Habitat Distribution Research Articles

Mapping the distribution of sea urchin (Echinoidea) and benthic habitat using drone in the waters of Lancang Island

Sea urchins are valuable marine creatures that live in the waters of Indonesia, and typically found in seagrass and coral reefs. This study aimed to determine the distribution of sea urchins and the benthic characteristics that serve as their habitat using high resolution drone images. Object-based image analysis (OBIA) with a support vector machine algorithm is used to identify benthic habitats, while the distribution of sea urchins is determined by thresholding pixel values. A total of 812 aerial photos with a spatial resolution of 3.98 cm/px were obtained and mapped into five classes of benthic habitat (sand, rubble, seagrass, living coral, and dead coral algae). The dominant habitat class obtained was dead coral algae, with an area of 234,035 m2 (29.63%), whereas seagrass was the smallest, with an area of 74,149 m2 (9.39%). The overall accuracy of the benthic classes was 65.44%, with kappa coefficient value of 0.57. The study found that the total number of sea urchins on Lancang Island was 61,551. The dominant distribution of sea urchins was found in the living coral class with 18,094 individuals, but the highest density was in the rubble class with 1358 individuals/ha.

Using ISSR markers to detect genetic variation for marine turtles populations in Egypt loggerhead (Caretta caretta) and green turtles (Chelonia mydas)

In Egypt, along the Mediterranean coast, the loggerhead (Caretta caretta) and green (Chelonia mydas) come during nesting season to lay their eggs or for food with a rare occurrence for the leatherback turtle (Dermochelys coriacea). In the Egyptian Red Sea there are five species that come to visit, the most common to observe are hawksbill (Eretmochelys imbricata) and green (Chelonia mydas). The goal of this study is to conduct some genetic and ecological analyses a) to generate new markers that include other segments of marine turtles’ genome, as a tool to investigate new areas of variation/polymorphism between, among, and within populations and individuals; b) determine genetic diversity between and within the Mediterranean and the Red Sea populations using (individuals from the same and different habitats using ISSR); and c) determine allele frequency. At the ecological level, this study aims to assess sea turtles' habitat and population distribution among different habitats in Egypt. Throughout the duration of this study, it was noted that there was a decrease in nesting areas attributable to the loss and fragmentation of habitats. Although there are some areas with no significant nesting prosperities it considered significant areas for foraging and highly important as migratory corridors, especially in the Mediterranean. The massive urbanization and unplanned touristic developments affect sea turtle habitat over the Egyptian Mediterranean coast. The Mediterranean coast showed demographic changes in the coastal regions. On the other hand, areas could still be valued with significant nesting areas for sea turtles, but an intense and regular monitoring programme should be established. The Red Sea needs a regular monitoring programme for better management conservation measures to be adopted. The polymorphism percentage resulting from ISSR marker was 45 and 36 for both loggerhead and green turtle populations in the Mediterranean, respectively; and 69 for the green turtle populations in the Red Sea.

A alta biodiversidade de organismos bentônicos em um ecossistema costeiro revelada por uma abordagem integrativa

Abstract Increasing habitat modification and species loss demand consistent efforts to describe and understand biodiversity patterns. The BIOTA/FAPESP Program was created in this context and it has been a successful initiative to promote studies on biodiversity and conservation in Brazil. The BIOTA/Araçá is an interdisciplinary project that provided a detailed evaluation of the biodiversity of Araçá Bay, a coastal seascape located on the North coast of the state of São Paulo, Southeast Brazil. The bay encompasses multiple habitats, such as beaches, mangroves, rocky shores, and a tidal flat, and provides important ecosystem services. Unfortunately, the bay is the subject of complex social-environmental conflicts that oppose economic, social, and environmental demands (i.e., the expansion of neighboring harbor activities vs. small-scale artisanal fisheries and protection of biodiversity). The present study presents a survey of the benthic species occurring in the different habitats of Araçá Bay, including data obtained during the BIOTA/Araçá project and previous assessments of the area. The benthic species play an important role in marine environments and studying the diversity of these organisms that live associated with the bottom is indispensable for comprehending the environment’s functioning. The macrofauna, meiofauna, and microorganisms associated with soft and hard bottom were listed, and additional information, such as the habitat and geographical distribution, were provided for each species. The checklist includes 826 species, almost 70% recorded during the BIOTA/Araçá project. The most speciose taxa were the annelids (225 spp.), mollusks (194 spp.), and crustaceans (177 spp.). Seven benthic species are endemic to Araçá Bay, 14 are considered threatened, and seven are economically exploited. Furthermore, the bay is the type locality of many taxa, and 11 new benthic species were described based on specimens sampled during the project. This project shows the importance of Araçá Bay as a unique biologically rich environment and highlights the need for conservation efforts in light of the current threats.

