Indicators Of Ecosystem Health Research Articles

Two-Dimensional Amphibian Diversity along a 3500 m Elevational Gradient at the Eastern Edge of the Qinghai-Xizang Plateau.

Amphibians serve as reliable indicators of ecosystem health and are the most threatened group of vertebrates. Studies on their spatial distribution pattern and threats are crucial to formulate conservation strategies. Gongga Mountains, with a peak at 7509 m a.s.l. and running latitudinally, are in the center of the Hengduan Mountains Range and at the eastern steep edge of the Qinghai-Xizang Plateau, providing heterogeneous habitats and varied niches for amphibians. In this study, we combined 83 days of field work with information from 3894 museum specimens that were collected over the past 80 years, and identified twenty amphibian species belonging to seven families and twelve genera by morphology. Of these species, seven were listed in the threatened categories of the Red List of China's Biodiversity and thirteen were endemic to China. Ten species were found on the plateau side (western slope) and eleven species were found on the other side close to the Sichuan Basin (eastern slope). Only one species was found on both sides, indicating different community structures horizontally. The species richness was unimodal vertically and peaking at mid elevation on both sides, with the maximum number (ten vs. nine) of species occurring at 3300-3700 vs. 1700-1900 m a.s.l. and in different types of vegetation. The elevation span and body length of species distributed on both slopes did not show significant differences. These findings help to understand the horizontal and vertical distribution pattern of amphibian diversity, laying a foundation for future biogeographical and conservation research in this area.

Assessing the suitability of a surveillance fauna-monitoring program for detecting future changes in reptile occupancy

Context Ecological surveillance monitoring typically targets multiple taxonomic groups by using standardised sampling across large spatial scales. Although surveillance monitoring confers advantages over hypothesis-driven monitoring in its broad taxonomic and spatial scope, the approach has been criticised for its disconnect from ecological management and failure to provide insights on the drivers of ecological change Aims To assess the adequacy of a plot-based general fauna-monitoring program for sampling reptiles as indicators of ecosystem health in a semi-arid upland region of the Northern Territory, Australia. Methods We surveyed reptiles at 90 sites, stratified between major landform and vegetation types, and using standard fauna-sampling methods, across the 2568 km2 Tjoritja National Park in the MacDonnell Ranges. We compiled a full inventory of the reptile fauna of the study area and identified species with potential utility as ecological indicators. We then used single-season occupancy models and power analyses to evaluate the adequacy of sampling for detecting potential future changes in occupancy. Key results We detected 57 of the 68 reptile species known from the protected area, 17 of which are potentially useful indicators of ecological health, mostly related to fire management. There was insufficient power to detect moderate (50%) future changes in reptile occupancy for all but the single most detected species. For the two ecological indicator species with sufficient detections for occupancy modelling, a positive association with a keystone structure (dense spinifex grass) was confirmed. However, increasing detection probability or the number of surveys would result in only minor improvements in power to detect occupancy change in these species. Conclusions Although reptiles are potentially useful indicators of ecological health, particularly in relation to fire regimes, the number of sites required to detect future changes in reptile occupancy by using standardised plot-based monitoring in this protected area is prohibitively high. Implications Our results suggest that once ecological associations are understood, monitoring ecological health remotely by using techniques such as fire-scar mapping to track proportions of long-unburnt vegetation should be considered over labour-intensive surveillance monitoring for reptiles. Targeted monitoring of threatened and other reptile species of conservation or cultural concern may also be warranted.

Environmental indicators of lake ecosystem health in Aotearoa New Zealand: current state and trends

