Taccole (15 taxa) than at Sieson (11 taxa), both caves hosted rare/endemic species, four of which are not described yet. At each cave, the ice water isotopic signatures differed among cave locations, suggesting the ice had formed under different climatic conditions, and/or resulted from different frequencies of thawing/freezing events. The occurrence of summer melt at both caves suggests that these unique ecosystems will quickly disappear, along with their specialized and unique biodiversity. [ABSTRACT FROM AUTHOR]

Functional redundancy, the potential for the functional role of one species to be fulfilled by another, is a key determinant of ecosystem viability. Scavenging transfers huge amount of energy through ecosystems and is, therefore, crucial for ecosystem viability and healthy ecosystem functioning. Despite this, relatively few studies have examined functional redundancy in scavenger communities. Moreover, the results of these studies are mixed and confined to a very limited range of habitat types and taxonomic groups.This study attempts to address this knowledge gap by conducting a field experiment in an undisturbed natural environment assessing functional roles and redundancy in vertebrate and invertebrate scavenging communities in a South African savanna.We used a large‐scale field experiment to suppress ants in four 1 ha plots in a South African savanna and paired each with a control plot. We distributed three types of small food bait: carbohydrate, protein and seed, across the plots and excluded vertebrates from half the baits using cages. Using this combination of ant suppression and vertebrate exclusion, allowed us explore the contribution of non‐ant invertebrates, ants and vertebrates in scavenging and also to determine whether either ants or vertebrates were able to compensate for the loss of one another.In this study, we found the invertebrate community carried out a larger proportion of overall scavenging services than vertebrates. Moreover, although scavenging was reduced when either invertebrates or vertebrates were absent, the presence of invertebrates better mitigated the functional loss of vertebrates than did the presence of vertebrates against the functional loss of invertebrates. There is a commonly held assumption that the functional role of vertebrate scavengers exceeds that of invertebrate scavengers; our results suggest that this is not true for small scavenging resources.Our study highlights the importance of invertebrates for securing healthy ecosystem functioning both now and into the future. We also build upon many previous studies which show that ants can have particularly large effects on ecosystem functioning. Importantly, our study suggests that scavenging in some ecosystems may be partly resilient to changes in the scavenging community, due to the potential for functional compensation by vertebrates and ants. [ABSTRACT FROM AUTHOR]

Disturbances can produce a spectrum of short‐ and long‐term ecological consequences that depend on complex interactions of the characteristics of the event, antecedent environmental conditions, and the intrinsic properties of resistance and resilience of the affected biological system.We used Hurricane Harvey's impact on coastal rivers of Texas to examine the roles of storm‐related changes in hydrology and long‐term precipitation regime on the response of stream invertebrate communities to hurricane disturbance.We detected declines in richness, diversity and total abundance following the storm, but responses were strongly tied to direct and indirect effects of long‐term aridity and short‐term changes in stream hydrology. The amount of rainfall a site received drove both flood duration and flood magnitude across sites, but lower annual rainfall amounts (i.e. aridity) increased flood magnitude and decreased flood duration. Across all sites, flood duration was positively related to the time it took for invertebrate communities to return to a long‐term baseline and flood magnitude drove larger invertebrate community responses (i.e. changes in diversity and total abundance). However, invertebrate response per unit flood magnitude was lower in sub‐humid sites, potentially because of differences in refuge availability or ecological‐evolutionary interactions. Interestingly, sub‐humid streams had temporary large peaks in invertebrate total abundance and diversity following recovery period that may be indicative of the larger organic matter pulses expected in these systems because of their comparatively well‐developed riparian vegetation.Our findings show that hydrology and long‐term precipitation regime predictably affected invertebrate community responses and, thus, our work underscores the important influence of local climate to ecosystem sensitivity to disturbances. [ABSTRACT FROM AUTHOR]

The construction of dams and other in‐stream structures for human use has altered river ecosystems worldwide. Dams degrade rivers, and environmental flow releases aim to mitigate flow alterations and restore rivers downstream of dams by returning elements of the pre‐regulation flow regime, resulting in an ecosystem that resembles a more natural state. We examined the responses of benthic invertebrate communities in riffles and pool‐edge habitats to an environmental flow regime (EFR) in the highly regulated Snowy River over 17 years (2000–2016). Benthic invertebrate communities significantly changed in response to prolonged increases in the magnitude of all components of the flow regime. The composition of the benthos in the regulated river became more dissimilar to pre‐EFR communities and more closely resembled those of nearby unregulated rivers. These changes were apparent in both riffle and pool‐edge habitats and were most pronounced when flow magnitudes were highest. Scrapers increased as flows increased, and in contrast, the relative abundances of gatherers declined with prolonged high flows and could be attributed to increased daily flows and high flow events mobilizing fine sediment and scouring benthic substrates. These results indicated that the EFR altered abiotic conditions or resources that previously limited invertebrate abundances, facilitating changes to the benthic community. Community changes we observed were in response to a flow regime that remained drastically lower than natural, demonstrating that restoration targets can be achieved with small flow increases that mimic natural flow patterns. [ABSTRACT FROM AUTHOR]

