Habitat Types Research Articles

Taking the bait: Environmental factors affecting bait retention and hook disposition in the Gulf of Maine Bottom Longline Survey

Longline fishery surveys are major contributors to groundfish species abundance estimates. Catchability is often assumed constant, but bait is lost or consumed at inconsistent rates during and across gear sets. Accounting for hook availability and gear saturation can improve abundance estimates, but these data are challenging to collect. Our objectives were to determine whether video camera systems can be used to collect these data from the Northeast Fisheries Science Center’s Gulf of Maine Bottom Longline Survey and to explore the associations between hook disposition percentages and environmental characteristics. Electronic monitoring camera systems were deployed on partner vessels during two fall and two spring seasons to capture video of gear retrieval. During post-survey review, individual hooks were recorded as one of the following hook dispositions: bait, empty hook, fish, and invertebrate. Percentages of these hook dispositions were characterized across categorical (season, day or night, and bottom substrata) and continuous (bottom temperature, bottom depth, and substrate rugosity) survey station variables. Nonmetric multidimensional scaling and logistic regression analyses revealed correlations between retained bait and low bottom temperatures, the spring season, shallow depths, rough bottom substrata, and high terrain rugosity. These characteristics were typical of shallow, inshore, and topographically variable survey strata, suggesting that catchability differs among habitat types. This information will be incorporated into catch rate models to develop standardized indices of abundance for groundfish stock assessments. This study is an example of the utility of electronic technologies to supplement on board data collection during cooperative fishery surveys.

Spatial Distribution of Fishing Cat (Prionailurus viverrinus) in Selected Wetlands of Colombo Ramsar Wetland City using Camera Traps

The first wetland capital city in the world, Colombo Ramsar Wetland City (CRWC), provides a diverse array of habitat types intermixed with one another to the faunal and floral communities. In this research, the spatial distribution of Fishing Cat (Prionailurus viverrinus) was studied in Baddagana Wetland Park (BWP), Diyasaru Wetland Park (DWP) and Heen Ela Marsh (HEM) located within the CRWC, from June 2021 to January 2022. Annona (Annona glabra) woodland, mixed woodland, herb dominated high vegetation and herb dominated low vegetation habitat types were selected and camera trap stations were established providing equal trapping effort for each habitat type. Camera trap locations were selected to ensure a sufficient coverage of each wetland. Trap locations were changed every 30 days, and cameras were set to function during both day and night for 24 hours a day. A total number of 2,831 camera trap records belonging to 6 species were identified as meso-mammals. Spatial distribution was determined by the habitat preference of P. viverrinus and Relative Abundance Index (RAI) was used for the analysis of preference in each habitat type. It was evident that P. viverrinus mostly preferred Annona woodlands in both BWP (RAI, 14.4) and DWP (RAI, 12.7). However, the most preferred habitat type in HEM (RAI, 9.1) was mixed woodlands. Herb dominated high vegetation was the least preferred habitat type of P. viverrinus in BWP (RAI, 6.7) while herb dominated low vegetation was the least preferred habitat type in both DWP (RAI, 4.7) and HEM (RAI, 3.6). Mixed woodlands were almost equally preferred by P. viverrinus in all study sites and the preference of herb dominated low vegetation and herb dominated high vegetation was relatively low in all the study sites compared to other habitat types. This study suggests that the preference of P. viverrinus varied among different habitat types and one of the major reasons for Annona woodlands being the most preferred habitat type is that they are directly accessible to water. This increases their prey availability within the Annona woodlands, compared to the other habitat types. Thus, it is greatly important to conserve the wetland habitat types associated with water, in order to protect and conserve the P. viverrinus in Colombo wetlands 
 Keywords: Colombo Ramsar Wetland City, Meso-mammals, Camera trapping, Biodiversity, Carnivores 

Dung Beetle Functional Diversity and Ecosystem Services (Resource Relocation) in Different Land Use Types in the Upper Walawe Basin Area

