Future Habitat Suitability Research Articles

Estimating Shifts in Phenology and Habitat Use of Cobia in Chesapeake Bay Under Climate Change

Cobia (Rachycentron canadum) is a large coastal pelagic fish species that represents an important fishery in many coastal Atlantic states of the U.S. They are heavily fished in Virginia when they migrate into Chesapeake Bay during the summer to spawn and feed. These coastal habitats have been subjected to warming and increased hypoxia which in turn could impact the timing of migration and the habitat suitability of Chesapeake Bay. With conditions expected to worsen, we project current and future habitat suitability of Chesapeake Bay for cobia and predict changes in their arrival and departure times as conditions shift. To do this we developed a depth integrated habitat model from archival tagging and physiology data from cobia that used Chesapeake Bay, and applied the model to contemporary and future temperature and oxygen output from a coupled hydrodynamic-biogeochemical model of Chesapeake Bay. We found that arrival occurs earlier and departure time occurs later when temperatures are warmer and that by mid- and end-of-century cobia may spend on average up to 30 and 65 more days, respectively, in Chesapeake Bay. By mid-century we do not expect habitat suitability to change substantially for cobia, but by end-of-century we project it will significantly decline and shift closer to the mouth of Chesapeake Bay. Our study provides evidence that cobia will have the capacity to withstand near term impacts of climate change, but that their migration phenology varies from year to year with changing temperatures. These findings emphasize the need to incorporate the relationship between fishes and their environment into how fisheries are managed. This information can also help guide managers when deciding the timing and allocation of a fishery.

Genetic Patterns and Climate Modelling Reveal Challenges for Conserving Sclerolaena napiformis (Amaranthaceae s.l.) an Endemic Chenopod of Southeast Australia

Sclerolaena napiformis is a perennial chenopod endemic to southeast Australia. Human-mediated habitat loss and fragmentation over the past century has caused a rapid decline in abundance and exacerbated reduced connectivity between remnant populations across three disjunct regions. To assess conservation requirements, we measured the genetic structure of 27 populations using double digest RADseq). We combined our genetic data with habitat models under projected climate scenarios to identify changes in future habitat suitability. There was evidence of regional differentiation that may pre-date (but also may be compounded) by recent habitat fragmentation. We also found significant correlation between genetic and geographic distance when comparing sites across regions. Overall, S. napiformis showed low genetic diversity and a relatively high proportion of inbreeding/selfing. Climate modelling, based on current occupancy, predicts a reduction in suitable habitat for S. napiformis under the most conservative climate change scenario. We suggest that the best conservation approach is to maximise genetic variation across the entire species range to allow dynamic evolutionary processes to proceed. We recommend a conservation strategy that encourages mixing of germplasm within regions and permits mixed provenancing across regions to maximise genetic novelty. This will facilitate shifts in genetic composition driven by individual plant fitness in response to the novel environmental conditions this species will experience over the next 50 years.

Mapping current and potential future distributions of the oak tree (Quercus aegilops) in the Kurdistan Region, Iraq

BackgroundThe oak tree (Quercus aegilops) comprises ~ 70% of the oak forests in the Kurdistan Region of Iraq (KRI). Besides its ecological importance as the residence for various endemic and migratory species, Q. aegilops forest also has socio-economic values—for example, as fodder for livestock, building material, medicine, charcoal, and firewood. In the KRI, Q. aegilops has been degrading due to anthropogenic threats (e.g., shifting cultivation, land use/land cover changes, civil war, and inadequate forest management policy) and these threats could increase as climate changes. In the KRI and Iraq as a whole, information on current and potential future geographical distributions of Q. aegilops is minimal or not existent. The objectives of this study were to (i) predict the current and future habitat suitability distributions of the species in relation to environmental variables and future climate change scenarios (Representative Concentration Pathway (RCP) 2.6 2070 and RCP8.5 2070); and (ii) determine the most important environmental variables controlling the distribution of the species in the KRI. The objectives were achieved by using the MaxEnt (maximum entropy) algorithm, available records of Q. aegilops, and environmental variables.ResultsThe model demonstrated that, under the RCP2.6 2070 and RCP8.5 2070 climate change scenarios, the distribution ranges of Q. aegilops would be reduced by 3.6% (1849.7 km2) and 3.16% (1627.1 km2), respectively. By contrast, the species ranges would expand by 1.5% (777.0 km2) and 1.7% (848.0 km2), respectively. The distribution of the species was mainly controlled by annual precipitation. Under future climate change scenarios, the centroid of the distribution would shift toward higher altitudes.ConclusionsThe results suggest (i) a significant suitable habitat range of the species will be lost in the KRI due to climate change by 2070 and (ii) the preference of the species for cooler areas (high altitude) with high annual precipitation. Conservation actions should focus on the mountainous areas (e.g., by establishment of national parks and protected areas) of the KRI as climate changes. These findings provide useful benchmarking guidance for the future investigation of the ecology of the oak forest, and the categorical current and potential habitat suitability maps can effectively be used to improve biodiversity conservation plans and management actions in the KRI and Iraq as a whole.

