Species Diversity Research Articles

Tree species diversity and spatial distribution of carbon stock in forests under different management regimes in Nepal's Western Terai Arc Landscape

Reliable tree species diversity and carbon stock data are crucial for establishing a baseline and aiding monitoring and management decision-making to ensure ecosystem functions and services, including carbon management. However, such data are not available for many primary forests, especially in developing countries like Nepal. For this study, we generated primary baseline data on tree species diversity, biomass, and carbon stock for forests under different management regimes in one of the critical landscapes of western Nepal. We sampled 94 clusters of concentric circular sample plots placed systematically at the nodes of 3 km by 3 km square grids in biological corridors (managed by community forest user groups) and a national park's buffer zones (managed by buffer zone user groups) to study the tree species composition and estimate the carbon stock. The number of tree species and botanical families reported in different sites did not differ significantly. The basal area was found to be highest in Brahmadev Corridor where tree density per unit area was also highest. Our study sites showed a basal area ranging from 26.42 to 40.65 m2/ha, which is higher than previously reported from similar forests. The total biomass (302.12 to 496 tons/ha) and carbon stock (142 to 233.12 tons/ha), both being highest in Brahmadev Corridor, were within the range of comparable data and national averages. The number of stems in all sites showed the reverse J-shaped pattern, indicating a stable population and good species recruitment. The buffer zones had a large proportion of forest area with the highest carbon stock classes of 300–400 tons/ha. The basal area and diameter at breast height showed a significant positive correlation with carbon stock, indicating that the basal area is a key determinant of carbon stock. Our study provides disaggregated information on tree species diversity, the quality of forests in terms of stem density and size-class distribution, and carbon stock and its distribution in different carbon stock classes in two forest management regimes. In this sense, our study is the first of its kind in providing important insights into forest and carbon management because areas with different carbon stocks need different management prescriptions.

Adaptation mechanism of clam Ruditapes philippinarum under polycyclic aromatic hydrocarbon stresses: Accumulation and excretion

Persistent organic pollutants (POPs) are easily accumulated in organisms due to its high lipophilicity. Bivalves are still one of the marine invertebrates with high species diversity despite experiencing with environmental pollution. However, studies investigating the adaptation mechanisms of bivalves towards POPs have been lacking. In this study, we chose benzo[a]pyrene (B[a]P), a typical POPs, to investigate the accumulation and excretion mechanism of clam Ruditapes philippinarum towards B[a]P. Laser confocal microscopy images of ovaries and testes confirmed significant colocalization between lipid droplets and B[a]P. However, B[a]P in the testes might mainly excrete with the excretory fluid. Furthermore, lipidomics results indicated that the upregulated TGs were TGs with 48–58 total carbon atoms and 6–12 double bonds in acyl side chains in ovaries, while the upregulated TGs mainly distributed in 48–58 total carbon atoms and 4–14 double bonds in acyl side chains in testes. In ovaries, gene expression of lipid metabolism and phospholipid metabolism basically presented an upward trend at Pro and Mat stages, while entirely performed a downregulation trend at Gro stage. Testes had the opposite regulation with that. Additionally, B[a]P prompted the excretion ability of female clams, but exhibited a complex effect in the male. This study provides a scientific basis for bivalve toxicology and healthy aquaculture, which is of great significance for marine ecological environment protection and aquatic product safety of China.

Remotely Sensed Variables Predict Grassland Diversity Better at Scales Below 1,000 km as Opposed to Abiotic Variables That Predict It Better at Larger Scales

AbstractGlobal spatial patterns of vascular plant diversity have been mapped at coarse grain based on climate‐dominated environment–diversity relationships and, where possible, at finer grain using remote sensing. However, for grasslands with their small plant sizes, the limited availability of vegetation plot data has caused large uncertainties in fine‐grained mapping of species diversity. Here we used vegetation survey data from 1,609 field sites (>4,000 plots of 1 m2), remotely sensed data (ecosystem productivity and phenology, habitat heterogeneity, functional traits and spectral diversity), and abiotic data (water‐ and energy‐related, characterizing climate‐dominated environment) together with machine learning and spatial autoregressive models to predict and map grassland species richness per 100 m2 across the Mongolian Plateau at 500 m resolution. Combining all variables yielded a predictive accuracy of 69% compared with 64% using remotely sensed variables or 65% using abiotic variables alone. Among remotely sensed variables, functional traits showed the highest predictive power (55%) in species richness estimation, followed by productivity and phenology (48%), spectral diversity (48%) and habitat heterogeneity (48%). When considering spatial autocorrelation, remotely sensed variables explained 52% and abiotic variables explained 41%. Moreover, Remotely sensed variables provided better prediction at smaller grain size (<∼1,000 km), while water‐ and energy‐dominated macro‐environment variables were the most important drivers and dominated the effects of remotely sensed variables on diversity patterns at macro‐scale (>∼1,000 km). These findings indicate that while remotely sensed vegetation characteristics and climate‐dominated macro‐environment provide similar predictions for mapping grassland plant species richness, they offer complementary explanations across broad spatial scales.

