Habitat Research Articles

Effect of open-area ratios on wave attenuation over a submerged reef breakwater: An experimental study

The reef-type submerged breakwater (RSB) has been implemented around the world to provide coastal protection and natural shelter and habitat for marine species at the same time. A series of laboratory experiments are conducted in a wave flume to study wave propagation and transmission over RSBs with the four open-area ratios of 0.047, 0.131, 0.257, and 0.560. The experimental results demonstrate that the RSB significantly alters the wave propagation characteristics. The RSBs with the open-area ratio of 0.047 and 0.131 reduce the wave height to ∼70%. The RSBs with the open-area ratio of 0.047 and 0.131 perform better in attenuating than those with the open-area ratio of 0.257, and 0.560. As the open-area ratio decreases, the transmission coefficient decreases, while the dissipation coefficient increases. An empirical formula is proposed to calculate the wave transmission coefficient as a function of the RSB open-area ratio and wave steepness under regular waves. A cubic empirical formula with one unknown is also proposed to relate the distance from RSB stoss face to wave breaking point and the open-area ratio. The present study is expected to optimize RSB design for coastal protection.

Further evidence for endozoochory in a mycoheterotrophic orchid Cyrtosia septentrionalis: seed dispersal by the masked palm civet Paguma larvata.

Cyrtosia septentrionalis, an orchid species, is notable for its sausage-shaped red fleshy fruits, which can reach up to 10 cm in length. Previous research identified frugivorous and omnivorous birds, especially the brown-eared bulbul Hypsipetes amaurotis (Pycnonotidae, Passeriformes), as key seed dispersers of C. septentrionalis in natural habitats. This finding challenges conventional belief that orchid seeds are primarily wind-dispersed. Moreover, given the rarity of specialized co-evolutionary relationships between fruits and frugivores, C. septentrionalis may also rely on mammals for seed dispersal in certain regions. We aimed to explore the fruit consumption habits of animals other than birds. Motion sensor-equipped cameras were used to observe interactions with the fruits of C. septentrionalis and assess the viability of seeds post-consumption. The observations revealed three animal species consuming the fruits, with the masked palm civet Paguma larvata (Viverridae, Carnivora) identified as a dominant consumer in the investigated population. Microscopy analysis of seeds retrieved from P. larvata faeces indicated that the seeds remained intact and viable after passing through the digestive system of this carnivorous mammal. The above discovery suggests a potential role for carnivorous mammals in seed dispersal of C. septentrionalis, alongside birds, thus broadening our understanding of the complex seed dispersal strategies employed by orchids.

Multi-Gene Phylogenetic Analyses Reveals Heteroxylaria Gen. Nov. and New Contributions to Xylariaceae (Ascomycota) from China.

An in-depth study of the phylogenetic relationships of Xylaria species associated with nutshells of fruits and seeds within the genus Xylaria and related genera of Xylaceaecea was conducted in China. The multi-gene phylogenetic analyses were carried out based on ITS, RPB2, and TUB sequences of 100 species of 16 known genera in Xylariaceae around the world. Based on molecular phylogenetic analyses, morphological observations, and ecological habitats, a new genus, Heteroxylaria, is established to accommodate four new species, viz. H. cordiicola, H. juglandicola, H. meliicola, and H. terminaliicola, and four new combinations, viz. H. oxyacanthae, H. palmicola, H. reevesiae, and H. rohrensis. The genus is characterized by cylindrical stromata with conspicuous to inconspicuous perithecial mounds, surface black, having brown to dark brown ascospores with a germ slit, and it grows on nutshell of fruits. The combined ITS+RPB2+TUB sequence dataset of representative taxa in the Xylariaceae demonstrate that Heteroxylaria is grouped with Hypocreodendron but forms a monophyletic lineage. All novelties described herein are morphologically illustrated and compared to similar species and phylogeny is investigated to establish new genera and species.

