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Gary Ervin Melissa Smothers Christopher Holly Cori Anderson Jeffrey Linville 《Biological invasions》2006,8(6):1425-1432
We assessed wetland invasibility by conducting surveys of three wetlands in each of five categories (riverine, depression, lacustrine fringe, mineral flat, and seepage slope). Invasibility was measured as the number of invasive species present, percent of plant species classified as invasive, percent cover of invasive plants, and percent of total cover represented by invasive species. The working hypothesis for this study was that certain types of wetlands (e.g., lacustrine fringe and riverine) would be more prone to invasion than others (spring-seep/slope wetlands or mineral flat wetlands). No significant differences were found among wetland types in any of the invasion metrics evaluated, despite high average invasibility in the riverine and lacustrine fringe categories. However, invasion was correlated very strongly with a qualitative index of anthropogenic modification to the surrounding landscape. A probable result of the substantial influence of human activities on wetland invasion in this study was that effects potentially attributable to greater opportunity for dispersal in certain types of wetlands were obscured. Another factor that likely contributed to the lack of differences among wetland types was the high variability in human activities observed among wetlands within types. These results further highlight the overwhelming contributions of anthropogenic habitat modification and human-assisted dispersal of invasive species to the currently observed homogenization of natural ecosystems. 相似文献
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Payton M. Phillips;Kelley E. Langhans;Matthew R. Helmus;Wendy A. M. Jesse;Yann Surget-Groba;Jocelyn E. Behm; 《Diversity & distributions》2024,30(7):e13858
The development of natural habitats into urban land uses has greatly accelerated in the recent past due to human activities. This habitat development disrupts species' natural dispersal processes and can lead to both direct and indirect impacts on dispersal. Whether human activities result in restricted or facilitated dispersal may depend on a species' development tolerance; however, this premise has not been tested. We examined the impact of urbanization and road networks on the dispersal of three lizard species in the context of their development tolerance. 相似文献
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Anthropogenic disturbances have serious impacts on ecosystems across the world. Understanding the effects of disturbance on woodlands, especially in regions where local people depend on these natural resources, is essential for sustainable natural resource management and biodiversity conservation. In this study, we evaluated the effects of anthropogenic disturbance, specifically selective logging of Brachystegia floribunda, on woodlands by comparing species composition, species diversity and functional diversity of woody plants between disturbed and undisturbed woodlands. We combined species data and functional trait data for leaves, fruits and other traits related to resource and disturbance responses to calculate functional indices (functional richness, evenness and divergence) and community‐weighted means of each trait. Shifts in taxonomic species composition were analysed using nonmetric multi‐dimensional scaling. Species composition differed significantly between disturbed and undisturbed woodlands. Tree density was greater in disturbed woodlands, whereas evenness, functional evenness and functional divergence were greater in undisturbed woodlands. In terms of forest cover, selective logging of B. floribunda appeared to have little impact on Miombo woodlands, but some shifts in functional traits, such as the shift from a deciduous to evergreen phenology, may increase the vulnerability of these ecosystems to environmental change, especially drought. 相似文献
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Samantha K. Dawson Carlos Prez Carmona Manuela Gonzlez&#x;Surez Mari Jnsson Filipe Chichorro Max Mallen&#x;Cooper Yolanda Melero Helen Moor John P. Simaika Alexander Bradley Duthie 《Ecology and evolution》2021,11(23):16434
Trait and functional trait approaches have revolutionized ecology improving our understanding of community assembly, species coexistence, and biodiversity loss. Focusing on traits promotes comparability across spatial and organizational scales, but terms must be used consistently. While several papers have offered definitions, it remains unclear how ecologists operationalize “trait” and “functional trait” terms. Here, we evaluate how researchers and the published literatures use these terms and explore differences among subdisciplines and study systems (taxa and biome). By conducting both a survey and a literature review, we test the hypothesis that ecologists’ working definition of “trait” is adapted or altered when confronting the realities of collecting, analyzing and