Conversion of forest habitat to different land uses will change the environmental quality of the altered land. Since the relationship between anthropogenic disturbance and animal diversity and ecosystem services emerged, much scientific research has been conducted on this aspect. The present study focuses on comparing dung beetles, a known biological indicator, on examining five diverse environs (large forests, forest patches, Pinus plantations (Pinus caribaea), home gardens, and tea plantations) Coprophagous beetles of the subfamily Scarabaeinae (Coleoptera: Scarabaeidae). This study examined whether dung beetles' diversity, species richness, functional groups, and ecosystem services (dung removal) vary with the habitat types. We also assumed that the intensity of anthropogenic activities varies in these habitats. The experiment was conducted for 48 hours each in five habitat types with three selected replicates per each habitat type. The Shannon-Weiner Diversity Index shows that the highest dung beetle diversity is recorded in large forest areas (2.1719). The highest species abundance (186) and richness (22) were recorded in the large forest. The lowest species abundance was recorded in tea plantations (109). The lowest species richness was recorded in pinus plantations (10). Moreover, functional group diversity is high in habitats with fewer human activities. The dominant species in large forests is Onthophagus favrei (dominancy index-2.9%). In forest patches and pinus plantations, Onthophagus amphinasus (19%) and Paracopris signatus (36.30%) appeared consecutively. In home gardens and tea plantations, the most dominant species is Onthophagus unifasiatus (26.50% and 28.40%). Habitats with anthropogenic activities have less species richness and a high dominancy index. Furthermore, dung beetle resource relocation efficiency was skewed toward forest areas. The highest dung removal percentage was recorded in forest areas (large forest-9.58% and forest patches-7.33%). The dung removal in the anthropogenic activities related to land uses was decreased as a home garden (7.17%), Pinus plantation (6.58%), and tea plantation (5.42%). Moreover, large dung beetles (body mass≥0.5 g) were only recorded in large forests and forest patches. Low diversity in tea plantations could be attributed to pesticide and fertilizer usage, as beetles are highly sensitive to these chemicals. Pinus plantations showed low rates of dung removal because resource availability in those habitats is less due to the fewer mammals. These findings indicate that replacing forests and forest areas with simplified human residential areas and agricultural systems can result in shifts towards less specialized dung beetle communities with altered proportions to other animal groups. 
 Keywords: Scarabaeinae, Dung removal, Species richness, Species abundance, Dominance index

Habitat Preference of Lesser Whistling Ducks (Dendrocygna javanica) in Selected Wetlands within Colombo Ramsar Wetland City

Lesser Whistling Ducks (LWD) (Dendrocygna javanica) mostly occur in flocks and inhabit lakes, ponds and marshes within freshwater wetlands. They feed mainly on plants taken from water (seed, shoots, tuber and leaves), vertebrates (fishes) and invertebrates (mollusks and worms). In this study, habitat preference of LWD in five selected wetlands in Colombo Ramsar Wetland City (CRWC); Beddagana Wetland Park (BWP), Diyasaru Park (DP), Heen Ela Marsh (HEM), Thalangama Marsh (TM) and Kimbulawala Wetland (KW) was studied from May 2021 to April 2022 as wetlands in urban areas act as the last resort for many resident and migratory bird species and play a major role in the assemblage and conservation of water birds. Habitats present in the selected wetlands were categorized as open water body, floating vegetation, trees, grassland, paddy field, shrubs, bare land. Percentage cover of each habitat type at each sampling site were estimated using quadrat method. LWD were surveyed using line transects of 100m in length, laid in each selected study site to cover representative habitats and observations were made up to 30m towards either side of each transect. Sampling was done in three time slots of the day, morning, mid-day and evening. Floating vegetation, open water body and grassland were the preferred habitat types of D. javanica in BWP, DP, HEM and TM. LWD were not recorded in KW. Floating vegetation (54.97%) was the most preferred habitat by LWD in each study site followed by open water body (24.70%) and grassland (15.82%) habitat types. Eicchornia crassipes (Common water hyacinth) and Salvinia molesta (Giant salvinia) were their most preferred floating vegetation type. Higher abundance of LWD was recorded in TM (83.22%) followed by DP (9.17%), BWP (4.16%) and HEM (3.45%). TM which had higher abundance of LWD had higher floating vegetation coverage (28%) and was rich with E. crassipes and S. molesta. Present study revealed that, LWD mostly used E. crassipes and S. molesta as their main foraging and resting sites. Management of invasive alien species have been undertaken in Colombo wetlands and as E. crassipes and S. molesta are alien species they are currently being removed. Therefore, outright removal of E. crassipes and S. molesta may not be suitable and a monitored removal program that will conserve this habitat type should be implemented in order to conserve the habitats preferred by LWD in CRWC. 
 Keywords: Lesser whistling ducks, Wetlands, Habitat preference

Influence of surface water and groundwater on functional traits and trade-off strategies of oasis communities at the end of the Keriya River, China.