Integrative taxonomy and biogeography of the genus Oxytrechus (Coleoptera: Carabidae: Trechini) in the tropical alpine ecosystem of Ecuadorian Andes, with the description of six new species

Summary This study presents a taxonomic revision of the species of the ground beetle genus Oxytrechus Jeannel, 1927 that inhabit the superpáramo of the Andes of Ecuador, which constitutes the uppermost zone of the tropical alpine ecosystem, above 4200 m. Sixteen species, displayed in three clades, were recorded in this environment, six of which are described as new: Oxytrechus antisanae n. sp. (Mt Antisana), O. giachinoi n. sp. (Mt Illiniza), O. hamatus n. sp. (Mt Atacazo and Pichincha), O. prunai n. sp. (Mt Guamaní), O. reflexus n. sp. (Mt Illiniza and Mt Corazón), and O. robbiolai n. sp. (Mt Pichincha). New distributional data are presented for O. chioriae Quéinnec & Ollivier, 2019, O. lallemandi Jeannel, 1927, O. moreti Mateu, 1988 and O. zoiai Casale & Sciaky, 1985. The first molecular phylogeny of the group, based on fragments of four mitochondrial and two nuclear genes, is given. Dichotomous identification keys are provided to the species groups and the included species. Based on systematic sampling, Oxytrechus exhibits the highest degree of microendemism among páramo ground beetles. No species has been found in more than two sky islands, and half of the species recorded in the superpáramo are single-mountain endemics. As regards their conservation status, eight species (two thirds) can be classified as vulnerable or endangered, due to a mix of low abundance, narrow distribution range, microendemism, limited ecological tolerance, habitat destruction and effects of climate change.

Can ecological zoning act as an environmental management tool for protecting regional habitat quality: Causal evidence from the national key ecological function zone in China

Habitat degradation is one of the most serious environmental problems worldwide, which threatens human wellbeing and sustainable development. Exploring how to protect natural habitats has become a research hotspot in the environmental management field. Ecological zoning has been widely used in habitat protection, but its actual effectiveness has been rarely revealed, especially with the robust and reliable causal inference method. Therefore, taking the Yangtze River Economic Belt (YREB) in China as the study area, we first quantified habitat quality and changes at the district/county scale during 2005–2019. Then, we used the National Key Ecological Function Zone (NKEFZ) as a representative ecological zone scheme, and explored the effectiveness of the NKEFZ in protecting habitat quality with the Propensity Score Matching and Difference-in-Difference combined method, which is a representative causal inference method. We found that habitat quality showed an uneven distribution during the study period, and habitat quality of districts/counties within the NKEFZ was higher than that outside the NKEFZ with statistical significance. Most districts/counties experienced a habitat quality decrease, but the decrease within the NKEFZ is less than that outside the NKEFZ. We observed that the NKEFZ can protect habitat quality from the causal relationship perspective, but there was the spatio-temporal heterogeneity of the NKEFZ effectiveness. In terms of the spatial dimension, the NKEFZ was the most effective in the Lower Reach of the YREB. In terms of the temporal dimension, there was a 1-year time-lag effect of the NKEFZ effectiveness, and NKEFZ effectiveness experienced a sharp increase from 2016. The NKEFZ contributed to protecting habitat quality through multiple management strategies such as urban land quota, high pollution industry prohibition, and ecological compensation. Overall, this study verified that the ecological zone scheme can contribute to habitat quality protection, and emphasizes that the effectiveness of ecological zoning may vary across time and space. This work can support ecological zoning implementation with robust evidence, and provides a novel perspective for understanding the effectiveness of ecological zoning.

