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1.
P. E. Berrozpe D. Lamattina M. S. Santini A. V. Araujo S. E. Torrusio O. D. Salomn 《Medical and veterinary entomology》2019,33(1):89-98
The spatiotemporal population dynamics of Lutzomyia longipalpis (Lutz & Neiva, 1912) (Diptera: Psychodidae) were evaluated in a city in Argentina in which visceral leishmaniasis is endemic. Over 14 sampling sessions, 5244 specimens of five species of Phlebotominae (Diptera: Psychodidae) were captured, of which 2458 (46.87%) specimens were L. longipalpis. Generalized linear models were constructed to evaluate the associations between L. longipalpis abundance and explanatory variables derived from satellite images. The spatial variable ‘stratum’ and the temporal variable ‘season’ were also included in the models. Three variables were found to have significant associations: the normalized difference vegetation index; land surface temperature, and low urban coverage. The last two of these were associated with L. longipalpis abundance only during summer and winter, respectively. This variation between seasons supports the development of models that include temporal variables because models of distributions of the abundance of a species may show different critical variables according to the climatic period of the year. Abundance decreased gradually towards the downtown area, which suggests that L. longipalpis responds to a meta‐population structure, in which rural–periurban source populations that persist over time may colonize adjacent areas. This information allows for a spatiotemporal stratification of risk, which provides public health authorities with a valuable tool to help optimize prevention measures against visceral leishmaniasis. 相似文献
2.
Mindy B. Rice Anthony D. Apa Michael L. Phillips James H. Gammonley Bradford B. Petch Karin Eichhoff 《The Journal of wildlife management》2013,77(4):821-831
The identification of core habitat areas and resulting prediction maps are vital tools for land managers. Often, agencies have large datasets from multiple studies over time that could be combined for a more informed and complete picture of a species. Colorado Parks and Wildlife has a large database for greater sage-grouse (Centrocercus urophasianus) including 11 radio-telemetry studies completed over 12 years (1997–2008) across northwestern Colorado. We divided the 49,470-km2 study area into 1-km2 grids with the number of sage-grouse locations in each grid cell that contained at least 1 location counted as the response variable. We used a generalized linear mixed model (GLMM) using land cover variables as fixed effects and individual birds and populations as random effects to predict greater sage-grouse location counts during breeding, summer, and winter seasons. The mixed effects model enabled us to model correlations that may exist in grouped data (e.g., correlations among individuals and populations). We found only individual groupings accounted for variation in the summer and breeding seasons, but not the winter season. The breeding and summer seasonal models predicted sage-grouse presence in the currently delineated populations for Colorado, but we found little evidence supporting a winter season model. According to our models, about 50% of the study area in Colorado is considered highly or moderately suitable habitat in both the breeding and summer seasons. As oil and gas development and other landscape changes occur in this portion of Colorado, knowledge of where management actions can be accomplished or possible restoration can occur becomes more critical. These seasonal models provide data-driven, distribution maps that managers and biologists can use for identification and exploration when investigating greater sage-grouse issues across the Colorado range. Using historic data for future decisions on species management while accounting for issues found from combining datasets allows land managers the flexibility to use all information available. © 2013 The Wildlife Society. 相似文献
3.
Atle Mysterud Brit Karen Vike Erling L. Meisingset Inger Maren Rivrud 《Ecology and evolution》2017,7(12):4448-4455
Large herbivores gain nutritional benefits from following the sequential flush of newly emergent, high‐quality forage along environmental gradients in the landscape, termed green wave surfing. Which landscape characteristics underlie the environmental gradient causing the green wave and to what extent landscape characteristics alone explain individual variation in nutritional benefits remain unresolved questions. Here, we combine GPS data from 346 red deer (Cervus elaphus) from four partially migratory populations in Norway with the satellite‐derived normalized difference vegetation index (NDVI), an index of plant phenology. We quantify whether migratory deer had access to higher quality forage than resident deer, how landscape characteristics within summer home ranges affected nutritional benefits, and whether differences in landscape characteristics could explain differences in nutritional gain between migratory and resident deer. We found that migratory red deer gained access to higher quality forage than resident deer but that this difference persisted even after controlling for landscape characteristics within the summer home ranges. There was a positive effect of elevation on access to high‐quality forage, but only for migratory deer. We discuss how the landscape an ungulate inhabits may determine its responses to plant phenology and also highlight how individual behavior may influence nutritional gain beyond the effect of landscape. 相似文献
4.
