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.

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 ◽  
Species Distributions ◽  
Predictive Modelling ◽  
Distribution Model ◽  
Ecological Processes ◽  
Pelagic Species ◽  
The North ◽  
The North Atlantic Oscillation ◽  
Over Time

Abstract Mobile pelagic species habitat is structured around dynamic oceanographic and ecological processes that operate and interact horizontally and vertically throughout the water column and change over time. Due to their extensive movements, pelagic species 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 that 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, varies 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 proactive ecosystem-based management.

scholarly journals Dynamical Response of the Oceanic Eddy Field to the North Atlantic Oscillation: A Model–Data Comparison

2004 ◽  
Vol 34 (12) ◽  
pp. 2615-2629 ◽  
Author(s):  
Thierry Penduff ◽  
Bernard Barnier ◽  
W. K. Dewar ◽  
James J. O'Brien
Keyword(s):  
Atlantic Ocean ◽  
North Atlantic Oscillation ◽  
Time Scales ◽  
North Atlantic ◽  
Distribution Model ◽  
Altimeter Data ◽  
Dynamical Response ◽  
The North ◽  
The North Atlantic ◽  
The North Atlantic Oscillation

Abstract Observational studies have shown that in many regions of the World Ocean the eddy kinetic energy (EKE) significantly varies on interannual time scales. Comparing altimeter-derived EKE maps for 1993 and 1996, Stammer and Wunsch have mentioned a significant meridional redistribution of EKE in the North Atlantic Ocean and suggested the possible influence of the North Atlantic Oscillation (NAO) cycle. This hypothesis is examined using 7 yr of Ocean Topography Experiment (TOPEX)/Poseidon altimeter data and three ⅙°-resolution Atlantic Ocean model simulations performed over the period 1979–2000 during the French “CLIPPER” experiment. The subpolar–subtropical meridional contrast of EKE in the real ocean appears to vary on interannual time scales, and the model reproduces it realistically. The NAO cycle forces the meridional contrast of energy input by the wind. The analysis in this paper suggests that after 1993 the large amplitude of the NAO cycle induces changes in the transport of the baroclinically unstable large-scale circulation (Gulf Stream/North Atlantic Current) and, thus, changes in the EKE distribution. Model results suggest that NAO-like fluctuations were not followed by EKE redistributions before 1994, probably because NAO oscillations were weaker. Strong NAO events after 1994 were followed by gyre-scale EKE fluctuations with a 4–12-month lag, suggesting that complex, nonlinear adjustment processes are involved in this oceanic adjustment.

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 Modelling the potential ecological niche of domesticated buckwheat in China: archaeological evidence, environmental constraints and climate change

2021 ◽  
Author(s):  
Marta Krzyzanska ◽  
Harriet V. Hunt ◽  
Enrico R. Crema ◽  
Martin K. Jones
Keyword(s):  
Ecological Niche ◽  
Species Distribution Model ◽  
Modern China ◽  
Distribution Model ◽  
Distribution Data ◽  
Environmental Niche ◽  
Dispersal Pattern ◽  
Present Distribution ◽  
Potential Area ◽  
Over Time

AbstractWe present a species distribution model (SDM) of Fagopyrum esculentum (buckwheat) in China using present distribution data and estimates for the past based on palaeoclimatic reconstructions. Our model estimates the potential area suitable for buckwheat cultivation over the last 8,000 years, with northeast China consistently showing the highest suitability, providing insights on the discrepancy between the location of the earliest archaeobotanical records in the area and its origins in southwest China based on biogeographic and genetic data. The model suggests little to no variation over time in the spatial extent of the potential area suitable for buckwheat cultivation. In the northern parts of China, the limits of the ecological niche largely fall within the borders of the study area, while to the west it never extends into the main Tibetan plateau, explaining the lack of fossil evidence from Central Asia. In the southwest, the niche overlaps with the borders of modern China, which supports this direction as a viable route of westward dispersal. The comparison between the prediction from the model and sites with archaeobotanical evidence for Fagopyrum indicates that the environmental niche it occupied remained stable over time. This may contrast with a dispersal pattern characterised by continuous adaptations to new environments facilitated by human activity, which may be suggested for other major and minor crops.

Variability of the North Atlantic Oscillation in the 20th century

2021 ◽  
Author(s):  
André Düsterhus ◽  
Leonard Borchert ◽  
Vimal Koul ◽  
Holger Pohlmann ◽  
Sebastian Brune
Keyword(s):  
North Atlantic Oscillation ◽  
20Th Century ◽  
North Atlantic ◽  
Seasonal Prediction ◽  
Prediction Skill ◽  
Major Influence ◽  
The North ◽  
The North Atlantic ◽  
The North Atlantic Oscillation ◽  
Over Time

<p>The North Atlantic Oscillation (NAO) has over the year a major influence on European weather. In many applications, being it in modern or paleo climate science, the NAO is assumed to varying in strength, but otherwise often understood as being a constant feature of the pressure system over the North Atlantic. In recent years investigations on the seasonal-predictability of the winter NAO has shown that the prediction skill is varying over time. This opens the question, why this is the case and how well models are able to represent the NAO in all its variability over the 20th century.</p><p>To investigate this further we take a look at a seasonal prediction of the NAO with the Max Planck Institute Earth System Model (MPI-ESM) seasonal prediction system, with 30 members over the 20th century. We analyse its dependence of prediction skill on various features of the NAO and the North Atlantic system, like the Atlantic Multidecadal Variability (AMV). As such we will demonstrate, that the NAO is a much less stable system over time as currently assumed and that models may not be in the position to predict its full variability appropriately.</p>

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.

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 Influence of the North Atlantic oscillation on the atmospheric levels of benzo[a]pyrene over Europe

2021 ◽  
Author(s):  
Pedro Jiménez-Guerrero ◽  
Nuno Ratola
Keyword(s):  
Spatial Pattern ◽  
North Atlantic Oscillation ◽  
North Atlantic ◽  
Transport Model ◽  
Regional Scale ◽  
The South ◽  
Climatic Fluctuations ◽  
The North ◽  
The North Atlantic ◽  
The North Atlantic Oscillation

AbstractThe atmospheric concentration of persistent organic pollutants (and of polycyclic aromatic hydrocarbons, PAHs, in particular) is closely related to climate change and climatic fluctuations, which are likely to influence contaminant’s transport pathways and transfer processes. Predicting how climate variability alters PAHs concentrations in the atmosphere still poses an exceptional challenge. In this sense, the main objective of this contribution is to assess the relationship between the North Atlantic Oscillation (NAO) index and the mean concentration of benzo[a]pyrene (BaP, the most studied PAH congener) in a domain covering Europe, with an emphasis on the effect of regional-scale processes. A numerical simulation for a present climate period of 30 years was performed using a regional chemistry transport model with a 25 km spatial resolution (horizontal), higher than those commonly applied. The results show an important seasonal behaviour, with a remarkable spatial pattern of difference between the north and the south of the domain. In winter, higher BaP ground levels are found during the NAO+ phase for the Mediterranean basin, while the spatial pattern of this feature (higher BaP levels during NAO+ phases) moves northwards in summer. These results show deviations up to and sometimes over 100% in the BaP mean concentrations, but statistically significant signals (p<0.1) of lower changes (20–40% variations in the signal) are found for the north of the domain in winter and for the south in summer.

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