The ecological suitability area of Cirsium lineare (Thunb.) Sch.-Bip. under future climate change in China based on MaxEnt modeling.

Many kinds of medicinal ingredients occur in Cirsium lineare that have good clinical efficacy, conferring on this species its high medicinal development value. However, with a rapidly changing global climate, it is increasingly imperative to study the factors affecting the habitat distribution and survival of species. We predicted the current and future distribution areas of suitable habitats for C. lineare, analyzed the importance of environmental variables in influencing habitat shifts, and described the alterations to suitable habitats of C. lineare in different periods (modern, 2050s, and 2070s) and scenarios (RCP2.6, RCP4.5, and RCP8.5). The results show that, under the current climate, the total suitable area of C. lineare is about 2,220,900 km2, of which the highly suitable portion amounts to ca. 292,600 km2. The minimum temperature of the coldest month, annual precipitation, and mean daily temperature range are the chief environmental variables affecting the distribution of habitat for C. lineare. In the same period, with rising greenhouse gas emission concentrations, the total suitable area will increase. In general, under future climate change, the suitable habitat for C. lineare will gradually migrate to the west and north, and its total suitable area will also expand. The results of this experiment can be used for the conservation and management of the wild resources of C. lineare. We can choose suitable growth areas to protect the medicinal resources of C. lineare through insitu conservation and artificial breeding.

Prediction of suitable habitat distribution and potential impact of climate change on distribution patterns of <i>Cupressus gigantea</i>

Prediction of suitable habitat distribution and potential impact of climate change on distribution patterns of <i>Cupressus gigantea</i>

Predicted Climate Change Impacts on Distribution and Habitat Structure of Forest Ungulates in Southwest China

Climate change will impact the distribution of species and their preferred habitat, thereby influencing the ecological processes intrinsic to these species. To investigate these phenomena, we analyzed the habitat distribution, structure, and connectivity of 6 forest ungulate species in Southwest China under current and future climate scenarios. Habitat projections indicate that forest ungulates will migrate to the southwest at higher elevations and the northwest at higher latitudes and elevations in the study area under climate change. The extent to which climate change affects the 6 forest ungulates is quite different. By 2050, there will still be a certain range of habitats for migration in the study area, but the habitat quality of species will have decreased to varying degrees after migration. By 2070, most forest ungulates will begin to experience significant habitat loss and habitat quality decline. The migration of species habitat also leads to a change in species habitat structure. Habitat landscape quality declines for most forest ungulate species. The loss of patches at the junction habitat has a huge impact on species habitat connectivity. The number and distance of corridors between the marginal habitat patches and the core habitat patches increase to a certain extent. To better achieve biodiversity conservation, we should strengthen the restoration and connectivity management of fragmented habitats to protect and restore the current habitats of species. Examples include the management of specific key areas and the establishment of large-scale integrated protected areas such as the Giant Panda National Park.

SSPs 기후변화 시나리오에 따른 서양금혼초(Hypochaeris radicata)의 개화 생물계절 및 적합 서식지 분포 예측

SSPs 기후변화 시나리오에 따른 서양금혼초(Hypochaeris radicata)의 개화 생물계절 및 적합 서식지 분포 예측

Мустеліди (Mustelidae) заповідних і антропогенних екосистем Придінцівської заплави

A summary of V. Sulyk’s original data based on the publication of 1979 (with corrections) and extracts from the Chronicle of Nature of the Luhansk Nature Reserve (LNR) for 1975–1981, when V. Sulyk was a researcher in the reserve and carried out fauna censuses in the Stanychno-Luhanske department, also known as the Prydintsivska floodplain. Information on the species composition and habitat distribution of mustelids, data on marten diet in anthropogenic conditions, as well as a selection of V. Sulyk’s records of observations of these carnivores in nature based on the researcher’s records submitted to the Chronicle of Nature of the LNR are given. In total, data on eight species of this family are presented.