Effects of soil compaction on above- and belowground interactions during the early stage of forest development

Forested green spaces in urban and peri-urban areas are expected to serve multiple roles, including providing ecosystem services and maintaining species diversity and soil health, both of which are particularly important for human health. However, soil compaction is a major cause of soil degradation in urban areas and brownfields (abandoned, previously developed land). We examined the effects of compaction on soil physicochemical properties, tree species richness, tree basal area, and the functional diversity of microbial communities in an immature volcanic soil through a long-term (14-year) field experiment. Our experimental results showed that soil compaction reduced not only both tree species richness and biomass but also the multifunctionality of soil microbial communities. Furthermore, tree species richness was significantly positively related to soil microbial decomposition activity. These findings provide evidence of above- and belowground interactions and underscore their importance in the design of urban forests using ecosystem-based solutions.

Metagenomic Insights into Coal Slag Remediation Effects on Soil and Microbial Health in Qinghai’s Muli Coal Mine

Long-term coal mining in the Muli coal mine area of Qinghai Province has degraded soil quality and reduced microbial diversity, making it imperative to implement effective ecological restoration measures to restore soil quality and enhance ecosystem functions. This study evaluated soil samples under 11 ecological restoration treatments using metagenomic sequencing combined with soil quality analysis to explore the responses of the microbial community structure and function to identify effective restoration measures. This study demonstrated that ecological restoration significantly increased the soil microbial diversity and richness, with the MLII1 (soil samples treated with a chemical weathering agent, attapulgite, and a microbial agent) and MLIII1 (soil samples treated with sheep manure (2.4 kg/m2), granular organic fertilizer (1.2 kg/m2), and the microbial agent) treatment groups performing exceptionally well. Further analysis of the functional networks revealed that although the MLII2 (soil samples treated with the chemical weathering agent and attapulgite) treatment group did not exhibit the highest species diversity, it exhibited the highest functional network complexity. The results of hierarchical clustering analysis showed that the microbial community of the MLII2 treatment group was most similar to that of the natural meadows compared to the other treatment groups. From the perspective of overall ecological restoration, this study concluded that the MLII2 treatment group exhibited the most favorable ecological restoration outcomes. This finding emphasizes the importance of not only enhancing microbial diversity but also prioritizing the restoration of community functions, especially for the recovery of fragile high-altitude ecosystems.

Soil cover heterogeneity associated with biocrusts predicts patch-level plant diversity patterns

ContextSoil resource heterogeneity drives plant species diversity patterns at local and landscape scales. In drylands, biocrusts are patchily distributed and contribute to soil resource heterogeneity important for plant establishment and growth. Yet, we have a limited understanding of how such heterogeneity may relate to patterns of plant diversity and community structure.ObjectivesWe explored relationships between biocrust-associated soil cover heterogeneity and plant diversity patterns in a cool desert ecosystem. We asked: (1) does biocrust-associated soil cover heterogeneity predict plant diversity and community composition? and (2) can we use high-resolution remote sensing data to calculate soil cover heterogeneity metrics that could be used to extrapolate these patterns across landscapes?MethodsWe tested associations among field-based measures of plant diversity and soil cover heterogeneity. We then used a Support Vector Machine classification to map soil, plant and biocrust cover from sub-centimeter resolution Unoccupied Aerial System (UAS) imagery and compared the mapped results to field-based measures.ResultsField-based soil cover heterogeneity and biocrust cover were positively associated with plant diversity and predicted community composition. The accuracy of UAS-mapped soil cover classes varied across sites due to variation in timing and quality of image collections, but the overall results suggest that UAS are a promising data source for generating detailed, spatially explicit soil cover heterogeneity metrics.ConclusionsResults improve understanding of relationships between biocrust-associated soil cover heterogeneity and plant diversity and highlight the promise of high-resolution UAS data to extrapolate these patterns over larger landscapes which could improve conservation planning and predictions of dryland responses to soil degradation under global change.

