scholarly journals Climate change enlarges China’s Great Bustards’ (Otis tarda dybowskii) suitable wintering distribution in the 21st century

2015 ◽  
Author(s):  
Chunrong Mi ◽  
Huettmann Falk ◽  
Yumin Guo
Keyword(s):  
Climate Change ◽  
Random Forest ◽  
21St Century ◽  
Species Distribution Model ◽  
Distribution Model ◽  
Current Conservation ◽  
Otis Tarda ◽  
Changing Climate ◽  
The North ◽  
Suitable Habitats

Rapidly changing climate makes humans realize that there is a critical need to rethink the current conservation and incorporate climate change adaptation into conservation planning. Whether Great Bustards’ (Otis tarda dybowskii), a globally endangered species whose population is approximately 1,500~2,200 individuals in China, would survive in a changing climate environment is an important protection issue. In this study, we selected the most suitable species distribution model for bustards from four machine learning models, combining two modelling approaches (TreeNet and Random Forest) with two sets of variables (correlated variables removed or not), using common evaluation methods (AUC, Kappa and TSS) and independent testing data. We found Random Forest with all environmental variables outperformed in all assessment methods. Projected the best model to the latest IPCC-CMIP5 climate scenarios (RCP 2.6, 4.5 and 8.5 in BCC-CSM1-1), we found suitable wintering habitats in the current bustards distribution would increase during the 21st century, and dramatically extend eastwards, lightly northwards and westwards, with ongoing climate change. Northeast Plain and the south of North China and the North of East China would become two major suitable wintering habitats of bustards. However, some current suitable habitats will experience a reduction, such as in Middle and Lower Yangtze. Although our results suggest the habitats quantity and quality would widen with climate changing, greater efforts should be undertaken on human disturbance, such as pollution, hunting, unsuitable agriculture development, infrastructure construction, habitat fragmentation, oil and mine exploitation. All of which are negatively and intensely linked with global change.

scholarly journals Climate change enlarges China’s Great Bustards’ (Otis tarda dybowskii) suitable wintering distribution in the 21st century

2015 ◽  
Author(s):  
Chunrong Mi ◽  
Huettmann Falk ◽  
Yumin Guo
Keyword(s):  
Climate Change ◽  
Random Forest ◽  
21St Century ◽  
Species Distribution Model ◽  
Distribution Model ◽  
Current Conservation ◽  
Otis Tarda ◽  
Changing Climate ◽  
The North ◽  
Suitable Habitats

Rapidly changing climate makes humans realize that there is a critical need to rethink the current conservation and incorporate climate change adaptation into conservation planning. Whether Great Bustards’ (Otis tarda dybowskii), a globally endangered species whose population is approximately 1,500~2,200 individuals in China, would survive in a changing climate environment is an important protection issue. In this study, we selected the most suitable species distribution model for bustards from four machine learning models, combining two modelling approaches (TreeNet and Random Forest) with two sets of variables (correlated variables removed or not), using common evaluation methods (AUC, Kappa and TSS) and independent testing data. We found Random Forest with all environmental variables outperformed in all assessment methods. Projected the best model to the latest IPCC-CMIP5 climate scenarios (RCP 2.6, 4.5 and 8.5 in BCC-CSM1-1), we found suitable wintering habitats in the current bustards distribution would increase during the 21st century, and dramatically extend eastwards, lightly northwards and westwards, with ongoing climate change. Northeast Plain and the south of North China and the North of East China would become two major suitable wintering habitats of bustards. However, some current suitable habitats will experience a reduction, such as in Middle and Lower Yangtze. Although our results suggest the habitats quantity and quality would widen with climate changing, greater efforts should be undertaken on human disturbance, such as pollution, hunting, unsuitable agriculture development, infrastructure construction, habitat fragmentation, oil and mine exploitation. All of which are negatively and intensely linked with global change.

scholarly journals Climate envelope predictions indicate an enlarged suitable wintering distribution for Great Bustards (Otis tarda dybowskii) in China for the 21st century

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e1630 ◽  
Author(s):  
Chunrong Mi ◽  
Huettmann Falk ◽  
Yumin Guo
Keyword(s):  
Climate Change ◽  
Random Forest ◽  
21St Century ◽  
Species Distribution Model ◽  
Distribution Model ◽  
Suitable Model ◽  
Otis Tarda ◽  
Changing Climate ◽  
Global Circulation Models ◽  
Suitable Habitats