Fine spatial scale assessment of structure and configuration of vegetation cover for northern bobwhites in grazed pastures

BackgroundMonitoring forage in livestock operations is critical to sustainable rangeland management of soil and ecological processes that provide both livestock and wildlife habitat. Traditional ground-based sampling methods have been widely used and provide valuable information; however, they are time-consuming, labor-intensive, and limited in their ability to capture larger extents of the spatial and temporal dynamics of rangeland ecosystems. Drones provide a solution to collect data to larger extents than field-based methods and with higher-resolution than traditional remote sensing platforms. Our objectives were to (1) assess the accuracy of vegetation cover height in grasses using drones, (2) quantify the spatial distribution of vegetation cover height in grazed and non-grazed pastures during the dormant (fall–winter) and growing seasons (spring–summer), and (3) evaluate the spatial distribution of vegetation cover height as a proxy for northern bobwhite (Colinus virginianus) habitat in South Texas. We achieved this by very fine scale drone-derived imagery and using class level landscape metrics to assess vegetation cover height configuration.ResultsEstimated heights from drone imagery had a significant relationship with the field height measurements in September (r2 = 0.83; growing season) and February (r2 = 0.77; dormant season). Growing season pasture maintained residual landscape habitat configuration adequate for bobwhites throughout the fall and winter of 2022–2023 following grazing. Dormant season pasture had an increase in bare ground cover, and a shift from many large patches of tall herbaceous cover (40–120 cm) to few large patches of low herbaceous cover (5–30 cm) (p < 0.05).ConclusionsDrones provided high-resolution imagery that allowed us to assess the spatial and temporal changes of vertical herbaceous vegetation structure in a semi-arid rangeland subject to grazing. This study shows how drone imagery can be beneficial for wildlife conservation and management by providing insights into changes in fine-scale vegetation spatial and temporal heterogeneity from livestock grazing.

Alterations in Suitable Cultivation Area for Scutellaria baicalensis under Future Climatic Scenarios in China: Geodetector-Based Prediction

The dried roots of Scutellaria baicalensis (S. baicalensis) have been widely used as a traditional medicine. Recently, climate change and human activities have caused the degeneration of its wildlife habitat. However, there is rare knowledge on the effect and interactive effect of different variables on the spatial heterogeneity of S. baicalensis and how the pattern of suitable cultivation area in China would shift in response to climate change. Based on the Geodetector and Habitat Suitability Index (HSI) method, we proposed an assessment model to identify the critical environmental variable(s) affecting the distribution of suitable cultivation area for S. baicalensis in China and to project its shift under climate change. The results showed that soil and mean annual temperature are two determining variables in its spatial heterogeneity in China. Compared to 1981–2010, future climate change may result in a decrease in its suitable area, and yet may result in an increase in the extremely suitable area (about 1.00–1.35 million km2). S. baicalensis in the southern and northwestern part of its current distribution and the southwestern part and small area of northern China may experience expansion during the 21st century, while S. baicalensis in southern China, the Huang-Huai-Hai plain, and the midwest of northwestern China may experience contractions. Meanwhile, climate warming is expected to shift its distribution northwest through an expansion at the northern (at least 84 km) and western (at least 62 km) boundary and contraction at the southern (at least 529 km) boundary, respectively. These results could provide valuable information to policy-makers for the conservation and scientific introduction of S. baicalensis.

Cold-water octocoral interactions with microplastics under laboratory conditions

Microplastic pollution is ubiquitous in the oceans, threatening the health of marine ecosystems. The deep sea is recognized as a sink for microplastics, but there is a paucity of information on how deep-sea organisms are being affected by this stressor. Considering their vulnerability to disturbance, this information is crucial to fully understand the need for conservation actions. Here, we develop a novel methodology to provide a detailed characterisation of the behavioural responses of the cold-water octocoral Viminella flagellum to microplastic exposure under laboratory conditions. Coral fragments were individually exposed to a concentration of 1500 items/L of fluorescent green polyethylene microspheres biofouled for three weeks, for a period of 24 h, and carefully monitored for the entire exposure period using high resolution time-lapse video. After exposure, each fragment was transferred to another tank, free of microplastics, and monitored for further 24 h. The coral fragments were dissected at the end of the experimental period to assess the number of microplastics that remained in the digestive tract of each polyp. Our results showed that during this short-term exposure period, V. flagellum was ingesting microspheres, but most importantly it demonstrated the capacity of egesting all particles within 24 h. These results are especially important when quantifying microplastic contamination in cold-water corals in their natural habitat, as only recently ingested microplastics may be detected, leading to potential underestimations of their exposure. Additionally, our results indicated that microplastics adhered to the coral tissue surface could be discarded through periodic shedding of the mucus. These observations suggest that cold-water octocorals can handle microplastics as they do with other foreign particles, although the cleaning mechanisms may require significant energy expenditures.