基于全球库存建模和制图研究(GIMMS)第三代归一化植被指数(NDVI3g)产品和气象数据,利用一元线性回归模型、偏相关分析和显著性T检验,分析了1982—2015年青藏高原高寒草甸和高寒草原春、夏、秋季NDVI时空演变的差异特征及其与气候因子的关系。研究表明：(1)高寒草甸春、夏、秋季NDVI整体均无明显变化趋势,高寒草原春季和夏季NDVI均显著增加,变化速率均为0.0002/a(P<0.05),而秋季NDVI变化趋势不明显。(2)空间上,高寒草甸春季NDVI显著增加面积占比31.95%,集中分布在祁连山区和三江源区,夏季NDVI显著增加的面积占比32.12%,主要分布在祁连山区、三江源地区和一江两河流域;秋季NDVI显著增加的比例为24.59%,集中分布于祁连山区和一江两河流域。高寒草原春、夏、秋季NDVI显著增加的区域均集中分布于西藏自治区北部和柴达木盆地南缘地区,分别占比44.20%、43.09%和37.99%。(3)高寒草甸春季和秋季NDVI均与气温显著正相关,偏相关系数达0.41(P<0.05)和0.23(P<0.05),夏季NDVI与气温、降水量和太阳辐... 相似文献
5.
Xiaohua Dai Chengpeng Long Jiasheng Xu Qingyun Guo Wei Zhang Zhihong Zhang Bater 《Ecology and evolution》2018,8(15):7633-7648
Dominant species significantly affect interspecific relationships, community structure, and ecosystem function. In the field, dominant species are often identified by their high importance values. Selective foraging on dominant species is a common phenomenon in ecology. Our hypothesis is that dominant plant groups with high importance values are more susceptible to leaf‐mining insects at the regional level. Here, we used the Saihanwula National Nature Reserve as a case study to examine the presence–absence patterns of leaf‐mining insects on different plants in a forest‐grassland ecotone in Northeast China. We identified the following patterns: (1) After phylogenetic correction, plants with high importance values are more likely to host leafminers at the species, genus, or family level. (2) Other factors including phylogenetic isolation, life form, water ecotype, and phytogeographical type of plants have different influences on the relationship between plant dominance and leafminer presence. In summary, the importance value is a valid predictor of the presence of consumers, even when we consider the effects of plant phylogeny and other plant attributes. Dominant plant groups are large and susceptible targets of leaf‐mining insects. The consistent leaf‐mining distribution pattern across different countries, vegetation types, and plant taxa can be explained by the “species‐area relationship” or the “plant apparency hypothesis.” 相似文献
6.
Hans‐Peter Piepho 《Biometrical journal. Biometrische Zeitschrift》2019,61(4):860-872
Extensions of linear models are very commonly used in the analysis of biological data. Whereas goodness of fit measures such as the coefficient of determination (R2) or the adjusted R2 are well established for linear models, it is not obvious how such measures should be defined for generalized linear and mixed models. There are by now several proposals but no consensus has yet emerged as to the best unified approach in these settings. In particular, it is an open question how to best account for heteroscedasticity and for covariance among observations present in residual error or induced by random effects. This paper proposes a new approach that addresses this issue and is universally applicable for arbitrary variance‐covariance structures including spatial models and repeated measures. It is exemplified using three biological examples. 相似文献
7.
