Habitat Value Research Articles

Analysing Turbulence Patterns in Nature‐Like Fishways: An Experimental Approach

ABSTRACTNature‐like fishways are an important measure for restoring fish passage, mitigating the impacts of barriers, and providing valuable habitat benefits in a more natural and effective way than traditional technical fishways. Their ecological advantages make them a preferred solution in many river restoration projects. The turbulence at the fishway's pool is a key challenge in the design of fishways. This study evaluated the hydraulic performance of the nature‐like fishway section of the Zongyang Fishway Project in China. This utilized a trapezoidal cross‐section with a 1:242 bottom slope, 1:2 side slopes, and an operating water depth of 1–3 m. The bottom and sides were paved with 0.2–0.5 m diameter pebbles to create suitable habitat for bottom‐dwelling fish. The target design velocity was 0.7–0.9 m s−1. A physical model was constructed to assess the hydraulic characteristics of the nature‐like fishway, including flow velocities within the slots and turbulence levels in the pools. The results showed that the slot velocities were within the target range, the head loss was parallel to the bottom elevation, and the flow field near the bottom mimicked technical fishway conditions, whereas the surface flow resembled open channel flow. Turbulence intensity remained below 60% of the design velocity. These findings provide valuable insights into the hydraulic performance and suitability of this nature‐like fishway design for facilitating fish passage of the target freshwater species along with directly aiding to SDGs 6 and 14.

Cold-water coral mortality under ocean warming is associated with pathogenic bacteria

Cold-water corals form vast reefs that are highly valuable habitats for diverse deep-sea communities. However, as the deep ocean is warming, it is essential to assess the resilience of cold-water corals to future conditions. The effects of elevated temperatures on the cold-water coral Lophelia pertusa (now named Desmophyllum pertusum) from the north-east Atlantic Ocean were experimentally investigated at the holobiont level, the coral host, and its microbiome. We show that at temperature increases of + 3 and + 5 °C, L. pertusa exhibits significant mortality concomitant with changes in its microbiome composition. In addition, a metagenomic approach revealed the presence of gene markers for bacterial virulence factors suggesting that coral death was due to infection by pathogenic bacteria. Interestingly, different coral colonies had different survival rates and, colony-specific microbiome signatures, indicating strong colony-specific variability in their response to warming waters. These results suggest that L. pertusa can only survive a long-term temperature increase of < 3 °C. Therefore, regional variations in deep-sea temperature increase should be considered in future estimates of the global distribution of cold-water corals.

Aquatic insect biodiversity, water quality variables, and microplastics in the living weir freshwater ecosystem

Most Thai rivers have not yet reached "good" ecological status. Furthermore, the scientific community is deeply concerned about the existence and abundance of microplastics (MPs) in freshwater. The live weirs' river health status was assessed using water quality and a variety of aquatic insect species. The research was conducted along Khlong-La, which was compared in the absence (R1, R2) and presence of living weirs (LWs) (M71, M62, M4, and M2). In 2023, aquatic insects and water samples were gathered during two months: January (rainy season) and July (dry season). The results revealed that the six sampling sites had similar physical and chemical properties, with the exception of total dissolved solids, which varied significantly. A total of 658 aquatic insects from 25 families and 6 orders were identified. The Hydropsychidae dominated the aquatic insect fauna at the LWs locations, followed by Chironomidae, Naucoridae, and Caenidae. Ten genera were discovered at the reference site (R1), whereas 16, 21, 24, and 19 were discovered at LWs (M71, M62, M4, M2), and 16 at the reference site (R2). The results of CCA ordination revealed that the most important factors influencing aquatic insect diversity were dissolved oxygen, water temperature, pH, electrical conductivity, and ammonia nitrogen. This study suggests that because of their significant responses to environmental factors, the species richness of aquatic insects may indicate the conservation value of habitats. The BMWPTHAI score was 41, 51, 57, 58, 73, 54, and the ASPTTHAI score was 5.12, 5.10, 5.18, 5.27, 4.86, and 5.40, respectively. Shannon-Weiner diversity index (Hʼ) values were 2.059, 2.461, 2.839, 2.777, and 2.587, respectively. The results showed that the water quality was average. The physicochemical data, as well as the BMWP and ASPT, revealed that the water at the living well was slightly polluted. Furthermore, larger MPs (&gt;500 µm) were found in the largest concentrations, in the shape of fibers, and primarily in the color violet.