Climate Change May Imperil Tea Production in the Four Major Tea Producers According to Climate Prediction Models

The threat of accelerating climate change on species distribution now and in the future is a topic of increasing research interest. However, little work has been undertaken to assess how shifting climates will affect the suitability of tea cultivation. Therefore, we used MaxEnt modelling to project the impact of current and future climatic scenarios on the potential distribution of tea across the four tea-producing countries of China, India, Kenya and Sri Lanka. Projections were made for the years 2050 and 2070 with three Representative Concentration Pathways (RCPs) using seven bioclimatic predictors under three global circulation models (GCMs). The current and future habitat suitability for tea predicted by the models produced a high accuracy rate, with high areas under the receiver operating characteristic curve (AUCs) for all tested RCPs under the three GCMs for the four countries. The mean true skill statistic (TSS) values for tea in Sri Lanka, Kenya, India and China were 0.80, 0.91, 0.91, and 0.74, respectively. The kappa values (k) of the current and future models for all four countries ranged from 0.40 to 0.75, which indicates that the overall performance of the model was good. The precipitation seasonality and annual precipitation were found to be the most influential variables in Sri Lanka and India, respectively, while annual mean temperature was the most effective contributor for determining the suitability of habitat for tea in Kenya and China. An important proviso is that some existing tea-growing areas will face reduced suitability for future tea cultivation suggesting that by 2050 there will be a drastic reduction in the optimal suitability by averages of 26.2%, 14%, and 4.7% in Kenya, Sri Lanka and China, respectively. The optimal suitability will be reduced by 15.1%, 28.6% and 2.6% in Kenya, Sri Lanka and China, respectively, by 2070. India displays an advantage in projected future climates as it gains optimal suitability areas of 15% by 2050 and 25% by 2070.

Study on Taiwania cryptomerioides under climate change: MaxEnt modeling for predicting the potential geographical distribution

Changes in future climate will have an important impact on biodiversity. Taiwania cryptomerioides has important scientific value for the study of paleogeography, paleoclimate and paleobotany. Based on the environmental data and future scenarios provided by previous studies, the present and future suitable habitat for Taiwania cryptomerioides was modeled, and the significance of environmental factors that shape its distribution were evaluated in this study. Furthermore, a maximum entropy model (MaxEnt) and geographical information system (ArcGIS) were used to identify suitable regions under climate change scenarios in China. The 112 occurrence records and nine environmental factors were further analyzed in this work. Our results show that Taiwania cryptomerioides has a suitable habitat of 211.21 × 104 km2 across most of northeast China. Moreover, the altitude, annual mean temperature, precipitation of the driest month and precipitation of the wettest quarter were identified as the essential factors shaping habitat availability for Taiwania cryptomerioides. Furthermore, the area under the curve (AUC) of the train was 0.944, placing the model in the “excellent” category. As predicted by concentrations of four greenhouse gases from increasing emissions, ranges of species may decrease as global warming intensifies. Overall, the range shift to higher latitudes would gradually become significant. Our research offers suggestions for conservation both in theory and in application, as well as long-term management strategies for the species.