研究青藏高原植被覆盖时空分布特征对加深气候变化的认识及生态环境保护具有重要的生态价值和现实意义。利用2000—2016年MODIS NDVI 1km/月分辨率数据以及气象观测数据,采用最大合成法、趋势性分析以及相关分析方法,探讨了不同时间尺度青藏高原地区NDVI的分布特征及其与降水、气温的关系。结果表明:(1)青藏高原东南部植被状况明显好于西北部,植被覆盖的分布格局与区域水热条件的时空分布保持了较好的一致性;近17年来青藏高原植被覆盖改善的地区要比退化的地区面积大,严重退化的区域主要位于青藏高原西南部;青藏高原NDVI值在2000—2016年呈幅度较小的增加趋势。(2)除夏季降水量外,研究时段内其他季节降水量均呈增加趋势;气温均呈增加趋势,尤其以春季增加最为显著,整体上青藏高原气候呈现\"暖湿化\"趋势。总体上年降水量与年最大合成NDVI呈较好的正相关;年平均气温与年最大合成NDVI在高原东南部呈正相关,西南部呈负相关。降水量和热量条件均是高原植被生长的影响因素,降水与植被覆盖的影响较气温密切。 相似文献
8.
Wittenburg D Guiard V Teuscher F Reinsch N 《Animal : an international journal of animal bioscience》2008,2(11):1559-1568
Genetics affects not only the weight of piglets at birth but also the variability of birth weight within litter. Previous studies on this topic assigned the sample standard deviation of piglet birth weights within litter as an observation to the sow. However, the contribution of the difference in mean birth weight per sex on the within-litter variance has been neglected so far. This work deals with the genetic effect on within-litter variance when different statistical models with different distributional assumptions are used and considers the sex effect and appropriate weights per trait. Traits were formed from the pooled sample variance of male and female birth weights within litter. A linear model approach was fitted to the logarithmized within-litter variance and the sample standard deviation. A generalized linear model with gamma-distributed residuals and log-link function was applied to the untransformed sample variance. Models were compared by analysing data from 9439 litters from Landrace and Large White of a commercial breeding programme. The estimates of heritability for different traits ranged from 7% to 11%. Although the generalized linear mixed model is preferred from a mathematical view, the rank correlations between breeding values of the linear mixed models and the generalized linear mixed model were relatively high, i.e. 94% to 98%. By residual diagnostics, a linear mixed model using the weighted and pooled within-litter standard deviation was identified as most suitable. 相似文献
9.
Luis Darcy Verde Arregoitia Simon P. Blomberg Diana O. Fisher 《Proceedings. Biological sciences / The Royal Society》2013,280(1765)
Phylogenetic information is becoming a recognized basis for evaluating conservation priorities, but associations between extinction risk and properties of a phylogeny such as diversification rates and phylogenetic lineage ages remain unclear. Limited taxon-specific analyses suggest that species in older lineages are at greater risk. We calculate quantitative properties of the mammalian phylogeny and model extinction risk as an ordinal index based on International Union for Conservation of Nature Red List categories. We test for associations between lineage age, clade size, evolutionary distinctiveness and extinction risk for 3308 species of terrestrial mammals. We show no significant global or regional associations, and three significant relationships within taxonomic groups. Extinction risk increases for evolutionarily distinctive primates and decreases with lineage age when lemurs are excluded. Lagomorph species (rabbits, hares and pikas) that have more close relatives are less threatened. We examine the relationship between net diversification rates and extinction risk for 173 genera and find no pattern. We conclude that despite being under-represented in the frequency distribution of lineage ages, species in older, slower evolving and distinct lineages are not more threatened or extinction-prone. Their extinction, however, would represent a disproportionate loss of unique evolutionary history. 相似文献
10.
稻-鸭农作系统对稻田生物种群的影响 总被引：4，自引：0，他引：4
通过田间试验,研究了稻-鸭农作系统对稻田有关生物种群的影响.结果表明：稻鸭共育对稻田相关昆虫、杂草、病原菌等有害生物的发生和危害及天敌数量具有较大影响.与不养鸭相比,稻鸭共育后12 d和42 d, 水稻基部害虫飞虱及叶蝉的数量平均减少64.8%和78.5%;稻鸭共育后15 d和45 d,稻田杂草平均减少67.7%和98.1%;水稻分蘖高峰期和齐穗期的纹枯病病情指数分别降低了40.4%和62.0%.稻鸭共育还增加了稻田害虫天敌蜘蛛的数量,抑制了水稻害虫的危害. 相似文献
11.