Botanical origins of honeys from pollen analysis during the main honey flow across agro-ecologies in kelala district, South Wollo, Ethiopia

This study aimed to identify the botanical origins of honey through pollen analysis across agro-ecologies of Kelala district, South Wollo, Ethiopia. Fifteen honey samples were collected from traditional beehives, with 5 samples from each of the highland, midland, and lowland agro-ecologies. Qualitative and quantitative pollen analyses revealed that 22 honeybee plants belonging to 8 families, with no families of poisonous origin, and 3 growth forms were identified. Among these plant species, 18 were found in the midland and 13 were recorded in each of the highland and lowland agro-ecologies. The family Fabaceae, with 7 (31.81 %) of the identified honeybee plants, was highly dominant (p < 0.03) compared to the other families. Herbs, with 18 plant species, were highly dominant (p < 0.001) compared to shrubs and trees. In terms of plant species diversity, 10 plant species (Bidens pachyloma, Guizotia scabra, Becium grandiflorum, Eleusine floccifolia, Lens culinaris, Lippia adoensis, Medicago polymorpha, Ocimum basilicum, Trifolium steudneri, and Zea mays) were found in more than 50 % of the honey samples, with the first 2 in all the samples studied. Analysis of each honey sample showed that 8 (53.33 %) of the samples were monofloral, 3 (20 %) were bifloral, and the rest were multifloral. However, all the honeys produced due to agro-ecology (geographical origin) were monofloral. Guizotia scabra in the highland and Bidens pachyloma in the midland and lowland agro-ecologies were the predominant pollen producing species and contributors of monofloral honey. In conclusion, the safe and healthy monofloral honey produced across agro-ecologies suggests the suitability of the honey for human consumption and can potentially attract investors.

DNA Barcoding for the Identification of Adult Mosquitoes (Diptera: Culicidae) in Western Australia

ABSTRACTPrecise mosquito identification is integral to effective arbovirus surveillance. Nonetheless, the conventional morphological approach to identifying mosquito species is laborious, demands expertise and presents challenges when specimens are damaged. DNA barcoding offers a promising alternative, surmounting challenges inherent in morphological identification. To integrate DNA barcoding into arbovirus surveillance effectively, a robust dataset of mosquito barcode sequences is required. This study established a comprehensive repository of Cytochrome Oxidase I (COI) barcodes, encompassing 177 samples representing 45 mosquito species from southern and northern Western Australia (WA), including 16 species which have not been previously barcoded. The average intraspecific and interspecific genetic distances were 1% and 6.8%, respectively. Anopheles annulipes sensu lato had the highest intraspecific distance at 9.1%, signifying a genetically diverse species. While validating the potential of COI barcodes to accurately differentiate mosquito species, we identified that some species pairs have low COI divergence. This includes Aedes clelandi and Ae. hesperonotius, Tripteroides atripes and Tp. punctolaeralis and Ae. turneri and Ae. stricklandi. In addition, we observed ambiguity in identification of the members of Culex sitiens subgroup (Cx. annulirostris, Cx. palpalis and Cx. sitiens) and three members of Cx. pipiens complex (Cx. australicus, Cx. globocoxitus, Cx. quinquefasciatus). In summary, despite presenting challenges in the identification of some mosquito species, the COI barcode accurately identified most of the species and generated a valuable resource that will support the WA arbovirus surveillance program and enhance public health intervention strategies for mosquito‐borne disease control.