Assessments of lake ecosystem health, based on indicators of physical–chemical water quality, ecological conditions, and human health risks, are needed to apprise the public and facilitate lake management. While unrefereed lake water quality reports exist, this is the first peer-reviewed study to report data processing and analysis methods and results for current state and recent trends in multiple environmental indicators in monitored lakes across Aotearoa New Zealand. Lake grading based on national criteria indicated that many lakes are failing to achieve statutory bottom lines for phytoplankton chlorophyll a, total nitrogen, and total phosphorus concentrations. In contrast, most monitored lakes had high grades for two human health risk indicators, E. coli and cyanobacteria concentrations, and for potential toxicity of ammonia for biological communities. We included 166 lakes and considered indicator state and trends for two lake classifications based on geomorphology and land cover. Elevated scores for an indicator of trophic state (the trophic level index; TLI) in most shoreline, riverine, peat, landslide, dam, and aeolian lakes indicated eutrophic conditions or worse. Lower TLI scores were indicative of oligotrophic conditions in most glacial lakes. Nutrient, E. coli and suspended sediment concentrations and TLI scores were positively correlated, and Secchi depths negatively correlated, with high-intensity agricultural land cover. Ten-year trend analyses indicated that lakes with increasing Secchi disk depth, chlorophyll a, dissolved reactive phosphorus, E. coli, ammoniacal nitrogen, TLI, total nitrogen, and total suspended solids trends outnumbered those with decreasing trends. Twenty-year trend analyses indicated that the numbers of lakes with increasing and decreasing trends in most of the indicators we assessed were comparable, but lakes with increasing 20-year trends in total nitrogen outnumbered those with decreasing trends, and lakes with decreasing 20-year trends in ammoniacal nitrogen, dissolved reactive phosphorus, total phosphorus, and nitrate nitrogen outnumbered those with increasing trends. This study presents clear data processing steps and trend analysis methods as applied to a nationwide dataset for Aotearoa New Zealand, while acknowledging data limitations. For example, the choice of trend periods is challenging and can greatly affect conclusions. The results of this empirical study and the collective results of preceding studies of lake ecosystem health indicate that eutrophication poses a threat to the ecological health of many if not most lakes in Aotearoa New Zealand. Recommendations include monitoring network expansion especially for the indicators bottom dissolved oxygen and cyanobacteria (toxic and total cyanobacteria biovolumes) and judicious selection of trend periods in lake-specific trend analyses to determine causes for increasing or decreasing trends in environmental indicators.

Ten new records of anomalies for eight species of anurans – amphibians from Honduras and Colombia

ABSTRACT In recent decades, there has been a significant increase in reported anomalies among amphibians worldwide, especially malformations. These anomalies not only signify a decline in the quality of their habitats but also hold special significance among anuran species as vital indicators of ecosystem health. Our study presents ten previously undocumented cases of anomalies within eight anuran species found in Honduras and Colombia. These species include Ameerega bilinguis, A. hahneli and A. ingeri (Dendrobatidae), Craugastor sp. (Craugastoridae), Engystomops pustulosus (Leptodactylidae), Incilius valliceps (Bufonidae), Lithobates maculatus (Ranidae), and Smilisca baudinii (Hylidae). The observed anomalies encompass a range of abnormalities, including a protuberant tumor (1), adactyly (1), amely (2), anophthalmy (1), brachydactyly (1), ectrodactyly (1), ectromely (5), and phocomely (1), which affect the mobility and vision of these individuals. While the root causes may differ, we suspect that pollution stemming from agricultural and urban activities in the observed areas could be a contributing factor. However, we do not dismiss the possibility of other physicochemical or biological stressors.

Quantifying the relative importance of influencing factors on NPP in Hengduan Mountains of the Tibetan Plateau from 2002 to 2021: A Dominance Analysis

Net primary productivity (NPP) stands as a crucial indicator of ecosystem health and carbon cycling, shaped by a complex interplay of climate change and anthropogenic disturbances. Understanding the relative contributions of these factors is essential for informing strategies aimed at achieving carbon neutrality and peaking emissions. In this study, we used the Carnegie-Ames-Stanford-Approach (CASA) model to assess NPP dynamics in the ecologically fragile area of the middle Hengduan Mountains on the southeastern Tibetan Plateau (TPHM). Dominance Analysis (DA) was employed to quantify and visualize the relative importance of climate change and anthropogenic disturbances on NPP. Our findings revealed significant annual fluctuations in NPP, with 61.8% of the area experiencing improvement in NPP, although the overall trend was not statistically significant. Needleleaf forests and mixed forests below medium elevation (< 4000 m) suffered negative impacts from human activity intensity, while vegetation at medium-high elevation (4000–5000 m) showed positive effects. The area dominated by anthropogenic disturbances influencing NPP accounted for 49.16% of the study area, followed by combined effects (36.86%) and climatic factors (13.98%). Human activity intensity, particularly in nature reserves, emerged as the predominant driver of NPP in plateau regions, while climatic factors primarily drove NPP decline in river valleys and a few alpine mountains. Moreover, combined effects contributed to NPP enhancement in most regions. This study underscores the critical role of human activity intensity in shaping NPP dynamics in high-elevation regions of the Tibetan Plateau, providing valuable insights for ecological conservation and carbon stock enhancement efforts in ecologically fragile areas.

