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Human Settlement Evaluation in Mountain Areas Based on Remote Sensing,GIS and Ecological Niche Modeling 被引量:7
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作者 ZHAO Jian XU Min +1 位作者 LU Shi-lei CAO Chun-xiang 《Journal of Mountain Science》 SCIE CSCD 2013年第3期378-387,共10页
The Qinghai-Tibet Plateau is the word's highest and largest plateau. Due to increasing demands for environment exploration and tourism, a large transitional area is required for altitude adaptation. Hehuang valley, w... The Qinghai-Tibet Plateau is the word's highest and largest plateau. Due to increasing demands for environment exploration and tourism, a large transitional area is required for altitude adaptation. Hehuang valley, which locates in the transition zone between the Loess Plateau and the Qinghai-Tibet Plateau, has convenient transportation and relatively low elevation. Our question is whether the geographic conditions here are appropriate for adapted stay before going into the Qinghai-Tibet Plateau. Therefore, in this study, we examined the potential use of ecological niche modeling (ENM) for mapping current and potential distribution patterns of human settlements. We chose the Maximum Entropy Method (Maxent), an ENM which integrates climate, remote sensing and geographical data, to model distributions and assess land suitability for transition areas. After preprocessing and selection, the correlation between variables and spatial auto- correlation input data were removed and 106 occurrence points and 9 environmental layers were determined as the model inputs. The threshold- independent model performance was reasonable according to lO times model running, with the area under the curve (AUC) values being 0.917± 0.01, and 0.923±0.002 for test data. Cohen's kappa coefficient of model performance was 0.848. Results showed that 82.22% of the study extent was not suitable for human settlement. Of the remaining areas, highly suitable areas aceounted for 1.19%, moderately for 5.3% and marginally for 11.28%. These suitable areas totaled 418.79 km2, and 86.25% of the sample data was identified in the different gradient of suitable area.The decisive environmental factors were slope and two climate variables: mean diurnal temperature range and temperature seasonality. Our model showed a good performance in mapping and assessing human settlements. This study provides the first predicted potential habitat distribution map for human settlement in Ledu County, which could also help in land use management. 展开更多
关键词 Human settlement Remote sensing Suitability assessment Ecological niche modeling
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Evolution of biogeographic disjunction between eastern Asia and North America in Chamaecyparis:Insights from ecological niche models 被引量:2
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作者 Ping Liu Jun wen Tingshuang Yi 《Plant Diversity》 SCIE CAS CSCD 北大核心 2017年第3期111-116,共6页
The disjunct distribution of plants between eastern Asia(EA) and North America(NA) is one of the most well-known biogeographic patterns. However, the formation and historical process of this pattern have been long deb... The disjunct distribution of plants between eastern Asia(EA) and North America(NA) is one of the most well-known biogeographic patterns. However, the formation and historical process of this pattern have been long debated. Chamaecyparis is a good model to test previous hypotheses about the formation of this disjunct pattern as it contains six species disjunctly distributed in EA, western North America(WNA)and eastern North America(ENA). In this study, we applied ecological niche models to test the formation of the disjunct pattern of Chamaecyparis. The model calibrated with the EA species was able to predict the distribution of eastern NA species well, but not the western NA species. Furthermore, the eastern Asian species were shown to have higher niche overlap with the eastern North American species. The EA species were also shown to share more similar habitats with ENA species than with WNA species in the genus. Chamaecyparis species in WNA experienced a significant niche shift compared with congeneric species. Chamaecyparis had a low number of suitable regions in Europe and the middle and western NA during the Last Glacial Maximum(LGM) period, and became extinct in the former region whereas it retains residual distribution in the latter. The extirpations in western NA and Europe in response to the late Neogene and Quaternary climatic cooling and the more similar habitats between ENA and EA ultimately shaped the current intercontinental disjunct distribution of Chamaecyparis. Both current hypotheses may be also jointly applied to explain more eastern Asian and eastern North American disjunctions observed today. 展开更多
关键词 DISJUNCTION Eastern Asia North America CHAMAECYPARIS Ecological niche models MAXENT
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Predicting the potential geographic distribution of Bactrocera bryoniae and Bactrocera neohumeralis(Diptera: Tephritidae) in China using MaxEnt ecological niche modeling 被引量:7