The rapidly changing climate makes humans realize that there is a critical need to incorporate climate change adaptation into conservation planning. Whether the wintering habitats of Great Bustards (Otis tarda dybowskii), a globally endangered migratory subspecies whose population is approximately 1,500–2,200 individuals in China, would be still suitable in a changing climate environment, and where this could be found, is an important protection issue. In this study, we selected the most suitable species distribution model for bustards using climate envelopes from four machine learning models, combining two modelling approaches (TreeNet and Random Forest) with two sets of variables (correlated variables removed or not). We used common evaluation methods area under the receiver operating characteristic curves (AUC) and the True Skill Statistic (TSS) as well as independent test data to identify the most suitable model. As often found elsewhere, we found Random Forest with all environmental variables outperformed in all assessment methods. When we projected the best model to the latest IPCC-CMIP5 climate scenarios (Representative Concentration Pathways (RCPs) 2.6, 4.5 and 8.5 in three Global Circulation Models (GCMs)), and averaged the project results of the three models, we found that suitable wintering habitats in the current bustard distribution would increase during the 21st century. The Northeast Plain and the south of North China were projected to become two major wintering areas for bustards. However, the models suggest that some currently suitable habitats will experience a reduction, such as Dongting Lake and Poyang Lake in the Middle and Lower Yangtze River Basin. Although our results suggested that suitable habitats in China would widen with climate change, greater efforts should be undertaken to assess and mitigate unstudied human disturbance, such as pollution, hunting, agricultural development, infrastructure construction, habitat fragmentation, and oil and mine exploitation. All of these are negatively and intensely linked with global change.

scholarly journals Species Favourability Shift in Europe due to Climate Change: A Case Study for Fagus sylvatica L. and Picea abies (L.) Karst. Based on an Ensemble of Climate Models

2013 ◽  
Vol 2013 ◽  
pp. 1-18 ◽  
Author(s):  
Wolfgang Falk ◽  
Nils Hempelmann
Keyword(s):  
Climate Change ◽  
Species Distribution ◽  
Climate Models ◽  
Species Distribution Model ◽  
Regional Climate ◽  
European Beech ◽  
Regional Climate Models ◽  
Distribution Model ◽  
Continental Scale ◽  
The North

Climate is the main environmental driver determining the spatial distribution of most tree species at the continental scale. We investigated the distribution change of European beech and Norway spruce due to climate change. We applied a species distribution model (SDM), driven by an ensemble of 21 regional climate models in order to study the shift of the favourability distribution of these species. SDMs were parameterized for 1971–2000, as well as 2021–2050 and 2071–2100 using the SRES scenario A1B and three physiological meaningful climate variables. Growing degree sum and precipitation sum were calculated for the growing season on a basis of daily data. Results show a general north-eastern and altitudinal shift in climatological favourability for both species, although the shift is more marked for spruce. The gain of new favourable sites in the north or in the Alps is stronger for beech compared to spruce. Uncertainty is expressed as the variance of the averaged maps and with a density function. Uncertainty in species distribution increases over time. This study demonstrates the importance of data ensembles and shows how to deal with different outcomes in order to improve impact studies by showing uncertainty of the resulting maps.

scholarly journals Predicting invasion potential of Senna didymobotrya (Fresen.) Irwin & Barneby under the changing climate in Africa

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Elias Ch. Weldemariam ◽  
Sintayehu W. Dejene
Keyword(s):  
Climate Change ◽  
Species Distribution Model ◽  
Characteristic Curve ◽  
Climatic Conditions ◽  
Eastern Africa ◽  
Distribution Model ◽  
Climate Conditions ◽  
Changing Climate ◽  
Bioclimatic Variables ◽  
Suitable Area

Abstract Background Senna didymobotrya is a native African flowering shrub. It is suspected that climate change encourages the introduction and spread of invasive alien species. The possible invasion of S. didymobotrya across the continent is expected to increase in the future due to ongoing climate change. Nonetheless, there is still paucity of empirical evidence on the extent to which the changing climate contributes to the surge of the flowering shrub. This study, therefore, investigated the present and potential invasion of S. didymobotrya using the species distribution model under changing climate conditions. The two representative concentration pathways (RCP4.5 and RCP8.5) and eight bioclimatic variables and one topographic variable were used to simulate the current and future (2050s and 2070s) invasion of S. didymobotrya in Africa. The model performance was assessed using the area under the receiver operating characteristic curve (AUC) and true skill statistics (TSS). Results The results of the study showed that under the current climatic conditions, 18% of Africa is suitable for the establishment and invasion of S. didymobotrya. The most suitable hotspot for S. didymobotrya invasion is eastern Africa, followed by southern Africa. The predicted model showed that by 2050, 3.3% and 3.12% of the continent would be highly suitable areas for the invasion of the species under RCP4.5 and RCP8.5, respectively. In the 2070s, under RCP4.5 and RCP8.5, the highly suitable area would be 3.13% and 2.7%, respectively. In relation to the current suitability, the cumulative projected areas of the low and moderate suitability class under RCP4.5 and RCP8.5 will rise by the years 2050 and 2070. However, under both RCPs, the non-suitable area for S. didymobotrya invasion would gradually decrease. Conclusions From the findings, it can be concluded that the ecosystem’s vulnerability to S. didymobotrya invasion under future climatic conditions will proliferate significantly. Hence, to prevent the projected harm to biodiversity and ecosystem services, governments need to focus their future biodiversity management and policy directions on the means and strategies of minimizing the invasion and the distribution rate of S. didymobotrya across habitat types.