Coastal vulnerability assessment for southeast coast of India using Coastal Hazard Wheel

Rapid urbanization coupled with climate change increases the vulnerability of coastal areas to different types of hazards. To understand and assess the vulnerability of the coastal environments, a published methodology Coastal Hazard Wheel (CHW) was adopted for the coastal taluks of Tamil Nadu. This methodology provides information on vulnerability of the coast by five major hazards. They are: Ecosystem Disruption, Gradual Inundation, Saltwater intrusion, Coastal Erosion and Flooding. The vulnerability assessment is carried out based on the datasets namely geomorphology, wave exposure, tidal range, flora/fauna, sediment balance and climate. The coastal regions of Tamil Nadu are evaluated based on the vulnerability severity levels of the hazards. The assessment depicts that 46% of the Tamil Nadu coastline is highly vulnerable to flooding, making flooding the most prevalent coastal hazard. About 10% of the coastal areas have very high vulnerability to saltwater intrusion, 43% of the coastal areas have high vulnerability to erosion, 54% of the coastal areas have high vulnerability to gradual inundation and 58% of the coastal areas are moderately vulnerable to ecosystem disruption. These appraisals are useful to support management decisions at local, regional and national level for the coastal management, mitigation and adaptation in response to climate and sea level change. Four types of ecosystems are based on their habitat type and distribution. They are marine, estuarine, coastal interface and coastal freshwater. The habitats on these ecosystems vary depending on their adaptability. These ecosystems also provide protection to coasts from the effects of climate change. They act as a basin during flooding from high rainfall and storm surges. Carbon sequestered within oceans is called blue carbon. Mangroves and salt marshes act as a reservoir of this carbon. Only 2% of the earth surface is covered by these ecosystems but stores ten times more carbon per unit area than other ecosystems. Non climatic pressure on ecosystems also increases rapidly due to rapid urbanization, industrial and agricultural outlets.

Studi Populasi dan Distribusi Palahlar (Dipterocarpus hasseltii Blume) di Resort Gunung Salak I, Taman Nasional Gunung Halimun Salak

Gunung Halimun Salak National Park (GHSNP) is a conservation area that a habitat for rare and protected flora and fauna. Palahlar (Dipterocarpus hasseltii Blume) is a rare plant species found in the GHSNP area with an endangered species and had declining population trend. This study aimed to analyze habitat conditions, population and distribution patterns of D. hasseltii at Gunung Salak I Resort of GHSNP. Data were collected by purposive sampling method based on the presence of D. hasseltii. Vegetation analysis used the grid-lined method of 5 lanes measuring @ 100 m × 20 m, so that the total area of the observation plots was 1 ha. The observation plots were dominated by puspa (Schima wallichii), which had the highest Importance Value Index (IVI) at the seedlings (26,80%), saplings (24,04%), and trees (53,86%). The regeneration rate of D. hasseltii, showed an abnormal condition, because the number of seedlings was less than the number of saplings. A total of 28 individuals of D. hasseltii were found at the observation plots consisted of 4 individual seedlings, 15 individual saplings, 3 individual poles, and 6 individual trees. The results showed that the distribution pattern of D. hasseltii was clustered.
 Keywords: Dipterocarpus hasseltii, endangered species, Gunung Halimun Salak National Park, palahlar

Identifying potential habitats of Himalayan Red Panda Ailurus fulgens (Cuvier, 1825) (Mammalia: Carnivora: Ailuridae) in Neora Valley National Park, West Bengal, India

The Himalayan Red Panda Ailurus fulgens (Cuvier, 1825) is a globally Endangered species whose population is reported to be declining in the wild. It is a priority species for the Neora Valley National Park (NVNP) since it is the flagship species of this ecosystem. Moreover, this landscape functions as an important connecting link of the Himalayan Red Panda habitat between the state of West Bengal and Sikkim. The spatial habitat of the Himalayan Red Panda in this National Park is little known. Our study attempts to identify the spatial distribution of potential habitats for the Himalayan Red Panda using the maximum entropy algorithm (MaxEnt 3.4.1). The model predicted a 55 km2 of potential habitat with the current climate scenario. With climate change, predicted potential habitats are likely to experience significant loss and upward shift to a relatively higher elevation. Hence, the management of the NVNP should identify the potential habitats and accomplish realistic goals to help conserve the Red Pandas.­­