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作者 Jing Wan QI Guo-jun +3 位作者 MA Jun Yonglin REN WANG Rui Simon MCKIRDY 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2020年第8期2072-2082,共11页
Bactrocera bryoniae and Bactrocera neohumeralis are highly destructive and major biosecurity/quarantine pests of fruit and vegetable in the tropical and subtropical regions in the South Pacific and Australia.Although ... Bactrocera bryoniae and Bactrocera neohumeralis are highly destructive and major biosecurity/quarantine pests of fruit and vegetable in the tropical and subtropical regions in the South Pacific and Australia.Although these pests have not established in China,precautions must be taken due to their highly destructive nature.Thus,we predicted the potential geographic distribution of B.bryoniae and B.neohumeralis across the world and in particular China by ecological niche modeling of the Maximum Entropy(Max Ent)model with the occurrence records of these two species.Bactrocera bryoniae and B.neohumeralis exhibit similar potential geographic distribution ranges across the world and in China,and each species was predicted to be able to distribute to over 20%of the globe.Globally,the potential geographic distribution ranges for these two fruit fly species included southern Asia,the central and the southeast coast of Africa,southern North America,northern and central South America,and Australia.While within China,most of the southern Yangtze River area was found suitable for these species.Notably,southern China was considered to have the highest risk of B.bryoniae and B.neohumeralis invasions.Our study identifies the regions at high risk for potential establishment of B.bryoniae and B.neohumeralis in the world and in particular China,and informs the development of inspection and biosecurity/quarantine measures to prevent and control their invasions. 展开更多
关键词 fruit fly Bactrocera bryoniae Bactrocera neohumeralis ecological niche modeling MAXENT potential geographic distribution habitat suitability
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A niche model to predict Microcystis bloom decline in Chaohu Lake, China 被引量:2
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作者 汪志聪 李钟杰 李敦海 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2012年第4期587-594,共8页
Cyanobacterial blooms occur frequently in lakes due to eutrophication. Although a number of models have been proposed to forecast algal blooms, a good and applicable method is still lacking. This study explored a simp... Cyanobacterial blooms occur frequently in lakes due to eutrophication. Although a number of models have been proposed to forecast algal blooms, a good and applicable method is still lacking. This study explored a simple and effective mathematical-ecological model to evaluate the growth status and predict the population dynamics of Microcystis blooms. In this study, phytoplankton were collected and identified from 8 sampling sites in Chaohu Lake every month from July to October, 2010. The niche breadth and niche overlap of common species were calculated using standard equations, and the potential relative growth rates of Microcystis were calculated as a weighted-value of niche overlap. In July, the potential relative growth rate was 2.79 (a.u., arbitrary units) but then rapidly declined in the following months to -3.99 a.u. in September. A significant correlation (R=0.998, P<0.01) was found in the model between the net-increase in biomass of Microcystis in the field and the predicted values calculated by the niche model, we concluded that the niche model is suitable for forecasting the dynamics of Microcystis blooms. Redundancy analysis indicated that decreases in water temperature, dissolved oxygen and total dissolved phosphorus might be major factors underlying bloom decline. Based on the theory of community succession being caused by resource competition, the growth and decline of blooms can be predicted from a community structure. This may provide a basis for early warning and control of algal blooms. 展开更多
关键词 Microcystis bloom niche breadth niche overlap predictive model Chaohu Lake
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EVOLUTIONARY DYNAMIC MODEL OF POPULATION WITH NICHE CONSTRUCTION AND ITS APPLICATION RESEARCH
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作者 李自珍 韩晓卓 李文龙 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2006年第3期327-334,共8页