Land use and climate change interaction triggers contrasting trajectories of biological invasion

Global change drivers such as land use and climate changes are known to interact in their effects on biodiversity. The impact of these drivers on global biodiversity is increasingly evident in many forms including the spread of invasive species. Climate and land use changes affect introduction, colonization and spread of invasive species by affecting niche availability and dispersal potential. We tested the combined effects of land use and climate changes on the current and future habitat suitability of Rhododendron ponticum in Wales using a MaxEnt-based ecological niche model. We used two policy-driven land use change projections for Wales, in combination with two General Circulation Models and two Representative Concentration Pathways to derive eight different land use and climate change scenarios. In seven out of eight scenarios, the habitat suitability for R. ponticum is likely to reduce by 2030. However, in the eighth scenario representing an extreme where land use change and greenhouse gas emissions both accelerate, the interaction of land use and climate change forces an increase of habitat suitability of R. ponticum. The study highlights the importance of considering the combined effect of land use and climate change and including regional policy-based land use change projections to test the potential of an invasive species to expand or retreat in future.

The role of connectivity in the interplay between climate change and the spread of alien fish in a large Mediterranean river.

Understanding how global change and connectivity will jointly modify the distribution of riverine species is crucial for conservation biology and environmental management. However, little is known about the interaction between climate change and fragmentation and how movement barriers might impede native species from adjusting their distributions versus limit the further spread of alien species. In this study, we modelled the current and future distributions of 11 native and five alien fishes in the large and heavily fragmented Ebro River, located within the Mediterranean region, which has many freshwater endemics severely threatened by global change. We considered 10 climate change models and five modelling algorithms and assessed the effects of connectivity on the accessibility of future suitable habitats. Thereby, we identify most conflict-prone river reaches, that is, where barriers pose a particular trade-off between isolating and negatively impacting native species versus potentially reducing the risk of alien species spread. Our results projected upstream habitat shifts for the vast majority of the species. Climate change affected species differently, with alien species generally showing larger habitat gains compared to natives. Most pronounced distributional changes (i.e. losses of native species and gains of alien species) and compositional turnover might be expected in the lower and mid reaches of large tributaries of the Ebro River. The role of anthropogenic barriers in this context is often ambiguous but rather unfavourable, as they not only restrict native fishes but also alter stream habitats and flow conditions. However, with our spatial modelling framework, we could identify specific river reaches where the connectivity trade-off in the context of climate change is particularly relevant. Overall, our findings emphasize the importance of the complex effects that climate change, riverine connectivity and alien species are expected to impose on river communities and the urgent need to adapt management strategies accordingly.

Climate Change and Alpine Screes: No Future for Glacial Relict Papaver occidentale (Papaveraceae) in Western Prealps

Glacial relicts, especially those with very narrow habitat requirements, are particularly affected by global warming. We considered Papaver occidentale, a glacial relict endemic to the Western Prealps, belonging to the alpine poppy complex (P. alpinum aggr.), as a model taxon to study the actual status and potential future distribution of species restricted to particular microrefugia. For this study, all known localities were visited, each population was georeferenced and the number of individuals was estimated. Species Distribution Modelling (SDM) was used to evaluate the present and future potential distribution range and habitat suitability, taking into account the specificity of its habitat (calcareous screes). According to our study, there are globally 19 natural populations of P. occidentale, and a total of about 30,000 individuals. The taxon is a highly specialized alpine plant growing in the majority of natural sites between 1900 and 2100 m a.s.l. on north-facing screes. Predictions for the end of the 21st century indicate that a suitable area will significantly decrease (0–30% remaining). Under the most severe climatic scenarios (RCP 8.5), the species risks complete extinction. The long-term in situ conservation of P. occidentale, and all other taxa of the P. alpinum complex, is unlikely to be achieved without slowing global climate change. More generally, our fine-scale study shows that local environmental buffering of large-scale climate change in high-mountain flora may be very limited in specialised taxa of patchy environments such as screes.

