scholarly journals Forecasting the potential distribution of the invasive vegetable leafminer using ‘top-down’ and ‘bottom-up’ models

2019 ◽  
Author(s):  
James L. Maino ◽  
Elia I. Pirtle ◽  
Peter M. Ridland ◽  
Paul A. Umina
Keyword(s):  
Species Distribution Model ◽  
Early Stage ◽  
Climatic Conditions ◽  
Distribution Model ◽  
Distribution Data ◽  
Top Down ◽  
Bottom Up ◽  
Population Growth Rates ◽  
Liriomyza Sativae ◽  
Establishment Potential

AbstractThe vegetable leafminer, Liriomyza sativae, is an internationally significant pest of vegetable and flower crops, that was detected for the first time on the Australian mainland in 2015. Due to the early stage of its invasion in Australia, it is unclear how climatic conditions are likely to support and potentially restrict the distribution of L. sativae as it expands into a novel range and threatens agricultural production regions. Here we predicted the future establishment potential of L. sativae in Australia, using both a novel ‘bottom-up’ process-based model and a popular ‘top-down’ correlative species distribution model (SDM), leveraging the unique strengths of each approach. Newly compiled global distribution data spanning 42 countries was used to validate the process-based model of establishment potential based on intrinsic population growth rates, as well as parameterise the correlative SDM. Both modelling approaches successfully captured the international distribution of L. sativae based on environmental variables and predicted the high suitability of non-occupied ranges, including northern regions of Australia. The largely unfilled climatic niche available to L. sativae in Australia demonstrates the early stage of its Australian invasion, and highlights locations where important vegetable and nursery production regions in Australia are highly vulnerable to L. sativae establishment.

scholarly journals Resident vegetation modifies climate-driven elevational shift of a mountain sedge

Alpine Botany ◽  
2020 ◽  
Author(s):  
Harald Crepaz ◽  
Georg Niedrist ◽  
Johannes Wessely ◽  
Mattia Rossi ◽  
Stefan Dullinger
Keyword(s):  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Species Distribution Model ◽  
Distribution Model ◽  
Distribution Data ◽  
Study Region ◽  
Potential Competitor ◽  
Elevational Shift ◽  
The Impact ◽  
Mountain Plant

Abstract Mountain plant species are changing their ranges in response to global warming. However, these shifts vary tremendously in rate, extent and direction. The reasons for this variation are yet poorly understood. A process potentially important for mountain plant re-distribution is a competition between colonizing species and the resident vegetation. Here, we focus on the impact of this process using the recent elevational shift of the sedge Carex humilis in the northern Italian Alps as a model system. We repeated and extended historical sampling (conducted in 1976) of the species in the study region. We used the historical distribution data and historical climatic maps to parameterize a species distribution model (SDM) and projected the potential distribution of the species under current conditions. We compared the historical and the current re-survey for the species in terms of the cover of important potential competitor species as well as in terms of the productivity of the resident vegetation indicated by the Normalized Difference Vegetation Index (NDVI). We found that Carex humilis has shifted its leading range margin upward rapidly (51.2 m per decade) but left many sites that have become climatically suitable since 1976 according to the SDM uncolonized. These suitable but uncolonized sites show significantly higher coverage of all dwarf shrub species and higher NDVI than the sites occupied by the sedge. These results suggest that resistance of the resident vegetation against colonization of migrating species can indeed play an important role in controlling the re-distribution of mountain plants under climate change.