Based on the theories and approaches in biomechanics, the mechanism and pattern of niche construction were discussed systematically. Through establishing the spatial pattern of niche and its measuring-fitness formula,... Based on the theories and approaches in biomechanics, the mechanism and pattern of niche construction were discussed systematically. Through establishing the spatial pattern of niche and its measuring-fitness formula, and the dynamic system models of single- and two-population with niche construction, including corresponding theoretical analysis and numerical simulation on their evolutionary dynamics of population and the mechanism of competitive coexistence, the co-evolutionary relationship between organisms and their environments was revealed. The results indicate that population dynamics is governed by positive feedback between primary ecological factors and resource content. Niche construction generates an evolutionary effect in system by influencing the fitness of population. A threshold effect exists in single population dynamic system, in dynamic system of two competitive populations, niche construction can lead to alternative competitive consequences, which may be a potential mechanism to explain the competitive coexistence of species. 展开更多
关键词 niche construction population dynamics evolutionary kinetics model competitive coexistence
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3D Bio-Printed Glioblastoma-Vascular Niche Models
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作者 Vivian KLee Hongyan Zou +1 位作者 Roland Friedel Guohao Dai 《医用生物力学》 EI CAS CSCD 北大核心 2019年第A01期23-23,共1页
Introduction Glioblastoma multiforme(GBM),a malignant brain tumor,is highly invasive and use brain microvessels to migrate and invade.Studying the perivascular invasion/migration of GBM may enable new possibilities in... Introduction Glioblastoma multiforme(GBM),a malignant brain tumor,is highly invasive and use brain microvessels to migrate and invade.Studying the perivascular invasion/migration of GBM may enable new possibilities in GBM therapy.However,the lack proper 3D study models that recapitulate GBM hallmarks restricts investigating cell-cell/cell-molecular interactions in tumor microenvironments.In this study,we created GBM-vascular niche models through 3D bioprinting [1-2] using patient-derived GBM cells with sternness(GSC:glioblastoma stem cells),vasculature endothelial cells(ECs),mural cells,and various hydrogels.Materials and methods Three GBM-vascular models were designed:Model A with large vessels and GBM spheroid;Model B with large-and micro-vessels,and GBM spheroid;Model C with large-and micro-vessels and scattered GBM cells.Large channels were created by sacrificial bioprinting.Microvessel network was formed through self-assembly of ECs(HUVEC or brain EC)and mural cells(fibroblast,pericytes,and/or astrocytes).Three GBM cell types were used in the study:SD02 and SD03 are GSCs;U87MG is a commercially-available GBM cell line.Collagen type I or fibrin hydrogel have been used as major scaffold materials.For drug treatment,Temozolomide in culture medium was perfused through large vasculatures in Model A.Results and discussion Three different GBM-vascular models were successfully fabricated and culture for 2-10.GSCs cultured in these models maintained sternness and heterogeneity during the long-term cultures.In Model A,GSCs actively invaded into the surrounding tissues(~Day26),initially regressed in response to the drug(~Day50),then developed therapeutic resistance and resumed aggressive invasion(~Day57).In Model B and C,three GBM types presented distinctive invasion patterns and EC-interactions.SD02 cells showed a spiky invasion pattern with elongated morphology.SD03 cells showed a more dispersed invasion pattern with many single cell migrations towards surrounding microvessels.U87MG cells showed a blunt invasion pattern,caused EC death in the spheroid form;however,the EC death was significantly reduced in the scattered single cell form.Conclusions In this study,we have created GBM-vascular niche models that can recapitulate various GBM characteristics such as cancer sternness,tumor type-specific invasion patterns,and drug responses with therapeutic resistance.Our models have a great potential in investigating patient-specific tumor behaviors under chemo-/radio-therapy conditions and consequentially helping to tailor personalized treatment strategy.The model platform is capable of modifying multiples variables including ECMs,cell types,vascular structures,and dynamic culture condition.Thus,it can be adapted to other biological systems and serve as a valuable tool for generating customized microenvironments. 展开更多
关键词 GBM niche Bio-Printed Glioblastoma-Vascular niche models
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Ecological Niche Modelling Reveals the Peculiarities of Ecological Disjunction Between Two Sympatric Racerunners in Kazakhstan:Eremias lineolata(Nikolsky,1897)and Eremias scripta(Strauch,1867)
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作者 Marina A.CHIRIKOVA Dmitry V.MALAKHOV 《Asian Herpetological Research》 SCIE CSCD 2023年第2期123-137,共15页