Plant functional traits reflect the capacity of plants to adapt to their environment and the underlying optimization mechanisms. However, few studies have investigated trade-off strategies for functional traits in desert-wetland ecosystems, the mechanisms by which surface water disturbance and groundwater depth drive functional trait variation at the community scale, and the roles of intraspecific and interspecific variation. Therefore, this study analyzed specific differences in community-weighted mean traits among habitat types and obtained the relative contribution of intraspecific and interspecific variation by decomposing community-weighted mean traits, focusing on the Daliyabuyi Oasis in the hinterland of the Taklamakan Desert. We also explored the mechanisms by which surface water and groundwater influence different sources of variability specifically. The results showed that plant height, relative chlorophyll content, leaf thickness, leaf nitrogen content, and nitrogen-phosphorus ratio were the key traits reflecting habitat differences. As the groundwater depth becomes shallower and surface water disturbance intensifies, plant communities tend to have higher leaf nitrogen content, nitrogen-phosphorus ratio, and relative chlorophyll content and lower height. Surface water, groundwater, soil water content, and total soil nitrogen can influence interspecific and intraspecific variation in these traits through direct and indirect effects. As arid to wet habitats change, plant trade-off strategies for resources will shift from conservative to acquisitive. The study concluded that community functional traits are mainly contributed by interspecific variation, but consideration of intraspecific variation and the covariation effects that exist between it and interspecific variation can help to further enhance the understanding of the response of community traits in desert-wetland ecosystems to environmental change. Surface water disturbance has a non-negligible contribution to this adaptation process and plays a higher role than groundwater depth.

Broad-scale perspective on body size-trophic position patterns of freshwater fishes at the intraspecific and community levels from individual-based data in China

As predators are generally larger than their prey, positive body size and trophic position relationships are typically assumed, and these relationships have helped in estimating and predicting the effects of global environmental change on the trophic dynamics of aquatic ecosystems. However, current efforts to confirm the generality of body size-trophic position relationships have focused mainly on interspecific patterns using species-aggregated and averaged data, and little effort has been devoted to assessing how trophic position scales with body size at the intraspecific and community levels as well as exploring its ecological drivers, particularly for fishes in freshwater ecosystems. To fill this gap, we present a broad-scale study of body size-trophic position relationships in freshwater ecosystems at both the intraspecific and community levels using an individual-based body size and isotopic signature dataset that includes 2564 samples of 65 fish species in China. Our results indicate that body size-trophic position patterns at both the intraspecific and community levels can be positive, negative or insignificant. Non-significant patterns predominated at both levels, with slightly more than 30 % showing positive relationships, which highlights that the positive body size-trophic position pattern is not universally prevalent and that body size should be used with caution as a proxy for the trophic position of fishes at both the intraspecific and community levels in freshwater ecosystems. No factor was related to body size-trophic position patterns at the community level, while habitat type, elevation, temperature and fishing pressure were identified as the key determinants of body size-trophic position patterns at the intraspecific level, implying that fishing and climate warming can shift the food-web size structure of freshwater ecosystems by affecting population trophic dynamics.

Faunal Diversity and Biodiversity Conservation within Homagama Mahinda Rajapaksha College, Sri Lanka

