Increase In Habitat Suitability Research Articles

Mapping the potential habitat suitability and opportunities of bush encroacher species in Southern Africa: a case study of the SteamBioAfrica project

Senegalia mellifera (Benth) Seigler & Ebinger., Dichrostachys cinerea (L.) Wight & Arn. and Terminalia sericea Burch. Ex DC., are three important bush encroacher species that contribute to the well-known ecological process named “thicketization” in Southern Africa. This issue has persisted for many years, impacting species distribution, plant communities, soil, and fauna dynamics. According to climate change projections, Southern Africa is expected to become drier and warmer in future scenarios, creating favourable conditions for proliferation of bush encroacher species. MaxEnt is a general-purpose machine learning method widely utilized in various ecological and biological scenarios to predict the potential suitable habitat of species. This is achieved by incorporating presence-only occurrence records and bioclimatic, and topographic variables. The analysis was performed in a Geographic Information System based on the current and future suitable areas for the respective Shared Socioeconomic Pathways (SSP) scenarios according to INM-CM5-0, UK-ESM1-0-LL and MPIES-M1-2-HR climate models. This was done to assess the potential effects of climate change on the distribution patterns of bush encroacher species. Model performance was assessed by the area under the curve (AUC) of the receiver operator characteristic (ROC), with 0.836, 0.822 and 0.738 as results to Terminalia sericea, Dichrostachys cinerea and Senegalia mellifera respectively. The current results show that Senegalia mellifera presents a habitat suitability of 56% (1,460,353 km²) of the total area, while Terminalia sericea and Dichrostachys cinerea have suitability over 37.9% (996,168 km²) and 43.9% (1,154,645 km²) of the area, respectively. These findings indicate that precipitation and temperature variables are the most important factors in explaining the spatial distribution of the bush encroacher species, predicting a future increase between 8–29.4%, 2.8–24%, and 3–24.2% for Senegalia mellifera, Terminalia sericea, and Dichrostachys cinerea respectively. Furthermore, each species has its own set of important variables and different ecological behaviour patterns. These results imply that an improved understanding of the response of woody species to a changing climate is important for managing bush encroachment in savanna ecosystems. Based on our analysis, Senegalia mellifera is currently suitable in 56% of the total area; while 43.9% of the total area is suitable for Dichrostachys cinerea, and 37.87% of the total area is currently suitable for Terminalia sericea. In the future scenarios, the habitat suitability increases for all three species compared to the current state. The unsuitable areas decrease in all the proposed scenarios with respect to the present, predicting a shrub expansion in the future throughout southern Africa. Furthermore, our results imply that Senegalia mellifera is the most potentially affected by bush encroachment in future changes, with a larger distribution area in future scenarios. These findings are supported by many studies, which indicate the probable increase of woody cover and loss of grasslands. Temperature and precipitation patterns are the main drivers behind the distribution of these bush encroachers, increasing or decreasing the competitiveness of these species according to these variables and their phenotypic plasticity. The increase in habitat suitability occurs throughout the case study, but there is a clear trend of shrub expansion towards the south of the case study. The change maps show a pattern of shrub movement towards South Africa and Botswana. This would fit with climate predictions for South Africa, which predict a decrease in rainfall in the east and north of the country, being more suitable for shrub competitive species.

Climate and urbanization drive changes in the habitat suitability of Schistosoma mansoni competent snails in Brazil

Schistosomiasis is a neglected tropical disease caused by Schistosoma parasites. Schistosoma are obligate parasites of freshwater Biomphalaria and Bulinus snails, thus controlling snail populations is critical to reducing transmission risk. As snails are sensitive to environmental conditions, we expect their distribution is significantly impacted by global change. Here, we used machine learning, remote sensing, and 30 years of snail occurrence records to map the historical and current distribution of forward-transmitting Biomphalaria hosts throughout Brazil. We identified key features influencing the distribution of suitable habitat and determined how Biomphalaria habitat has changed with climate and urbanization over the last three decades. Our models show that climate change has driven broad shifts in snail host range, whereas expansion of urban and peri-urban areas has driven localized increases in habitat suitability. Elucidating change in Biomphalaria distribution—while accounting for non-linearities that are difficult to detect from local case studies—can help inform schistosomiasis control strategies.