The ecological-niche models for two sympatric species,Eremias lineolata(Nikolsky,1897)and Eremias scripta(Strauch,1867),reveal evidence of spatial and temporal disjunction in the actual niches of both species.Eremias ... The ecological-niche models for two sympatric species,Eremias lineolata(Nikolsky,1897)and Eremias scripta(Strauch,1867),reveal evidence of spatial and temporal disjunction in the actual niches of both species.Eremias lineolata demonstrates a wide range of adaptations and,at the same time,has a greater need for winter precipitation and minimal temperature than E.scripta.Possible explanations for the thermal diversity of both species are provided.Thermal variables(monthly temperatures,monthly solar radiation,etc.)are traditionally important for ectotherm animals.Interestingly,as many as half of the key variables in both species are related to different aspects of environmental water balance(precipitation,air humidity,vapor pressure).There are several ways in which moisture may impact the lizard’s life cycle.Soil humidity is related to soil temperature and may be important during winter hibernation.In summer,soil humidity may support successful embryogenesis.Precipitation during the warm months is a key factor in maintaining the moisture content of the soil.In winter,snow cover provides a better thermal balance of the soil’s top layers where winter shelters are housed.Ecological niche modeling(ENM)is an interdisciplinary approach combining the geographical,climatic,ecological,and biological aspects of the wellbeing of species.This interdisciplinary approach lifts biological studies onto a new,integrative level,providing a comprehensive view on species biology and answering the questions that might not be answered if the traditional methods for studying animals were used alone. 展开更多
关键词 ECOLOGY Kazakhstan niche modelling racerunners species distribution
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基于Niche GA的灰色模型预测天然气管道腐蚀速率 被引量:6
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作者 秦政先 李长俊 +3 位作者 胡安鑫 陈开智 吴科 孙华锋 《油气储运》 CAS 北大核心 2007年第2期47-50,共4页
建立了管道腐蚀预测的基于小生境遗传算法灰色模型,将此预测模型应用于四川气田某输气管道的腐蚀速率和腐蚀深度的预测。预测结果表明,该模型的预测结果误差小,可以用于现场管道的腐蚀预测,是管道腐蚀预测的一种新方法。
关键词 天然气管道 灰色模型 小生境遗传算法 腐蚀速率 预测
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Inverting reservoir parameters in a two-phase fractured medium with a niche genetic algorithm
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作者 张生强 韩立国 +2 位作者 刘春成 张益明 巩向博 《Applied Geophysics》 SCIE CSCD 2012年第4期440-450,496,共12页
In this paper we calculate a synthetic medium surface displacement response that is consistent with real measurement data by applying the least-square principle and a niche genetic algorithm to the parameters inversio... In this paper we calculate a synthetic medium surface displacement response that is consistent with real measurement data by applying the least-square principle and a niche genetic algorithm to the parameters inversion problem of the wave equation in a two-phase medium. We propose a niche genetic multi-parameter (including porosity, solid phase density and fluid phase density) joint inversion algorithm based on a two-phase fractured medium in the BISQ model. We take the two-phase fractured medium of the BISQ model in a two- dimensional half space as an example, and carry out the numerical reservoir parameters inversion. Results show that this method is very convenient for solving the parameters inversion problem for the wave equation in a two-phase medium, and has the advantage of strong noise rejection. Relative to conventional genetic algorithms, the niche genetic algorithm based on a sharing function can not only significantly speed up the convergence, but also improve the inversion precision. 展开更多
关键词 Parameters inversion niche genetic algorithm BISQ model two-phase fracturedmedium wave equation
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基于Niche GA的灰色GM(1,1,λ,△t_k)优化模型 被引量:1
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作者 穆勇 李素昉 《山东理工大学学报(自然科学版)》 CAS 2003年第4期65-67,共3页
在非等间隔GM(1,1,D,△t_k)模型基础上,建立了更具一般性的非等间隔GM(1,1,λ,△t_k)模型,并给出了求解最优GM(1,1,λ,△t_k)模型的小生境遗传算法,实例证明,用GM(1,1,λ,△t_k)模型进行预测能取得好的效果。
关键词 灰色系统理论 灰色模型 非等间隔序列 GM(1 1 λ △tk)模型 nicheGA 小生境遗传算法
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Ecological Niche Divergence between Trapelus ruderatus(Olivier,1807)and T.persicus(Blanford,1881)(Sauria:Agamidae)in the Middle East 被引量:1
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作者 Seyyed Saeed HOSSEINIAN YOUSEFKHANI Omid MIRSHAMSI +2 位作者 Cetin ILGAZ Yusuf KUMLUTAS Aziz AVCI 《Asian Herpetological Research》 SCIE CSCD 2016年第2期96-102,共7页
Modeling the potential distribution areas for a given species is important in understanding the relationship between the actual distribution and the most suitable habitat for a species. In this study, we obtained all ... Modeling the potential distribution areas for a given species is important in understanding the relationship between the actual distribution and the most suitable habitat for a species. In this study, we obtained all available records of Trapelus ruderatus and Trapelus persicus from museums, literature and fieldwork and used them with environmental layers in the Maximum Entropy algorithm to predict highly suitable habitat areas. The distribution model of T. ruderatus and T. persicus showed excellent performance for both models (T. ruderatus AUC = 0.964 ± 0.001 and T. persicus AUC = 0.996 ± 0.003), and predicted suitable regions in Iran, Turkey, Iraq and Syria. Niche overlap was measured between the two groups by ENMtools and 13% overlapped. We used a niche identity test to determine differences between the niches of the two species. Finally, by comparing our null hypothesis to the true niche overlap of the two species, we were able to reject our null hypothesis of no difference between the niches. Due to the sympatric distribution pattern of these species, we do not need a background test for niche divergence. 展开更多