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.

scholarly journals Habitat suitability modelling to assess the introductions of Aedes albopictus (Diptera, Culicidae) in the Netherlands

2020 ◽  
Author(s):  
Adolfo Ibañez-Justicia ◽  
Juan Diego Alcaraz-Hernández ◽  
Ron van Lammeren ◽  
Constantianus J.M. Koenraadt ◽  
Aldo Bergsma ◽  
...  
Keyword(s):  
The Netherlands ◽  
Aedes Albopictus ◽  
Habitat Suitability ◽  
Species Distribution Model ◽  
Climatic Conditions ◽  
Distribution Model ◽  
Adult Survival ◽  
Climatic Data ◽  
Model Based ◽  
Lst Model

Abstract Background In the Netherlands, Aedes albopictus has been found each year since 2010 during routine exotic mosquito species surveillance at companies that import used tires. We developed habitat suitability models to investigate the potential risk of establishment and spread of this invasive species at these locations. Methods We used two methodologies: first, a species distribution model based on the maximum entropy modelling approach (MaxEnt) taking into consideration updated occurrence data of the species in Europe, and second, a spatial logic conditional model based on the temperature requirements of the species and using land surface temperature data (LST model). Results Suitability assessment obtained with the MaxEnt model at European level accurately reflect the current distribution of the species and these results also depict moderately low values in parts of the Netherlands, Belgium, Denmark, the British islands and southern parts of Scandinavia. Winter temperature was the variable that contributed most to the performance of the model (47.3%). The results of the LST model show that 1) coastal areas are suitable for overwintering of eggs, 2) large areas in the northern part of the country have a low suitability for adult survival, and 3) the entire country is suitable for successful completion of the life cycle if the species is introduced after the winter months. Results of the LST model reveal that temperatures in 2012 and 2014 did not limit the overwintering of eggs or survival of adults at the locations where the species was found. By contrast, for the years 2010, 2011 and 2013, overwintering of eggs at these locations is considered unlikely. Conclusions Results using two modelling methodologies show differences in predicted habitat suitability values. Based on the results of both models, the climatic conditions could hamper the successful overwintering of eggs of Ae. albopictus and their survival as adults in many areas of the country. However, during warm years with mild winters, many areas of the Netherlands offer climatic conditions suitable for developing populations. Regular updates of the models, using updated occurrence and climatic data, are recommended to study the areas at risk.

scholarly journals Evaluation of species distribution models for estimating animal dark diversity

2021 ◽  
Author(s):  
Camilo Matus-Olivares ◽  
Jaime Carrasco ◽  
José Luis Yela ◽  
Paula Meli ◽  
Andres Weintraub ◽  
...  
Keyword(s):  
Spatial Patterns ◽  
Species Distribution ◽  
Species Distribution Model ◽  
Predictive Performance ◽  
The Other ◽  
Distribution Model ◽  
Distribution Data ◽  
Ensemble Model ◽  
Distribution Models ◽  
Software Environment

Abstract Aim Applying wide and effective sampling of animal communities is rarely possible due to the associated costs and the use of techniques that are not always efficient. Thus, many areas have a faunistic hidden diversity we denote Animal Dark Diversity (ADD), defined as the diversity that is present but not yet detected plus the diversity defined by Pärtel et al. (2011) that is not (yet) present despite the area’s favourable habitat conditions. We evaluated different species distribution model types (SDM techniques) on the basis of three requirements for ADD estimate reliability: 1) estimated spatial patterns of ADD do not differ significantly from other SDM techniques; 2) good predictive performances; and 3) low overfitting. Location Iberian Peninsula. Taxon Chiroptera and Noctuoidea (Lepidoptera) Methods We used distribution data for 25 species of bats and 352 species of moths. We evaluated eleven SDM techniques using biomod2 package implemented in the R software environment. We fitted the various SDM techniques to the data for each species and compared the resulting ADD estimates for the two animal groups under three threshold types. Results The results demonstrated that estimated ADD spatial patterns vary significantly between SDM techniques and depend on the threshold type. They also showed that SDM techniques with overfitting tend to generate smaller ADD sizes, thus reducing the possible species presence estimates. Among the SDMs studied, the ensemble models delivered ADD geographic patterns more like the other techniques while also presenting a high predictive performance for both faunal groups. However, the Ensemble Model Committee Average (ECA) performed much better on the sensitivity metric than all other techniques under any of the thresholds tested. In addition, ECA stood out clearly from the other ensemble model techniques in displaying low-medium overfitting. Main conclusions SDM techniques should no differ among each other in their ADD estimations, have good predictive performances and exhibit low overfitting. Furthermore, to reduce estimate uncertainty it is suggested that the threshold type be one that transforms high values of presences probabilities into binary information and furthermore that the SDM technique have a sensitivity bias, as otherwise the estimates will perform better for species absence in cases where it is not in fact known whether a species is truly absent.