Warming waters lead to increased habitat suitability for juvenile bull sharks (Carcharhinus leucas)

Coastal ecosystems are highly vulnerable to the impacts of climate change and other stressors, including urbanization and overfishing. Consequently, distributions of coastal fish have begun to change, particularly in response to increasing temperatures linked to climate change. However, few studies have evaluated how natural and anthropogenic disturbances can alter species distributions in conjunction with geophysical habitat alterations, such as changes to land use and land cover (LU/LC). Here, we examine the spatiotemporal changes in the distribution of juvenile bull sharks (Carcharhinus leucas) using a multi-decadal fishery-independent survey of coastal Alabama. Using a boosted regression tree (BRT) modeling framework, we assess the covariance of environmental conditions (sea surface temperature, depth, salinity, dissolved oxygen, riverine discharge, Chl-a) as well as historic changes to LU/LC to the distribution of bull sharks. Species distribution models resultant from BRTs for early (2003–2005) and recent (2018–2020) monitoring periods indicated a mean increase in habitat suitability (i.e., probability of capture) for juvenile bull sharks from 0.028 to 0.082, concomitant with substantial increases in mean annual temperature (0.058°C/yr), Chl-a (2.32 mg/m3), and urbanization (increased LU/LC) since 2000. These results align with observed five-fold increases in the relative abundance of juvenile bull sharks across the study period and demonstrate the impacts of changing environmental conditions on their distribution and relative abundance. As climate change persists, coastal communities will continue to change, altering the structure of ecological communities and the success of nearshore fisheries.

The Gulf toadfish goes south: assessing the potential habitat suitability of Opsanus beta in response to climate change

Climate change can directly influence invasive species range, and may reflect in greater habitat suitability, consequently increasing losses in native biodiversity. Habitat suitability modelling can help identify priority areas for conservation and rapid response for invasive taxa. This study aimed to model the habitat suitability of Opsanus beta, an invasive fish species, in South America under current and future climate change scenarios. Three modelling techniques, Generalized Linear Model (GLM), Maximum Entropy Algorithm (Maxent), and Random Forest (RF), were applied, and their results were compared and then put together in an Ensemble model to visualize habitat suitability. We found that the current habitat suitability of O. beta in South America is relatively low, with its occurrences mostly related to coastal port areas, suggesting that the species was introduced from ballast water. The increase in mean temperature at mean depth and temperature range were the most relevant variables influencing the species habitat suitability. The gradual increase in habitat suitability for the 2100 climate change scenarios, particularly in more severe climate change scenarios, such as the RCP 8.5, was also observed. The study highlights the critical need to use habitat suitability models to mitigate the impact of future climate change scenarios on invasive species. The findings call for preventive measures to be taken in time to prepare areas that may become the target of dispersal and establishment of O. beta.

Future distribution patterns of nine cuttlefish species under climate change

While most coastal communities are expected to, or have been, negatively impacted by climate change, cephalopods have generally thrived with shifting ocean conditions. However, whilst benefitting from the same physiological flexibility that characterizes cephalopods in general, cuttlefish have depth constraints imposed by the presence of a cuttlebone and are limited to specific locations by their particularly low vagility. To evaluate the potential effects of marine climate change on cuttlefish, Species Distribution Models (SDM) were applied to nine species of genus Sepiidae to assess potential changes to their future distribution (2050 and 2100), under four representative concentration pathway (RCP) scenarios (i.e., RCP 2.6, 4.5, 6.0, and 8.5; CMIP5). We show that future cuttlefish habitat suitability and distribution will potentially decrease. The species with the most extreme impacts, Doratosepion braggi (Verco, 1907), was observed to decline as much as 30.77% in average habitat suitability (from present 55.26% to 24.48% at RCP 8.5 in 2100), to Sepia officinalis Linnaeus, 1758 with a low maximum decrease of 1.64% in average habitat suitability (from present 59.62% to 57.98% at RCP 8.5 in 2100). Increases in habitat suitability were projected mostly at higher latitudes, while habitat decrease was predicted for the tropical regions and lower latitudinal limits of species’ distributions. As their habitats decrease in terms of habitat suitability, cuttlefish may not benefit from future changes in climate. Additionally, as potential “sea canaries” for coastal ecosystems, we may see many species and habitats from these systems affected by climate change, particularly in tropical regions.