Predicting past, current and future habitat suitability and geographic distribution of the Iranian endemic species Microgecko latifi (Sauria: Gekkonidae)

The genus Microgecko Nikolsky 1907 belongs to the family Gekkonidae and contains eight species distributed in Iran, Pakistan, Afghanistan, northwestern India and, probably, in Iraq. Among them, the Latifi's dwarf gecko, Microgecko latifi, is endemic to central and southwestern Iran. We used MaxEnt modeling approach to investigate the effects of climate change and potential distribution of M. latifi. A total of 29 presence records and five factors related to precipitation and temperature were collected and used in the modeling approach for past, present and future. Our findings showed that Central Persia, the largest terrestrial ecoregion of Iran, hosts the most suitable environment for M. latifi under the current climate as well as under future scenarios. Differently, Zagros Mountains hosted the most suitable environment for this species under past climate. This is in line with previous studies that identified Zagros, Alborz, Kopet-Dagh Mountains and northwestern Iran as important Pleistocene refugia. Among environmental variables, precipitation of the warmest quarter was the most important driving factor for all models. According to other studies, species richness and diversity of lizards in Iran are higher in hot and arid environments; also considering the possible effects of global warming, further investigations are required in those environments.

Predicting the habitat distribution of rubber plantations with topography, soil, land use, and climatic factors.

Commercial demand is the prerequisite for the expansion of rubber plantation, which is highly dependent on climate, topography, and soil factors. Without the contextual knowledge on these factors, the expansion of rubber plantation would remain unproductive. This study thereby aimed to evaluate the current and future suitable habitat distributions of rubber using maximum entropy (MaxEnt) species distribution model in Xishuangbanna, Southwest China. A total of 148 field-based presence locations and environmental variables (soil, bioclimatic, topography, and land use) were used to predict the suitable areas of rubber plantations using HadGEM2-ES climate model. Medium and high climatic representative concentration pathways (RCPs) (4.5 and 8.5) were selected to predict the suitable habitats for the years 2050 and 2070. Among various factors, annual mean temperature, annual precipitation, precipitation of wettest month, precipitation seasonality, precipitation of warmest quarter, and soil exchangeable H+ contributed significantly to the distribution of rubber. Currently, 1119 km2 and 2716 km2 were predicted as high and moderately suitable areas respectively. It is predicted with increase rates in the high suitable areas, 49.96% and 328.95% by 2050 and 2070 respectively under RCP 4.5. This result indicates that the medium climate change of RCP 4.5 may have a direct positive effect on the expansion of habitat suitability of rubber. We also found potential areas for rubber cultivation in Jinghong and Mengla townships, where the further expansion is anticipated with desirable land-use planning by conserving reserve forest and native vegetation.

Climate change models predict decreases in the range of a microendemic freshwater fish in Honduras

Despite their incredible diversity, relatively little work has been done to assess impacts of climate change on tropical freshwater organisms. Chortiheros wesseli is a species of Neotropical cichlid (Cichlidae: Cichlinae) restricted to only a few river drainages in the Caribbean-slope of Honduras. Little is known about this species and few specimens had been collected until recently; however, our work with this species in the wild has led to a better understanding of its ecology and habitat preferences making it an excellent model for how freshwater fishes can be affected by climate change. This study assesses the distribution and habitats of Chortiheros wesseli using a combination of field data and species distribution modeling. Results indicate this species is largely limited to its current range, with no realistic suitable habitat nearby. Empirical habitat data show that this species is limited to narrow and shallow flowing waters with rapids and boulders. This habitat type is highly influenced by precipitation, which contributed the greatest influence on the models of present and future habitat suitability. Although several localities are within boundaries of national protected areas, species distribution models all predict a reduction in the range of this freshwater fish based on climate change scenarios. The likelihood of a reduced range for this species will be intensified by adverse changes to its preferred habitats.

Climate change and bird extinctions in the Amazon

In recent years, carbon dioxide emissions have been potentiated by several anthropogenic processes that culminate in climate change, which in turn directly threatens biodiversity and the resilience of natural ecosystems. Tropical rainforests are among the most impacted biological realms. The Belém endemism center, which is one of the several endemism centers in Amazon, is located in the most affected area within the so-called “Deforestation Arc.” Moreover, this region harbors a high concentration of Amazonian endangered bird species, of which 56% of them are considered to be under the threat of extinction. In this work, we sought to evaluate the current and future impacts of both climate change and deforestation on the distribution of endemic birds in the Belém Area of Endemism (BEA). Thus, we generated species distribution models for the 16 endemic bird species considering the current and two future gas emission scenarios (optimistic and pessimistic). We also evaluated climate change impacts on these birds in three different dispersal contexts. Our results indicate that BAE, the endemic taxa will lose an average of 73% of suitable areas by 2050. At least six of these birds species will have less than 10% or no future suitable habitat in all emission scenarios. One of the main mechanisms used to mitigate the impacts of climate change on these species in the near future is to assess the current system of protected areas. It is necessary to ensure that these areas will continue being effective in conserving these species even under climate change. The “Gurupi Mosaic” and the “Rio-Capim” watershed are areas of great importance because they are considered climate refuges according to our study. Thus, conservation efforts should be directed to the maintenance and preservation of these two large remnants of vegetation in addition to creating ecological corridors between them.