Belowground invertebrate communities are dominated by species-rich and very small microarthropods that require long handling times and high taxonomic expertise for species determination. Molecular based methods like metabarcoding circumvent the morphological determination process by assigning taxa bioinformatically based on sequence information. The potential to analyse diverse and cryptic communities in short time at high taxonomic resolution is promising. However, metabarcoding studies revealed that taxonomic assignment below family-level in Collembola (Hexapoda) and Oribatida (Acariformes) is difficult and often fails. These are the most abundant and species-rich soil-living microarthropods, and the application of molecular-based, automated species determination would be most beneficial in these taxa. In this study, we analysed the presence of a barcoding gap in the standard barcoding gene cytochrome oxidase I (COI) in Collembola and Oribatida. The barcoding gap describes a significant difference between intra- and interspecific genetic distances among taxa and is essential for bioinformatic taxa assignment. We collected COI sequences of Collembola and Oribatida from BOLD and NCBI and focused on species with a wide geographic sampling to capture the range of their intraspecific variance. Our results show that intra- and interspecific genetic distances in COI overlapped in most species, impeding accurate assignment. When a barcoding gap was present, it exceeded the standard threshold of 3% intraspecific distances and also differed between species. Automatic specimen assignments also showed that most species comprised of multiple genetic lineages that caused ambiguous taxon assignments in distance-based methods. Character-based taxonomic assignment using phylogenetic trees and monophyletic clades as criteria worked for some species of Oribatida but failed completely for Collembola. Notably, parthenogenetic species showed lower genetic variance in COI and more accurate species assignment than sexual species. The different patterns in genetic diversity among species suggest that the different degrees of genetic variance result from deep evolutionary distances. This indicates that a single genetic threshold, or a single standard gene, will probably not be sufficient for the molecular species identification of many Collembola and Oribatida taxa. Our results also show that haplotype diversity in some of the investigated taxa was not even nearly covered, but coverage was better for Collembola than for Oribatida. Additional use of secondary barcoding genes and long-read sequencing of marker genes can improve metabarcoding studies. We also recommend the construction of pan-genomes and pan-barcodes of species lacking a barcoding gap. This will allow both to identify species boundaries, and to cover the full range of variability in the marker genes, making molecular identification also possible for species with highly diverse barcode sequences. [ABSTRACT FROM AUTHOR]

The cross-hybridization of American chestnut (Castanea dentata (Marsh.) Borkh.) with Chinese chestnut (Castanea mollissima Bl.) is a promising strategy for restoring a blight-resistant strain of this keystone species to the Appalachian mountains. To assess the ecological impacts of hybridization on invertebrate communities, we conducted a study across chestnut plots with varying degrees of hybridization (75%, 94%, or 100% American chestnut). Our findings indicate American chestnut hybridization impacted invertebrate communities above- and belowground. Aboveground insect community composition, insect herbivory, gall infestation, and belowground invertebrate diversity were all altered. While some of these differences could be explained by different growth habits or environmental differences, stark differences in Asian chestnut gall wasp infestation (Dryocosmus kuriphilus Yasumatsu.) suggest a genetic component. These results suggest that chestnut hybridization, and particularly expanded restoration efforts using chestnut hybrids, could impact invertebrate communities above- and belowground in addition to pest dynamics. Understanding these effects is crucial for successful chestnut restoration and ecosystem management. [ABSTRACT FROM AUTHOR]