A shifting carnivore’s community: habitat modeling suggests increased overlap between the golden jackal and the Eurasian lynx in Europe

IntroductionThe European large carnivore community is recently showing positive trends. Beyond those, other species are expanding in Europe. In recent decades, the golden jackal (Canis aureus), a medium-sized canid, has rapidly expanded to western and northern Europe, after being historically confined to the Balkans. The Eurasian lynx (Lynx lynx), an apex predator once widely distributed throughout Europe, was nearly eradicated in the 19th century. Recent reintroductions, legal protection, and its natural expansion brought the lynx to recover, though some populations still face extinction. As the carnivores’ community across Europe is rearranging, ecological interactions are changing as well. Indeed, recent observations reported the golden jackal to kleptoparasitize the lynx. Our research aims to predict the potentially suitable habitats for the golden jackal and the Eurasian lynx, detailing the areas where those are expected to coexist soon.MethodsWe model their distribution in Europe for current and future scenarios, using both citizen-science and literature data, using the latter to buffer the possible biases of the former. For this aim, we included not only climatic variables, but also several biotic and abiotic predictors relevant to both species. Moreover, given his strong influence on the golden jackal, we compare our results with the predicted distribution of the grey wolf (Canis lupus).ResultsOur predictions show an increase in habitat suitability for the golden jackal, while an opposite trend is predicted for the Eurasian lynx. Also, we predict the target species to share a large portion of their range in the future, with most of these areas suitable for wolves, too.DiscussionOur results may have several impacts in the context of large-scale management, helping to predict further expansion of the golden jackal, and to identify critical areas for lynx conservation, supporting the management of possible reintroductions, also shedding light on the large carnivores’ changing community

Impact of climate change on the distribution and habitat suitability of the world’s main commercial squids

Climate change is expected to have major negative effects on marine life across phylogenetic groups. Cephalopods, however, have life history characteristics that suggest they may benefit from certain climate change scenarios. Of all cephalopods, squids reach the greatest biomasses; as a result, they are of substantial importance for human and predator consumption. To test the hypothesis that the effects of climate change are beneficial for commercial squid, we used species distribution models on climate scenarios for the period between 2000 and 2014, as well as the years 2050 and 2100 (RCP [representative concentration pathway] 2.6, 4.5, 6.0, and 8.5; CMIP5). Our results suggest that consequences of climate change scenarios are species specific. In the North Pacific and Northwest Atlantic, squid’s habitat suitability may increase (from + 0.83% [Doryteuthis pealeii] to + 8.77% increase [Illex illecebrosus]), while it is predicted to decrease in other regions (from − 1.03% [Doryteuthis opalescens] to − 15.04% decrease [Loligo reynaudii]). Increases in habitat suitability occurred mostly at higher latitudes (north of 50° N), while suitable habitat decrease was predicted for the tropical regions. These shifts in future habitat suitability were stronger under harsher emission scenarios. Starting in 2050 (with RCP scenarios 4.6, 6.0 and 8.5), as a result of warming of the Arctic, squid habitat may increase along both coasts of North America. In the Southern Hemisphere, squids may lose habitat with no poleward habitat alternatives to move into. Contrary to our hypothesis, these commercial squid do not stand to benefit from climate change. Since these squid are an important food source for marine megafauna and humans, it is imperative that climate change biogeographic impacts are considered for a sustainable management of this important group of molluscs.

Distribution modeling for predicting habitat suitability for citron (Citrus medica L.) under climate change scenarios

Citron (Citrus medica) is one of the major citrus fruits of commerce. It is cultivated mostly in the warm temperate Mediterranean coastal region, and in the tropical and subtropical regions of South and Southeast Asia. It also grows naturally in northeast India, Myanmar, and Yunnan (China). Citron populations are declining in their natural habitats due to forest degradation and change in land use patterns. To predict the habitat suitability for citron, we evaluated four widely used species distribution models (SDMs), namely Generalized Linear Models (GLM), Support Vector Machine (SVM), Random Forest (RF), and Maximum Entropy (MaxEnt) in ‘sdm’ package. Based on Area under ROC Curve (AUC; >0.97) and True Skill Statistics (TSS; >0.9) of all four models, an ensemble modeling was carried out using 111 geo-referenced datasets and 19 bioclimatic and three topographic variables under three climate change scenarios (current, 2050 and 2070). Precipitation of warmest quarter (bio18, 69.6%), elevation (11.1%), mean temperature of wettest quarter (bio8, 10.6%), and temperature seasonality (bio4, 10.1%) were the most important environmental variables for determining the distribution of citron in the study area. Potentially suitable habitat for citron was predicted to occur from 12 – 29 °N to 79 – 108 °E. The total suitable habitat covers about 875,868 km2, including 195,846 km2, 274,386 km2, and 405,636 km2, representing high, moderate, and least suitable areas, respectively. Increase in habitat suitability was predicted for 2050 and 2070 under four representative concentration pathways (RCPs), i. e., RCP2.6, RCP4.5, RCP6.0, and RCP8.5. This study predicted that northeast India and northern Myanmar would remain moderately or highly suitable for citron.