Voluntary and Stimulus-Induced Attention Detected as Motion Sensation

Perception ◽  
1993 ◽  
Vol 22 (5) ◽  
pp. 517-526 ◽  
Author(s):  
Okihide Hikosaka ◽  
Satoru Miyauchi ◽  
Shinsuke Shimojo
Keyword(s):  
Information Processing ◽  
Response Bias ◽  
Visual Information ◽  
Stimulus Change ◽  
Early Stage ◽  
Visual Information Processing ◽  
Salient Object ◽  
Voluntary Attention ◽  
Top Down ◽  
Bottom Up

Attention may be drawn passively to a visually salient object. We may also actively direct attention to an object of interest. Do the two kinds of attention, passive and active, interact and jointly influence visual information processing at some neural level? What happens if the passive and active attentions come into conflict? These questions were addressed with the aid of a novel psychophysical technique which reveals an attentional gradient as a sensation of motion in a line which is presented instantaneously. The subjects were asked to direct attention with voluntary effort: to the side opposite to a stimulus change, to an object with a predetermined colour, and to an object moving smoothly. In every case the same motion sensation was induced in the line from the attended side to the unattended side. This voluntary attention, however, can easily and quickly be distracted by a change in the periphery, though it can be regained within a period of 200 to 500 ms. The results suggest that the line motion can be induced in voluntary (top-down) as well as stimulus-driven (bottom-up) situations, thus indicating the truly attentional nature of the effect, rather than it being some kind of retinotopic sensory artifact or response bias. The results also suggest that these two kinds of attention have facilitatory effects acting together on a relatively early stage of visual information processing.

scholarly journals Modelling the Effects of Climate Change on the Distribution of Endangered Cypripedium japonicum in China

Forests ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 429
Author(s):  
Yadong Xu ◽  
Yi Huang ◽  
Huiru Zhao ◽  
Meiling Yang ◽  
Yuqi Zhuang ◽  
...  
Keyword(s):  
Climate Change ◽  
Environmental Variables ◽  
Potential Distribution ◽  
Species Distribution Model ◽  
Characteristic Curve ◽  
Climatic Conditions ◽  
Distribution Model ◽  
Suitable Habitat ◽  
Mountainous Area ◽  
The Impact

Cypripedium japonicum is an endangered terrestrial orchid species with high ornamental and medicinal value. As global warming continues to intensify, the survival of C. japonicum will be further challenged. Understanding the impact of climate change on its potential distribution is of great significance to conserve this species. In this study, we established an ensemble species distribution model based on occurrence records of C. japonicum and 13 environmental variables to predict its potential distribution under current and future climatic conditions. The results show that the true skill statistic (TSS), Cohen’s kappa statistic (Kappa), and the area under the receiver operating characteristic curve (AUC) values of the ensemble model were 0.968, 0.906, and 0.995, respectively, providing more robust predictions. The key environmental variables affecting the distribution of C. japonicum were the precipitation in the warmest quarter (Bio18) and the mean temperature in the driest quarter (Bio9). Under future climatic conditions, the total suitable habitat of C. japonicum will increase slightly and tend to migrate northwestward, but the highly suitable areas will be severely lost. By 2070, the loss of its highly suitable habitat area will reach 57.69–72.24% under representative concentration pathway (RCP) 4.5 and 8.5 respectively, and the highly suitable habitats in Zhejiang and Anhui will almost disappear. It is noteworthy that the highly suitable habitat of C. japonicum has never crossed the Qinba mountainous area during the migration process of the suitable habitat to the northwest. Meanwhile, as the best-preserved area of highly suitable habitat for C. japonicum in the future, the Qinba mountainous area is of great significance to protect the wild germplasm resources of C. japonicum. In addition, we found that most of the changes predicted for 2070 will already be seen in 2050; the problem of climate change may be more urgent than it is believed.