Effects of river infrastructure, dredged material placement, and altered hydrogeomorphic processes: The stress ecology of floodplain wetlands and associated fish communities

Recognition of the habitat values of coastal and floodplain wetlands has inspired research and engineering to restore biological functions after widespread species declines. However, the restoration and management of tidal river floodplains requires a more complete understanding of anthropogenic stressors on hydrogeomorphology and ecological processes. River floodplains near the ocean are affected by localized diking and dredging as well as basin-wide stressors such as dams. We evaluated the effects of stressors versus spatial position, both longitudinal and lateral to the mainstem, using physical and biological response variables in river floodplain wetlands. We categorized historical and modern stressors on the hydrogeomorphic regime of the lower Columbia River and estuary, northeast Pacific coast, including basin-scale management and local impacts. Using this categorization, we analyzed 44 attributes using field-collected data from 50 floodplain wetlands. Attributes represent channels, floods, plant communities, and fish communities. Here we show that plant and fish communities are stratified by position along the estuarine–riverine gradient, in contrast to physical habitat characteristics, which are stratified by stressors on hydrogeomorphic regimes and in some cases the lateral distance from the mainstem river on tributaries. Spatial position relative to water-level dynamics and salinity more strongly affect the biota than does stressor history. Stressor effects were greatest on the geomorphology observed in formerly diked, now reconnected wetlands and in wetlands with a history of dredged material placement; historically diked sites had anomalously deep channels with larger cross-sectional areas while sites with dredged material had shallow channels and lower levels of organic carbon in sediment. In wetlands subject only to landscape-scale stressors such as flow alterations by dams, organic carbon levels were higher. These findings provide natural resource managers with opportunities to enhance similarity to natural conditions and better understand future wetland evolution from different baselines of stressor history and river position.

Effects of a large-scale bioretention installation on the species composition of an urban bird community as determined by passive acoustic monitoring.

As urbanization accelerates worldwide, municipalities are attempting to construct new green spaces within their borders. The perceived ecological value of these places is frequently tied to their ability to attract urban wildlife, such as birds, which can easily be observed and enjoyed. As one strategy, stormwater is now frequently managed with green infrastructure: planted areas that retain and treat stormwater rather than merely directing it to surface waters. While these practices have the potential to provide habitat for urban wildlife, the ecological effects of these systems are largely unknown. To assess whether one green infrastructure project increases habitat value, we used passive acoustic monitoring to survey urban bird communities in and near a large green infrastructure project in Columbus, Ohio (USA). Bird communities near bioretention cells (rain gardens) were compared to those at nearby lawns and remnant or restored natural areas. We found that recently installed bioretention cells tended to support more omnivores, lower-canopy foraging species, and species from a higher diversity of feeding guilds than did nearby lawn control sites. We were unable to detect effects of nearby bioretention installations on bird species richness at other sites. The observed differences in species richness were fairly small, and we urge caution when anticipating the habitat value of bioretention cells, at least for bird species. However, the results that we observed suggest that bioretention cells could have a more positive impact on bird communities in different contexts or using different design strategies. The bioretention cells surveyed in this study were small and only planted in grasses and forbs, potentially limiting their ability to offer complex habitat. They were also relatively young, and future work is needed to determine their long-term effect on avian communities and biodiversity of other taxa.

Hessische Rhön – mountain grassland, rough grazing and their birds

Hessische Rhön – mountain grassland, rough grazing and their birds The project is particularly dedicated to conservation and development measures for the species-rich mountain grassland and the protection of endangered bird species in open areas of the Hessian low mountain ranges of the Rhön. By implementing different types of landscape maintaining measures in close cooperation with local farmers and municipalities valuable habitats in the Natura 2000 protected area network were substantially improved.

Biodiversity of a temperate karst landscape-ice cave collapse doline supports high α-diversity of the soil mesofauna.