关键词 MaxEnt modeling habitat suitability niche differentiation Trapelus ruderatus Trapelus persicus MiddleEast
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Limiting climatic factors in shaping the distribution pattern and niche differentiation of Prunus dielsiana in subtropical China 被引量:2
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作者 Hong Zhu Xiangui Yi +3 位作者 Yongfu Li Yifan Duan Xianrong Wang Libing Zhang 《Journal of Forestry Research》 SCIE CAS CSCD 2021年第4期1467-1477,共11页
Subtropical forest in China has received much attention due to its complex geologic environment and bioclimatic heterogeneity.There have been very few studies addressing which climatic factors have shaped both distrib... Subtropical forest in China has received much attention due to its complex geologic environment and bioclimatic heterogeneity.There have been very few studies addressing which climatic factors have shaped both distribution patterns and niche differentiation of species from this region.It also remains unclear whether phylogenetic niche conservatism retains in plant species from this biodiversityrich subtropical region in China.In this study,we used geographic occurrence records and bioclimatic factors of Prunus dielsiana(Rosaceae),a wild cherry species,combined with the classical ENM-based DIVA-GIS software to access contemporary distribution and richness patterns of its natural populations.The current distribution of P.dielsiana occupied a relatively wide range but exhibited an uneven pattern eastward in general,and the core distribution zone of its populations are projected to concentrate in the Wushan and Wuling Mountain ranges of western China.Hydrothermic variables,particularly the Temperature Seasonality(bio4)are screened out quantitatively to be the most influential factors that have shaped the current geographical patterns of P.dielsiana.By comparison with other sympatric families,climatic niche at regional scale showed a pattern of phylogenetic niche conservatism within cherry species of Ros aceae.The effect of habitat filtering from altitude is more significant than those of longitude and latitude.We conclude that habitat filtering dominated by limiting hydrothermic factors is the primary driving process of the diversity pattern of P.dielsiana in subtropical China. 展开更多
关键词 BIOCLIM Climatic adaptation Most limiting factors Phylogenetic niche conservatism Species distribution modeling
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Combined Novel Gate Level Model and Critical Primary Input Sharing for Genetic Algorithm Based Maximum Power Supply Noise Estimation
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作者 田志新 刘勇攀 杨华中 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2007年第9期1375-1380,共6页
A gate level maximum power supply noise (PSN) model is defined that captures both IR drop and di/dt noise effects. Experimental results show that this model improves PSN estimation by 5.3% on average and reduces com... A gate level maximum power supply noise (PSN) model is defined that captures both IR drop and di/dt noise effects. Experimental results show that this model improves PSN estimation by 5.3% on average and reduces computation time by 10.7% compared with previous methods. Furthermore,a primary input critical factor model that captures the extent of primary inputs' PSN contribution is formulated. Based on these models,a novel niche genetic algorithm is proposed to estimate PSN more effectively. Compared with general genetic algorithms, this novel method can achieve up to 19.0% improvement on PSN estimation with a much higher convergence speed. 展开更多
关键词 power supply noise gate level model niche genetic algorithm
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Species abundance distribution models of Toona ciliata communities in Hubei Province,China 被引量:4
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作者 Yang Wang Huoming Zhou +2 位作者 Jingyong Cai Congwen Song Linzhao Shi 《Journal of Forestry Research》 SCIE CAS CSCD 2021年第1期103-117,共15页