Respective Advantages of Growing Different Green Manure With Nitrogen Fertilization in Cotton‐Based Cropping Systems: Insights From a Three‐Year Field Study

ABSTRACTPlanting green manure to improve cash crop yield and soil health has been widely recognized, and understanding cash crop performance after green manure integration is pivotal for determining its potential to bolster and enhance crop productivity and sustainable production. However, it is unclear whether the effects of different types of green manure on subsequent cash crops are uniform. In order to clarify this issue, we systematically analyzed the effects of green manure types and nitrogen (N) application rates on succeeding cotton agronomic performance, yield, biomass, yield stability, and nutrient uptake. A split‐plot experiment with two factors was designed, main factor includes four cover cropping systems monoculture cotton (MC), February orchid/cotton cover cropping (FoC), hairy vetch/cotton cover cropping (HvC), and a mixture of February orchid and hairy vetch/cotton cover cropping (FHC), and sub‐main factor include four N application levels (0 (N0), 112.5 (N1), 168.75 (N2), and 225 (N3) kg N ha−1). Results suggests that nonlegume green manure (February orchid) accumulated more biomass, N, P, and K nutrients than the legume green manure (hairy vetch) and green manure mixture. Compared with cotton yield of MC, the FoC, HvC, and FHC system increased by 5.8%, 7.6%, and 15%, respectively. N use efficiency was more significantly influenced by the N application rates than by cropping systems. Specifically, as N application rates increased, N use efficiency decreased under MC, HvC, and FHC systems, while it increased under the FoC system. Additionally, we observed a trade‐off between cotton yield and yield stability, with the highest yield stability when cotton yield reached 2633 kg ha−1. This study provides evidence that nonlegume green manure (February orchid) with greater advantages on cotton vegetative organ growth, legume green manure (hairy vetch) can promote nutrient uptake compared to other green manure, while green manure mixture (February orchid and hairy vetch mixture) significantly increased cotton yield and yield stability. These findings provide evidence‐based insights highlighting the respective benefits of incorporating diverse species of green manure into cotton‐based cropping systems in the Yellow River Basin of China.

Trends in Tree Species Selection for Urban Street Planting: A Thematic Review

In major cities, street tree failures pose ongoing challenges related to user safety, tree management, and maintenance. This study evaluates trends in urban street tree selection by analysing 45 articles from 2019 to 2024 using keywords such as “street,” “tree species,” and “selection.” The thematic analysis identifies five key themes: species diversity, ecosystem services, climate adaptability, public perception, and management challenges. Findings highlight the need for a multifaceted approach, recommending criteria to reduce conflicts and ensure proper tree placement. The proposed framework aims to enhance urban tree resilience and coexistence with humans by emphasising genetic diversity and ecological benefits. Keywords: Street tree, species selection, urban forestry, thematic review

Combining Morphological and Molecular Tools Can Enhance Tick Species Identification for Improved Tick-Borne Disease Surveillance Among Pastoral Communities in Kenya.

Background: Ticks are ecto-parasites of domestic animals, rodents, and wildlife living for periods at a time on one or more vertebrate hosts. They are important vectors of viral, bacterial, or parasitic diseases in livestock and humans. Crimean-Congo haemorrhagic fever virus and the spotted fever rickettsiae are some of the tick-borne diseases of public health importance reported in Kenya. Their distribution and public health risks among communities, especially pastoralists, remain poorly characterized due to limited surveillance, affected partly by inadequate capacity for tick identification arising from a limited number of skilled taxonomists. Materials and Methods: The aim of this survey was to identify tick species currently circulating in different livestock hosts in northern Kenya. Ticks were sampled from cattle, sheep, goats, and camels in Turkana, Isiolo, Baringo, and West Pokot counties, and differential identification was carried out using morphological identification keys followed by molecular characterization based on the cytochrome c oxidase I gene (cox1). Haplotypes were determined using the DnaSP v6 software and phylogenetic relationships inferred using the maximum likelihood algorithm. Results: A total of 12,206 ticks were collected, from Turkana (45.4%), Isiolo (23.1%), Baringo (22.7%), and West Pokot (8.8%) counties in Kenya. Ten species were confirmed by molecular analysis; H. rufipes, H. impeltatum, H. dromedarii, R. pravus, R. camicasi, R. pulchellus, R. evertsi evertsi, A. variegatum, A. gemma, and A. lepidum. There was no disparity in the morphological and molecular identification of Amblyomma species. However, molecular analysis provided insight into the complexity of morphological identification especially among Hyalomma and Rhipicephalus species. High haplotype diversities (0.857-1.000) and low nucleotide diversities (0.00719-0.06319) were observed in all the tick samples tested. Conclusion: The findings highlight the diversity of tick species in dry pastoral ecologies in Kenya and the importance of confirming morphological identification by molecular analysis thus contributing to accurate mapping of tick-borne disease distribution and risk.