Caves represent a specific environment with a special microclimate and fauna adapted to it. However, we have still a restricted knowledge on soil fauna communities in an environments with a marked microclimate gradient at the interface between cave and surface habitats. In the present study, we investigated the community patterns of dominant soil microarthropod group, oribatid mites, and their relationship to environmental factors across the microclimate gradient along a transect with seven study sites from cold and wet cave entrance zone to warm and drier deciduous forest. The cold and wet sites showed low oribatid abundances and a high spatial clustering of individuals in comparison to the warm sites. The oribatid mites showed significantly higher abundance and species richness at warm forest sites. Indicator species analysis indicated specific cold-tolerant species that dominated at cold sites of the gradient, but which were absent at the warmest sites. Variance analysis clarified that community composition at sites were significantly driven by environmental factors: temperature, soil moisture, pH and C/N ratio. The study underlines the importance of ice cave entrances as sources of high α-diversity of soil mesofauna and thus the conservation priority of these valuable habitats.

Anthropogenic landscape features affect the ground habitat use of Penelope superciliaris (Cracidae), a large seed disperser bird in southeastern Brazil

AbstractThe expansion of agriculture and forest plantations over tropical biomes has caused significant species loss, while others persist in remnant native areas and anthropogenic lands. Penelope superciliaris, a large seed disperser bird, inhabits human‐modified landscapes; however, its habitat use is poorly known. We investigated how native land covers, distance to water sources, and anthropogenic landscape features affect the species' ground habitat use in disturbed and undisturbed areas of three landscapes in Southeastern Brazil. We expected the species to use the ground more in native areas and near water sources because of the higher habitat quality. We collected presence‐absence data during two dry seasons at 205 sampling stations with camera traps. Using occupancy models, we calculated the cumulative AICc weights of covariates for occupancy (interpreted as probability of use, Ψ) and detection (interpreted as frequency of use, p) parameters. The proportion of managed forests negatively influenced the species' frequency of use. The probability of use was higher when camera trap stations were located on unpaved roads. Model averaged prediction showed that the species uses about 56% of the landscapes. Our results suggest that intensively managed forests are not favorable or attractive habitats for the species. Unpaved roads associated with native vegetation edges may provide valuable habitats for the species during the dry season, possibly associated with movement and resource tracking. These findings may help guide conservation strategies in such modified landscapes, with caution in considering unpaved roads as secure habitats until further data on population abundance are available.Abstract in Portuguese is available with online material.

Native Forbs Provide Pollinator Resources and Improve Forage Nutrient Composition, Animal Performance, and Pasture Productivity

Pollinator declines and expectations for more sustainable agriculture, including pasture-based enterprises, bring attention to strategies to enhance the habitat value of grazing lands. We evaluated native warm-season grass (NWSG) pastures with (FORB) and without (CONT) interseeded native forbs in 2021–2023. An analysis was conducted using R with the significance set at p ≤ 0.05. The grass appeared to be weakened predominantly by grazing management practices. Forb density and mass had an inverse relationship in seasons two and three. Total forage mass declined in response to increased grazing days and weakened stands. The forage nutritive compositions differed, with more stable, season-long crude protein and lower fiber concentrations in late-season FORB, which supported higher bodyweight gains and season-long average daily gain. Black-eyed Susan (Rudbeckia hirta; BESU), lanceleaf coreopsis (Coreopsis lanceolata; LCOR), and showy ticktrefoil (Desmodium canadensis; STTF) were the most abundant forbs, and BESU, LCOR, and purple coneflower (Echinacea purpurea; PURC) produced long flowering windows. Cattle grazed STTF, cup plant (Silphium perfoliatum; CUPP), and oxeye sunflower (Helopsis helianthoides) the most. Under continuous stocking, a blend of BESU, LCOR, PURC, STTF, and CUPP produced acceptable cattle gains and provided pollinator resources, suggesting that this model may be a viable means to enhance the sustainability of pastures.