Copyright of Biotropica is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

As the world becomes more urbanized, multiple stressors act in complex ways, but their effects remain poorly studied in coastal island streams. Due to the small length and isolation and the limited amount of freshwater available in the islands, these ecosystems are particularly vulnerable to anthropogenic pressures. Here, we investigated the effects of urbanization on taxonomic and functional diversity of aquatic invertebrate of a subtropical coastal island. Benthic invertebrate communities were sampled using litter bags (10 mm mesh) containing mixtures of leaf litter that were colonized in the stream bottom over 30 days. We hypothesized that invertebrate communities would show alteration in taxonomic and functional composition over the urbanization gradient. Based on the invertebrate communities and their biological traits, we computed the taxonomic richness and four functional diversity indices. Significant changes in taxonomic, functional richness, evenness, and dispersion were observed. Sites with low urbanization (< 5% urbanized area) had a higher proportion of taxa with gill respiration than sites with high level of urbanization (> 15% urbanized area) had higher proportion of taxa with tegument respiration. Sites with medium (15–5% urbanized area) and high urbanization levels exhibited higher proportions of scrapers and collector–gatherers, whereas sites with low urbanization had higher proportions of shredders and collector–filters. Our results show that urbanization changed the benthic communities and their biological traits. These changes can determine variations in the ecosystem processes and compromise the ecosystem services they supply. [ABSTRACT FROM AUTHOR]

Understanding which factors shape and maintain biodiversity is essential to understand how ecosystems respond to crises. Biodiversity observed in ecological communities is a result of the interaction of various factors which can be classified as either neutral‐ or niche‐based. The importance of these processes has been debated, but many scientists believe that both processes are important. Here, we use unique ecosystems in groundwater‐filled lava caves near Lake Mývatn, to examine the importance of neutral‐ versus niche‐based factors for shaping invertebrate communities. We studied diversity in benthic and epibenthic invertebrate communities and related them to ecological variables. We hypothesized that if neutral processes are the main drivers of community structure we would not see any clear relationship between the structure of community within caves and ecological factors. If niche‐based processes are important we should see clear relationships between community structure and variation in ecological variables across caves. Both communities were species poor, with low densities of invertebrates, showing the resource limited and oligotrophic nature of these systems. Unusually for Icelandic freshwater ecosystems, the benthic communities were not dominated by Chironomidae (Diptera) larvae, but rather by crustaceans, mainly Cladocera. The epibenthic communities were not shaped by environmental variables, suggesting that they may have been structured primarily by neutral processes. The benthic communities were shaped by the availability of energy, and to some extent pH, suggesting that niche‐based processes were important drivers of community structure, although neutral processes may still be relevant. The results suggest that both processes are important for invertebrate communities in freshwater, and research should focus on understanding both of these processes. The ponds we studied are representative of a number of freshwater ecosystems that are extremely vulnerable for human disturbance, making it even more important to understand how their biodiversity is shaped and maintained. [ABSTRACT FROM AUTHOR]

Although mesophotic coral ecosystems account for approximately 80% of coral reefs, they remain largely unexplored due to their challenging accessibility. The acoustic richness within reefs has led scientists to consider passive acoustic monitoring as a reliable method for studying both altiphotic and mesophotic coral reefs. We investigated the relationship between benthic invertebrate sounds (1.5–22.5 kHz), depth, and benthic cover composition, key ecological factors that determine differences between altiphotic and mesophotic reefs. Diel patterns of snaps and peak frequencies were also explored at different depths to assess variations in biorhythms. Acoustic recorders were deployed at 20 m, 60 m, and 120 m depths across six islands in French Polynesia. The results indicated that depth is the primary driver of differences in broadband transient sound (BTS) soundscapes, with sound intensity decreasing as depth increases. At 20–60 m, sounds were louder at night. At 120 m depth, benthic activity rhythms exhibited low or highly variable levels of diel variation, likely a consequence of reduced solar irradiation. On three islands, a peculiar peak in the number of BTS was observed every day between 7 and 9 PM at 120 m, suggesting the presence of cyclic activities of a specific species. Our results support the existence of different invertebrate communities or distinct behaviors, particularly in deep mesophotic reefs. Overall, this study adds to the growing evidence supporting the use of passive acoustic monitoring to describe and understand ecological patterns in mesophotic reefs. [ABSTRACT FROM AUTHOR]