Species composition and conservation of amphibians in Central Panay Mountain Range, Antique, Philippines

Abstract. Flores GMA, Torres AG, Flores ABA, Jakosalem PGC, Guihawan JQ, Roa-Quiaoit HA. 2024. Species composition and conservation of amphibians in Central Panay Mountain Range, Antique, Philippines. Biodiversitas 25: 1797-1808. Assessing amphibian species composition and conservation status in Central Panay Mountain Range (CPMR), the largest contiguous forest in West Visayas in central Philippines, provides relevant and updated information on the status and conservation needs of the amphibians. Opportunistic, visual encounter and acoustic surveys were employed across diverse habitats-lowland and lower montane forests, streams, and grasslands. A total of 11 amphibian species from six families were documented, with notable findings including endemic species such as Rough-backed forest frog Platymantis corrugatus Duméril 1853, Dumeril’s wrinkled ground frog Platymantis dorsalis Duméril 1853, and Philippine narrow-mouth toad Kaloula conjuncta negrosensis Taylor 1922, as well as threatened species Panay forest frog Platymantis panayensis Brown, Brown and Alcala 1997, which is endemic to Panay Island. The P. dorsalis emerged as the most abundant, with 127 individuals recorded. Furthermore, two new distribution records of amphibians, narrow-mouth toad Kaloula sp. and panther flying frog Rhacophorus pardalis Günther 1858 were identified, potentially representing previously undocumented species endemic to the Philippines. The survey also revealed local threats posing significant risks to amphibian populations in the area. Several conservation measures have been proposed to protect amphibians and their habitats within CPMR. Given the area's rich biodiversity and ecological integrity, efforts are currently being implemented to establish CPMR as a nationally protected area, and this study contributes to this initiative by providing baseline data on amphibian diversity, underscoring the role of amphibians as ecological indicators of ecosystem health.

Seasonal variation in marine bird distribution in the northeast Pacific Ocean

Human activities have profound influences on marine ecosystems. Marine birds are particularly sensitive to these impacts and, given their ease of observation and diverse life histories, often represent good indicators of ecosystem health. Conserving marine birds and their ecosystems requires robust predictions of species distribution to help mitigate human disturbance in areas where large aggregations of diverse species occur. We modelled variation in marine bird species diversity (Shannon-Wiener Index) and taxonomic family level probability of occurrence to map the intensity and extent of highly diverse ‘hotspots’ in Canada’s Pacific Exclusive Economic Zone. To do so, we paired 20 yr of survey data from the North Pacific Pelagic Seabird Database (1997-2017) and remote sensing data describing marine conditions and local geography (sea surface temperature, chlorophyll a, bathymetry, distance to shore, and benthic substrate type). These data were used to illustrate how seasonality within years and the El Niño-Southern Oscillation (ENSO) across years influenced spatial patterns in diversity. Hotspots were most persistent in Hecate Strait, off the west coast of Vancouver Island, and surrounding the Scott Islands in most seasons. Changes in hotspot locations and intensity were observed across seasons and within season under varying ENSO conditions. Our results provide a template for mapping marine species distribution for the purpose of identifying hotspots of diversity, and thereby facilitate planning to minimize harmful impacts in highly diverse and dynamic systems.

Conserving biodiversity in coffee agroecosystems: Insights from a herpetofauna study in the Colombian Andes with sustainable management proposal

Amphibians and reptiles are important indicators of ecosystem health, yet their populations are declining worldwide due to habitat loss and climate change. Agroecosystems, such as coffee plantations, can provide important habitat for these species. We conducted field surveys in the Sumapaz region of Colombia to identify the habitat structural variables that influence the diversity and abundance of herpetofauna in coffee crops. The canonical correspondence analysis revealed that abundance of leaf litter, leaf litter moisture, shade percentage, plantation area, and plantation age category were the most important variables for determining herpetofauna diversity. Our findings suggest that shaded coffee plantations can sustain herpetofauna diversity, and maintaining a thick layer of leaf litter is critical for establishing complex and structured animal communities. This study proposes a set of sustainable agricultural management principles to promote the existence of amphibians and reptiles in coffee crops. By adopting these practices, it is possible to prevent the decline in the population of amphibians and reptiles due to the expansion of the agricultural frontier, as seen in other coffee-growing regions. The findings of this study contribute to a better understanding of how to balance agricultural production and biodiversity conservation in the context of agroecosystems.