Riparian buffer strips promote biomass, species richness and abundance of flying insects in agricultural landscapes

Agricultural intensification is debated as one of the major drivers for the decline of insect biodiversity. Agri-environmental schemes (AES) are a common measure to promote biodiversity in agriculture by granting compensational payments to farmers for environmentally friendly practices. In this study we examined the effect of buffer strips of at least 5 m width, adjacent to small watercourses and drainage ditches, on insect biomass and insect species richness in agricultural landscapes. We selected ten arable fields in each of four regions in lower and upper Bavaria, Southern Germany. 25 out of 40 sites had a buffer strip between arable crops and watercourse. Insects were sampled at three time periods (May/June, June/July and August/September) for two weeks each. In each period two samples were collected (one per week). On each site Malaise traps were set up in 5 and 80 m distance to the embankment of the watercourse. Half of the samples was then subjected to metabarcoding and the other half was classified into different insect groups by morphological identification and the number of the individuals for each group was counted. For hoverflies (Syrphidae), individuals were identified at species-level. Data on vegetation structure (cover of grasses and herbs) in the studied riparian buffer strips was collected and correlated with number of species, abundances and biomass of flying insects. The five taxonomic orders with the highest species richness and individual numbers were: Diptera, Hymenoptera, Coleoptera, Lepidoptera and Hemiptera. Diptera dominated hereby with 34% of all species and 81% of all individuals. On average, mixed models indicated 31% higher insect biomass, 15% higher species richness and 29% higher individual numbers of flying insects in buffer strips at 5 m distance to the watercourse compared to sites with no buffer strip. The effect was even stronger for butterflies (32% higher species species richness, 70% more individuals) and hoverflies (24% higher species richness, 51% more individuals). In the presence of a buffer strip significantly higher numbers were found for total individuals, Diptera, Hymenoptera and Coleoptera. In 80 m distance to the watercourse, the samples of flying insects were not significantly influenced by a riparian buffer strip. This study highlights the importance of buffer strips in agricultural regions and their multifunctional potential in fostering biodiversity additionally to their acknowledged use for water protection. Ideally, buffer strips are rich in herbs and inflorescences and are therefore beneficial for the insect fauna by serving as valuable habitat with high potential connectivity at landscape level.

The contribution of traditional-homegardens to bird conservation in human-modified landscapes

AbstractTraditional-homegardens are important for the food security, economy, and culture of rural communities, but also contributing to biodiversity conservation. The objective of this study was to evaluate the role of traditional-homegardens as a refuge for birds, how the birds used them, and which of their attributes were associated with the frequency of bird visits. We compared the percentage of visits among groups of birds by habitat preference. Also, we compared the frequency of visits to different vegetation strata and the use that birds made within traditional-homegardens (forage, perching or nesting). Finally, we analyzed the relationship between the number of visits and some characteristics of the traditional-homegardens (size area, richness of large plants and distance to the nearest forest fragment). Birds visited different vegetation stratum of traditional-homegardens to perch, to forage, and even to nest. In general, we found that larger traditional-homegardens area increased the number of bird visits, while distance to the native forest fragments and the species richness of large plants did not have significant effects. Insectivores and frugivores had a similar pattern to the general; to the granivores, the distance to the forest fragment had a positive effect on the number of visits; to the omnivores, the species richness of large plants had negative effect, to the nectarivores, none of the variables had a significant effect. Overall, this study sheds light on the significance of traditional-homegardens not only for human communities but also for biodiversity conservation by providing valuable habitats for a variety of bird species.

Rice Bund Management by Filipino Farmers and Willingness to Adopt Ecological Engineering for Pest Suppression

Ecological engineering is defined as the design of ecosystems for the benefit of human society and the environment. In Asia, the ecological engineering of rice fields by establishing vegetation on bunds/levees for natural enemies has recently gained traction; however, its success depends on farmers’ willingness to implement changes. We surveyed 291 rice farmers in four regions of the Philippines to assess their bund management practices and willingness to establish bund vegetation that restores rice regulatory ecosystem services for pest management. During pre- and post-open field day (OFD) interviews, we assessed farmers’ perceptions of ecological engineering practices and sought their advice concerning bund vegetation. Over 60% of the farmers grew crops or allowed weeds on their bunds. Vegetables were grown as a source of extra food or income, and flowers were grown for pest management. Among the remaining farmers, their willingness to try ecological engineering increased from 36 to 74% after the OFDs. Furthermore, after the OFDs, willing farmers increasingly (from 2.6 to 15%) cited pest management as a reason to grow vegetables on bunds, and farmers almost exclusively focused on growing vegetables rather than flowers to adapt the system. While 46.5% of farmers who grew vegetables on their bunds applied insecticides, only ca 20% indicated that they would do so after the OFDs, if needed. Farmers had differing opinions on how vegetables would be incorporated into their rice farms. This range of options could be encouraged wherever farmers recognize the potential harm from pesticides for biodiversity and the restoration value of a diversified farm habitat.