Genetic analyses of Anisakis pegreffii (Nematoda: Anisakidae) from the East Asian finless porpoise Neophocaena asiaeorientalis sunameri (Cetacea: Phocoenidae) in Korean waters

The East Asian finless porpoise, Neophocaena asiaeorientalis sunameri, is an endangered species that inhabits the coastal marine environments of East Asia. In the present study, we investigated the overall infection status of anisakid nematodes in East Asian finless porpoises from three sea sectors off the Korean Peninsula. The genetic diversity and population genetic structure of the identified nematode species were evaluated. The prevalence of all stages of anisakid nematodes collected from the stomach was 57.55% (61 among the 106 porpoises examined), and 16 of the hosts were found to have adult worms. The mean number of infected adults was 211 (± 419.54, 5–1455 per host). Only one species of anisakids, Anisakis pegreffii, was identified from randomly selected worms by molecular approaches. Analysis of the mitochondrial (mt) cox2 partial gene in 50 newly generated sequences of A. pegreffii revealed 24 haplotypes, including 14 new haplotypes. We observed below-average levels of nucleotide diversity and haplotype diversity compared to other seas around the world. The mtDNA cox2 haplotypes of the species in the three Korean sea areas showed no genetic structure, suggesting well-connected gene flow within these areas. This study represents the first record of a definitive host of A. pegreffii in Korean waters, providing important information regarding anisakids genetic diversity in the cetacean species inhabiting limited regions.

The Microbiota of the Outer Gut Mucus Layer of the Migrating Northeast Arctic Cod (Gadus morhua) as Determined by Shotgun DNA Sequencing

Animals form functional units with their microbial communities, termed metaorganisms. Despite extensive research on some model animals, microbial diversity in many species remains unexplored. Here, we describe the taxonomic profile of the microbes from the outer gut mucus layer from the Northeast Arctic cod using a shotgun DNA sequencing approach. We focused on the mucus to determine if its microbial composition differs from that of the fecal microbiota, which could reveal unique microbial interactions and functions. Metagenomes from six individuals were analyzed, revealing three different taxonomic profiles: Type I is dominated in numbers by Pseudomonadaceae (44%) and Xanthomonadaceae (13%), Type II by Vibrionaceae (65%), and Type III by Enterobacteriaceae (76%). This stands in sharp contrast to the bacterial diversity of the transient gut content (i.e., feces). Additionally, binning of assembled reads followed by phylogenomic analyses place a high-completeness bin of Type I within the Pseudomonas fluorescens group, Type II within the Photobacterium phosphoreum clade, and Type III within the Escherichia/Shigella group. In conclusion, we describe the adherent bacterial diversity in the Northeast Arctic cod’s intestine using shotgun sequencing, revealing different taxonomic profiles compared to the more homogenous transient microbiota. This suggests that the intestine contains two separate and distinct microbial populations.

Diversity of Soil Macro Arthropods in the Arable Land of Cotton Zone, North Cameroon

Arthropods constitute the most diverse and dominant species of biodiversity in terrestrial ecosystems. Despite this great abundance, our understanding of their ecological organization and diversity remains unknown in certain habitats. The present study aimed to evaluate the diversity of soil macro-arthropods in the arable land of six localities in the arable land of cotton zone of Cameroon. For this purpose, collections of soil macro-arthropods were carried out using Barber traps and subpots for two consecutive years 2018-2019. During the entire duration of the study, nearly 33.423 soil macro-arthropods were collected belonging to 67 species divided into 11 orders and 27 families. After classification, the most abundant insect groups were Coleoptera (36.9%), Hymenoptera (33.5%), and Orthoptera (22.9%), while the groups of Neuroptera, Hemiptera and Isoptera practically a low level of relative abundance. The proportions of the different families of soil macro-arthropods sampled varies from one locality to another and three large families were in the majority: Formicidae (32.4%), Acrididae (19.5%) and Tenobrionidae (15.7%). Soil macro-arthropod samples collected in Kodek, Sanguere Njoï and Gashiga, respectively recorded the highest species richness as well as the Shanon-Weaver Diversity and Evenness index. In all the arable soils of the localities studied, the soil arthropods tend to have an Equidistribution of individuals and Equitability varies from 0.5 to 0.8. The soil macro-arthropods collected in the arable land of the cotton zone of North Cameroon were mainly phytophagous and saprophagous with a strong beneficial potential in these different ecosystems.