Mapping Impacts of Climate Change on the Distributions of Two Endemic Tree Species under Socioeconomic Pathway Scenarios (SSP)

Pistacia eurycarpa Yalt and Pistacia khinjuk Stocks are two important endemic tree species inhabiting mountainous regions in Iraq. Their cultural, medical, and ecological benefits have captured the interest of this study. Numerous researchers have revealed how and to what extent global climate change alters species’ habitats and distribution. This approach aims to quantify the current and future distribution of these tree species in the region and to provide baseline data on how Pistacia respond to the changing environment. Three socioeconomic pathway scenarios (SSP 126, 245, and 585) in two general circulating models (GCMs), MIROC-ES2L and BCC-CSM2-MR, have been utilized to examine the probable future geographical shift of these species during different time periods (2041–2060, 2061–2080, and 2081–2100). This study used the MaxEnt model and geospatial techniques for: (i) anticipating the present level of distributions and assessing the impact of climate change on these species’ possible future distributions; (ii) estimating the areas of species overlap; and (iii) finding the most significant environmental variables shaping their distributions, according to 11 environmental variables and 161 known localities. The findings revealed that 30 out of 36 modeling results showed range expansion in both the MIROC-ES2L and BCC-CSM2-MR models with 16/18 for P. eurycarpa and 14/18 for P. khinjuk. The overall species range expansions and increase in habitat suitability (mainly in the north and northeast) were related to precipitation during the wettest months, topography, and soil type structure (i.e., Chromic Vertisols, Lithosols, and Calcic Xerosols). These recent discoveries provide priceless new information for forestry management efforts and the conservation plan in Iraq, particularly in the overlapping areas in the mountainous regions and highlands. Geospatial approaches and correlation-based modeling are effective tools for predicting the spatial pattern of tree species in the mountain environment.

Geographic distribution and impacts of climate change on the suitable habitats of Glycyrrhiza species in China

Climate change has a major impact on the growth and distribution of plants. Glycyrrhiza is widely used in the treatment of many diseases in China. However, with the overexploitation and the growing demand for medicinal uses in of Glycyrrhiza plants. The investigation of the geographical distribution of Glycyrrhiza plants and the analysis of future climate change are of great significance for the conservation of Glycyrrhiza. In this study, combined with administrative maps of Chinese provinces, the present and future of geographical distribution and richness of six Glycyrrhiza plants in China were studied by using DIVA-GIS and MaxEnt software. A total of 981 herbarium records of these six species of Glycyrrhiza were collected to research. Results show that the change of climate in the future will lead to an increase in habitat suitability for some Glycyrrhiza species as follows: Glycyrrhiza inflata by 61.6%, Glycyrrhiza squamulosa by 47.5%, Glycyrrhiza pallidiflora by 34.0%, Glycyrrhiza yunnanensis by 49.0%, Glycyrrhiza glabra by 51.7%, and Glycyrrhiza aspera by 65.9%. Glycyrrhiza plants have considerable medicinal and economic value, so it is necessary to adopt targeted development and rational management strategies for it.

Predicting the Impact of Climate Change on the Distribution of Rhipicephalus sanguineus in the Americas