Quantifying habitat and biodiversity services and hotspots of Indian forests: A GIS-Based assessment

The present study attempted to quantify and value of supporting services of India's forest ecosystem. The supporting services comprises by habitat and biodiversity services across India's sixteen forest types was estimated using data for various factors through Remote Sensing and secondary sources as per the proposed model. Indicators were combined using an Analytical Hierarchical Process, and various class of each service was also estimated using the equal interval method in QGIS. Hotspot analysis was used to identify key areas for forest conservation. The results suggest that littoral and swamp forest had maximum habitat services and tropical semi-evergreen forest had maximum biodiversity service and tropical wet evergreen forest had maximum supporting services. Out of total forest of country, 11.52%, 17.48% and 10.34% forest area was having high value for habitat, biodiversity and supporting service, respectively. Hotspot analysis revealed that 22.93%, 23.61% and 26.44% Indian forest had high habitat, biodiversity and supporting service, respectively. The annual per hectare economic value using Benefit Transfer method for habitat, biodiversity and supporting services of forests was US$ 4330.71, US$ 5987.38 and US$ 10,624.23, respectively. The annual economic value of habitat, biodiversity and supporting services from Indian forests was US$ 303,506.09 million, US$ 419,609.45 million and US$ 744,570.85 million, respectively. In totality, tropical dry deciduous forest, tropical moist deciduous and tropical semi-deciduous forest had high economic value for supporting service. Monetary valuation of forest ecosystem services assists to determine the net present value and costs for conservation interventions. Biodiversity hotspots as the Western Ghats, Indo-Burma region, and Eastern Himalayas offer high ecosystem service and thus attach prime importance for conservation, while the Western Himalayas, with lower ecosystem service, requires customized ecosystem management strategies.

Impacts of estuarine habitat degradation on the modeled life history of marine estuarine-dependent and resident fish species.

Shallow coastal and estuarine habitats play an essential role in the life cycles of many fish species, providing spawning, nursery, feeding, and migration areas. However, these ecologically valuable habitats are increasingly threatened by anthropogenic activities, causing substantial changes in both habitat availability and quality. Fish species use these shallow coastal habitats and estuaries during various life stages, leading to their categorization into guilds based on how and when they rely on these areas. This differential functional use of estuaries means that changes to these habitats may affect each guild differently. To understand the impact of estuarine habitat degradation on fish populations, it is therefore necessary to consider the full life cycle of fish and when they rely on these coastal habitats. Here, we use conceptual size-structured population models to study how estuarine habitat degradation affects two functionally different guilds. We use these models to predict how reduced food productivity in the estuary affects the demographic rates and population dynamics of these groups. Specifically, we model estuarine residents, which complete their entire life cycle in estuaries, and marine estuarine-dependent species, which inhabit estuaries during early life before transitioning offshore. We find that total fish biomass for both guilds decreases with decreasing food productivity. However, the density of juveniles of the marine estuarine-dependent guild can, under certain conditions, increase in the estuary. This occurs due to a shift in the population biomass distribution over different life stages and a simultaneous shift in which life stage is most limited by food. At the individual level, somatic growth of juveniles belonging to the estuarine-dependent guild decreased with lower food supply in the estuary, due to increased competition for food. The somatic growth rates of fish belonging to the resident guild were largely unaffected by low food supply, as the total fish density decreased at the same time and therefore the per-capita food availability was similar. These outcomes challenge the assumption that responses to habitat degradation are similar between fish guilds. Our study highlights the need to assess not only fish biomass but also size distributions, survival, and somatic growth rates for a comprehensive understanding of the effects of habitat degradation on fish populations. This understanding is crucial not only for estuary fish communities but also for successful conservation and management of commercially harvested offshore population components.