Influence of diverse pasture species and reduced nitrogen fertiliser inputs on soil health on four irrigated Canterbury dairy pastures

Maintaining and improving the health of pastoral soils is important to enable the provision of ecosystem services for sustainable production. We investigate the impacts of increasing pasture species diversity and reducing nitrogen (N) fertiliser inputs on pasture productivity and the flow on effects for soil health on four irrigated dairy farms in Canterbury. The soils had generally good health prior to pastures being resown. During the establishment of both simple and diverse pastures there was a decline in Olsen P, soil organic carbon (C), total N and potentially available N to below target levels. In the year following pasture establishment there was no difference in herbage accumulation between the simple and more diverse pastures under irrigation. For both simple and diverse pastures, grass species contributed approximately 50%, legumes 15%, and herbs 20% of the total dry matter harvested. Although there was a reduction in pasture growth as N fertiliser inputs were reduced, legume content did not decline significantly and differences in soil health were not observed at this stage. Despite the farms being intensive dairy systems, the data suggests good soil health prior to pasture establishment. Hence maintaining soil health as well as its restoration following disturbance present opportunities for these farms.

Designing e-modules on mangrove species diversity leveraging local potential through pbl to foster environmental attitudes

This study aims to develop e-modules of mangrove species diversity as local potential in learning. The development model used is the Lee &amp; Owens (2004) development model. There are five phases in the development of research, namely the analysis, design, development, implementation and evaluation. The used learning model is Problem-Based Learning by presenting authentic mangrove problems in Banten. The e-module that has been developed will be tested for validity, practicality and effectiveness so that it can be disseminated for student learning activities. E-modules are tested for validity by conducting a 100% material expert validation test, 98.77% media and teaching material validation results and 100% validation results from field practitioners. Before being used in learning, the e-module was tested for practicality with a one-on-one trial getting a score of 93.33%, a small group trial of 89.41%, a field trial of 86.2% and a field test of 95.04%. Based on the results of student response testing, it can be concluded that the e-module of mangrove diversity is practically used in learning. The results of effectiveness testing to see the improvement of students' environmental attitudes were analyzed. The results of effectiveness testing to see an increase in students' environmental attitudes are measured qualitatively with an N-Gain measurement of 0,46 which is included in medium effectiveness and quantitatively measured using a simple paired t test with p-value of 1.88 which means there is a significant difference before and after using e-module in learning.

Southeastern Ohio Hemlock Stands Prior to Hemlock Woolly Adelgid Infestation: Baseline Conditions from 2 Surveys a Decade Apart

The Hocking Hills of southeastern Ohio are situated at the western range boundary of eastern hemlock, where this foundation species occurs in isolated pockets in ravines and on steep slopes. The goal of this study is to characterize these hemlock stands prior to infestation by hemlock woolly adelgid (HWA), which recently entered the state and is likely to cause high mortality if untreated. Individuals in 30 plots established from 2008 to 2011 were resurveyed in 2020, allowing determination of growth rates and mortality rates. Each plot was paired with an upslope transect in the resurvey to record non-hemlock species likely to seed in from above. Tree species diversity in the plots is low (Shannon H’ &lt; 1), as eastern hemlock remained the dominant species in all plots; storm damage and competitive thinning appeared to account for most mortality across all species. Hemlock growth rates were comparable to deciduous species. Common co-occurring species are statistically associated with particular topographic and soil properties on the plots. Following future hemlock mortality, tulip-poplar, chestnut oak, white oak, sweet birch, and red maple may be among the first species to dominate the canopy; Japanese stiltgrass currently appears to be the invasive species of greatest concern. An understanding of pre-HWA composition, structure, and forest dynamics can inform restoration efforts, if in the future long-term, sustainable HWA control or host-tree resistance is developed; this understanding can also apprise management and conservation efforts in the unique hemlock stands of southeast Ohio.

