scholarly journals Use of a spatially explicit individual-based model to predict population trajectories and habitat connectivity for a reintroduced ursid

Oryx ◽  
2021 ◽  
pp. 1-10
Author(s):  
Desiree Andersen ◽  
Yoonjung Yi ◽  
Amaël Borzée ◽  
Kyungmin Kim ◽  
Kwang-Seon Moon ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Radio Telemetry ◽  
Suitable Habitat ◽  
Large Carnivores ◽  
Environmental Interactions ◽  
Dispersal Capability ◽  
The Republic ◽  
Suitable Habitats ◽  
Mixed Modelling ◽  
Population Equilibrium

Abstract Reintroductions of large carnivore species present unique opportunities to model population dynamics as populations can be monitored from the beginning of a reintroduction. However, analysis of the population dynamics of such reintroduced populations is rare and may be limited in incorporating the complex movements and environmental interactions of large carnivores. Starting in 2004, Asiatic black bears Ursus thibetanus were reintroduced and tracked in the Republic of Korea, along with their descendants, using radio telemetry, yielding 33,924 tracking points over 12 years. Along with information about habitat use, landscape, and resource availability, we estimated the population equilibrium and dispersal capability of the reintroduced population. We used a mixed modelling approach to determine suitable habitat areas, population equilibria for three different resources-based scenarios, and least-cost pathways (i.e. corridors) for dispersal. Our population simulations provided a mean population equilibrium of 64 individuals at the original reintroduction site and a potential maximum of 1,438 individuals in the country. The simulation showed that the bear population will disperse to nearby mountainous areas, but a second reintroduction will be required to fully restore U. thibetanus. Northern suitable habitats are currently disconnected and natural re-population is unlikely to happen unless supported. Our methodologies and findings are also relevant for determining the outcome and trajectories of reintroduced populations of other large carnivores.

scholarly journals The Impact of Human Pressure and Climate Change on the Habitat Availability and Protection of Cypripedium (Orchidaceae) in Northeast China

Plants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 84
Author(s):  
Huanchu Liu ◽  
Hans Jacquemyn ◽  
Xingyuan He ◽  
Wei Chen ◽  
Yanqing Huang ◽  
...  
Keyword(s):  
Climate Change ◽  
Northeast China ◽  
Habitat Destruction ◽  
Changbai Mountains ◽  
Suitable Habitat ◽  
Human Pressure ◽  
Terrestrial Orchids ◽  
The Future ◽  
Suitable Habitats ◽  
The Impact

Human pressure on the environment and climate change are two important factors contributing to species decline and overall loss of biodiversity. Orchids may be particularly vulnerable to human-induced losses of habitat and the pervasive impact of global climate change. In this study, we simulated the extent of the suitable habitat of three species of the terrestrial orchid genus Cypripedium in northeast China and assessed the impact of human pressure and climate change on the future distribution of these species. Cypripedium represents a genus of long-lived terrestrial orchids that contains several species with great ornamental value. Severe habitat destruction and overcollection have led to major population declines in recent decades. Our results showed that at present the most suitable habitats of the three species can be found in Da Xing’an Ling, Xiao Xing’an Ling and in the Changbai Mountains. Human activity was predicted to have the largest impact on species distributions in the Changbai Mountains. In addition, climate change was predicted to lead to a shift in distribution towards higher elevations and to an increased fragmentation of suitable habitats of the three investigated Cypripedium species in the study area. These results will be valuable for decision makers to identify areas that are likely to maintain viable Cypripedium populations in the future and to develop conservation strategies to protect the remaining populations of these enigmatic orchid species.

scholarly journals Predicting Impacts of Climate Change on Northward Range Expansion of Invasive Weeds in South Korea

Plants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1604
Author(s):  
Sun Hee Hong ◽  
Yong Ho Lee ◽  
Gaeun Lee ◽  
Do-Hun Lee ◽  
Pradeep Adhikari
Keyword(s):  
Climate Change ◽  
South Korea ◽  
Habitat Suitability ◽  
Management Strategies ◽  
Southern Region ◽  
Suitable Habitat ◽  
Invasive Weeds ◽  
Northern Regions ◽  
Suitable Habitats ◽  
Control And Management

Predicting the distribution of invasive weeds under climate change is important for the early identification of areas that are susceptible to invasion and for the adoption of the best preventive measures. Here, we predicted the habitat suitability of 16 invasive weeds in response to climate change and land cover changes in South Korea using a maximum entropy modeling approach. Based on the predictions of the model, climate change is likely to increase habitat suitability. Currently, the area of moderately suitable and highly suitable habitats is estimated to be 8877.46 km2, and 990.29 km2, respectively, and these areas are expected to increase up to 496.52% by 2050 and 1439.65% by 2070 under the representative concentration pathways 4.5 scenario across the country. Although habitat suitability was estimated to be highest in the southern regions (<36° latitude), the central and northern regions are also predicted to have substantial increases in suitable habitat areas. Our study revealed that climate change would exacerbate the threat of northward weed invasions by shifting the climatic barriers of invasive weeds from the southern region. Thus, it is essential to initiate control and management strategies in the southern region to prevent further invasions into new areas.

scholarly journals Scaling up ideals to freedom: are densities of red knots across western Europe consistent with ideal free distribution?