Appraisal of the potential habitat distribution of Madhuca longifolia manifested remarkable resilience under various socio-climatic scenarios pan-India

Appraisal of the potential habitat distribution of Madhuca longifolia manifested remarkable resilience under various socio-climatic scenarios pan-India

Climate-related habitat variations of Humboldt squid in the eastern equatorial Pacific Ocean

An integrated habitat suitability index (HSI) model was developed in this study for Dosidicus gigas in the eastern equatorial waters of the Pacific Ocean to explore climate-related spatial and temporal variability in the habitat distribution pattern based on three crucial environmental variables: sea surface temperature (SST), sea surface salinity (SSS) and chlorophyll-a concentration (Chl-a). Results revealed that the HSI model could accurately predict potential habitats for D. gigas. The habitat suitability varied significantly by month, with highest suitability in April and lowest in March. Besides, from December to May, the longitudinal gravity center of the fishing grounds (LONG) and the HSI overall shifted eastward and the latitudinal gravity center shifted northward then southward. In comparison to the warm ENSO phases in 2019, the cold ENSO phases in 2018 produced increased suitable habitat from December to May, leading to a significantly higher CPUE. Prospective high-quality habitats in 2018 primarily occurred in the western regions, with the exception of December, which resulted in a more westward distribution of LONG from January to May. High-quality habitats moved northward from December to February and southward from March to May 2018, compared to minor latitudinal movement in 2019. It was inferred that annual variations in squid abundance and distribution were largely affected by the SST-related habitat pattern of D. gigas in the eastern equatorial waters. Our findings suggested that D. gigas habitats clearly varied by month and year and were greatly influenced by climate-induced environmental changes.

The increasing strength of higher-order interactions may homogenize the distribution of infections in Turing patterns

The spatial pattern of epidemic is one key metric describing epidemiological spread features, beneficial to formulation of the intervention measures. Networked reaction–diffusion (RD) systems have become popular to mathematically portray such patterns due to discrete distribution of human habitat. However, most of the current research focused on diffusion along pairwise interactions. Effect of diffusion along higher-order interactions is still understood poorly. To this end, in the paper, based on one classic SIR epidemic RD model, we study its Turing instability in simplicial complexes and analyze the impact of the simplex strength on Turing patterns. It is found by theoretical analysis and simulation that the distribution of infections in patterns tends to become homogeneity with the increase of the simplex strength, i.e., infection density of most nodes concentrates near the steady state. Obviously, for a newly emerging epidemic, such homogeneous scenario is unfavorable to epidemic control. Because it may lead to the decentralized allocation of limited resources, which is not enough to contain epidemic. In contrast, heterogeneous scenario that nodes with low and high infection density prominently distribute in two sides of steady state allows to put all limited resources into the targeted treatment of nodes with high infection density. Our findings link epidemic control with higher-order interactions and may provide a new insight into intervening epidemic from higher-order networks.

Biodiversity conservation in Myanmar's coastal wetlands: Focusing on saltwater crocodile habitats and connectivity

Landscape-level conservation strategies are needed to protect the saltwater crocodile population and habitats in Myanmar. Identifying the remaining habitats and movement corridors is essential due to population decline across coastal regions and insufficient habitat coverage, even within protected areas. This study predicts the distribution of habitats and creates low-resistance corridors that facilitate movement across the landscape. Occurrence dataset encompassing a 20-year period (1999–2019) was used incorporating records gathered from the Global Biodiversity Information Facility—GBIF, crocodile counting reports from the Meinmahla Kyun wildlife sanctuary of Myanmar, and recent spotlight and camera-trap surveys. Using landscape connectivity tools, structural compositions of habitat classes were determined, and habitat patches were delineated to simulate the least-cost corridor and dispersal pathways. Two patches in Rakhine, two in Ayeyarwady and Yangon, one in Mon, and two in Tanintharyi, were identified that include 1247 km2 of core suitable habitat areas. The Ayeyarwady Delta exhibits a plethora of suitable habitats, while the Rakhine and Tanintharyi regions have higher marginal habitats that are largely unprotected. Only 12 % of the extent of occurrence of saltwater crocodiles are suitable habitats with a high potential for occupancy. Habitats are highly fragmented and four bottlenecks are identified to assist population connectivity in those fragmented patches. Despite notable challenges in ensuring connectivity to restore populations across the habitat patches, we highlighted connectivity as the foundation for establishing an ecological network of Myanmar's coastal habitats, leveraging the saltwater crocodile as an umbrella species for the region's coastal wetlands, and identifying key areas for enhanced protection.