Southeastern Ohio Hemlock Stands Prior to Hemlock Woolly Adelgid Infestation: Baseline Conditions from 2 Surveys a Decade Apart

The Hocking Hills of southeastern Ohio are situated at the western range boundary of eastern hemlock, where this foundation species occurs in isolated pockets in ravines and on steep slopes. The goal of this study is to characterize these hemlock stands prior to infestation by hemlock woolly adelgid (HWA), which recently entered the state and is likely to cause high mortality if untreated. Individuals in 30 plots established from 2008 to 2011 were resurveyed in 2020, allowing determination of growth rates and mortality rates. Each plot was paired with an upslope transect in the resurvey to record non-hemlock species likely to seed in from above. Tree species diversity in the plots is low (Shannon H’ &lt; 1), as eastern hemlock remained the dominant species in all plots; storm damage and competitive thinning appeared to account for most mortality across all species. Hemlock growth rates were comparable to deciduous species. Common co-occurring species are statistically associated with particular topographic and soil properties on the plots. Following future hemlock mortality, tulip-poplar, chestnut oak, white oak, sweet birch, and red maple may be among the first species to dominate the canopy; Japanese stiltgrass currently appears to be the invasive species of greatest concern. An understanding of pre-HWA composition, structure, and forest dynamics can inform restoration efforts, if in the future long-term, sustainable HWA control or host-tree resistance is developed; this understanding can also apprise management and conservation efforts in the unique hemlock stands of southeast Ohio.

Unpacking the complex relationships between agricultural investments and biodiversity in Ghana

The expansion of large-scale agricultural investments (LSAI) in Ghana has substantial implications for biodiversity and rural community well-being. This study explores the complex relationships between LSAI and biodiversity, focusing on species richness, evenness, Enhanced Vegetation Index, and Soil Adjusted Vegetation Index to assess ecosystem health. Using a mixed-methods approach, we combine panel datasets, remote sensing, and qualitative data to evaluate both ecological and social impacts of LSAI. While LSAI has potential economic benefits, it also poses risks to biodiversity by reducing species diversity and altering ecosystem services essential for rural communities' livelihoods. Our findings reveal that while LSAI increase vegetation cover and species evenness, they frequently lead to the loss of access to critical resources such as fuelwood, medicinal plants, and wild foods, impacting community resilience and social cohesion. These findings underscore the importance of balancing agricultural investments with policies that preserve biodiversity and maintain social equity, ensuring that long-term societal impacts of LSAI do not compromise ecosystem or local livelihoods. It calls for robust monitoring systems, and the inclusion of local communities in decision-making to ensure sustainable development. The study offers critical insights for policymakers and conservationists aiming to harmonize economic development with environmental conservation in Ghana and beyond.

Accumulation of road salt in a calcareous fen: Kampoosa Bog, western Massachusetts.

Road salt poses a threat to the quality of soils and water resources. Wetlands located in salt contaminated areas are at risk of experiencing lower plant and animal species diversity. Therefore, it is critical to understand how modifications to salt application rates and hydrological events impact wetland water quality. Here, we use chloride mass flux, discharge, groundwater chloride concentration, meteorological, and salt application data from 2012-2020 to estimate chloride accumulation and outflux rates in the Kampoosa Bog subwatersheds, located in Stockbridge and Lee, Massachusetts, and bordered by major highways (Interstate-90 and U.S. Route 7). We also investigate the correlation between wetland size and chloride retention rate. During the 2018-2019 period, mean annual chloride application rates in the major watershed increased from 363000 kg/year (2012-2017) to 479000 kg/year. This led to a net chloride accumulation (KB100 subwatershed: 339000 kg; KB150 subwatershed: 188000 kg) and increased groundwater chloride concentrations in the fen. Chloride outflux from these subwatersheds was primarily driven by discharge. We found that the relationship between wetland percent cover and chloride retention is complex. Although the percent wetland cover is greater in the KB100 main wetland region compared to the KB150 subwatershed, high precipitation in 2018 resulted in similar chloride retention efficiencies (~26%). During the drier year (2019), chloride retention was higher in the wetland region due to its gentle slopes which promote water accumulation and consequently higher evaporation rates which lowers discharge and chloride outfluxes. The chloride steady-state concentration analysis also suggests that there is potential for chloride accumulation to continue because the watershed has not yet reached steady-state chloride concentrations. Without major modifications to salting practices, chloride concentrations will continue increasing and potentially promote the re-growth of invasives (Phragmites) and continued growth of salt tolerant species (Typha angustifolia/xglauca) that diminish plant diversity.