Slimy sculpin (Uranidea cognata) inhabit coldwater streams in southeastern Minnesota, USA, many of which were subjected to probable 2000-year flood events in August 2007. Floods scoured streambeds, created new stream channels, and greatly reduced benthic invertebrate communities that serve as the primary food resource for sculpin. Diets and Fulton condition of sculpin in Gilmore Creek (with moderate flooding) and Garvin Brook (with very severe flooding) had been examined just prior to flooding and were re-examined 2 weeks after flooding to assess possible diet and condition changes. Diets, body condition, and reproductive fitness of sculpin were examined 7 months post-flood in these same two streams, plus nearby Trout Run (which also experienced very severe flooding). Sculpin condition declined slightly post-flood in Garvin Brook but improved in Gilmore Creek. Prior to spring spawning, the condition of Garvin Brook sculpin had improved, but Gilmore Creek fish condition had worsened. Sculpin diets were more diverse before and after flooding in Gilmore Creek than in Garvin Brook, although the diets of fish from both streams were dominated (>55%) by midge (Diptera: Chironomidae) larvae. Diets remained largely unchanged before versus after flooding in the more severely flooded Garvin Brook, but they changed in Gilmore Creek, becoming more midge-dominated. Prey number per sculpin stomach declined post-flood in Gilmore Creek but not in Garvin Brook, although the dry mass of prey/fish wet mass declined post-flood in both streams. Pre-spawn sculpin displayed no patterns in reproductive fitness (gonadosomatic index, hepatosomatic index, oocyte number) among the three streams that may have been related to flooding severity the previous summer. Sculpin diets and condition were not altered as expected by flooding, and food resource recovery apparently was rapid enough to prevent longer-term impacts on sculpin condition and reproductive fitness in the streams examined. [ABSTRACT FROM AUTHOR]

Rivers form meta‐ecosystems, in which disturbance and connectivity control biodiversity, ecosystem functioning and their interactions across the river network, but also across connected instream and riparian ecosystems. This aquatic–terrestrial linkage is modified by drying, a disturbance that also naturally fragments river networks and thereby modifies organism dispersal and organic matter (OM) transfers across the river network. However, little evidence of the effects of drying on river network‐scale OM cycling exists. Here, we assessed the effects of fragmentation by drying at the river meta‐ecosystem scale by monitoring leaf resource stocks, invertebrate communities and decomposition rates, across three seasons and 20 sites, in the instream and riparian habitats of a river network naturally fragmented by drying. Although instream leaf resource quantity and quality increased, leaf‐shredder invertebrate richness and abundance decreased with flow intermittence. Decomposition was, however, mainly driven by network‐scale fragmentation and connectivity. Shredder richness and invertebrate‐driven decomposition both peaked at sites with intermediate amounts of intermittent reaches upstream, suggesting that upstream drying can promote the biodiversity and functioning of downstream ecosystems. Shredder richness, however, had a negative effect on decomposition in perennial sites, likely due to interspecific competition. Leaf quantity, invertebrate communities and invertebrate‐driven decomposition became more similar between instream and riparian habitats as drying frequency increased, likely due to homogenization of environmental conditions between both habitats as the river dried. Our study demonstrates the paramount effects of drying on the dynamics of resources, communities and ecosystem functioning in rivers and presents evidence of one of the first network‐scale examples of the co‐drivers of ecosystem functions across terrestrial–aquatic boundaries. [ABSTRACT FROM AUTHOR]

Infectious disease can shape community structure, particularly when pathogens affect foundation species. Seagrasses are foundation species that form meadows along coasts worldwide, controlling sediment deposition and biogeochemical cycling while supporting a diverse community of fish and invertebrates. These plants are hosts to wasting diseases that cause necrotic tissue lesions, which could alter seagrass value as food, habitat and mediators of ecosystem processes. However, such biotic interactions and influences on disease dynamics are still not well understood. We investigated whether a common herbivore affected the development of wasting disease on eelgrass.We measured the severity and prevalence of eelgrass wasting disease in a meadow across two summers through repeated field surveys. We assessed the role of the eelgrass herbivore on disease spread and growth using microcosm and mesocosm experiments. We further explored herbivore feeding preferences in a choice trial, which was paired with chemical analysis of plant tissue and analysed using a structural equation model.While the herbivore facilitates the growth of new disease lesions among isolated leaves, on balance they reduce lesion severity by more than 50% in comparison with no‐herbivore controls in field‐realistic settings. This was likely because the herbivore strongly prefers to eat diseased rather than healthy tissue, consuming nearly twice as much lesion area in choice trials. This preference arises from pathogen‐driven changes in the host plant; lesioned tissue requires less force to penetrate than non‐lesioned tissue. Additionally, as lesions increase in size, their polyphenolic concentrations drop, which further increases the magnitude of preference for lesioned tissue.Synthesis: These results suggest that these herbivores could help maintain disease in this system at a high prevalence (by facilitating disease development) but low severity (through preferential consumption), which is consistent with our field observations of nearly 100% prevalence and low severity in a natural bed where herbivore density is high. Describing such multi‐species interactions in marine systems will advance our predictions of future disease states, as current understandings focus primarily on how environmental change contributes to pathogen outbreaks. [ABSTRACT FROM AUTHOR]