Trophic downgrading of an adaptable carnivore in an urbanising landscape

Urbanisation critically alters wildlife habitat and resource distribution, leading to shifts in trophic dynamics. The loss of apex predators in human-transformed landscapes can result in changes in the ecological roles of the remaining mesocarnivores. Decreased top–down control together with increased bottom–up forcing through greater availability of anthropogenic foods can result in a predation paradox. Understanding these changes is important for conserving ecological function and biodiversity in rapidly urbanising systems. Here, we use stable isotope analysis to provide insight into longer term changes in trophic position, niche width and overlap of an elusive, medium-sized urban adapter, the caracal (Caracal caracal) in and around the city of Cape Town, South Africa. Using fur samples (n = 168) from individuals along a gradient of urbanisation we find that overall caracals have a broad isotopic dietary niche that reflects their large variation in resource use. When accounting for underlying environmental differences, the intensity of anthropogenic pressure, measured using the Human Footprint Index (HFI), explained variation in both food subsidy use (δ13C values) and trophic status (δ15N values). The significantly higher δ13C values (P < 0.01) and lower δ15N values (P < 0.001) of caracals in more urbanised areas suggest that predator subsidy consumption occurs via predictable, anthropogenic resource subsidies to synanthropic prey. These prey species are predominantly primary consumers, resulting in shifts in diet composition towards lower trophic levels. Further, caracals using areas with higher HFI had narrower isotope niches than those in less impacted areas, likely due to their hyperfocus on a few lower trophic level prey species. This pattern of niche contraction in urban areas is retained when accounting for caracal demographics, including sex and age. The removal of apex predators in human-transformed landscapes together with reliable resource availability, including abundant prey, may paradoxically limit the ecological influence of the remaining predators, and bring about a degree of predator trophic downgrading. The dampening of top–down control, and thus ecosystem regulation, likely points to widespread disruption of trophic dynamics in rapidly developing areas globally.

Sympatry and parapatry among rocky reef cichlids of Lake Victoria explained by female mating preferences.

Work on the Lake Victoria cichlids Pundamilia nyererei (red dorsum males, deeper water), Pundamilia pundamilia (blue males, shallower water) and related species pairs has provided insights into processes of speciation. Here, we investigate the female mating behaviour of 5 Pundamilia species and 4 of their F1 hybrids through mate choice trials and paternity testing. Complete assortative mating was observed among all sympatric species. Parapatric species with similar depth habitat distributions interbred whereas other parapatric and allopatric species showed complete assortative mating. F1 hybrids mated exclusively with species accepted by females of the parental species. The existence of complete assortative mating among some currently allopatric species suggests that pre-existing mating barriers could be sufficient to explain current patterns of co-existence, although, of course, many other factors may be involved. Regardless of the mechanism, mating preferences may influence species distribution in potentially hybridizing taxa, such as in the adaptive radiation of cichlid fish. We suggest that this at least partly explains why some species fail to establish breeding populations in locations where they are occasionally recorded. Our results support the notion that the mating preferences of potentially cross-breeding species ought to be included in coexistence theory.

Modelling Red-Crowned Parrot (Psittaciformes: Amazona viridigenalis [Cassin, 1853]) distributions in the Rio Grande Valley of Texas using elevation and vegetation indices and their derivatives.