Climate change may influence the incidence of infectious diseases including those transmitted by ticks. Rhipicephalus sanguineus complex has a worldwide distribution and transmits Rickettsial infections that could cause high mortality rates if untreated. We assessed the potential effects of climate change on the distribution of R. sanguineus in the Americas in 2050 and 2070 using the general circulation model CanESM5 and two shared socioeconomic pathways (SSPs), SSP2-4.5 (moderate emissions) and SSP2-8.5 (high emissions). A total of 355 occurrence points of R. sanguineus and eight uncorrelated bioclimatic variables were entered into a maximum entropy algorithm (MaxEnt) to produce 50 replicates per scenario. The area under the curve (AUC) value for the consensus model (>0.90) and the partial ROC value (>1.28) indicated a high predictive capacity. The models showed that the geographic regions currently suitable for R. sanguineus will remain stable in the future, but also predicted increases in habitat suitability in the Western U.S., Venezuela, Brazil and Bolivia. Scenario 4.5 showed an increase in habitat suitability for R. sanguineus in tropical and subtropical regions in both 2050 and 2070. Habitat suitability is predicted to remain constant in moist broadleaf forests and deserts but is predicted to decrease in flooded grasslands and savannas. Using the high emissions SSP5-8.5 scenario, habitat suitability in tropical and subtropical coniferous forests and temperate grasslands, savannas, and shrublands was predicted to be constant in 2050. In 2070, however, habitat suitability was predicted to decrease in tropical and subtropical moist broadleaf forests and increase in tropical and subtropical dry broadleaf forests. Our findings suggest that the current and potential future geographic distributions can be used in evidence-based strategies in the design of control plans aimed at reducing the risk of exposure to zoonotic diseases transmitted by R. sanguineus.

Vulnerability of the Small-Scale Fishery to Climate Changes in the Northern-Central Adriatic Sea (Mediterranean Sea)

Climate change is altering the functioning of ecosystems and species distribution worldwide, with negative impacts on human activities, including fisheries. The Adriatic Sea is an extremely productive area for fisheries, due to the strong outflow of nutrients from rivers and the periodic mixing of nutrients from the Mediterranean. However, the Adriatic Sea is also a semi-closed basin, where species do not have the ability to move to higher latitudes to avoid warming of the waters. Climate change acts on biodiversity in a variety of ways, such as causing changes in the trophic network—favoring the intake of thermophilic alien species, often in competition with local species—and altering the biological cycles of acclimatized marine species to temperate–cold climates. These problems become critical factors for the survival of species and for fisheries relying on these resources. Within this context, to have estimates of possible modifications of the nektonic community in the near future could be quite useful for preparing adaptation plans. In this paper, using Maximum Entropy models under RCP 4.5 and 8.5 scenarios, we estimated the future habitat suitability for a set of marine nektonic species of different thermal affinity (e.g., cold, temperate and warm species) within GSA17 (Northern and Central Adriatic Sea), among the most productive—and most exploited—areas of the Mediterranean Sea. This study shows how, at the current pace, climate change could modify marine ecosystems to the extent that future habitat suitability will decrease for nearly half of the species considered, with a decrease in landings from 13.5 to 86.9%, depending on the scenario. Only for the blue crab Callinectes sapidus has an increase in habitat suitability been observed. For most of the species considered, temperature was the most important variable to explain the probability of relative presence within the GSA17. On the other hand, GSA17 climatic conditions in the near future under the tested scenarios could become a suitable environment for tropical species, which could find here a suitable habitat, at least in terms of thermal features. Results of the present study can help the management of fishery resources and local markets in the near future, providing information to predict changes in the composition of the aquatic community and draw up management plans that take into account the effects of climate change.

Predicting habitat suitability and range shifts under projected climate change for two octocorals in the north-east Atlantic.

Species distribution models have become a valuable tool to predict the distribution of species across geographic space and time. In this study, maximum entropy models were constructed for two temperate shallow-water octocoral species, the pink sea fan (Eunicella verrucosa) and dead man’s fingers (Alcyonium digitatum), to investigate and compare habitat suitability. The study area covered the north-east Atlantic from the Bay of Biscay to the British Isles and southern Norway; this area includes both the northern range of E. verrucosa and the middle-northern range of A. digitatum. The optimal models for each species showed that, overall, slope, temperature at the seafloor and wave orbital velocity were important predictors of distribution in both species. Predictions of habitat suitability showed areas of present-day (1951–2000) suitable habitat where colonies have not yet been observed, particularly for E. verrucosa, where areas beyond its known northern range limit were identified. Moreover, analysis with future layers (2081–2100) of temperature and oxygen concentration predicted a sizable increase in habitat suitability for E. verrucosa beyond these current range limits under the Representative Concentration Pathway 8.5 scenario. This suggests that projected climate change may induce a potential range expansion northward for E. verrucosa, although successful colonisation would also be conditional on other factors such as dispersal and interspecific competition. For A. digitatum, this scenario of projected climate change may result in more suitable habitat in higher latitudes, but, as with E. verrucosa, there is a degree of uncertainty in the model predictions. Importantly, the results from this study highlight present-day areas of high habitat suitability which, if combined with knowledge on population density, could be used to identify priority areas to enhance protection and ensure the long-term survival of these octocoral species in the region.