The study of plant species abundance distribution(SAD)in natural communities is of considerable importance to understand the processes and ecological rules of community assembly.With the distribution of tree,shrub and... The study of plant species abundance distribution(SAD)in natural communities is of considerable importance to understand the processes and ecological rules of community assembly.With the distribution of tree,shrub and herb layers of eight natural communities of Toona ciliata as research targets,three diff erent ecological niche models were used:broken stick model,overlapping niche model and niche preemption model,as well as three statistical models:log-series distribution model,log-normal distribution model and Weibull distribution model,to fi t SAD of the diff erent vegetation layers based on data collected.Goodness-of-fi t was compared with Chi square test,Kolmogorov–Smirnov(K–S)test and Akaike Information Criterion(AIC).The results show:(1)based on the criteria of the lowest AIC value,Chi square value and K–S value with no signifi cant diff erence(p>0.05)between theoretic and observed SADs.The suitability and goodness-of-fi t of the broken stick model was the best of three ecological niche models.The log-series distribution model did not accept the fi tted results of most vegetation layers and had the lowest goodness-of-fi t.The Weibull distribution model had the best goodness-of-fi t for SADs.Overall,the statistical SADs performed better than the ecological ones.(2)T.ciliata was the dominant species in all the communities;species richness and diversity of herbs were the highest of the vegetation layers,while the diversities of the tree layers were slightly higher than the shrub layers;there were fewer common species and more rare species in the eight communities.The herb layers had the highest community evenness,followed by the shrub and the tree layers.Due to the complexity and habitat diversity of the diff erent T.ciliata communities,comprehensive analyses of a variety of SADs and tests for optimal models together with management,are practical steps to enhance understanding of ecological processes and mechanisms of T.ciliata communities,to detect disturbances,and to facilitate biodiversity and species conservation. 展开更多
关键词 Toona ciliata community Tree-shrubherb layers niche models Statistical models Species abundance distribution(SAD) model fi t
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Potential distributional shifts in North America of allelopathic invasive plant species under climate change models 被引量:3
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作者 Anson Wang Anthony E.Melton +1 位作者 Douglas ESoltis Pamela SSoltis 《Plant Diversity》 SCIE CAS CSCD 2022年第1期11-19,共9页
Predictive studies play a crucial role in the study of biological invasions of terrestrial plants under possible climate change scenarios.Invasive species are recognized for their ability to modify soil microbial comm... Predictive studies play a crucial role in the study of biological invasions of terrestrial plants under possible climate change scenarios.Invasive species are recognized for their ability to modify soil microbial communities and influence ecosystem dynamics.Here,we focused on six species of allelopathic flowering plants-Ailanthus altissima,Casuarina equisetifolia,Centaurea stoebe ssp.micranthos,Dioscorea bulbifera,Lantana camara,and Schinus terebinthifolia-Xhat are invasive in North America and examined their potential to spread further during projected climate change.We used Species Distribution Models(SDMs)to predict future suitable areas for these species in North America under several proposed future climate models.ENMEval and Maxent were used to develop SDMs,estimate current distributions,and predict future areas of suitable climate for each species.Areas with the greatest predicted suitable climate in the future include the northeastern and the coastal northwestern regions of North America.Range size estimations demonstrate the possibility of extreme range loss for these invasives in the southeastern United States,while new areas may become suitable in the northeastern United States and southeastern Canada.These findings show an overall northward shift of suitable climate during the next few decades,given projected changes in temperature and precipitation.Our results can be utilized to analyze potential shifts in the distribution of these invasive species and may aid in the development of conservation and management plans to target and control dissemination in areas at higher risk for potential future invasion by these allelopathic species. 展开更多
关键词 ALLELOPATHY Invasive species Species distribution models Ecological niche models Invasion impacts Multi-species assessment
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Additions of landscape metrics improve predictions of occurrence of species distribution models 被引量:1
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作者 rica Hasui Vinícius X.Silva +6 位作者 Rogrio G.T.Cunha Flavio N.Ramos Milton C.Ribeiro Mario Sacramento Marco T.P.Coelho Diego G.S.Pereira Bruno R.Ribeiro 《Journal of Forestry Research》 SCIE CAS CSCD 2017年第5期963-974,共12页