presenting data. From 486 survey responses and 712 reviewed papers, we identified inconsistencies in the understanding and use of terminology among researchers, but also limited inclusion of definitions within the published literature. Discrepancies were not explained by subdiscipline, system of study, or respondent characteristics, suggesting there could be an inconsistent understanding even among those working in related topics. Consistencies among survey responses included the use of morphological, phonological, and physiological traits. Previous studies have called for unification of terminology; yet, our study shows that proposed definitions are not consistently used or accepted. Sources of disagreement include trait heritability, defining and interpreting function, and dealing with organisms in which individuals are not clearly recognizable. We discuss and offer guidelines for overcoming these disagreements. The diversity of life on Earth means traits can represent different features that can be measured and reported in different ways, and thus, narrow definitions that work for one system will fail in others. We recommend ecologists embrace the breadth of biodiversity using a simplified definition of “trait” more consistent with its common use. Trait‐based approaches will be most powerful if we accept that traits are at least as diverse as trait ecologists. 相似文献
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Richard T. Corlett 《Biotropica》2006,38(1):116-121
Hong Kong (22°N) is on the northern margins of the Asian tropics and has a native fig flora of 24 species. A total of 3.4 km2 of the urban area on Hong Kong Island was surveyed for spontaneous and planted fig plants of reproductive size. The 1124 individuals included 14 species in four subgenera: seven native species (F. fistulosa, F. hirta, F. hispida, F. microcarpa, F. pumila, F. subpisocarpa, and F. variegata), four of which were sometimes planted, one probably native (F. virens), one naturalizing species (F. religiosa), and five exotic species that occurred only in cultivation, two of which (F. altissima, F. rumphii) are pollinated and produce viable seeds. The native species in the two most common subgenera form distinct ecological guilds: those in subgenus Sycomorus bear large, many‐seeded, green or yellow figs and are bat‐dispersed pioneers on exposed soil; those in subgenus Urostigma bear small, few‐seeded, dark‐purple figs and are largely bird‐dispersed and epilithic. The density of potentially fruiting fig plants in the study area (2.3/ha) was within the range reported for tropical forests and between them they were visited by the entire urban frugivore fauna. This study shows the importance of the urban fig flora to urban wildlife and also highlights the risk of cultivated Ficus species becoming invasive, despite their obligate species‐specific pollinator mutualisms. 相似文献
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Krista K. Ingram Gabriel Bernardello Stefan Cover Edward O. Wilson 《Biological invasions》2006,8(2):383-387
A first study of the ants on the three main islands of the Juan Fernández Archipelago (Chile) has revealed the presence of just three species, Hypoponera confinis, Linepithema humile, and Tetramorium bicarinatum, all widely distributed invasive species. Most notable among them is the Argentine ant, L. humile, an ecologically destructive species that has established several populations and appears to be expanding. 相似文献
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Matthew A. Campbell Matthew C. Hale Chase S. Jalbert Kristine Dunker Adam J. Sepulveda J. Andrés López Jeffrey A. Falke Peter A. H. Westley 《Evolutionary Applications》2023,16(6):1119-1134
Invasive species are a major threat to global biodiversity, yet also represent large-scale unplanned ecological and evolutionary experiments to address fundamental questions in nature. Here we analyzed both native and invasive populations of predatory northern pike (Esox lucius) to characterize landscape genetic variation, determine the most likely origins of introduced populations, and investigate a presumably postglacial population from Southeast Alaska of unclear provenance. Using a set of 4329 SNPs from 351 individual Alaskan northern pike representing the most widespread geographic sampling to date, our results confirm low levels of genetic diversity in native populations (average 𝝅 of 3.18 × 10−4) and even less in invasive populations (average 𝝅 of 2.68 × 10−4) consistent with bottleneck effects. Our analyses indicate that invasive northern pike likely came from multiple introductions from different native Alaskan populations and subsequently dispersed from original introduction sites. At the broadest scale, invasive populations appear to have been founded from two distinct regions of Alaska, indicative of two independent introduction events. Genetic admixture resulting from introductions from multiple source populations may have mitigated the negative effects associated with genetic bottlenecks in this species with naturally low levels of genetic diversity. Genomic signatures strongly suggest an excess of rare, population-specific alleles, pointing to a small number of founding individuals in both native and introduced populations consistent with a species' life history of limited dispersal and gene flow. Lastly, the results strongly suggest that a small isolated population of pike, located in Southeast Alaska, is native in origin rather than stemming from a contemporary introduction event. Although theory predicts that lack of genetic variation may limit colonization success of novel environments, we detected no evidence that a lack of standing variation limited the success of this genetically depauperate apex predator. 相似文献