Modeling of Valeriana wallichii Habitat Suitability and Niche Dynamics in the Himalayan Region under Anticipated Climate Change.

Simple SummaryIn the modern era of the anthropocene, an increase in the accumulation of greenhouse gases in the atmosphere has resulted in the global rise of the Earth’s temperature. This has resulted in the habitat shift of various plant and animal species. Plant species that are endemic show a narrow distribution range and inhabit higher elevations are highly susceptible to the impacts of global warming. The present study discusses the habitat distribution of Valeriana wallichi, an endangered medicinal herb. We also predicted the impact of climate change on its distribution range and niche dynamics. Results reveal significant contraction in the possible habitats of this herb under future climatic scenarios, with RCP 8.5 for 2070 showing the highest habitat loss. Niche equivalency and similarity tests describe that the habitats could be compared but not identical between current and future climatic scenarios. From the current study, we conclude that the habitats of Valeriana wallichii are highly vulnerable to climate shifts. This study can not only be used to alleviate the threat to this plant by documenting the unexplored populations, restoring the degraded habitats through rewilding and launching species recovery plans in the natural habitats but could also be used by various conservation biologists to recover the declining status of various highly valued species across the globe.An increase in atmospheric greenhouse gases necessitates the use of species distribution models (SDMs) in modeling suitable habitats and projecting the impact of climate change on the future range shifts of the species. The present study is based on the BIOMOD ensemble approach to map the currently suitable habitats and predict the impact of climate change on the niche shift of Valeriana wallichii. We also studied its niche dynamics using the ecospat package in R software. Values of the area under curve (AUC) and true skill statistics (TSS) were highly significant (>0.9), which shows that the model has run better. From 19 different bioclimatic variables, only 8 were retained after correlation, among which bio_17 (precipitation of driest quarter), bio_1 (annual mean temperature), and bio_12 (annual mean precipitation) received the highest gain. Under future climate change, the suitable habitats will be significantly contracted by −94% (under representative concentration pathway RCP 8.5 for 2070) and −80.22% (under RCP 8.5 for 2050). There is a slight increase in habitat suitability by +16.69% (RCP 4.5 for 2050) and +8.9% (RCP 8.5 for 2050) under future climate change scenarios. The equivalency and similarity tests of niche dynamics show that the habitat suitability for current and future climatic scenarios is comparable but not identical. Principal Component Analysis (PCA) analysis shows that climatic conditions will be severely affected between current and future scenarios. From this study, we conclude that the habitats of Valeriana wallichii are highly vulnerable to climate shifts. This study can be used to alleviate the threat to this plant by documenting the unexplored populations, restoring the degraded habitats through rewilding, and launching species recovery plans in the natural habitats.

Assessing the geographical distribution of 76 Dendrobium species and impacts of climate change on their potential suitable distribution area in China.

The geographical distribution of plant resources is of great significance for studying the origin, distribution, and evolution of species. Climate and geographical factors help shape the distribution of plant species. Dendrobium is a commonly used traditional medicine and a precious economic crop in China. Owing to the over-exploitation and increasing medicinal demand of Dendrobium species plants, systematic investigation of the geographical distribution of the plants and analysis of their potential distribution under climate change are important for protecting Dendrobium plants. We adopted DIVA-GIS to analyze the georeferenced records of 76 species of the Dendrobium species collected from 2166 herbarium records. We analyzed the eco-geographical distribution and species richness of the genus Dendrobium to simulate the distribution of current and future scenarios using MaxEnt. The results revealed the distribution of Dendrobium in 30 provinces of China, with species abundance in Yunnan, Guangxi, Guangdong, and Hainan. Our model identified the following bioclimatic variables: precipitation in the driest months and the warmest seasons, isothermality, and range of annual temperature. Among them, annual precipitation is the most crucial bioclimatic variable affecting the distribution of 16 selected Dendrobium species. The change of climate in the future will lead to an increase in habitat suitability for some Dendrobium species as follows: D. officinal 2.12%, D. hancockii by 6.00%, D. hercoglossum by 8.25%, D. devonianum by 7.71%, D. henryi by 9.40%, and D. hainanense by 13.70%. By contrast, habitat suitability will dramatically decrease for other Dendrobium species: D. chrysotoxum by 0.89%, D. chrysanthum by 12.68%, D. fimbriatum by 5.07%, D. aduncum by 11.44%, D. densiflorum by 18.47%, D. aphyllum by 8.05%, D. loddigesii by 16.45%, D. nobile by 5.41%, D. falconeri by 8.73%, and D. moniliforme by 10.61%. The reduction of these species will be detrimental to the medicinal and economic value of the genus Dendrobium. Therefore, targeted development and reasonable management strategies should be adopted to conserve these valuable resources.