A faunal diversity survey was carried out to analyze the faunal diversity in Homagama Mahinda Rajapaksha College in Colombo District, Sri Lanka. The survey site is located in a suburban area that is surrounded by disturbed properties. The aim of the survey was to analyze the faunal diversity and recognize the special habitat types in the school premises for conservation purposes. It could recognize five major zones which have different types of microhabitats and rich in faunal diversity. The survey was done as a visual encounter survey, and smartphones, digital cameras and binoculars were used to collect data of the fauna species for documenting and identifying purposes. Also, pitfalls traps, light traps and beating were used as survey methods. The study was done for three days including three random sampling events during both day and night. Standard guides were used for identifying and photographs, notes on observations were sent to experts on each taxon for further confirmation. A total of 188 fauna species were recorded during the survey including 55 species of vertebrates including five classes (Aves, Amphibia, Mammalia, Reptilia, Actinopterygii) and 133 species of invertebrates including six classes (Insecta, Gastropoda, Diplopoda, Clitellata, Chilopoda, Arachnida). The study could document 30 bird, 14 reptile, 6 mammals, 4 amphibian and 1 ray-finned fish species as vertebrates and 95 insect, 5 mollusks, 3 millipede, 2 clitellate, 2 centipede, 26 arachnid species as invertebrate fauna species in the school premises. Based on the results of the survey, the fauna diversity of the studied site is stable and depends on the microhabitat types in the different zones. As a suburban area, the species richness of the site is in well conditions. To keep stable and increase the fauna diversity of the site, doing regular surveys and recording data, generating microhabitats, and conserving highly diverse habitat types are suggested. Unique species like Indian Hare (Lepus nigricollis), Indian Crested Porcupine (Hystrix indica) were observed and as the only venomous snake species, Merrem‘s hump-nosed viper (Hypnale hypnale) was recorded. The faunal diversity of the studied site helps to keep the unique surroundings there and keeping frequent records and data on the site will help to maintain the biodiversity with constructions in and around the school premises. 
 Keywords: Faunal diversity, Suburban, Citizen Science, Conservation, Visual encounter

Species- or habitat- based assessments of vulnerability to climate change? Informing climate change adaptation in Special Protection Areas for birds in England

It is increasingly important to understand the impacts of climate change on biodiversity and ecosystems to support the development of effective adaptation strategies. The impact of climate change will vary for different species and habitats, with some at greater risk than others in any given location. Assessments of climate vulnerability are frequently the starting point for adaptation planning but there are a variety of different approaches and it is not clear which is best in different circumstances.Protected areas are core to nature conservation and are the focus of this study. We compare two commonly used approaches, one focused on species, the other on the vegetation which forms the habitats these species utilise, to assess the vulnerability to climate change of Special Protection Areas (SPAs) for birds in England. Our aim was to test whether the two approaches identify the same locations as being of high vulnerability and to inform the prioritisation of adaptation actions.The vulnerability of bird communities varied significantly between protected areas with differing predominant habitat types but there was no simple relationship between vulnerability of habitats and species. Bird communities in upland habitats were most vulnerable, with lower vulnerability found in other habitats and many species potentially able to benefit from climate change. In contrast the habitat vulnerability assessment showed that the upland habitats had relatively low vulnerability, but others, particularly coastal sites were more vulnerable.It is therefore important to develop adaptation strategies based on an understanding of the vulnerability of both the species and their habitats, with different prioritisations in different contexts.SPAs were grouped according to the vulnerability of bird species which they were intended to protect and the broad habitat type. Six broad habitat types were identified; freshwater/wetland, coastal, grassland, heathland, woodland and upland.These groupings were used to help determine which sites are at greatest risk and the type of action that may be required, particularly whether intervention should focus on adaptation for the habitats, the species or both.

First Molecular Data of Gongylonema pulchrum (Rhabditida: Gongylonematidae) in European Fallow Deer Dama dama from Romania.

Due to its adaptive versatility to numerous types of habitats, extremely diverse both in terms of composition and specificity, developed in various areas of the Western Plains of Romania, the European fallow deer (Dama dama) is a species with high ecological plasticity. In this area, the D. dama interacts with other species of wild fauna but also with numerous domestic animals, an important aspect in terms of the sanitary-veterinary status of animal populations, as well as the existence of a potential risk of infection with various species of parasites that can cause the D. dama specimens to obtain certain diseases and even zoonoses. A total of 133 esophagi from D. dama have been examined for helminths. Of the 133 esophagus samples from D. dama, nematodes of the genus Gongylonema were identified in 25 (18.80%). Sequencing revealed that the nematode identified in the samples was 99% similar to the sequence of Gongylonema pulchrum (GenBank no. LC026018.1, LC388754.1, AB646061). The present research is the first report of the nematode G. pulchrum from D. dama in Romania.