Prevalence of Pathogens in Free-Living Adult Chimango Caracaras (Milvago chimango) in Three Areas with Different Levels of Urbanization in the Pampas Ecoregion, Argentina

ABSTRACT Urbanization can adversely impact animal populations through factors such as loss of natural habitat, introduction of nonnative competitors and predators, pollution, and increased exposure to pathogens. Because they are top predators, raptors are considered good indicators of ecosystem health. However, there is limited information about how environmental factors associated with urbanization can alter raptors’ susceptibility to pathogens. We evaluated exposure to selected pathogens of the Chimango Caracara (Milvago chimango), a generalist and opportunistic species endemic to South America. This species is distributed over a wide range of environments, including urban areas, and often takes advantage of human-generated resources such as domestic waste, urban garbage, and carrion, potentially increasing its exposure to pathogens. We captured adult Chimango Caracaras in three areas that varied in level of urbanization, in the southeastern region of the Buenos Aires Province, Argentina. Captured individuals were tested for exposure to Bacillus anthracis, Salmonella spp., and Trichomonas spp. All individuals tested were negative for these pathogens. Whether this represents a true lack of exposure to these microorganisms, the ability of this raptor to effectively inhibit the colonization of the gastrointestinal tract by these microorganisms, or an inability of the pathogen to colonize the Chimango Caracara’s gastrointestinal tract remains to be determined. This is the first study to assess the prevalence of selected pathogens in Chimango Caracaras inhabiting areas with different levels of urbanization.

Ant and spider diversity of Karuvatta, a coastal island in Vembanad, Kerala, India

Ants and spiders are good indicators of ecosystem health; therefore, the present work aims to understand the ant and spider diversity of the region Karuvatta a coastal island in Vembanad wetland ecosystem of Kerala. For the purpose of this study, the island was divided into Karamuttu and Naluchira regions. The study conducted by different collection methods like litter sifting, umbrella method, and handpicking, revealed, 72 species of spiders and 36 species of ants. Diversity indices, species accumulation curves, functional group analyses, and PCA of soil factors were worked out. The results showed that Naluchira had better diversity than Karamuttu.

How uncertain and observable are marine ecosystem indicators in shelf seas?

Operational analysis and forecast products of shelf sea biogeochemistry often lack reliable information on uncertainty. This is problematic, as good quality uncertainty information is both requested by the product end-users and essential for data assimilation. To address this problem we developed a quality-assessed ensemble representation of many leading sources of uncertainty in a coupled marine physical-biogeochemical model of the North-West European Shelf. Based on these ensembles we have estimated the uncertainty of several marine ecosystem health indicators (MEHIs), acting as proxies for biological productivity, phytoplankton community structure, trophic fluxes, deoxygenation, acidification and carbon export. We have also evaluated how observable these MEHIs are from the most widely available observations of total chlorophyll (mostly from the surface), highlighting those MEHIs and locations that need to be better monitored. Our results show that the most uncertain and the least observable MEHI is the phytoplankton community composition, highlighting the value of its observations (and their assimilation) particularly in the UK regional waters. We demonstrate that daily operational estimates of the other MEHIs, produced by the Met Office, are fairly well constrained. We also quantify how much MEHI uncertainties are reduced when one substantially coarsens the MEHI spatial and temporal resolution, as in the global and/or climate applications.

Collaborative Monitoring of Plant Biodiversity and Research on Sweet Acorn Oaks within Paths of Knowledge and Sustainability Education

Numerous studies have shown the multiple benefits of plant biodiversity and the crucial role of residents’ awareness of conservation and land management. Plant biodiversity was investigated in an analytical monitoring report conducted jointly with the local population engaged in livestock activities and young residents who were shifting toward hospitality and tourism. The study area, covering over 800 km2 in Sardinia, is half forested and attracts interest in its landscape. During our research, genotypes of Quercus ilex L., with sweet acorns rich in polyphenols, as the oldest ecosystem services in these rural communities, were discovered. Collaborative monitoring focused attention on the benefits of plants in different habitats as follows: 53% were known to livestock farmers as food for local breeds of goats and pigs, 15% were official, and 13% were endemic. They had also been used for human nutrition within the Mediterranean diet and attracted interest for their use in landscapes and gardens. This study analyzes numerical data from critical and educational perspectives. These data serve as indicators of ecosystem health for the purpose of sustainable management policies and attest to collaborative monitoring as a tool for analyzing human activities and the necessary balance between profit and biodiversity conservation, given the current challenging climate change conditions.