Modelling the biogeographic boundary shift of Calanus finmarchicus reveals drivers of Arctic Atlantification by subarctic zooplankton.

Biological communities in the Arctic are changing through the climate-driven encroachment of subarctic species. This "Atlantification" extends to keystone Calanoid copepods, as the small-bodied Calanus finmarchicus increases in abundance in areas where it overlaps with larger Arctic congeners. The environmental factors that are facilitating this shift, whether related to optimal conditions in temperature or seasonality, remain unclear. Assessing these drivers at an Arctic-wide scale is necessary to predict future ecosystem change and impacts. Here we have compiled range-wide occurrences of C.finmarchicus and a suite of seasonal biophysical climatologies to build a boreo-Arctic ecological niche model. The data set was divided into two eras, 1955-1984 and 1985-2017, and an optimized MaxEnt model was used to predict the seasonal distribution of the abiotic niche of C.finmarchicus in both eras. Comparing outputs between eras reveals an increase in habitat suitability at the Arctic range edge. Large and significant increases in suitability are predicted in the regions of the Greenland, Labrador, and Southern Barents Seas that have experienced reduced sea-ice cover. With the exception of the Barents Sea, these areas also show a seasonal shift in the timing of peak habitat suitability toward an earlier season. Our findings suggest that the Atlantification of Arctic zooplankton communities is accompanied by climate-driven phenology changes. Although seasonality is a critical constraint to the establishment of C.finmarchicus at Arctic latitudes, earlier sea-ice retreat and associated productivity is making these environments increasingly favorable for this subarctic species.

Diminishing potential for tropical reefs to function as coral diversity strongholds under climate change conditions

AbstractAimForecasting the influence of climate change on coral biodiversity and reef functioning is important for informing policy decisions. Dominance shifts, tropicalization and local extinctions are common responses of climate change, but uncertainty surrounds the reliability of predicted coral community transformations. Here, we use species distribution models (SDMs) to assess changes in suitable coral habitat and associated patterns in biodiversity across Western Australia (WA) under present‐day and future climate scenarios (RCP 2.6 and RCP 8.5).LocationCoral reef systems and communities in WA.MethodsWe developed SDMs with model prediction uncertainty analyses, using specimen‐based occurrence records of 188 hermatypic scleractinian coral species and seven variables to estimate present‐day and future changes to coral species distribution and biodiversity patterns in WA under climate change conditions.ResultsWe found that suitable habitat is predicted to increase across all regions in WA under , and scenarios with all tropical and subtropical regions remaining coral biodiversity strongholds. Under the extreme scenario, however, a clear tropicalization trend could be observed with coral species expanding their range to mid‐high latitude regions, while a substantial drop in coral species richness was predicted at low latitude tropical coral reefs, such as the inshore Kimberley and offshore NW reefs. Despite the predicted expansion south, we identified a net decline in coral biodiversity across the WA coastline.Main conclusionsResults from the models predicted higher net coral biodiversity loss at low latitude tropical regions compared with net gains at mid‐high latitude regions under . These results are likely to be representative of latitudinal trends across the Southern Hemisphere and highlight that increases in habitat suitability at higher latitudes may not lead to equivalent biodiversity benefits. Urgent action is needed to limit climate change to prevent spatial erosion of tropical coral communities, extinction events and loss of tropical ecosystem services.