Differentiating spillover: an examination of cross-habitat movement in ecology spillover in ecology.

Organisms that immigrate into a recipient habitat generate a movement pattern that affects local population dynamics and the environment. Spillover is the pattern of unidirectional movement from a donor habitat to a different, adjacent recipient habitat. However, ecological definitions are often generalized to include any cross-habitat movement, which limits within- and cross-discipline collaboration. To assess spillover nomenclature, we reviewed 337 studies within the agriculture, disease, fisheries and habitat fragmentation disciplines. Each study's definition of spillover and the methods used were analysed. We identified four descriptors (movement, habitat type and arrangement, and effect) used that differentiate spillover from other cross-habitat movement patterns (dispersal, foray loops and edge movement). Studies often define spillover as movement (45%) but rarely measure it as such (4%), particularly in disease and habitat fragmentation disciplines. Consequently, 98% of studies could not distinguish linear from returning movement out of a donor habitat, which can overestimate movement distance. Overall, few studies (12%) included methods that matched their own definition, revealing a distinct mismatch. Because theory shows that long-term impacts of the different movement patterns can vary, differentiating spillover from other movement patterns is necessary for effective long-term and inter-disciplinary management of organisms that use heterogeneous landscapes.

Breeding birds of high-elevation mixed-conifer forests have declined in national parks of the southwestern U.S. while lower-elevation species have increased, with responses to drought varying by habitat

Abstract Climate change is considered a major driver of recent avian population declines, particularly in the drought-stricken southwestern United States. Predicting how bird populations will respond requires understanding the climatic drivers influencing population density across the region’s diverse habitats. We modelled breeding-season densities of 50 bird species in relation to spring and summer drought and the timing of North American monsoon rainfall over a 12-year period (2007–2018) and across 4 habitats comprising an approximately 1,500 m elevational gradient. We estimated annual breeding-season population density in relation to climate in the previous year by fitting a Bayesian hierarchical N-mixture model to point-count data from each of 6 national parks on the Colorado Plateau. Specifically, we asked whether (1) population trends were stable, increasing, or decreasing in the focal parks; (2) breeding densities were affected by drought or the timing of monsoon rains; and (3) climatic effects differed across habitat types and among species that molt on the breeding grounds, the nonbreeding grounds, or stopover to molt in the monsoon region of northwestern Mexico (molt migrants). Population trends varied with habitat. Species of high-elevation mixed-conifer forest declined over the study period, matching regional Breeding Bird Survey trends, likely in response to climate-related habitat loss and disturbance. By contrast, lower-elevation pinyon-juniper and grassland-shrubland species density generally increased. Effects of drought varied by habitat with elevation: mixed-conifer species responded positively to drought in the previous year, likely due to earlier snowmelt and breeding phenology, whereas pinyon-juniper species were unaffected, and grassland-shrubland species responded negatively, perhaps due to reduced nest survival. Later arrival of monsoon rains, a common prediction of climate models, had a positive effect on grassland bird densities, but a negative effect on molt-migrant densities. Late monsoon rains may result in a phenological mismatch between migration timing and the pulse of resources required to molt.

Distribution of Colchicum speciosum Steven in Trabzon Province, Türkiye

Colchicum speciosum Steven belongs to the Colchicaceae family and is native to the Eastern Black Sea Region of Anatolia. The genus Colchicum is used in the pharmaceutical industry due to the colchicine alkaloids contained in both its corms and seeds. This study was carried out to determine the distribution areas of Colchicum speciosum, an important medicinal aromatic plant, in Türkiye. To reach this purpose, field studies were carried out, collecting samples of the plant during suitable vegetation periods between 2015 and 2021 in Trabzon province. The present study was done using a full-field screening method. All field information about the taxon was recorded in the GIS database, and the distribution map of the taxon including Trabzon province was created. It was determined that Colchicum speciosum has a wide distribution in the study area, from 349 to 2560 m asl. In the study area, the specimens was determined at 192 different points and 12 different habitat types. These habitat types are mainly: pasture-meadow areas, both deciduous and conifer forest clearings, agricultural areas, hazelnut plantations, deciduous forests, coniferous forests dominated by Picea orientalis, roadsides, stony areas, scrubs, beech forests, seasonal stream edges, and swamp-reed areas. Additionally, it has been observed that the flowering time of the plant is between September and October.