Genomic diversity and population structure of Carniolan honey bee in its native habitat

BackgroundResearch into the genetic diversity of honey bee (Apis melliferaL.) populations has become increasingly significant in recent decades, primarily due to population declines attributed to human activities and climate change. As a species of great importance, breeding programs that leverage understanding of genomic diversity could offer solutions to mitigate these challenges. The objective of this study was to examine the genomic diversity and population structure of Carniolan honey bees (Apis mellifera carnica) using the Illumina SNP chip on a large honey bee sample collected from Central and South-Eastern European countries. The study also aims to offer recommendations for future breeding programs.ResultsOur analysis involved Discriminant Analysis of Principal Components (DAPC), heterozygosity, admixture analysis, fixation indices (FST), Neighbour-Joining tree, gene flow and Isolation-by-distance analysis. DAPC indicated distinct separation between the Carniolan and Italian honey bee (Apis mellifera ligustica) populations, whereas the admixture analysis revealed varying levels of gene flow and genetic admixture within the Carniolan honey bee populations, demonstrating closer relationships between specific geographic regions (confirmed by Isolation-by-distance analysis). Furthermore, the research of heterozygosity, genomic inbreeding, pairwise FST values, and Neighbour-Joining tree provided insights into the patterns of genetic differentiation and similarity among the populations of Carniolan honey bee within its natural habitat. We have observed genetic homogeneity of the Carniolan honey bee population when considered in a broader genetic/geographical context. However, the Carniolan honey bee has sufficient genetic diversity in its geographical home range that needs to be carefully monitored and maintained.ConclusionsThis study provides important insights into the genetic composition, differentiation, and relationships among Carniolan honey bee populations in Central and South-Eastern European countries. The findings are crucial for conservation efforts, breeding programs, and sustainable beekeeping practices. They emphasise the importance of considering genetic factors and population structure in the breeding and management of honey bees. By understanding these genetic relationships, we can develop strategies to preserve genetic diversity, improve breeding outcomes, and ensure the resilience of honey bee populations in the face of environmental changes and challenges. This knowledge can also inform policy makers and stakeholders on best practices to maintain healthy bee populations, which are vital for ecosystem services and agricultural productivity.

Ecological restoration amplifies riverine fish catch of Gudusia chapra (Hamilton, 1822): an impact study in the river Ganga using multivariate statistical tools and water quality indices.

Fish residing in the aquatic ecosystem are considered the best ecological indicator for monitoring environmental habitat. To evaluate the changes that occurred due to relative restoration in the ecological habitat, a study was conducted in the freshwater zone of the river Ganga between Buxar, Bihar, and Ballia, Uttar Pradesh, between July 2021 and July 2022. In the monitoring, the physico-chemical condition, as well as the food and feeding habits of the fish Gudusia chapra, were monitored with the help of various pollution evaluating indices, namely, the algal pollution index (API) for planktons, the comprehensive pollution index (CPI-WQI), and the National Sanitation Foundation Water Quality Indices (NSF-WQI) for water. The study showed that the relative restoration facilitated the amplification of the fish catch from 5.60 to 98.98% in two consecutive years. The reduction in the API (15 to 4) as well as CPI (0.80 to 0.72) during both years signified the reduction of the pollution status of the river in the region. The NSF-WQI also decreased from 88.27 to 79.27 from 2021 to 2022. The electivity index for the fish showed that fish preferred the groups Cyanobacteria, Rotifera, and Copepoda. The multivariate, as well as univariate analyses, revealed that the fish G. chapra is significantly influenced by multiple abiotic as well as biotic variables, among which the major contributors are riverine velocity, transparency, conductivity, pH, dissolved oxygen, total alkalinity, carbonate, bicarbonate, salinity, total hardness, calcium, silicate, and biochemical oxygen demand.