黄河流域位于我国干旱、半干旱地区,生态环境脆弱,探究其植被指数变化和对气候因子的响应对该地区生态建设具有重要意义。基于黄河流域2000—2018年MODIS归一化植被指数、增加型植被指数和气象数据,利用最大值合成法、趋势分析和相关分析等方法,分析了两种植被指数的时空变化特征及受气候因子的影响机制,探讨了NDVI与EVI在反映植被变化和对气候因子响应的差异。结果表明：2000—2018年,黄河流域地区植被NDVI、EVI分别以0.059/10a、0.038/10a的变化率增加,空间上以显著改善为主,面积占比分别为77.13%和75.27%,大多分布在1000—1500 m海拔处,中游地区改善较为良好,林地改善率最高。显著退化区域较小,主要分布在巴颜喀拉山西北部、西宁市、银川市、包头市、呼和浩特市、太原市、西安市及关中盆地和洛阳市周边,建设用地退化率最高。在生长季期间,植被指数变化与气温和降水以正相关为主,气温滞后时间为1个月,降水滞后时间为3个月,都为草地最为相关;与辐射之间为负相关,滞后时间为3个月,其中林地最为相关。在0.05显著性检验水平下,驱动黄河流域生长季植被变化的主要气候因子... 相似文献
12.
Modeling individual heterogeneity in capture probabilities has been one of the most challenging tasks in capture–recapture studies. Heterogeneity in capture probabilities can be modeled as a function of individual covariates, but correlation structure among capture occasions should be taking into account. A proposed generalized estimating equations (GEE) and generalized linear mixed modeling (GLMM) approaches can be used to estimate capture probabilities and population size for capture–recapture closed population models. An example is used for an illustrative application and for comparison with currently used methodology. A simulation study is also conducted to show the performance of the estimation procedures. Our simulation results show that the proposed quasi‐likelihood based on GEE approach provides lower SE than partial likelihood based on either generalized linear models (GLM) or GLMM approaches for estimating population size in a closed capture–recapture experiment. Estimator performance is good if a large proportion of individuals are captured. For cases where only a small proportion of individuals are captured, the estimates become unstable, but the GEE approach outperforms the other methods. 相似文献
13.
为了解黄河三角洲地区植被空间分布与环境因子之间的关系,通过局地植被样方调查、区域遥感影像提取归一化植被指数(NDVI)及地形高度、地下水位埋深、表层土壤Cl~-含量等环境数据采集,综合样地植被与环境数据进行了除趋势对应分析(DCA)和除趋势典范对应分析(DCCA),并对区域NDVI与主要环境变量进行了单因子相关性分析和多元逐步回归分析。结果显示:DCA排序可将黄河三角洲植被分为翅碱蓬、柽柳-翅碱蓬、芦苇-柽柳、芦苇4个主要群落类型(群丛),DCCA与DCA排序图总体相似,但DCCA更清晰地表明其第一轴主要代表的是潜水Cl~-浓度等关键水盐因子,且随着水土环境系统盐分含量的减小,群落由翅碱蓬逐渐向芦苇演变。区域典型植被群落和NDVI分布格局与变化趋势受地下水位埋深和潜水Cl~-浓度2个环境因素影响较大(NDVI与2个环境变量间建立的二元回归方程R~2=0.57),而土壤Cl~-含量的植被效应实际上受地下水位埋深和潜水Cl~-浓度的影响。在区域地下水普遍浅埋条件下,地下水成为影响植被生长与分布的生态环境最敏感要素,而地下水位埋深和潜水Cl~-浓度是这一要素中的2个关键因子,尤其是后者梯度变化对天然植被分布格局起重要的控制作用。 相似文献
14.