Species distribution models are used to aid our understanding of the processes driving the spatial patterns of species’ habitats. This approach has received criticism, however, largely because it neglects landscape m... Species distribution models are used to aid our understanding of the processes driving the spatial patterns of species’ habitats. This approach has received criticism, however, largely because it neglects landscape metrics. We examined the relative impacts of landscape predictors on the accuracy of habitat models by constructing distribution models at regional scales incorporating environmental variables (climate, topography, vegetation, and soil types) and secondary species occurrence data, and using them to predict the occurrence of 36 species in 15 forest fragments where we conducted rapid surveys. We then selected six landscape predictors at the landscape scale and ran general linear models of species presence/absence with either a single scale predictor (the probabilities of occurrence of the distribution models or landscape variables) or multiple scale predictors (distribution models + one landscape variable). Our results indicated that distribution models alone had poor predictive abilities but were improved when landscape predictors were added; the species responses were not, however, similar to the multiple scale predictors. Our study thus highlights the importance of considering landscape metrics to generate more accurate habitat suitability models. 展开更多
关键词 Ecological niche model Generalized linear models Habitat suitability Landscape structure MAXENT
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Towards a multiscale model of colorectal cancer 被引量:1
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作者 Ingeborg MM van Leeuwen Carina M Edwards +1 位作者 Mohammad Ilyas Helen M Byrne 《World Journal of Gastroenterology》 SCIE CAS CSCD 2007年第9期1399-1407,共9页
Colorectal cancer (CRC) is one of the best characterised cancers, with extensive data documenting the sequential gene mutations that underlie its development. Complementary datasets are also being generated describing... Colorectal cancer (CRC) is one of the best characterised cancers, with extensive data documenting the sequential gene mutations that underlie its development. Complementary datasets are also being generated describing changes in protein and RNA expression, tumour biology and clinical outcome. Both the quantity and the variety of information are inexorably increasing and there is now an accompanying need to integrate these highly disparate datasets. In this article we aim to explain why we believe that mathematical modelling represents a natural tool or language with which to integrate these data and, in so doing, to provide insight into CRC. 展开更多
关键词 Intestinal epithelium Crypt fission APC mutations Mathematical modelling Stem cell niche Wnt signalling
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Modelling the nesting-habitat of threatened vulture species in the caucasus:An ecosystem approach to formalising environmental factors in species distribution models
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作者 Rustam Pshegusov Victoria Chadaeva 《Avian Research》 SCIE CSCD 2023年第4期572-585,共14页
Abiotic factors play an important role in species localisation,but biotic and anthropogenic predictors must also be considered in distribution modelling for models to be biologically meaningful.In this study,we formal... Abiotic factors play an important role in species localisation,but biotic and anthropogenic predictors must also be considered in distribution modelling for models to be biologically meaningful.In this study,we formalised the biotic predictors of nesting sites for four threatened Caucasian vultures by including species distribution models(wild ungulates,nesting tree species)as biotic layers in the vulture Maxent models.Maxent was applied in the R dismo package and the best set of the model parameters were defined in the R ENMeval package.Performance metrics were continuous Boyce index,Akaike's information criterion,the area under receiver operating curve and true skill statistics.We also calculated and evaluated the null models.Kernel density estimation method was applied to assess the overlap of vulture ecological niches in the environmental space.The accessibility of anthropogenic food resources was estimated using the Path Distance measure that considers elevation gradient.The availability of pine forests(Scots Pine)and wild ungulates(Alpine Chamois and Caucasian Goat)contributed the most(29.6%and 34.3%)to Cinereous Vulture(Aegypius monachus)nesting site model.Wild ungulate distribution also contributed significantly(about 46%)to the Bearded Vulture(Gypaetus barbatus)model.This scavenger nests in the highlands of the Caucasus at a minimum distance of 5–10 km from anthropogenic facilities.In contrast,livestock as a food source was most important in colony distribution of Griffon Vulture(Gyps fulvus).The contribution of distances to settlements and agricultural facilities to the model was 45%.The optimal distance from Egyptian Vulture(Neophron percnopterus)nesting sites to settlements was only 3–10 km,to livestock facilities no more than 15 km with the factor contribution of about 57%.Excluding the wild ungulate availability,the ecological niches of studied vultures overlapped significantly.Despite similar foraging and nesting requirements,Caucasian vultures are not pronounced nesting and trophic competitors due to the abundance of nesting sites,anthropogenic food sources and successful niche sharing. 展开更多