Stream Restoration Effects on Habitat and Abundance of Native Cutthroat Trout

ABSTRACTRestoration practitioners spend more than $1 billion each year restoring US rivers and streams but commit comparatively few resources to evaluating project effectiveness. Meanwhile, monitoring and disseminating the outcomes of restoration projects remains our best opportunity to learn from past successes and failures and to, ultimately, improve the cost effectiveness of restoration. We monitored the physical and biological outcomes of a stream restoration project in the Rocky Mountains, the goals of which were to improve habitat for and productivity of native Colorado River Cutthroat Trout (CRCT) and the scope of which included three contiguous reaches under different restoration treatments. Moreover, we evaluated the efficacy of the restoration project relative to its stated goals and objectives. To test for restoration effects on physical and biological indicators we coupled a before‐after, control‐impact (BACI) study design with (generalized) linear mixed models. Over the course of 7 years, we detected restoration‐related increases in floodplain connectivity, streambank stability, and riparian shrub cover, as well as decreases in summer stream temperature. Despite measured improvements in native trout habitat, we detected no evidence of a restoration effect on density or biomass of age‐1 and older CRCT. Although our study was somewhat limited in scope, our findings contribute toward a relatively small body of work on monitoring and effectiveness of river restoration.

Spring migration strategies of Anas platyrhynchos (Mallard) necessitate individual time-energy trade-offs despite wintering origins or migratory destinations

Abstract Spring migration is hypothesized to be time-constrained because of competition for optimal nesting and brood-rearing sites. Therefore, individuals are predicted to minimize migration time to breeding destinations; however, migration strategies likely lie on a continuum based on wintering and stopover habitat quality, environmental conditions, or individual-level factors. In other words, individuals and wintering subpopulations may differentially prioritize time-energy trade-offs during migration depending on where they are from, when they leave, and where they are going. We tested these hypotheses by characterizing spatial and temporal variation in spring migration strategies in female Anas platyrhynchos (Mallards), using global positioning system (GPS) data from ~150 individuals captured across the Mississippi Alluvial Valley and Gulf Coast Chenier Plain, USA. We used principal components analysis to classify a series of migratory behaviors into distinct time- and energy-minimization migration strategies, and tested whether migration strategies were related to wintering origins (habitat quality or latitudinal differences influencing migration initiation), migratory destinations (resource predictability), and individual-level factors (age and body condition). Additionally, we estimated individual and wintering subpopulation space-use to identify geographic regions of high and overlapping use that may facilitate time- or energy-minimizing migration strategies. Our results indicated a gradient of time-minimization migration strategies but migration strategy was not influenced by wintering origins nor migratory destination. Instead, time-energy trade-offs manifested at the individual level with time-minimization depending on experience and body condition. We also revealed stopovers and migration corridors of continental importance for spring-migrating A. platyrhynchos and space-use therein suggested migration strategies varied spatially with increasing time-minimization behavior as A. platyrhynchos neared their breeding grounds. Future research should link migration strategies and settling patterns to demographic rates.