Distribution and Conservation Status of the Eichwald’s Toad, Bufo eichwaldi in Azerbaijan

2020 ◽  
Vol 27 (1) ◽  
pp. 11-18
Author(s):  
Artem A. Kidov ◽  
Kseniya A. Matushkina ◽  
Spartak N. Litvinchuk
Keyword(s):  
Species Distribution Model ◽  
Conservation Status ◽  
Distribution Model ◽  
The Caspian Sea ◽  
The West ◽  
The North ◽  
State Boundary ◽  
Northwestern Iran ◽  
Main Factors ◽  
Suitable Habitats

Distribution of Bufo eichwaldi in Azerbaijan was analyzed with the modeling application in Maxent. Based on 36 localities of the species, we developed a species distribution model for identification of suitable habitats. Two variables (annual precipitation and environmental habitat heterogeneity) accounted for 70% of the predicted range. The range of the species is limited in the East by a coast of the Caspian Sea, in the North and the West by dray steppes. In the South, the range crosses the state boundary and extends into northwestern Iran. All localities of this species are ranged from -26 m to 1000 m above sea level. The following main factors infuse the decline of B. eichwaldi populations: introduction of fishes and raccoons, destruction and contamination of suitable breeding ponds, and deforestation.

Identifying suitable habitats and current conservation status of a rare and elusive reptile in Iran

2018 ◽  
Vol 39 (3) ◽  
pp. 355-362 ◽  
Author(s):  
Rosa M. Chefaoui ◽  
Mahboubeh Sadat Hosseinzadeh ◽  
Meysam Mashayekhi ◽  
Barbod Safaei-Mahroo ◽  
Seyed Mahdi Kazemi
Keyword(s):  
Protected Areas ◽  
Species Distribution ◽  
Species Distribution Model ◽  
Conservation Status ◽  
Distribution Model ◽  
Reliable Estimate ◽  
Current Conservation ◽  
Mountain Ranges ◽  
Maximum Entropy Modeling ◽  
Suitable Habitats

Abstract Knowledge gaps regarding species distribution and abundance are great in remote regions with political instability, and they might be even larger concerning elusive and rare species. We predict the potential distribution for Hierophis andreanus, a poorly known endemic snake in the Iranian Plateau, and assess its conservation status in relation to existing protected areas. We used a maximum entropy modeling tool and Mahalanobis distance to produce an ensemble species distribution model. The most suitable habitats where located mainly in mountain ranges and adjacent areas of Iran and Afghanistan. Mean temperature and slope were the most important predictors for our models. Furthermore, just five localities for H. andreanus were inside the Iranian protected areas. A 10 km expansion from existing boundaries of protected areas in all directions would double protected localities to 10, and a 20 km buffer would result in 13 protected localities. Our findings are particularly valuable to select locations to conduct new surveys and produce a more reliable estimate of current population size to improve conservation and management for this reptile in the Irano-Anatolian region.

scholarly journals The effects of climate change on persistent organic pollutants (POPs) in the North Sea

2013 ◽  
Vol 10 (5) ◽  
pp. 1525-1557
Author(s):  
K. O'Driscoll ◽  
B. Mayer ◽  
J. Su ◽  
M. Mathis
Keyword(s):  
Climate Change ◽  
Organic Pollutants ◽  
North Sea ◽  
21St Century ◽  
Persistent Organic Pollutants ◽  
Global Ocean ◽  
Open Boundary ◽  
The North ◽  
The Future ◽  
The North Sea