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.

scholarly journals Possible changes in spatial distribution of walnut (Juglans regia L.) in Europe under warming climate

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Sonia Paź-Dyderska ◽  
Andrzej M. Jagodziński ◽  
Marcin K. Dyderski
Keyword(s):  
Environmental Management ◽  
Species Distribution Model ◽  
Juglans Regia ◽  
Range Shift ◽  
Distribution Model ◽  
Distribution Area ◽  
Distribution Data ◽  
Global Circulation Models ◽  
Annual Range ◽  
Bioclimatic Variables

AbstractJuglans regia L. is a species of great importance for environmental management due to attractive wood and nutritious fruits, but also high invasive potential. Thus, uncertainties connected with its range shift are essential for environmental management. We aimed to predict the future climatic optimum of J. regia in Europe under changing climate, to assess the most important climatic factors that determine its potential distribution, and to compare the results obtained among three different global circulation models (GCMs). We used distribution data from the Global Biodiversity Information Facility and completed it with data from the literature. Using the MaxEnt algorithm, we prepared a species distribution model for the years 2061–2080 using 19 bioclimatic variables. We applied three emission scenarios, expressed by representative concentration pathways (RCPs): RCP2.6, RCP4.5, and RCP8.5 and three GCMs: HadGEM2-ES, IPSL-CM5A-LR, and MPI-SM-LR. Our study predicted northward shift of the species, with simultaneous distribution loss at the southern edge of the current range, driven by increasing climate seasonality. Temperature seasonality and temperature annual range were the predictors of highest importance. General trends are common for the projections presented, but the variability of our projections among the GCMs or RCPs applied (predicted range will contract from 17.4 to 84.6% of the current distribution area) shows that caution should be maintained while managing J. regia populations. Adaptive measures should focus on maintaining genetic resources and assisted migration at the southern range edge, due to range contraction. Simultaneously, at the northern edge of the range, J. regia turns into an invasive species, which may need risk assessments and control of unintended spread.

scholarly journals Complex numerical responses to top–down and bottom–up processes in vertebrate populations

2002 ◽  
Vol 357 (1425) ◽  
pp. 1221-1231 ◽  
Author(s):  
A. R. E. Sinclair ◽  
Charles J. Krebs
Keyword(s):  
Growth Rate ◽  
Population Growth ◽  
Social Interactions ◽  
Growth Rates ◽  
Primary Standard ◽  
Primary Control ◽  
Top Down ◽  
Bottom Up ◽  
Population Growth Rates ◽  
Complex Interactions

Population growth rate is determined in all vertebrate populations by food supplies, and we postulate bottom–up control as the universal primary standard. But this primary control system can be overridden by three secondary controls: top–down processes from predators, social interactions within the species and disturbances. Different combinations of these processes affect population growth rates in different ways. Thus, some relationships between growth rate and density can be hyperbolic or even have multiple nodes. We illustrate some of these in marsupial, ungulate and rabbit populations. Complex interactions between food, predators, environmental disturbance and social behaviour produce the myriad observations of population growth in nature, and we need to develop generalizations to classify populations. Different animal groups differ in the combination of these four processes that affect them, in their growth rates and in their vulnerability to extinction. Because conservation and management of populations depend critically on what factors drive population growth, we need to develop universal generalizations that will relieve us from the need to study every single population before we can make recommendations for management.

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