Dynamic archetypes of agricultural land systems in Germany from 1992 to 2019

Grasslands, important agricultural land systems, are undergoing significant shifts such as intensification, abandonment, and conversion to alternative land uses in Europe, leading to biodiversity loss. Despite major efforts, the European Union´s Common Agricultural Policy (CAP) has been unable to halt the decline of grasslands and to appropriately adjust management intensity because implemented policies have not considered the heterogeneity of grassland systems. However, accounting for this heterogeneity is essential to increase the policies´ effectiveness. In this study, we used archetype analysis to identify recurrent patterns in the heterogeneity of farm configurations, using Germany as an example, that can help tailor policy instruments to specific regional conditions. By applying self-organising maps, we reveal nine archetypes integrating 16 farm accountancy indicators. Advancing archetype analysis, we discuss their dynamics (including their emergence, disappearance and persistence) between 1992 and 2019 at the level of federal states and interpret these dynamics in the light of CAP. For example, archetypes in the western federal states are dominated by small crop and dairy farms, while archetypes in the eastern federal states are more diverse, including larger subsidised farms and medium crop farms. Moreover, archetype dynamics in the southern federal states indicate a decline in small dairy farms and an increase in small crop farms, implying the loss of valuable habitats for wild species. Policy instruments tailored to such regional conditions could more appropriately halt this loss. These insights derived from agricultural land systems in Germany can enrich the debate about how to better tailor policy instruments to regional conditions to preserve functional grassland systems in Europe and worldwide.

Fire protection priorities in the oak forests of Iran with an emphasis on vertebrate habitat preservation

This study examines the impact of fire incidents on wildlife and habitats in the western oak forests of Iran (Zagros region). These forests are globally recognized for their exceptional biodiversity but are frequently threatened by wildfires. To achieve this, the study uses the space–time scan statistics permutation (STSSP) model to identify areas with a higher frequency of fires. The study also analyzes the effects of fires on the Zagros forests from 2000 to 2021 using remote-sensing MODIS data. Also, to understand the elements at risk of fire, burned areas were assessed based on the richness of vertebrate species, determined by the distribution of 88 vertebrate species. The results show that the annual fire rate in the Zagros forests is 76.2 (fire occurrences per year), calculated using the Poisson distribution. Findings show the highest fire rates are found in the northwest and a part of the south of the Zagros. The northwest of the Zagros also has the largest number of single fires and clusters, indicating a wide spatial distribution of fire in these regions. On the other side, it was unexpectedly found that these regions have the richest number of species and higher habitat value. The results demonstrate a significant correlation between the value of the habitat and the extent of burned areas (p < 0.05). The study also reveals that the greatest impact of fires is on small vertebrates. The overlap of frequent fire spots with the richest regions of Zagros oak forests in terms of vertebrate diversity emphasizes the need for strategic forest risk reduction planning, especially in these priority zones.

Assessment of suitability for photovoltaic power generation in periurban seminatural grasslands: toward the coexistence of seminatural grasslands and photovoltaic power generation

Renewable energy has grown substantially in recent years due to its efficacy in mitigating climate change. The rapid proliferation of solar photovoltaic (PV) systems and subsequent alterations in land use have led to concerns about the impact on local ecosystems. Particularly in Japan, seminatural grasslands, which are valuable habitats, are being developed as solar PVs. Here, we focused on stilt-mounted agrivoltaic systems, capable of both photovoltaic power generation and plant growth beneath solar panels. By repurposing this technology, the coexistence of vegetation and solar PV systems can be possibly ensured. To assess the feasibility of this proposed approach, we initially examined the suitability of installing solar PV in seminatural grasslands. The suitability of seminatural grasslands, solar PVs, and random points for solar PV was evaluated in terms of electricity generation and construction costs. The environmental conditions of seminatural grasslands were found to be advantageous for electricity generation. On the other hand, in terms of construction costs, seminatural grasslands were comparable to randomly selected sites. These findings indicate that the suitability of existing seminatural grasslands for solar PV plant installations is not considerably lower than that of other land types. The idea of reconciling solar power generation with ecosystem conservation holds promise and warrants further investigation toward its realization.