Abstract. The fate and cycling of two selected legacy persistent organic pollutants (POPs), PCB 153 and γ-HCH, in the North Sea in the 21st century have been modelled with combined hydrodynamic and fate and transport ocean models. To investigate the impact of climate variability on POPs in the North Sea in the 21st century, future scenario model runs for three 10 yr periods to the year 2100 using plausible levels of both in situ concentrations and atmospheric, river and open boundary inputs are performed. Since estimates of future concentration levels of POPs in the atmosphere, oceans and rivers are not available, our approach was to reutilise 2005 values in the atmosphere, rivers and at the open ocean boundaries for every year of the simulations. In this way, we attribute differences between the three 10 yr simulations to climate change only. For the HAMSOM and atmospheric forcing, results of the IPCC A1B (SRES) 21st century scenario are utilised, where surface forcing is provided by the REMO downscaling of the ECHAM5 global atmospheric model, and open boundary conditions are provided by the MPIOM global ocean model. Dry gas deposition and volatilisation of γ-HCH increase in the future relative to the present. In the water column, total mass of γ-HCH and PCB 153 remain fairly steady in all three runs. In sediment, γ-HCH increases in the future runs, relative to the present, while PCB 153 in sediment decreases exponentially in all three runs, but even faster in the future, both of which are the result of climate change. Annual net sinks exceed sources at the ends of all periods.

Projections of future habitat use by Atlantic bluefin tuna: mechanistic vs. correlative distribution models

2016 ◽  
Vol 74 (3) ◽  
pp. 698-716 ◽  
Author(s):  
Barbara A. Muhling ◽  
Richard Brill ◽  
John T. Lamkin ◽  
Mitchell A. Roffer ◽  
Sang-Ki Lee ◽  
...  
Keyword(s):  
Climate Change ◽  
North Atlantic ◽  
Species Distribution Model ◽  
Bluefin Tuna ◽  
Distribution Model ◽  
Balance Model ◽  
Oxygen Balance ◽  
Spatiotemporal Resolution ◽  
Atlantic Bluefin Tuna ◽  
Fishing Fleets

Climate change is likely to drive complex shifts in the distribution and ecology of marine species. Projections of future changes may vary, however, depending on the biological impact model used. In this study, we compared a correlative species distribution model and a simple mechanistic oxygen balance model for Atlantic bluefin tuna (Thunnus thynnus: ABFT) in the North Atlantic Ocean. Both models gave similar results for the recent historical time period, and suggested that ABFT generally occupy favourable metabolic habitats. Projections from an earth system model showed largely temperature-induced reductions in ABFT habitat in the tropical and sub-tropical Atlantic by 2100. However, the oxygen balance model showed more optimistic results in parts of the subpolar North Atlantic. This was partially due to an inherent ability to extrapolate beyond conditions currently encountered by pelagic longline fishing fleets. Projections included considerable uncertainty due to the simplicity of the biological models, and the coarse spatiotemporal resolution of the analyses. Despite these limitations, our results suggest that climate change is likely to increase metabolic stress on ABFT in sub-tropical habitats, but may improve habitat suitability in subpolar habitats, with implications for spawning and migratory behaviours, and availability to fishing fleets.

scholarly journals Modelling the spatial-temporal distributions and associated determining factors of a keystone pelagic fish

2020 ◽  
Author(s):  
Samantha Andrews ◽  
Shawn J. Leroux ◽  
Marie-Josée Fortin
Keyword(s):  
Species Distribution Model ◽  
Spatial Dynamics ◽  
Predictive Modelling ◽  
Distribution Model ◽  
Ecological Processes ◽  
Pelagic Species ◽  
The North ◽  
Determining Factors ◽  
The North Atlantic Oscillation ◽  
Over Time

AbstractMobile pelagic species habitat is structured around dynamic oceanographic and ecological processes which operate and interact horizontally and vertically throughout the water column and change over time. However, pelagic species movements and distributions are often poorly understood. We use the Maxent species distribution model to assess how changes in the relative importance of modelled oceanographic (e.g., temperature) and climatic variables (e.g., the North Atlantic Oscillation) over 17-years affect the monthly average horizontal and vertical distribution of a keystone pelagic forage species, Atlantic Canadian capelin (Mallotus villosus). We show the range and distribution of capelin occurrence probabilities vary across horizontal and vertical axes over time, with binary presence/absence predictions indicating capelin occupy between 0.72% (April) and 3.45% (November) of the total modelled space. Furthermore, our analysis reveals that the importance of modelled oceanographic variables, such as temperature, vary between months (44% permutation importance in August to 2% in May). By capturing the spatial dynamics of capelin over horizontal, vertical, and temporal axes, our analysis builds on work that improves our understanding and predictive modelling ability of pelagic species distributions under current and future conditions for pro-active ecosystem-based management.

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