2011 ◽  
Vol 278 (1719) ◽  
pp. 2728-2736 ◽  
Author(s):  
Gwenaël Quaintenne ◽  
Jan A. van Gils ◽  
Pierrick Bocher ◽  
Anne Dekinga ◽  
Theunis Piersma
Keyword(s):  
Uniform Distribution ◽  
Western Europe ◽  
Ideal Free Distribution ◽  
Scale Up ◽  
Suitable Habitat ◽  
Distribution Models ◽  
Free Distribution ◽  
Wintering Areas ◽  
Wintering Area ◽  
Suitable Habitats

Local studies have shown that the distribution of red knots Calidris canutus across intertidal mudflats is consistent with the predictions of an ideal distribution, but not a free distribution. Here, we scale up the study of feeding distributions to their entire wintering area in western Europe. Densities of red knots were compared among seven wintering sites in The Netherlands, UK and France, where the available mollusc food stocks were also measured and from where diets were known. We tested between three different distribution models that respectively assumed (i) a uniform distribution of red knots over all areas, (ii) a uniform distribution across all suitable habitat (based on threshold densities of harvestable mollusc prey), and (iii) an ideal and free distribution (IFD) across all suitable habitats. Red knots were not homogeneously distributed across the different European wintering areas, also not when considering suitable habitats only. Their distribution was best explained by the IFD model, suggesting that the birds are exposed to interference and have good knowledge about their resource landscape at the spatial scale of NW Europe, and that the costs of movement between estuaries, at least when averaged over a whole winter, are negligible.

scholarly journals Assessing Suitable Habitats for Treefrog Species after Previous Declines in Costa Rica

Diversity ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 577
Author(s):  
Héctor Zumbado-Ulate ◽  
Catherine L. Searle ◽  
Gerardo Chaves ◽  
Víctor Acosta-Chaves ◽  
Alex Shepack ◽  
...  
Keyword(s):  
Costa Rica ◽  
Sympatric Species ◽  
Costa Rican ◽  
Suitable Habitat ◽  
Minimum Convex Polygon ◽  
Amphibian Species ◽  
Environmental Threats ◽  
The Status ◽  
Suitable Habitats ◽  
Iucn Assessment

Treefrogs represent 22% of amphibian species in Costa Rica, but gaps in the knowledge about this group of amphibians can impede conservation efforts. In this study, we first updated the status of Costa Rican treefrogs and found that a total of 38% of treefrog species are threatened according to the most recent IUCN assessment in 2019. Additionally, 21% of Costa Rican treefrog species have a high vulnerability to extinction according to environmental vulnerability scores. Then, we predicted the historical climatic suitability of eight target species that we expected to have exhibited changes in their ranges in the last 20 years. We assessed the location of new occurrence records since 2000 to identify recovery, range expansion, or previously underestimated ranges due to methodological limitations. We also estimated the area of each species’ suitable habitat with two metrics: extent of suitable habitat (ESH) and area of minimum convex polygon (AMCP). Six declined species exhibited recovery (i.e., new occurrences across historical range after 2000), with the widest recovery found in Agalychnis annae. We also found that Isthmohyla pseudopuma appears to have spread after the decline of sympatric species and that the range of I. sukia was originally underestimated due to inadequate detection. We found that the ESH was 32–49% smaller than the AMCP for species that are slowly recovering; however, the ESH is similar or greater than the AMCP for species that are recovering in most of their ranges, as well as rare species with widespread ranges. Results of this work can be used to evaluate the risk of environmental threats and prioritize regions for conservation purposes.

scholarly journals The modeled distribution of corals and sponges surrounding the Salas y Gómez and Nazca ridges with implications for high seas conservation

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11972
Author(s):  
Samuel Georgian ◽  
Lance Morgan ◽  
Daniel Wagner
Keyword(s):  
Suitable Habitat ◽  
Distribution Models ◽  
Seafloor Topography ◽  
Saturation State ◽  
Direct Observations ◽  
Rich Diversity ◽  
Spatial Management ◽  
Phosphate Silicate ◽  
Glass Sponges ◽  
Suitable Habitats