Assessing climate change risks to the geographical distribution of grass species

ABSTRACT There is extensive evidence showing the impact of climate change on the biology and biogeography of species. Adopting drought-tolerant plants to conserve water is a potential adaptation to reduce the consequences of climate change. Accordingly, it was hypothesized that climate change would not affect potential distributions of drought-tolerant species. Here, this hypothesis was tested to model the potential distribution of three drought-resistant plant. Here, the potential distribution of Agropyron cristatum, Agropyron desertorum, and Festuca arundinacea was studied in Iran under current and future climate conditions, using 10 species distribution models. Sixty-two climate change scenarios (19 global climate models (GCMs) under four Representative Concentration Pathways (RCPs)) were used to model the potential distribution of the three plants in Iran in the future. The three species have different responses to predicted climate change due to species-environment interactions, species morphological and physiological advancement. The three species showed different responses to predicted climate change due to species-environment interactions. Festuca arundinacea and Agropyron cristatum will, respectively, experience the most and least severe decline in suitable habitats in the next 50 years. This result is because decreased annual precipitation caused an increase in habitat suitability for A. cristatum, while the same variable had the opposite effect for A. desertorum and F. arundinacea. On the other hand, F. arundinacea grows on moist soils that decreased annual precipitation caused a decrease in habitat suitability. Also, our results have clearly shown that plant species drought-stress tolerant are not immune to climate change and their current distributions undergo significant changes as a result of the changing of climate.

Projected Rapid Habitat Expansion of Tropical Seagrass Species in the Mediterranean Sea as Climate Change Progresses.

During the last 150 years, the tropical seagrass species Halophila stipulacea has established itself in the southern and eastern parts of the Mediterranean Sea. More recently (2018), Halophila decipiens was observed for the first time in the eastern Mediterranean, and was described as the second non-native seagrass species in the Mediterranean Sea. We implemented a species distribution model (SDM) approach to (1) hindcast the habitat suitability of H. stipulacea over the last 100 years in the Mediterranean basin, and (2) to model the increase in the potential habitat suitability of H. stipulacea and H. decipiens during the current century under two very different climate scenarios, RCP 2.6 (lowest carbon emission scenario) and RCP 8.5 (highest carbon emission scenario). In addition, a principal component analysis (PCA) and k-means cluster based on temperature and salinity drivers were applied to visualize the distance and relatedness between the native and invasive H. stipulacea and H. decipiens populations. Results from this PCA suggest that the H. stipulacea populations of the Mediterranean and Red Sea are likely to be similar. In contrast, H. decipiens from the Mediterranean is more related to the Atlantic populations rather than to the Red Sea populations. The hindcast model suggests that the expansion of H. stipulacea was related to the increases in seawater temperatures in the Mediterranean over the last 100 years. The SDMs predict that more suitable habitat will become available for both tropical species during this century. The habitat suitability for H. stipulacea will keep expanding westward and northward as the Mediterranean continues to become saltier and warmer. In comparison, the SDMs built for H. decipiens forecast a restricted habitat suitability in the south-eastern Mediterranean Sea at the present environmental conditions and predicts a progressive expansion with a potential increase in habitat suitability along 85% of the Mediterranean coastline. The predicted rapid expansion of non-native seagrass species could alter the Mediterranean’s seagrass community and may entail massive impacts on associated ecosystem functions and services, impacts that have severe socio-economic consequences.

Double-edged effects of climate change on plant invasions: Ecological niche modeling global distributions of two invasive alien plants

The prediction of the potential distribution of invasive alien species is key for the control of their proliferation. This study developed ensemble niche models to explore the distribution patterns of Cecropia peltata and Ulex europaeus under baseline and future conditions, as well as the factors that regulate them. The models were based on occurrence records as well as climate, land-use and topography datasets. Climatic factors played a stronger role than land-use and topographical factors in their distribution patterns. Additionally, temperature seasonality and temperature annual range were the optimal predictor for the global distributions of C. peltata and U. europaeus, respectively. Under the baseline-RCP 8.5 scenario in 2070, significant increases in habitat suitability for C. peltata were generally detected in tropical regions, while for U. europaeus under the same condition, significant increases in habitat suitability were generally observed in west coast of South America and Europe, suggesting the impacts of climate changes on species distribution may be species specific. The contrast changes of suitable habitat areas for U. europaeus under the baseline-2.6 and 8.5 scenarios may suggest that the scenarios of climate changes may modify its distribution patterns and variations in suitable habitats. The double-edged effects of global warming on plant invasions may be a result of the scenario specific climate change and the species-specific responses to changes in climate. Our findings highlight the importance of climate change scenario specific and species-specific research on the impact of climate change on plant invasions.