Two-decade satellite observations reveal variability in size-fractionated phytoplankton primary production in the South China Sea

Understanding variations in marine phytoplankton primary production (PP) is crucial for assessing the response of the marine environment to climate change and for quantifying the ocean carbon cycle. However, the spatiotemporal variability of size-fractionated PP in the South China Sea (SCS) remains ambiguous. Our study investigated the monthly, seasonal, and inter-annual variability of size-fractionated PP in the SCS using satellite observations from 2002 to 2022. There were noticeable seasonal and monthly variations in size-fractionated PP, with notably high PP values appearing during the cold season. The disparities in distribution and the distinct fluctuation patterns between size-fractionated PP suggest that total PP alone is not a comprehensive indicator of marine ecosystem health. Over the past two decades in the SCS, there were more pronounced decreases in total, pico-, and nano-PP, whereas micro-PP displayed no significant trend. The most pronounced decline occurred in the northern SCS, contrasted by increases in coastal areas. These size-fractionated PP anomalies showed strong correlations with climate change indices, highlighting the impact of environmental factors on these anomalies, such as sea surface temperature, mixed layer depth, and wind speed. Our findings emphasize the importance considering size-fractionated PP to gain a more nuanced understanding of the ocean carbon cycle and the marine ecosystem's response to climate changes.

Photo-Identification and Skin Lesion Prevalence of Bottlenose Dolphins (Tursiops erebennus) in the Waters of New York and New Jersey

Cetaceans can serve as sentinel species in marine environments as long-lived, apex predators that can concentrate environmental contaminants with potential health consequences. Thus, monitoring the well-being of these species may provide an additional indicator of ecosystem health. In cetaceans, one method for assessing individual and population health is by examining skin conditions. For decades, skin lesions have been increasingly documented in coastal populations of bottlenose dolphins (Tursiops spp.) worldwide. Lesion presence can indicate diminished health and may reflect environmental stressors. Herein, we document the prevalence of epidermal lesions/marks in bottlenose dolphins from the waters off New York and New Jersey during their seasonal presence from spring to fall. Photographs of distinct individuals sighted from May to October 2017 to 2021 were compiled into a catalog, and skin lesions were categorized and counted. Annually, the lowest skin lesion prevalence was in 2021 (p = 0.31), and the highest was in 2017 (p = 0.81). By month, prevalence generally decreased from spring to fall. Overall lesion prevalence in this population was higher than reported estimates for other populations in the coastal waters of the United States. The five most common categories were cloudy white spots, dark spots, white amorphous lesions, tattoo lesions, and dark fringe lesions; and the three most common groups were potentially pathogenic lesions, hypopigmentation, and rake mark-associated potentially pathogenic lesions. Some of the observed lesions have been associated with viral infections that may be exacerbated by environmental stressors. This research establishes an important baseline for further studies into bottlenose dolphin population health in and around the New York–New Jersey Harbor Estuary, particularly given the continued expansion of anthropogenic activities, including those related to forthcoming offshore wind development.

Interactions of common species of family Hippoboscidae in Slovakia with their avian and mammalian hosts: their diversity and potential for disease transmission

The hippoboscids play important roles in ecosystem functioning and can serve as indicators of biodiversity and ecosystem health. These bloodsucking ectoparasites are important from a public health perspective, as they can serve as vectors of various endoparasitic pathogens in animals and humans, although our understanding is still limited in this case. The current study provides information on the host species and distribution, which can contribute to the understanding of the ecology and epidemiology of these important arthropods with a potential impact on both animal and human health. We present an ecological parasite-host interaction network of louse flies and deer keds (Diptera: Hippoboscidae) collected from various sites in Slovakia from this time. A total of 123 new samples of eight hippoboscid fly species were captured on 17 species, including 15 birds and two mammals. New host-parasite interactions were recorded for the first time.

Improving ecosystem health in highly altered river basins: a generalized framework and its application to the Mississippi-Atchafalaya River Basin.