How seasonality, semi-natural habitat cover and compositional landscape heterogeneity affect pollen collection and development of Apis mellifera colonies in Mediterranean agro-sylvo-pastoral systems

ContextThe reduction in the abundance and diversity of flowering plant species, mainly due to landscape alteration and consequent habitat loss, negatively affects honey bee populations and is the main driver of their decline. To safeguard pollination service and food security, we need to know how landscape characteristics affect the availability of pollen sources and consequently colony performance across seasons.ObjectivesWe therefore here explore how seasonality, percentage of semi-natural habitat cover and compositional landscape heterogeneity affect the abundance, richness, diversity and composition of pollen collected by honey bees and the development of their colonies in a Mediterranean area where agro-sylvo-pastoral systems are widely spread.MethodsFor the purpose of our study, pollen samples were collected over a year from colonies of Apis mellifera placed in four sampling sites selected across a gradient of landscape heterogeneity and where semi-natural habitats were predominant at various levels within an agro-sylvo-pastoral zone. Simultaneously, the extension of the sealed brood of the same colonies was periodically evaluated.ResultsWe found that the amount of pollen collected by honey bees was positively correlated with the percentage of semi-natural habitat cover and that increasing habitat diversity at the landscape level had a significant positive effect on the richness and diversity of pollen collected by honey bees. In addition, season significantly affected the amount, diversity and composition of pollen collected by honey bees. Furthermore, bee colony growth was positively correlated with richness, diversity and amount of pollen collected by honey bees.ConclusionOur study highlights the importance of an abundant and diverse pollen diet for honey bee colony development, which in agro-sylvo-pastoral systems seems to be ensured by a heterogeneous landscape dominated by different types of semi-natural habitats.

Trends of Land Cover Change and Conservation Challenges of Grevy’s Zebra (Equus grevyi, Oustalet 1882) in Hallaydeghe Asebot Proposed National Park, Southeast Ethiopia

Large parts of biodiversity in protected areas (PAs) and their ecosystem services have been deteriorated due to land cover change over time. To reverse these effects, analysis of land cover change is essential. One of the protected areas, Hallaydeghe Asebot Proposed National Park (HAPNP), was assumed its land cover change and was undergone from one habitat type to others during the last three decades. As a result, wildlife species particularly Grevy’s zebra (Equus grevyi) in HAPNP are facing conservation challenges. Here, we aimed to examine the land cover changes of HAPNP for the period of 1990–2021 and assess Grevy’s zebra conservation challenges so as to improve the protection of the park and conservation of the species. Landsat images for the years 1990, 2006, and 2021 were generated to analyze land cover change of the study area. In addition, ground control points and information from elder and knowledgeable informants were collected to substantiate the result. Household survey, key informant interviews, and field observation checklist were utilized to collect data on conservation challenges. To generate land cover change maps, the satellite image for each period was classified using supervised classification. Content analysis was used to analyze conservation challenges of the species. The findings of this study revealed that 12.2% of grassland cover lost from 1990 to 2021 (i.e., an estimated annual average loss 0.4%). The remaining grassland cover in the HAPNP was aggregated in a small land area. On the other hand, the size of bushland increased by 26.4% during the same year (i.e., an estimated annual average gain 0.9%). These findings have implications for conservation and management of grazers. Major drivers for conservation challenges of Grevy’s zebra were habitat degradation, unintegrated development, and poor law enforcement practices. Grassland restoration program and species conservation challenges’ intervention strategy should be designed and implemented to safeguard the natural habitat and the species that occur in the HAPNP.

Functional trait dataset of European groundwater Amphipoda: Niphargidae and Typhlogammaridae

Groundwater represents a vast, but mostly hidden and inaccessible ecosystem. Although often overlooked in freshwater research, groundwater organisms form a significant part of freshwater biodiversity, whereas their functions are crucial in different ecosystem processes. Knowledge on functional traits is generally lacking for most groundwater species worldwide, yet European groundwater amphipods, particularly the family Niphargidae, are an exception. They are well-researched and used as a model system in ecological and evolutionary studies. We focused on this group to assemble a first functional trait dataset dedicated to groundwater species. We gathered data for eight morphological functional traits quantified through 27 measurements for 1123 individuals which represent 180 species and 314 MOTUs. Besides functional trait data, every entry is accompanied with locality information, including habitat type, and DNA sequences if available. The structure of the dataset and data processing information provided along enable wide applicability and extension to other amphipod taxa. When coupled with phylogeny, the dataset may further enhance different aspects of groundwater research, including biodiversity patterns, community assembly processes, and trait evolution.