Modelling sexually deceptive orchid species distributions under future climates: the importance of plant\u2013pollinator interactions

Biotic interactions play an important role in species distribution models, whose ignorance may cause an overestimation of species' potential distributions. Species of the family Orchidaceae are almost totally dependent on mycorrhizal symbionts and pollinators, with sexually deceptive orchids being often highly specialized, and thus the interactions with their pollinators are expected to strongly affect distribution predictions. We used Maxent algorithm to explore the extent of current and future habitat suitability for two Greek endemic sexually deceptive orchids (Ophrys argolica and Ophrys delphinensis) in relation to the potential distribution of their unique pollinator (Anthophora plagiata). Twelve climate change scenarios were used to predict future distributions. Results indicated that the most important factors determining potential distribution were precipitation seasonality for O. argolica and geological substrate for O. delphinensis. The current potential distribution of the two orchids was almost of the same extent but spatially different, without accounting for their interaction with A. plagiata. When the interaction was included in the models, their potentially suitable area decreased for both species. Under future climatic conditions, the effects of the orchid-pollinator interaction were more intense. Specifically, O. argolica was restricted in specific areas of southern Greece, whereas O. delphinensis was expected to become extinct. Our findings highlighted the significant role of plant–pollinator interactions in species distribution models. Failing to study such interactions might expose plant species to serious conservation issues.

Species distribution modelling of invasive alien species; Pterois miles for current distribution and future suitable habitats

The present study aims to predict the potential geographic distribution and future expansion of invasive alien lionfish (Pterois miles) with ecological niche modelling along the Mediterranean Sea. The primary data consisted of occurrence points of P. miles in the Mediterranean and marine climatic data layers were collected from global databases. All the used models run 100% success predictions, and true skill statistics and area under the receiver operating characteristic curve values ranged from 0.42 and 0.71 to 0.86 and 0.95 for current distribution modelling; and 0.0 and 0.0 to 0.83 and 0.94 for the future distribution modelling, respectively. The mean sea surface temperature and maximum bathymetry played an important role in the prediction of the model and explained relatively higher biological importance to the extension and adaptation of P. miles with extreme environmental factors. The predicted suitable habitats of P. miles under the current climate dominantly occurred in the east parts of coastal areas of the Mediterranean. The predicted future suitable habitats of P. miles revealed that P. miles increase its range of distribution dominantly to the central and west part of the Mediterranean in a spatial extent, indicating high suitability of these areas for its future distribution.

Anticipatory Marine Conservation Outcomes: Management Scenarios for Whale Shark in Southeast Asia

The whale shark is a globally endangered species that is distributed in tropical and warm temperate waters. This study modeled the present-day and future habitat suitability of this species in the Sunda tectonic plate region in Southeast Asia to identify changes and highlight potential areas for conservation. Presence data from the International Union for Conservation of Nature were combined with six environment variables to model habitat suitability under three climate change scenarios. The present-day model results showed that most areas of high suitability matched the occurrence data. The future models generated revealed a small decrease in habitat suitability on the Sunda plate. In all of the three future models, two areas of high suitability were predicted: the central islands of the Philippines and southern Thailand. Areas of high suitability remained the same in the parts of the Gulf of Thailand, southern Indonesia, and the central islands of the Philippines. Based on this information, suggestions on how to protect the environment in these areas were made, including a regional assessment of the whale shark status and implementing a species recovery plan in Southeast Asia.