Continued large-scale public investment in declining ecosystems depends on demonstrations of "success". While the public conception of "success" often focuses on restoration to a pre-disturbance condition, the scientific community is more likely to measure success in terms of improved ecosystem health. Using a combination of literature review, workshops and expert solicitation we propose a generalized framework to improve ecosystem health in highly altered river basins by reducing ecosystem stressors, enhancing ecosystem processes and increasing ecosystem resilience. We illustrate the use of this framework in the Mississippi-Atchafalaya River Basin (MARB) of the central United States (U.S.), by (i) identifying key stressors related to human activities, and (ii) creating a conceptual ecosystem model relating those stressors to effects on ecosystem structure and processes. As a result of our analysis, we identify a set of landscape-level indicators of ecosystem health, emphasizing leading indicators of stressor removal (e.g., reduced anthropogenic nutrient inputs), increased ecosystem function (e.g., increased water storage in the landscape) and increased resilience (e.g., changes in the percentage of perennial vegetative cover). We suggest that by including these indicators, along with lagging indicators such as direct measurements of water quality, stakeholders will be better able to assess the effectiveness of management actions. For example, if both leading and lagging indicators show improvement over time, then management actions are on track to attain desired ecosystem condition. If, however, leading indicators are not improving or even declining, then fundamental challenges to ecosystem health remain to be addressed and failure to address these will ultimately lead to declines in lagging indicators such as water quality. Although our model and indicators are specific to the MARB, we believe that the generalized framework and the process of model and indicator development will be valuable in an array of altered river basins.

Diel variation of seawater volatile organic compounds, DMSP-related compounds, and microbial plankton inside and outside a tropical coral reef ecosystem

Biogenic volatile organic compounds (VOCs) play key roles in coral reef ecosystems, where, together with dimethylated sulfur compounds, they are indicators of ecosystem health and are used as defense strategies and infochemicals. Assessment and prediction of the exchange rates of VOCs between the oceans and atmosphere, with implications for atmospheric reactivity and climate, are hampered by poor knowledge of the regulating processes and their temporal variability, including diel cycles. Here, we measured the variation over 36h of the concentrations of DMSPCs (dimethylsulfoniopropionate (DMSP)-related compounds, namely DMSP, dimethylsulfoxide, acrylate, dimethylsulfide, and methanethiol as dimethyl disulfide) and VOCs (COS, CS2, isoprene, the iodomethanes CH3I and CH2ClI, and the bromomethanes CHBr3 and CH2Br2), in surface waters inside the shallow, northern coral-reef lagoon of Mo’orea (French Polynesia) and 4 km offshore, in the tropical open ocean. Comparisons with concurrent measurements of sea surface temperature, solar radiation, biogeochemical variables (nutrients, organic matter), and the abundances and taxonomic affiliations of microbial plankton were conducted with the aim to explain interconnections between DMSPCs, VOCs, and their environment across diel cycles. In open ocean waters, deeper surface mixing and low nutrient levels resulted in low phytoplankton biomass and bacterial activity. Consequently, the diel patterns of VOCs were more dependent on photochemical reactions, with daytime increases for several compounds including dissolved dimethylsulfoxide, COS, CS2, CH3I, and CH2ClI. A eukaryotic phytoplankton assemblage dominated by dinoflagellates and haptophytes provided higher cell-associated DMSP concentrations, yet the occurrence of DMSP degradation products (dimethylsulfide, dimethyl disulfide) was limited by photochemical loss. Conversely, in the shallow back reef lagoon the proximity of seafloor sediments, corals and abundant seaweeds resulted in higher nutrient levels, more freshly-produced organic matter, higher bacterial activity, and larger algal populations of Mamiellales, diatoms and Cryptomonadales. Consequently, DMSP and dimethylsulfoxide concentrations were lower but those of most VOCs were higher. A combination of photobiological and photochemical processes yielded sunny-daytime increases and nighttime decreases of dimethylsulfide, dimethyl disulfide, COS, isoprene, iodomethanes and bromomethanes. Our results illustrate the important role of solar radiation in DMSPC and VOC cycling, and are relevant for the design of sampling strategies that seek representative and comparable measurements of these compounds.

Molecular and morphological characterisation of larvae of the genus Diamesa Meigen, 1835 (Diptera: Chironomidae) in Alpine streams (Ötztal Alps, Austria).