Effects of habitat biotic features on hymenopteran diversity in East Africa

PurposeOriginally, the coastal region of East Africa was largely covered with coastal forest. With the human settlement, the majority of these forests have been transformed into agricultural land for subsistence farming. Today, only small and geographically isolated forest remnants exist and form a mosaic of different habitat types, including natural, semi-natural and anthropogenic ones. The forest remnants may still represent valuable habitats for typical forest plant and animal species.MethodsIn this study, we surveyed hymenopteran diversity and community composition in different habitat types in southern Kenya. Hereby we considered a small remnant of East African coastal forest, adjoining orchards, shrublands, tree plantations, agricultural fields, and settlements. Hymenoptera represent a large variety of taxa and provide relevant ecosystem services such as pollination to the local people. Hymenoptera were collected with coloured pan traps, identified to family or genus level, and sorted to morphospecies. Habitat parameters such as dead wood, leaf litter, vegetation structure, and the availability of flowers has been assessed for each study site.ResultsIn total, we found 419 Hymenoptera individuals of 153 morphospecies. The different habitat types showed distinct species communities of Hymenoptera. Increasing shrub layer and increasing herb cover had a negative effect on hymenopteran species richness and abundance. Flowers, trees, leave litter, and deadwood showed no significant effect on hymenopteran diversity.ConclusionOur results underline that small-scale habitat diversity lead to high overall diversity of Hymenoptera. Implications for insect conservation: The coastal forest remnant still holds a unique hymenopteran community with 20 Hymenoptera species exclusively found in this habitat type. It is thus of very high conservation value.

Habitat distinctness doesn't influence on the abundance and relative growth of the juveniles Atherinella brasiliensis (Quoy & Gaimard, 1824) in a subtropical estuarine ecosystem

Shallow coastal habitats with and without vegetation may perform nursery function from distinct way for many species, raising questions about the role of vegetation on structuring nursery ground. Unfortunately, degradation and inappropriate human use of these areas associated with the lack of ecological data about fish populations can limit appropriate strategies to protect both species and habitats. In this paper we examine the nursery value of different estuarine habitats by comparing the abundance and relative growth of juveniles Atherinella brasiliensis. Fish were sampled once a month from November 2018 to October 2019 in five habitats: no vegetation close to the ocean, no vegetation close to the river, no vegetation and distant from other sampling points (control), mangrove and saltmarsh. Juveniles are present and abundant in all habitats and specimens had similar relative growth in the salt marsh, mangrove habitats and non vegetated habitats. The results indicate that estuarine habitats offers suitable conditions to A. brasiliensis in early stages of life, indicating that these sites have nursery value for juveniles of this species. Conservation and/or preservation of estuarine shallows habitats along the coast is important for A. brasiliensis and probably for other species, and the identification of priority areas could help to provide subsidies to management policies on conservation of coastal marine environments.

Assessing the combined effects of catchment land use and runoff on estuarine fish assemblages

Connectivity between land and sea through the movement of species, energy and nutrients means that land-based impacts can affect the structure and functioning of nearby coastal ecosystems. As the interface between land and sea, estuaries are often faced with increasing pressures from catchment modifications (e.g. the removal of terrestrial vegetation) which can alter the overall health of estuaries (e.g. the degradation of coastal water quality due to an increase in terrestrial runoff) and change the value of habitat for many marine species. These landscape-scale impacts can, however, be mediated through variations in the context and connectivity of seascapes (e.g. greater extent of vegetated ecosystems help to filter nutrients). We surveyed fish across five estuaries over four years using underwater videography and sought correlations between fish biodiversity and abundance with variables indexing catchment land use, seascape connectivity, and coastal water quality. Fish assemblages were more abundant and diverse at sites which had lower chlorophyll-a concentrations and were nearer to the estuary mouth, in conjunction with catchments containing higher percent of natural land and heterogenous seascapes. Sites with lower concentrations of chlorophyll-a supported indicator species from more diverse functional groups that had greater fisheries values, in comparison to indicator species from sites with high concentrations of chlorophyll-a. This research can help direct coastal management to better prioritise management in coastal ecosystems, thereby enhancing fish richness and abundance, functional group richness and fisheries value.