Texas Rio Grande Valley Red-crowned Parrots (Psittaciformes: Amazona viridigenalis [Cassin, 1853]) primarily occupy vegetated urban rather than natural areas. We investigated the utility of raw vegetation indices and their derivatives as well as elevation in modelling the Red-crowned parrot's general use, nest site, and roost site habitat distributions. A feature selection algorithm was employed to create and select an ensemble of fine-scale, top-ranked MaxEnt models from optimally-sized, decorrelated subsets of four to seven of 199 potential variables. Variables were ranked post hoc by frequency of appearance and mean permutation importance in top-ranked models. Our ensemble models accurately predicted the three distributions of interest ([Formula: see text] Area Under the Curve [AUC] = 0.904-0.969). Top-ranked variables for different habitat distribution models included: (a) general use-percent cover of preferred ranges of entropy texture of Normalized Difference Vegetation Index (NDVI) values, entropy and contrast textures of NDVI, and elevation; (b) nest site-entropy textures of NDVI and Green-Blue NDVI, and percent cover of preferred range of entropy texture of NDVI values; (c) roost site-percent cover of preferred ranges of entropy texture of NDVI values, contrast texture of NDVI, and entropy texture of Green-Red Normalized Difference Index. Texas Rio Grande Valley Red-crowned Parrot presence was associated with urban areas with high heterogeneity and randomness in the distribution of vegetation and/or its characteristics (e.g., arrangement, type, structure). Maintaining existing preferred vegetation types and incorporating them into new developments should support the persistence of Red-crowned Parrots in southern Texas.

Modelling the current and future distribution potential areas of Peperomia abyssinica Miq., and Helichrysum citrispinum Steud. ex A. Rich. in Ethiopia

BackgroundThe aim of this study is to investigate how climate change influences the distribution of economically and environmentally important species of P. abyssinica and H. citrispinum in Ethiopia. The species distribution modeling intends to forecast species' ecological niche ranges and habitat suitability by employing a variety of environmental parameters as predictors, which is vital for conservation planning and restoration success. Six representative concentration pathways (RCP 2.6, 4.5, and 8.5 for the years 2050 and 2070) with the same resolution of 2.5 min that shows the emission scenarios were used for the prediction. To predict the current and future distributions of H. citrispinum and P. abyssinica 56 and 45 occurrence records from National Herbarium, Addis Ababa University, GBIF, and available literatures were used respectively.ResultsThe MaxEnt model predicted habitat suitability for H. citrispinum species with an Area Under Curve (AUC) value of 0.961 ± 0.027, and 0.809 ± 0.045 for P. abyssinica, indicating excellent discriminatory ability or accuracy under the current climate scenario. The Future distribution of suitable habitat for both H. citrispinum and P. abyssinica plant species was accurately predicted with AUC values of 0.960 ± 0.017 and 0.780 ± 0.35, respectively under future climatic scenarios. The jackknife test result indicates that environmental variables such as topographic position index (92.5%), precipitation of the driest quarter (3%) and precipitation in the coldest quarter (1.8%) are associated with the distributions of H. citrispinum, while topographic position index (36.6%), precipitation of driest quarter (21.4%), precipitation of warmest quarter (16.2%) and precipitation seasonality (13.9%) were found to be limiting environmental variables for P. abyssinica under current and future climatic conditions in Ethiopia. The prediction map and interception calculation for both present and projected (in the 2050s and again in the 2070s) climate change scenarios indicate significant habitat loss, decreased, and fragmentation under all RCPs (2.6, 4.5, and 8.5) scenarios for P. abyssinica while habitat gain, and increasing for H. citrispinum in Ethiopia.ConclusionsTopographic position index (TPI) is the most impactful predictor variable on the distribution of the two species. Consequently, potentially habitable areas (with diverse aspects and slopes) are increasing for H. citrispinum while decreasing for P. abyssinica.

Taxonomic diversity and structure of phytoplankton of the Polui River (tributary of the Ob River)

The study of the Polui River algoflora are resulted. A total of 249 taxa of species and subspecies ranks from 86 genera, 52 families and 8 divisions were identified: Cyanoprokariota, Chrysophyta, Bacillariophyta, Xanthophyta, Cryptophyta, Dinophyta, Euglenophyta, Chlorophyta. For the first time, a systematic list of algae is given, indicating the habitat, saprobicity and geographical distribution of species. The most diverse in the number of families, genera and species are the divisions Chlorophyta (41 % of the total number of taxa) and Bacillariophyta (34 %), as well as Cyanoprokariota (10 %) and Euglenophyta (9 %). Other divisions are not numerous in composition (6 %). Ten genera are leading, and 4 of them are from the Chlorophyta and Bacillariophyta divisions, 2 genera are from the Euglenophyta. Planktonic species with the presence of benthic forms, beta-mesosaprobes and cosmopolitan species predominate. Discovered cryptomonads in the modern period indicate eutrophication.