The Salas y Gómez and Nazca ridges are two adjacent seamount chains off the west coast of South America that collectively contain more than 110 seamounts. The ridges support an exceptionally rich diversity of benthic and pelagic communities, with the highest level of endemism found in any marine environment. Despite some historical fishing in the region, the seamounts are relatively pristine and represent an excellent conservation opportunity to protect a global biodiversity hotspot before it is degraded. One obstacle to effective spatial management of the ridges is the scarcity of direct observations in deeper waters throughout the region and an accompanying understanding of the distribution of key taxa. Species distribution models are increasingly used tools to quantify the distributions of species in data-poor environments. Here, we focused on modeling the distribution of demosponges, glass sponges, and stony corals, three foundation taxa that support large assemblages of associated fauna through the creation of complex habitat structures. Models were constructed at a 1 km2 resolution using presence and pseudoabsence data, dissolved oxygen, nitrate, phosphate, silicate, aragonite saturation state, and several measures of seafloor topography. Highly suitable habitat for each taxa was predicted to occur throughout the Salas y Gómez and Nazca ridges, with the most suitable habitat occurring in small patches on large terrain features such as seamounts, guyots, ridges, and escarpments. Determining the spatial distribution of these three taxa is a critical first step towards supporting the improved spatial management of the region. While the total area of highly suitable habitat was small, our results showed that nearly all of the seamounts in this region provide suitable habitats for deep-water corals and sponges and should therefore be protected from exploitation using the best available conservation measures.

scholarly journals Global distribution of soapberries (Sapindus L.) habitats under current and future climate scenarios

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jiming Liu ◽  
Lianchun Wang ◽  
Caowen Sun ◽  
Benye Xi ◽  
Doudou Li ◽  
...  
Keyword(s):  
Large Scale ◽  
Global Climate ◽  
Future Climate ◽  
Environmental Data ◽  
Climate Projections ◽  
Suitable Habitat ◽  
Maxent Model ◽  
Mean Temperature ◽  
Suitable Habitats ◽  
Large Scale Cultivation

AbstractSapindus (Sapindus L.) is a widely distributed economically important tree genus that provides biodiesel, biomedical and biochemical products. However, with climate change, deforestation, and economic development, the diversity of Sapindus germplasms may face the risk of destruction. Therefore, utilising historical environmental data and future climate projections from the BCC-CSM2-MR global climate database, we simulated the current and future global distributions of suitable habitats for Sapindus using a Maximum Entropy (MaxEnt) model. The estimated ecological thresholds for critical environmental factors were: a minimum temperature of 0–20 °C in the coldest month, soil moisture levels of 40–140 mm, a mean temperature of 2–25 °C in the driest quarter, a mean temperature of 19–28 °C in the wettest quarter, and a soil pH of 5.6–7.6. The total suitable habitat area was 6059.97 × 104 km2, which was unevenly distributed across six continents. As greenhouse gas emissions increased over time, the area of suitable habitats contracted in lower latitudes and expanded in higher latitudes. Consequently, surveys and conservation should be prioritised in southern hemisphere areas which are in danger of becoming unsuitable. In contrast, other areas in northern and central America, China, and India can be used for conservation and large-scale cultivation in the future.

scholarly journals The Extent of Seasonally Suitable Habitats May Limit Forage Fish Production in a Temperate Estuary

2021 ◽  
Vol 8 ◽  
Author(s):  
Mary C. Fabrizio ◽  
Troy D. Tuckey ◽  
Aaron J. Bever ◽  
Michael L. MacWilliams
Keyword(s):  
Chesapeake Bay ◽  
Habitat Suitability ◽  
Reference Points ◽  
Suitable Habitat ◽  
Habitat Conditions ◽  
Forage Production ◽  
Forage Fishes ◽  
Annual Variations ◽  
Suitable Habitats ◽  
Bay Anchovy

The sustained production of sufficient forage is critical to advancing ecosystem-based management, yet factors that affect local abundances and habitat conditions necessary to support aggregate forage production remain largely unexplored. We quantified suitable habitat in the Chesapeake Bay and its tidal tributaries for four key forage fishes: juvenile spotted hake Urophycis regia, juvenile spot Leiostomus xanthurus, juvenile weakfish Cynoscion regalis, and bay anchovy Anchoa mitchilli. We used information from monthly fisheries surveys from 2000 to 2016 coupled with hindcasts from a spatially interpolated model of dissolved oxygen and a 3-D hydrodynamic model of the Chesapeake Bay to identify influential covariates and construct habitat suitability models for each species. Suitable habitat conditions resulted from a complex interplay between water quality and geophysical properties of the environment and varied among species. Habitat suitability indices ranging between 0 (poor) and 1 (superior) were used to estimate seasonal and annual extents of suitable habitats. Seasonal variations in suitable habitat extents in Chesapeake Bay, which were more pronounced than annual variations during 2000–2016, reflected the phenology of estuarine use by these species. Areas near shorelines served as suitable habitats in spring for juvenile spot and in summer for juvenile weakfish, indicating the importance of these shallow areas for production. Tributaries were more suitable for bay anchovy in spring than during other seasons. The relative baywide abundances of juvenile spot and bay anchovy were significantly related to the extent of suitable habitats in summer and winter, respectively, indicating that Chesapeake Bay habitats may be limiting for these species. In contrast, the relative baywide abundances of juvenile weakfish and juvenile spotted hake varied independently of the spatial extent of suitable habitats. In an ecosystem-based approach, areas that persistently provide suitable conditions for forage species such as shoreline and tributary habitats may be targeted for protection or restoration, thereby promoting sufficient production of forage for predators. Further, quantitative habitat targets or spatial thresholds may be developed for habitat-limited species using estimates of the minimum habitat area required to produce a desired abundance or biomass; such targets or thresholds may serve as spatial reference points for management.