TRÁFICO ILICITO DE ANIMAIS SILVESTRES

Animal trafficking has been gaining momentum in Brazil and, as a result of this crime, it has become one of the main causes of threats to animals, endangered species and biodiversity. The illegal trade in these animals is the third largest trafficking, behind only arms and drug trafficking, with exorbitant numbers of animals exploited, with approximately 38 million animals being removed from Brazil each year. It is estimated that for every 10 animals stolen from their natural habitat, 9 do not survive due to the precarious conditions they are subjected to during transportation, which is one of the main reasons for the threat to biodiversity. Since this is a crime that produces several negative effects and occurs mostly to satisfy human desires, stricter laws need to be regulated to reduce this crime, considering that in addition to the low routine imposed, sometimes the penalty is not properly applied, leaving the crime unpunished so that the act continues and more animals become victims of this situation. The topic of animal trafficking involves several fields, going beyond the possible loss of biodiversity, such as violation of animal welfare, ecology, law, biology, public health, mistreatment, ethics, among others, thus offering a possible opportunity for comprehensive and multidisciplinary research, enriching academic knowledge and bringing more visibility to the subject. The study of this topic contributes to the understanding and awareness about environmental protection, in addition to affecting not only ecosystems, but also social, economic and public health consequences. In view of the facts mentioned, investigating this problem can help identify solutions to mitigate its negative impacts on society.

Geographic location shapes fungal communities associated with Epidendrum roots

Fungal biodiversity significantly influences ecosystem dynamics through various interactions with plants, ranging from pathogenic to mutually beneficial associations. This study explores the fungal diversity associated with an ornamental orchid genus Epidendrum that is widely propagated globally but native to northern South America. Root samples were collected from Epidendrum in diverse geographic locations: Brazil, Colombia, Germany, Spain and six South African provinces. Fungal biodiversity was catalogued from the genomic DNA extracted from these roots using fungal-specific primers and Illumina MiSeq sequencing. Bioinformatic and statistical analyses revealed significant fungal diversity in the roots, with distinct dominant orders in each geographic region. Among the South African samples, significant differences were found in alpha diversity indices and species richness. Even though samples originating from different provinces overlapped in the PCoA plot, PERMANOVA indicated a significant difference in the fungal biodiversity, which was further supported by PERMDISP. In the global dataset, alpha diversity indices were insignificant, but species richness was. In the PCoA plot, data points clustered by sampling sites, indicating substantial differences in fungal biodiversity between the samples. This was validated by PERMANOVA and PERMDISP analyses. Outcomes from the core fungal analyses showed Epidendrum retained a conserved set of fungal orders from its native habitat when it transitioned to exotic regions, while it also formed new associations with local fungal communities in these introduced regions. These findings highlight the role of both core and region-specific fungal communities in the ecological adaptability and success of this widely planted orchid genus.

Timing mowing for maximal energy gain - Managing foraging habitat of wintering geese under extreme drought conditions

The availability of high-quality food resources is a critical determinant of wildlife fitness. Over the past two decades, phenological mismatch - the temporal misalignment between animals’ peak nutrient demand and optimal resource availability - has emerged as a significant conservation challenge. This issue is particularly worrisome for migratory birds, which must accumulate energy reserves to meet the elevated metabolic demands of migration between breeding and wintering grounds. In Poyang Lake, a crucial wintering ground along the East Asian-Australasian flyway, increasing asynchrony between vegetation growth and the migration of herbivorous waterbirds significantly impedes conservation efforts and presents a major management challenge for this Ramsar wetland. This study evaluates the efficacy of mowing, a grassland management measure, in regulating plant growth processes and restoring food resources for geese. In-situ mowing experiments were conducted with varying timings in Carex wet meadows, the primary foraging habitats of geese. Optimal mowing times were identified, and the maximum goose carrying capacity was assessed by comparing Carex growth and nutritional dynamics with goose dietary requirements. The results reveal that mowing effectively slows down the aging process of Carex, and protein content is identified as a critical limiting factor for geese foraging. Different mowing timings extend the suitable foraging period by 11–25 days. Estimates suggest varying carrying capacities with different mowing timings, supporting goose populations ranging from 133 to 2,046 in Changhuchi Lake during wintering. The optimal mowing window is early October, avoiding dates before late September and after late November. Moreover, multiple-stage mowing is recommended to accommodate different wintering stages. The study highlights mowing as a potential habitat restoration approach for goose conservation, effectively mitigating the challenges imposed by phenological mismatch directly and indirectly caused by anthropogenic activities.