Diamesa species (Diptera, Chironomidae) are widely distributed in freshwater ecosystems, and their life cycles are closely linked to environmental variables such as temperature, water quality, and sediment composition. Their sensitivity to environmental changes, particularly in response to pollution and habitat alterations, makes them valuable indicators of ecosystem health. The challenges associated with the morphological identification of larvae invoke the use of DNA barcoding for species determination. The mitochondrial cytochrome oxidase subunit I (COI) gene is regularly used for species identification but faces limitations, such as similar sequences in closely related species. To overcome this, we explored the use of the internal transcribed spacers (ITS) region in addition to COI for Diamesa larvae identification. Therefore, this study employs a combination of molecular markers alongside traditional morphological identification to enhance species discrimination. In total, 129 specimens were analysed, of which 101 were sampled from a glacier-fed stream in Rotmoostal, and the remaining 28 from spring-fed streams in the neighbouring valleys of Königstal and Timmelstal. This study reveals the inadequacy of utilizing single COI or ITS genes for comprehensive species differentiation within the genus Diamesa. However, the combined application of COI and ITS markers significantly enhances species identification resolution, surpassing the limitations faced by traditional taxonomists. Notably, this is evident in cases involving morphologically indistinguishable species, such as Diamesa latitarsis and Diamesa modesta. It highlights the potential of employing a multi-marker approach for more accurate and reliable Diamesa species identification. This method can be a powerful tool for identifying Diamesa species, shedding light on their remarkable adaptations to extreme environments and the impacts of environmental changes on their populations.

Pontederia crassipes invasiveness on Jeju island is linked to a decline in water pH and climate change-driven overwintering

Freshwater ecosystems are vulnerable to the invasion of exotic aquatic plant species because of the great likelihood of the introduction of exotic species, and the lack of barriers that block introduced species. Water hyacinth, Pontederia crassipes Mart., is one of the world’s most invasive alien plant species damaging freshwater ecosystems worldwide. Here, we monitored the water hyacinth population on Jeju island, Korea, to assess current invasion risks. Furthermore, we investigated how water hyacinth affects water pH because pH is an important determinant of the distribution of other aquatic plants, and thus a good indicator of aquatic ecosystem health. Water containing water hyacinth had a pH of 5.3, while that with water hyacinth and soil had a pH of 4.8 72 hours after the start of the experiment. Water hyacinth extracts contained shikimic acid, stearic acid, and palmitic acid, which are possible compounds that caused a decline in water pH. Water hyacinth also inhibited the growth of the aquatic plant species, Spirodela polyrhiza and Lemna perpusilla. These results imply that invasion of water hyacinth adversely impacts the abiotic and biotic characteristics of aquatic ecosystems. Moreover, monitoring the water hyacinth population suggests that this invasive aquatic plant overwinters on Jeju island. Therefore, regular monitoring and subsequent control of water hyacinth population can prevent its expansion in the aquatic habitats of Jeju island and the southern region of the Korean peninsula.

Occupancy trends of overwintering coastal waterbird communities reveal guild-specific patterns of redistribution and shifting reliance on existing protected areas.

Climate change and anthropogenic stressors are redistributing species and altering community composition globally. Protected areas (PAs) may not sufficiently protect populations of species undergoing distributional shifts, necessitating that we evaluate existing PAs and identify areas for future protection to conserve biodiversity across regional and temporal scales. Coastal waterbirds are important indicators of marine ecosystem health, representing mobile, long-lived, higher trophic-level consumers. Using a 20-year citizen science dataset (1999-2019) with a before-after control-intervention sampling framework for habitat protection, we applied dynamic occupancy models to assess winter occupancy trends along the Pacific coast of Canada. Specifically, we sought to understand potential drivers of regional declines, spatial commonalities among guilds, and changes in habitat use before and after PA designation, as well as between PAs and non-PAs. Occupancy trends varied regionally, with greater declines in the south compared to the north. Regional differences underlined potential range shifts, particularly for species with traits linked to temperature tolerance, movement, and high productivity foraging, as cold-tolerant, migratory benthivores and piscivores wintered farther north relative to 20 years ago or retreated to cold-water fjords. While 21 of 57 (36.8%) species responded positively to PA designation (before-after), greater occupancy declines tended to occur in PAs established pre-1999 relative to non-PAs (control-intervention). Since PAs are currently concentrated in the south, negative associations were most apparent for species retreating northward, but existing PAs may have a stabilizing or transitory effect on southern wintering species shifting into the region from farther south. We emphasize that conservation strategies must balance persistence of current communities with preserving the climate-adapted biodiversity of tomorrow by accounting for community-level effects of species moving into and out of existing PAs. Incorporating range shifts into PA planning by predicting distributional changes will allow conservation practitioners to identify priority habitats, such as cold-water refugia, for persistent wildlife communities.