采用MODIS归一化植被指数(Normalized Difference Vegetation Index,NDVI)和地表温度(Land Surface Temperature,LST)产品数据分析新疆2000—2015年生长季3阶段NDVI与LST的时空变化特征及相关关系;利用多元线性回归方法分析不同时期影响NDVI-LST相关关系的气象因子;并按不同土地覆盖与土地利用(Land-Use and Land-Cover Change,LUCC)类型分析NDVILST相关关系时空变化特征。结果表明:(1)生长季3时期LST与NDVI均存在显著相关关系,可利用两者的特殊关系进行干旱评估。(2)不同时期气象因子对NDVI-LST相关关系影响程度不一;并且不同LUCC类型的NDVI-LST相关关系也存在明显差异。(3)在生长季中期利用植被健康指数(Vegetation Health Index,VHI)对新疆大部分地区的植被健康和干旱进行监测是可行有效的,而初期与末期的干旱评估需要利用其他干旱指数进行补充研究。 相似文献
15.
The specificity of the interactions between plants and their consumers varies considerably. The evolutionary and ecological factors underlying this variation are unclear. Several potential explanatory factors vary with latitude, for example plant species richness and the intensity of herbivory. Here, we use comparative phylogenetic methods to test the effect of latitude on host range in scale insects. We find that, on average, scale insects that occur in lower latitudes are more polyphagous. This result is at odds with the general pattern of greater host-plant specificity of insects in the tropics. We propose that this disparity reflects a high cost for host specificity in scale insects, stemming from unusual aspects of scale insect life history, for example, passive wind-driven dispersal. More broadly, the strong evidence for pervasive effects of geography on host range across insect groups stands in stark contrast to the weak evidence for constraints on host range due to genetic trade-offs. 相似文献
16.
区域归一化植被指数(NDVI)变化特征对环境容量和生态发展方向有重要指示作用。基于SPOT/VEGETATION NDVI数据和ESA CCI-LC植被分类数据,利用Theil-Sen+Mann-Kendall、变异系数、Hurst指数和相关性分析方法,对辽宁省2000—2019年不同植被类型归一化植被指数时空变化特征和气候因子之间的响应关系进行分析。结果表明：(1)NDVI均值呈现从乔木到草原逐渐降低的趋势,不同植被类型在生长季具有不同的生长习性;(2)各植被类型都呈增加趋势,结合Hurst指数和Sen趋势,辽宁省36.26%的植被将趋于改善,约有61.51%的植被将趋于退化;(3)变异系数结果表明：所有植被类型中以乔木植被最为稳定,草原型植被最不稳定。(4)辽宁省各植被类型NDVI与降水显著正相关,与气温相关性相对较低。结果可为辽宁省生态评价和碳循环研究提供植被覆盖动态参考。 相似文献
17.
Aim To examine potential impacts of climatic change on bird species richness of the fynbos and grassland biomes, especially on species of conservation concern, and to consider implications for biodiversity conservation strategy. Location Southern Africa, defined for this study as South Africa, Lesotho and Swaziland. Methods Climate response surfaces were fitted to model relationships between recorded distributions and reporting rates of 94 species and current bioclimatic variables. These models were used to project species’ potential ranges and reporting rates for future climatic scenarios derived from three general circulation models for 30‐year periods centred on 2025, 2055 and 2085. Results were summarized for species associated with each biome and examined in detail for 12 species of conservation concern. Results Species richness of fynbos and grassland bird assemblages will potentially decrease by an average of 30–40% by 2085 as a result of projected climatic changes. The areas of greatest richness are projected to decrease in extent and to shift in both cases. Attainment of projected shifts is likely to be limited by extent of untransformed habitat. Most species of conservation concern are projected to decrease in range extent, some by > 60%, and to decrease in reporting rate even where they persist, impacts upon their populations thus being greater than might be inferred from decreases in range extent alone. Two species may no longer have any areas of suitable climatic space by 2055; both already appear to be declining rapidly. Main conclusions Species losses are likely to be widespread with most species projected to decrease in range extent. Loss of key species, such as pollinators, may have far‐reaching implications for ecosystem function and composition. Conservation strategies, and identification of species of conservation concern, need to be informed by such results, notwithstanding the many uncertainties, because the certainties of climatic change make it essential that likely impacts not to be ignored. 相似文献
18.