Assessment of the Efficiency of Problematic Animal Interventions in Mitigating Human-Wildlife Conflicts in Uganda: A Case Study of Lake Mburo National Park

Human-wildlife conflict is a significant challenge in Uganda, particularly in areas where human populations and wildlife habitats overlap. This study examines the efficiency of various interventions aimed at mitigating human wildlife conflicts in and around Lake Mburo National Park, a region renowned for its rich biodiversity and diverse ecosystems. Lake Mburo National Park is surrounded by agricultural and pastoralist communities that frequently experience crop raiding, livestock predation, and threats to human safety from wildlife. Various interventions, including physical barriers, deterrents, translocation of problematic animals, and community engagement initiatives, have been implemented to address these conflicts. This study employs a mixed-methods approach, incorporating both quantitative and qualitative data collection methods, including field observations, community surveys, and analysis of intervention outcomes. A total of 125 households were interviewed across several parishes of Rurambira, Rwamuhuku, Rwabarata, Kizimbi, Kashojwa and Rwetango in Kiruhura and Isingiro districts. The findings indicate that the majority of respondents have lived in the area for over 20 years, providing them with extensive knowledge of local wildlife interactions. The results highlight that hippos (76%) are the most problematic animals, primarily causing crop damage, which significantly impacts local livelihoods. The study reveals that guarding property (98%), though stressful and time-consuming, is the most effective and commonly used intervention. Other measures, such as strong shelters, trapping, translocation, and various deterrents, show varying degrees of effectiveness depending on the species involved. The study concludes that understanding the species-specific and context-specific effectiveness of these interventions is crucial for developing sustainable strategies to mitigate HWC. The insights gained from this research can inform future conflict mitigation strategies and contribute to the broader discourse on human-wildlife coexistence in Uganda and similar settings worldwide

Composition and temporal dynamics of the phytoplankton community in Laizhou Bay revealed by microscopic observation and rbcL gene sequencing

Laizhou Bay, a major breeding ground for economic marine organisms in the northern waters of China, is facing rapid environmental degradation. In this study, field surveys in this area were conducted in the spring, summer, and autumn of 2020. Microscopic observation and RuBisCO large subunit (rbcL) gene analysis were employed to understand the community structure and temporal dynamics of phytoplankton. The phytoplankton community structures detected by the two methods showed significant differences. Microscopic observation revealed the dominance of dinoflagellates in spring that shifted to the dominance of diatoms in summer and autumn. However, rbcL gene sequencing consistently identified diatoms as dominant throughout all three seasons, with their relative abundance showing an increasing trend. Conversely, the relative abundance of the second- and third-most abundant taxa, namely, haptophytes and ochrophytes, decreased as the seasons transitioned. rbcL gene sequencing annotated more species than microscopy. It could detect haptophytes and cryptophytes, which were overlooked by microscopy. In addition, rbcL gene sequencing detected a remarkable amount of Thalassiosira profunda, which was previously unidentified in this sea area. However, it appeared to underestimate the contribution of dinoflagellates considerably, with most taxa being only identified through microscopic identification. The two methods jointly identified 28 harmful algal bloom taxa with similar detection quantities but substantial differences in species composition. Phytoplankton communities were influenced by temperature, salinity, and nutrients. The results of this work suggest that a combination of multiple techniques is necessary for a comprehensive understanding of phytoplankton.