关键词 Caucasian vultures Ecological niche differentiation Maxent Nesting sites Species distribution models
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Modelling the probability of presence of Aedes aegypti and Aedes albopictus in Iran until 2070
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作者 Mohammad Mehdi Sedaghat Faramarz Bozorg Omid +2 位作者 Mohammad Karimi Sajjad Haghi Ahmad Ali Hanafi-Bojd 《Asian Pacific Journal of Tropical Medicine》 SCIE CAS 2023年第1期16-25,共10页
Objective:To determine the suitable ecological habitats of Aedes(Ae.)aegypti and Ae.albopictus in Iran due to climate change by the 2070s.Methods:All data relating to the spatial distribution of Ae.aegypti and Ae.albo... Objective:To determine the suitable ecological habitats of Aedes(Ae.)aegypti and Ae.albopictus in Iran due to climate change by the 2070s.Methods:All data relating to the spatial distribution of Ae.aegypti and Ae.albopictus worldwide,which indicated the geographical coordinates of the collection sites of these mosquitoes,were extracted from online scientific websites and entered into an Excel file.The effect of climatic and environmental variables on these mosquitoes was evaluated using the MaxEnt model in the current and future climatic conditions in the 2030s,2050s,and 2070s.Results:The most suitable areas for the establishment of Ae.aegypti are located in the southern and northern coastal areas of Iran,based on the model outputs.The modelling result for suitable ecological niches of Ae.albopictus shows that in the current climatic conditions,the southern half of Iran from east to west,and parts of the northern coasts are prone to the presence of this species.In the future,some regions,such as Gilan and Golestan provinces,will have more potential to exist/establish Ae.albopictus.Also,according to the different climate change scenarios,suitable habitats for this species will gradually change to the northwest and west of the country.The temperature of the wettest season of the year(Bio8)and average annual temperature(Bio1)were the most effective factors in predicting the model for Ae.aegypti and Ae.albopictus,respectively.Conclusions:It is required to focus on entomological studies using different collection methods in the vulnerable areas of Iran.The future modelling results can also be used for long-term planning to prevent the entry and establishment of these invasive Aedes vectors in the country. 展开更多
关键词 Aedes aegypti Aedes albopictus Dengue fever CHIKUNGUNYA Ecological niche modeling Climate change
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Visualizing Patterns of Genetic Landscapes and Species Distribution of Taxus wallichiana(Taxaceae),Based on GIS and Ecological Niche Models 被引量:7
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作者 于海彬 张镱锂 +1 位作者 高俊刚 祁威 《Journal of Resources and Ecology》 CSCD 2014年第3期193-202,共10页
The Chinese yew(Taxus wallichiana),which is widely distributed in the Himalayas and in southern China,is now on the edge of extinction.In order to understand the evolutionary processes that control the current diver... The Chinese yew(Taxus wallichiana),which is widely distributed in the Himalayas and in southern China,is now on the edge of extinction.In order to understand the evolutionary processes that control the current diversity within this species at the genetic and ecological levels,its genetic patterns and range dynamics must first be identified and mapped.This knowledge can then be applied in the development of an effective conservation strategy.Based on molecular data obtained from 48 populations of T.wallichiana,we used GIS-based interpolation approach for the explicit visualization of patterns of genetic divergence and diversity,and a number of potential evolutionary hotspots have been specifically identified within the genetic landscape maps.Within the maps of genetic divergence and diversity,five areas of high inter-population genetic divergence and six areas of high intra-population genetic diversity have been highlighted in a number of separate mountain regions,and these evolutionary hotspots should have the priority to be protected.Furthermore,four geographical barriers have been identified: the eastern Himalayas,the Yunnan Plateau,the Hengduan Mountains and the Taiwan Strait.According to ecological niche modeling(ENM),the populations of T.wallichiana within the Sino-Himalayan Forest floristic subkingdom experienced westward expansion from the periods of Last Inter-glacial to Last Glacial Maximum(LGM).Following the LGM,the distribution range overall became reduced and fragmented.These findings challenge the classic mode of contraction-expansion in response to the last glaciation.In conclusion,our findings suggest that the changes in geographical landscapes and climate that occurred during the Quaternary resulted in current genetic landscape patterns. 展开更多
关键词 genetic landscape PHYLOGEOGRAPHY GIS Ecological niche models(ENMs) HIMALAYAS
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