城市地表温度与关键景观要素的关系 总被引：1，自引：0，他引：1
利用Landsat ETM+遥感影像,提取上海市外环线范围内的地表温度、不透水面率、归一化差值植被指数、改进的归一化差异水体指数,定量研究地表温度与城市关键景观类型之间的关系.结果表明:地表温度与不透水面率呈显著的线性正相关( R2=0.837);地表温度与归一化差值植被指数和改进的归一化差异水体指数呈非线性关系,但地表温度与正的归一化差值植被指数和正的改进的归一化差值水体指数呈显著线性关系.鉴于归一化差值植被指数和改进的归一化差异水体指数大于0时才能真正代表植被和水体,因此,建议今后研究地表温度时使用正的归一化差值植被指数和改进的归一化差异水体指数;地表温度与不透水面率、归一化差值植被指数和改进的归一化差值水体指数的多元线性回归分析表明,不透水面起着增温作用,植被、水体起降温作用,植被较水体的降温作用大. 相似文献
19.
Eliane S. Meier Heike Lischke Dirk R. Schmatz Niklaus E. Zimmermann 《Global Ecology and Biogeography》2012,21(2):164-178
Aim Species ranges have adapted during the Holocene to altering climate conditions, but it remains unclear if species will be able to keep pace with recent and future climate change. The goal of our study is to assess the influence of changing macroclimate, competition and habitat connectivity on the migration rates of 14 tree species. We also compare the projections of range shifts from species distribution models (SDMs) that incorporate realistic migration rates with classical models that assume no or unlimited migration. Location Europe. Methods We calibrated SDMs with species abundance data from 5768 forest plots from ICP Forest Level 1 in relation to climate, topography, soil and land‐use data to predict current and future tree distributions. To predict future species ranges from these models, we applied three migration scenarios: no migration, unlimited migration and realistic migration. The migration rates for the SDMs incorporating realistic migration were estimated according to macroclimate, inter‐specific competition and habitat connectivity from simulation experiments with a spatially explicit process model (TreeMig). From these relationships, we then developed a migration cost surface to constrain the predicted distributions of the SDMs. Results The distributions of early‐successional species during the 21st century predicted by SDMs that incorporate realistic migration matched quite well with the unlimited migration assumption (mean migration rate over Europe for A1fi/GRAS climate and land‐use change scenario 156.7 ± 79.1 m year?1 and for B1/SEDG 164.3 ± 84.2 m year?1). The predicted distributions of mid‐ to late‐successional species matched better with the no migration assumption (A1fi/GRAS, 15.2 ± 24.5 m year?1 and B1/SEDG, 16.0 ± 25.6 m year?1). Inter‐specific competition, which is higher under favourable growing conditions, reduced range shift velocity more than did adverse macroclimatic conditions (i.e. very cold or dry climate). Habitat fragmentation also led to considerable time lags in range shifts. Main conclusions Migration rates depend on species traits, competition, spatial habitat configuration and climatic conditions. As a result, re‐adjustments of species ranges to climate and land‐use change are complex and very individualistic, yet still quite predictable. Early‐successional species track climate change almost instantaneously while mid‐ to late‐ successional species were predicted to migrate very slowly. 相似文献
20.
《Evolutionary Applications》2018,11(5):739-747
According to the pre‐adaptation hypothesis, the evolution of insecticide resistance in plant‐eating insects co‐opts adaptations that initially evolved during chemical warfare with their host plants. Here, we used comparative statistics to test two predictions of this hypothesis: (i) Insects with more diverse diets should evolve resistance to more diverse insecticides. (ii) Feeding on host plants with strong or diverse qualitative chemical defenses should prime an insect lineage to evolve insecticide resistance. Both predictions are supported by our tests. What makes this especially noteworthy is that differences in the diets of plant‐eating insect species are typically ignored by the population genetic models we use to make predictions about insecticide resistance evolution. Those models surely capture some of the differences between host‐use generalists and specialists, for example, differences in population size and migration rates into treated fields, but they miss other potentially important differences, for example, differences in metabolic diversity and gene expression plasticity. Ignoring these differences could be costly. 相似文献