Mercury bioaccumulation and Hepatozoon spp. infections in two syntopic watersnakes in South Carolina.

Mercury (Hg) is a ubiquitous environmental contaminant known to bioaccumulate in biota and biomagnify in food webs. Parasites occur in nearly every ecosystem and often interact in complex ways with other stressors that their hosts experience. Hepatozoon spp. are intraerythrocytic parasites common in snakes. The Florida green watersnake (Nerodia floridana) and the banded watersnake (Nerodia fasciata) occur syntopically in certain aquatic habitats in the Southeastern United States. The purpose of this study was to investigate relationships among total mercury (THg) concentrations, body size, species, habitat type and prevalence and parasitemia of Hepatozoon spp. infections in snakes. In the present study, we sampled N. floridana and N. fasciata from former nuclear cooling reservoirs and isolated wetlands of the Savannah River Site in South Carolina. We used snake tail clips to quantify THg and collected blood samples for hemoparasite counts. Our results indicate a significant, positive relationship between THg and snake body size in N. floridana and N. fasciata in both habitats. Average THg was significantly higher for N. fasciata compared to N. floridana in bays (0.22 ± 0.02 and 0.08 ± 0.006 mg/kg, respectively; p < 0.01), but not in reservoirs (0.17 ± 0.02 and 0.17 ± 0.03 mg/kg, respectively; p = 0.29). Sex did not appear to be related to THg concentration or Hepatozoon spp. infections in either species. We found no association between Hg and Hepatozoon spp. prevalence or parasitemia; however, our results suggest that species and habitat type play a role in susceptibility to Hepatozoon spp. infection.

Assessment of Forest Biomass and Carbon Storage in Habitat 9340 Quercus ilex L. to Support Management Decisions for Climate Change Mitigation

The assessment of forest biomass has been a focus of research, aiming to understand matter–energy relationships in forest ecosystems and address forestry practice issues. In recent decades there has been increased societal interest in rational forest resource exploitation, necessitating accurate biomass estimation. In Greece there has been limited efforts in estimating forest biomass, and the current study focuses on habitat type 9340, “Quercus ilex and Quercus rotundifolia forests,” located in the protected areas “GR1420004–Karla–Mavrovouni–Kefalovryso Velestinou–Neochori” and “GR1430001–Oros Pilio and Paraktia Thalassia Zoni (Mount Pilion and Coastal Sea Zone)” in the Natura 2000 network. The habitat falls within the thermo-Mediterranean zone and the study aims to estimate the biomass and carbon storage to contribute to sustainable EU forest strategies. Due to resource limitations, a generalized allometric equation was proposed as an alternative to traditional biomass estimation methods. The above-ground biomass per hectare was estimated, ranging from 16.10 to 205.27 Mg ha−1 (mean 61.91 Mg ha−1). Furthermore, two approaches were used to estimate the total biomass in the habitat: regional averages based on spatial distribution and spatial interpolation using a geographic information system. The total estimated biomass for habitat 9340 is 183,505 Mg, with the carbon storage in standing dry biomass amounting to 83,725.25 Mg. Despite the absence of sampled biomass specimens, this study combines robust statistical techniques with published empirical values to provide a solid framework for estimating assimilated CO2. Sequestered CO2 in the study area is estimated at 306,992.58 Mg. Therefore, the significant role of Quercus ilex L. in carbon storage in Mediterranean forest ecosystems is highlighted by sequestering a substantial amount of CO2.