Muskellunge Management: Fifty Years of Cooperation Among Anglers, Scientists, and Fisheries Biologists

2017 ◽  
Keyword(s):  
Aquatic Vegetation ◽  
Lake Michigan ◽  
Radio Telemetry ◽  
Habitat Preferences ◽  
Vegetation Coverage ◽  
Limiting Factor ◽  
Suitable Habitat ◽  
Spawning Habitat ◽  
Green Bay ◽  
Natural Reproduction

<em>Abstract</em>.—The identification, protection, and restoration of spawning habitat for Muskellunge <em>Esox masquinongy </em>in Green Bay, Lake Michigan are vital steps for re-establishing a self-sustaining population. This study was designed to locate spawning areas, document and model spawning habitat preferences, assess natural recruitment, and determine if suitable habitat was found throughout Green Bay (Fox River, lower Green Bay, Menominee River, and Little Sturgeon Bay). Radio transmitters were inserted into the oviduct of mature female Muskellunge prior to spawning and expelled transmitters were later located using radio telemetry to identify spawning locations. Between 2009 and 2010, 26 of 37 (70%) implanted transmitters were located as deposited at spawning locations. Using identified spawning locations, habitat selection was estimated for key environmental variables, and MaxEnt (maximum entropy) was utilized to model Muskellunge spawning habitat in the Menominee River, as it was the only study area where natural reproduction was documented. Menominee River Muskellunge showed significant preferences for spawning in areas with shallow bottom slopes (5%), with medium-to-high submerged aquatic vegetation coverage (>33%), where coarse woody debris was present, and where dominant substrates were sand or cobble. MaxEnt modeling predicted a ~2.5 magnitude greater likelihood of spawning at an average spawning location compared to an average background location. Comparisons of available habitat among study areas showed the Menominee River contained more spawning habitat with preferred characteristics. Results from this study are important steps in identifying spawning habitat as a potential limiting factor to successful Muskellunge reintroduction and models could be used to locate suitable areas to stock and guide delineation of critical spawning habitat to designate for protection.

scholarly journals Diversity of Pteridophyte Flora in Rajamala, Eravikulam National Park, Kerala, India

2021 ◽  
pp. 28-36
Author(s):  
M. S. Arjun ◽  
Raju Antony ◽  
A. Azhar Ali ◽  
C. Abhirami ◽  
M. M. Sreejith
Keyword(s):  
Western Ghats ◽  
National Park ◽  
Sampling Method ◽  
Suitable Habitat ◽  
Purposive Sampling ◽  
Field Guides ◽  
Grassland Ecosystems ◽  
Preliminary Study ◽  
Suitable Habitats ◽  
Impacted Site

Aims: To enumerate the fern diversity in the disturbed landscapes of Rajamala part of Eravikulam National Park, Western Ghats Study Design: Purposive sampling method was adopted in the study area and habitats suitable for ferns were surveyed. Place and Duration of Study: The study area is Rajamala, a tourist impacted site inside Eravikulam National Park in Kerala, India. Intensive field explorations were carried out in this area during February 2018- April 2019, to document the ferns and fern-allies. Methodology: A preliminary study was conducted in February 2018 to identify the probable habitats of ferns for further detailed study. Purposive sampling was done in the study area considering the most suitable habitats in both shola ecosystems and grassland ecosystems of the area. Materials for herbaria were processed using standard methods. The collected plants were identified with the help of standard field guides and flora. The potential medicinally important ferns were also listed out. Results: 54 species of pteridophytes including fern and fern allies belonging to sixteen different families were found from the Rajamala region of Eravikulam National Park. Aspleniaceae was the most common family with 11 species followed by Polypodiaceae. The majority of the Pteridophytes found in the region are showing terrestrial habit. Eleven species found in the study site are medicinally important. Conclusion: Despite the high tourism pressure in the study area, pteridophyte species richness is higher in the Rajamala region of Western Ghats. The suitable habitat with ideal substrate conditions and year-long moisture availability in the substrates could be the reason for a higher number of pteridophyte species in this area.

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