Combining US and Canadian forest inventories to assess habitat suitability and migration potential of 25 tree species under climate change

AbstractAimTo evaluate current and future dynamics of 25 tree species spanning United States and Canada.LocationUnited States and Canada.MethodsWe combine, for the first time, the species compositions from relative importance derived from the USA’s Forest Inventory Analysis (FIA) with gridded estimates based on Canada's National Forest Inventory (NFI‐kNN))‐based photo plot data to evaluate future habitats and colonization potentials for 25 tree species. Using 21 climatic variables under RCP 4.5 and RCP 8.5, we model climatic habitat suitability (HQ) within a consensus‐based multimodel ensemble regression approach. A migration model is used to assess colonization likelihoods (CL) for ~100 years and combined with HQ to evaluate the various combinations of HQ + CL outcomes for the 25 species.ResultsAt a continental scale, many species in the conterminous United States lose suitable climatic habitat (especially under RCP 8.5) while Canada and USA’s Alaska gain climate habitat. For most species, even under optimistic migration rates, only a small portion of overall future suitable habitat is projected to be naturally colonized in ~100 years, although considerable variation exists among species.Main conclusionsFor the species examined here, habitat losses were primarily experienced along southern range limits, while habitat gains were associated with northern range limits (especially under RCP 8.5). However, for many species, southern range limits are projected to remain relatively intact, albeit with reduced habitat quality. Our models predict that only a small portion of the climatic habitat generated by climate change will be colonized naturally by the end of the current century—even with optimistic tree migration rates. However, considerable variation among species points to the need for significant management efforts, including assisted migration, for economic or ecological reasons. Our work highlights the need to employ range‐wide data, evaluate colonization potentials and enhance cross‐border collaborations.

Genetic Diversity and Range Dynamics of Helleborus odorus subsp. cyclophyllus under Different Climate Change Scenarios

Research Highlights: The effects of climate change on habitat loss, range shift and/or genetic impoverishment of mid-elevation plants has received less attention compared to alpine species. Moreover, genetic diversity patterns of mountain forest herbaceous species have scarcely been explored in the Balkans. In this context, our study is the first that aims to examine Helleborus odorus subsp. cyclophyllus, a medicinal plant endemic to the southern part of the Balkan Peninsula. Background and Objectives: We compare its genetic diversity and structure along the continuous mountain range of western Greece with the topographically less structured mountains of eastern Greece, and predict its present and future habitat suitability, using several environmental variables. Materials and Methods: Inter Simple Sequence Repeat (ISSR) markers were used to genotype 80 individuals from 8 populations, covering almost the species’ entire distribution range in Greece. We investigated the factors shaping its genetic composition and driving its current and future distribution. Results: High gene diversity (0.2239–0.3319), moderate population differentiation (0.0317–0.3316) and increased gene flow (Nm = 1.3098) was detected. According to any GCM/RCP/climate database combination, Helleborus odorus subsp. cyclophyllus is projected to lose a significant portion of its current distribution by 2070 and follow a trend towards genetic homogenization. Conclusions: Populations exhibit in terms of genetic structure a west–east genetic split, which becomes more evident southwards. This is mainly due to geographic/topographic factors and their interplay with Quaternary climatic oscillations, and to environmental constraints, which may have a negative impact on the species’ future distribution and genetic composition. Pindos mountain range seems to buffer climate change effects and will probably continue to host several populations. On the other hand, peripheral populations have lower genetic diversity compared to central populations, but still hold significant evolutionary potential due to the private alleles they maintain.

Impact of climate on ecology and suitable habitat of Garcinia kola heckel in Nigeria

Garcinia kola is an indigenous multipurpose tree species, with significant cultural value and medical benefits, commonly found in the tropical rain forest zone of West and Central Africa. The species has been reported to be over-used and are now classified as vulnerable species close to commercial extinction. Hence, requires immediate conservation action. This study assessed the impact of climate on habitat for cultivation of G. kola in Nigeria. Ecological niche modelling approach was used to estimate the current geographical range and predicts the future distribution of G. kola in Nigeria, using the nineteen (19) bioclimatic environment layers at a 30 ′secs resolution. Two climate models were used (HadGEM2-ES and CNRM-CM5) with two Representative Concentration Pathways (RCP), RCP 4.5 and RCP 8.5 scenarios as predictor variables for projections of the potential geographical range of this species for 2050 horizon. Results revealed that about 397,094 km2 area, corresponding to 43.6% of Nigeria land surface, are currently suitable for cultivating G. kola. The future projections showed a significant decrease in area suitable for propagating G. kola under the RCP scenarios used in the two climate models. HadGEM2-ES predicts 27.2 and 26.1% loss of suitable habitats under RCP 4.5 and 8.5, respectively, by 2050 while CNRM-CM5 projects 26.7 and 35.8% decrease for the corresponding RCPs. Furthermore, the HadGEM2-ES predicts that 149,365 and 159,384 km2 corresponding to 16.4% and 17.5% of total land area will be suitable for cultivation of G. kola in Nigeria under RCP 4.5 and 8.5, respectively. The model results showed that climate change would have significant influence on the future suitable habitat of G. kola in Nigeria and the species is more subservient in moist, humid area and some part of derived savanna zone in Nigeria. The results underscore the significant influences of climate change on the ecology of G. kola. Based on these results, immediate action should be initiated to conserve this valued species and secure their inherent agro-ecosystems services