Anas platyrhynchos (Mallard) has been replacing Anas rubripes (American Black Duck) in human-altered landscapes in Ontario, 1996 to 2019

Abstract Anas rubripes (American Black Duck) has received much attention over the years as a popular game bird species that experienced historical declines on its wintering grounds. Declines may be due to changes in the quality and quantity of breeding habitat, competition with A. platyrhynchos (Mallard), or both. Although the A. rubripes population has stabilized, spatial variation in regional population trends of A. rubripes on their breeding grounds can provide insight into the relative importance of these alternative hypotheses at provincial and local scales. We analyzed indicated breeding pairs count data collected in Ontario between 1996 and 2019 through the Eastern Waterfowl Survey to evaluate the correlation in breeding densities and trends of the 5 most abundant waterfowl species. We also tested whether habitat and anthropogenic disturbance variables could explain the distribution of those species. Overall, A. platyrhynchos breeding pair densities increased across the survey area, whereas A. rubripes breeding pair densities decreased in the southern and northern part of the survey area but remained stable in the central part. Densities of breeding pairs of A. rubripes and A. platyrhynchos were negatively correlated across survey plots but the trends in breeding densities were not correlated. Densities of A. platyrhynchos breeding pairs increased in human altered landscapes, whereas the density of A. rubripes breeding pairs was negatively correlated with agriculture. Our results suggest that A. platyrhynchos did not competitively exclude A. rubripes on the breeding grounds, but instead, A. rubripes were replaced by A. platyrhynchos following encroachment of agriculture into A. rubripes breeding habitat. Habitat management plans focused on breeding A. rubripes should emphasize reduction in the expansion of anthropogenic perturbations and increases in habitat conservation efforts in the central area of the breeding range in Ontario.

Assessing the Impact of Sustainable Agriculture Practices on Biodiversity Conservation

An important component in attaining environmental resilience and sustainability is the effect of sustainable agricultural practices on biodiversity conservation. Using examples from a variety of environments, this article assesses how well alternative sustainable agriculture approaches encourage biodiversity conservation. Improving environmental health, reducing ecological footprint, and ensuring long-term productivity are all goals of sustainable agriculture. organic farming, integrated pest management, conservation tillage, and agroforestry are all examples of sustainable agricultural methods. We look at how these activities affect soil organisms, plant variety, and wildlife habitats, among other layers of biodiversity. These methods aid in the protection and improvement of biodiversity by analysing current empirical research and case studies from a variety of geographical areas. Results show that sustainable agricultural techniques can lessen environmental stresses, increase species variety, and improve habitat quality, all of which are important for biodiversity conservation. By reducing chemical inputs and providing a variety of ecological niches, systems like agroforestry and organic farming are able to support a wide variety of plant and animal species. Soil health is improved and habitat disruption is reduced through integrated pest control and conservation tillage, both of which contribute to an ecosystem that is more resilient.

Wildlife resilience in an urban landscape: understanding land-use impacts in Cape Town

AbstractUrbanisation is rapidly transforming and fragmenting natural habitats, disrupting ecosystems and negatively impacting biodiversity. The City of Cape Town (CoCT) is situated in a global biodiversity hotspot, but sustained anthropogenic activities have resulted in the local extirpation of most medium and large mammals. A recent survey of mammals within urban protected areas of CoCT revealed that a few, mostly medium-sized generalist species, persist. It is uncertain which native mammal species, if any, inhabit the unprotected green belts and parks in suburban and urban areas of the city. A total of 37 camera trap sites were established along four transects for a period of four months between 31 January and 31 May 2022. A total of 12 terrestrial mammal species were detected, nine of which were wild native mammals and three domestic species. Most detections were in natural habitat followed by suburban, with urban areas having the lowest detection rate of wildlife. Single season hierarchical multi-species occupancy models revealed that tree cover had a significant positive effect on both community and individual species occupancy. Contrary to our predictions, neither human population density nor the extent of the impervious surface at sites significantly affected occupancy. Cape grysbok (Raphicerus melanotis) were significantly more likely to occur at sites with a higher proportion of impervious surfaces supporting other recent research, which showed this species together with water mongoose (Atilax paludinosus) and Cape porcupine (Hystrix africaeaustralis) are one of only a few native mammals that appear to persist and may even thrive in human-modified landscapes. Our findings underscore the complexity of urban biodiversity conservation and the species-specific responses to environmental factors, emphasising the importance of tree cover in urban wildlife management.