Saffron-cowled Blackbirds’ reduced nest success in Argentina’s agricultural land highlights the importance of non-agricultural habitat for its conservation

Abstract The Saffron-cowled Blackbird (Xanthopsar flavus) is a globally endangered icterid endemic to the southern South American grasslands. Temperate grasslands are among the most threatened ecosystems in South America due to their high rate of land use change. In northeastern Argentina, over the last century, the conversion of natural grasslands to livestock farming, croplands, and afforestation has resulted in significant losses of breeding habitat for the Saffron-cowled Blackbird. Consequently, it has suffered severe populational declines, and its remaining populations are fragmented. In order to understand the impact of agricultural systems on the Saffron-cowled Blackbird populations, we studied its breeding biology (clutch size, hatching success, nestling production, and fledgling success) and the main parameters that influence nest survival rate in five breeding habitat types. During the breeding seasons of 2015 to 2019, we located nests and monitored their fate. We found that the cumulative probability of nest survival over the entire nesting cycle (i.e. laying, incubation, and chick rearing) was 0.06, and was lower for nests situated in grazed land covers. Conversely, nest survival was greater in breeding sites without agricultural use, particularly in marshes. Predation was the main cause of nest failure (76%), followed by brood parasitism (10%), and trampling by cattle and agricultural machinery (6%). Brood parasitism rates were higher in grazed paddocks, contributing together with predation to the failure of nests in this habitat. Our findings indicate a negative impact of livestock ranching on Saffron-cowled Blackbird reproduction. Non-agriculture habitats, such as wetlands and flooded areas, are important as refuges for nesting. Thus, the creation of breeding refuges (non-productive sites) within agricultural matrices, in association with biodiversity-friendly agricultural practices, is crucial to ensure the Saffron-cowled Blackbird’s maintenance.

Bee-diverse habitats positively affect seed set in wild plant species

IntroductionInteractions between flowering plants and visiting wild bees are crucial for ensuring pollination and subsequent plant reproductive success. However, bee diversity in an area has rarely been recorded in relation to seed set in native plants. In this project, we investigated the effect of local wild bee communities on seed set in four common wild plant species.MethodsPotted plants of Centaurea jacea, Cichorium intybus, Sinapis arvensis, and Salvia pratensis were placed for pollination experiments, in two distinct habitat types that we expected to show distinct bee communities, namely near-natural grassland and perennial wild flower strips, in Germany.ResultsOur results showed that near-natural grassland had a higher bee species richness and an increased seed set compared with flower strips that displayed a higher bee abundance in most study locations. Although we found effects of bee diversity on seed set, we did not detect a significant effect of bee abundance. Furthermore, the seed set in response to wild bee diversity differed across the plant species.DiscussionWe conclude that bee-friendly habitats ensure a high seed set in wild plants, but that the impact varies between different plant species.

Specialist or refugee: Microhabitat use and competition between two sympatric woodland salamanders

AbstractCo‐occurrence between species may be mediated by ecological differences or competitive interactions, but the nature of these interactions can vary across spatial scales. At coarse scales, species may appear to broadly co‐occur, but at fine scales, particularly for species with small home ranges, species may utilize different aspects of the microhabitat such that co‐occurrence is limited and competitive interactions are reduced or eliminated. We investigated the microhabitat use of two morphologically and ecologically similar woodland salamanders (the Red‐backed Salamander, Plethodon cinereus, and the Northern Ravine Salamander, P. electromorphus) that are distributed throughout the Alleghany Plateau in eastern North America to determine whether they partition habitat at finer scales. We also tested if P. electromorphus is a specialist on habitat types that allow it to exclude P. cinereus, or if P. electromorphus uses lower quality habitat as a refuge to avoid P. cinereus. At a site of microsympatry, we repeatedly sampled plots during two seasons, each within a different area of the landscape, and used occupancy and abundance modeling to assess the extent of co‐occurrence and test whether the species use different microhabitat conditions. Plethodon cinereus greatly outnumbered P. electromorphus and occupied a greater proportion of plots, most plots where we detected P. electromorphus we also detected P. cinereus. In contrast to patterns documented in some montane species pairs, in which a high‐elevation habitat specialist excludes a low‐elevation generalist, we found that P. electromorphus primarily used microhabitat conditions favorable for both species, such as north‐facing slopes, yet did not have a negative effect on the abundances of P. cinereus. In the presence of an abundant competitor, microhabitat use of the less abundant species may narrow toward optimal conditions with sufficient resources to facilitate co‐occurrence.