Predicting current and future suitable habitat and productivity for Atlantic populations of maritime pine (Pinus pinaster Aiton) in Spain

By combining inventory data and spatially-continuous environmental information, we were able to develop models for Atlantic populations of maritime pine ( Pinus pinaster Aiton) in Spain in order to predict suitable habitat and site index at a spatial resolution of 250 × 250 m. Currently available, spatially continuous environmental information was used to make reliable predictions about suitable habitat and forest productivity. To develop raster-based distribution and productivity models for Atlantic populations of maritime pine in Spain to predict current and future suitable habitat and productivity. Occurrence data and site index values were obtained from the Third Spanish National Forest Inventory and research plots, respectively. After testing different algorithms, random forest were selected for modelling the relationships between maritime pine occurrence, site index and spatially continuous environmental variables. The overall accuracy of the suitable habitat model was 73%, and climate (mainly thermal properties) and soil physical properties were the most important variables. The site index model explained 60% of the observed variability, and lithological properties were the most important variables. A slight increase in site index (0.46–0.51%) and a large increase in suitable habitat (50–66%) are expected for 2070 under the most pessimistic climate change scenario. The currently available spatial continuous information enables the development of accurate raster data models for predicting suitable habitat and site productivity without the need for fieldwork. Climate change is expected to increase the potentially suitable habitat of Atlantic maritime pine populations in Spain in the coming decades.

Paired air-water annual temperature patterns reveal hydrogeological controls on stream thermal regimes at watershed to continental scales

Despite decades of research into air and stream temperature dynamics, paired air-water annual temperature signals have been underutilized to characterize watershed processes. Annual stream temperature dynamics are useful in classifying fundamental thermal regimes and can enhance process-based interpretation of stream temperature controls, including deep and shallow groundwater discharge, when paired with air signals. In this study, we investigated multi-scale variability in annual paired air-water temperature patterns using sine-wave linear regressions of multi-year daily temperature data from streams of various sizes. A total of 311 sites from two spatially intensive regional datasets (Shenandoah National Park and Olympic Experimental State Forest) and a spatially extensive national dataset spanning the contiguous United States (U.S. Geological Survey gages) were evaluated. We calculated three annual air-water thermal metrics (mean ratio, phase lag, and amplitude ratio) to deduce the influence of groundwater and other watershed processes on stream thermal regimes at multiple spatial scales. Site-specific values of the three annual air-water thermal metrics ranged from 0.69 to 5.29 (mean ratio), −9 to 40 days (phase lag), and 0.29 to 1.12 (amplitude ratio). Regional patterns in the annual thermal metrics revealed persistent yet spatially variable influences of shallow groundwater discharge and high levels of thermal variability within watersheds, indicating the importance of local hydrogeological controls on stream temperature. Furthermore, annual thermal metric patterns from the regional datasets were generally concordant with the national dataset suggesting the utility of these annual thermal metrics for analysis at multiple scales. Analysis of the national dataset showed that previously defined thermal regimes based on water temperature alone could be further refined using air-water metrics and these metrics were related to physiographic watershed characteristics such as contributing area, elevation, and slope. This research demonstrates the importance of spatial scale and heterogeneity for inferring hydrological process in streams and provides guidance for the interpretation of annual air-water temperature metrics that can be efficiently applied to the growing database of multi-year temperature records. Results from this research can aid in the prediction of future thermal habitat suitability for coldwater-adapted species at ecologically and management-relevant spatial scales with readily available data.