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Xiaoxia Huang Zhilu Sheng Kejian He Yong Zhang Bin Kang Jiao Ding Dongmei Liu 《Journal of Plant Ecology》2021,14(5):870
人为干扰下的亚高山草甸功能多样性和功能冗余人为干扰程度的加剧会引起植物群落物种多样性和功能多样性的改变,并降低生态系统的稳定性。较高水平的功能冗余对于物种损失引起的生态系统功能和稳定性的改变起到了重要的缓冲作用。然而,关于亚高山草甸植物群落功能冗余对干扰的响应的研究相对较少。本研究的目的是,确定人为干扰下不同退化程度的亚高山草甸,其植物群落功能多样性和功能冗余对干扰的响应特征,及不同物种对功能冗余的贡献程度及其在干扰梯度上的变化规律。研究区位于青藏高原东南缘玉龙雪山上的亚高山草甸。本研究识别出4类干扰强度(无干扰、弱干扰、中度干扰和重度干扰),测定了干扰梯度上的植物物种组成、土壤性质和5个关键的植物功能性状等指标,进一步计算了Simpson多样性指数、功能多样性指数(RaoQ)、功能冗余度、群落的植物功能性状加权平均值(CWM)以及物种水平的功能冗余等指数。研究结果表明,功能多样性和功能冗余在干扰梯度上呈现单峰变化规律,即二者分别在中度干扰、弱干扰下达到最大值。物种多样性在干扰梯度上整体呈下降趋势。随着干扰程度的增加,采取保守生长策略并具有相关性状特征(如较低比叶面积和较高的干物质含量)的物种的丰富度降低,采取资源获取策略并具有相关性状(如低矮植株、较高的比叶面积和较低的干物质含量)的物种增加。不同物种的功能冗余程度存在差异。值得注意的是,一些物种在群落中扮演着独特的功能角色,如无干扰梯度下的网脉橐吾(Ligularia dictyoneura)以及中度和重度干扰梯度下的滇西委陵菜(Potentilla delavayi)。 相似文献
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Pierre-Yves Henry Catalina Landeta Salgado Fanny Paucar Mu?oz Martin C. Wikelski 《Biology letters》2013,9(5)
All colonizing individuals have to settle in a novel, conspecific-free environment. The introduction process should be poorly compatible with a good rest. We compared the resting behaviour of radio-tagged house sparrows (Passer domesticus) experimentally translocated into new, conspecific-free areas (introduced individuals, n = 10), with that of translocated sparrows that settled in naturally established populations (controls, n = 5). Resting habits of introduced sparrows markedly differed from those of control birds: they did not vocalize before going to roost, they changed their roosting habitat and they roosted 24 ± 7 min later and departed 13 ± 4 min earlier from the roost, resulting in a 5% rest debt. Because colonizing a new environment is expected to require heightened cognitive and physical activities, which in turn are constrained by the quality and duration of rest, we hypothesize that rest disorders and resulting cognitive impairments of newly released individuals could functionally contribute to the low post-release survival observed in (re)introduction attempts. 相似文献
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Claudio S. Quilodrn Beatrice Nussberger Juan I. Montoya‐Burgos Mathias Currat 《Evolution; international journal of organic evolution》2019,73(4):750-761
Interbreeding between historically allopatric species with incomplete reproductive barriers may result when species expand their range. The genetic consequences of such hybridization depend critically on the dynamics of the range expansion. Hybridization models during range expansion have been developed but assume dispersal to be independent from neighboring population densities. However, organisms may disperse because they are attracted by conspecifics or because they prefer depopulated areas. Here, through spatially explicit simulations, we assess the effect of various density‐dependent dispersal modes on the introgression between two species. We find huge introgression from the local species into the invasive one with all dispersal modes investigated, even when the hybridization rate is relatively low. This represents a general expectation for neutral genes even if the dispersal modes differ in colonization times and amount of introgression. Invasive individuals attracted by conspecifics need more time to colonize the whole area and are more introgressed by local genes, whereas the opposite is found for solitary individuals. We applied our approach to a recent expansion of European wildcats in the Jura Mountains and the hybridization with domestic cats. We show that the simulations explained better the observed level of introgression at nuclear, mtDNA, and Y chromosome markers, when using solitary dispersal for wildcats instead of random or gregarious dispersal, in accordance with ecological knowledge. Thus, use of density‐dependent dispersal models increases the predictive power of the approach. 相似文献
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Julian Schrader Ian J. Wright Holger Kreft Mark Westoby 《Biological reviews of the Cambridge Philosophical Society》2021,96(6):2851-2870
Island biogeography is the study of the spatio-temporal distribution of species, communities, assemblages or ecosystems on islands and other isolated habitats. Island diversity is structured by five classes of process: dispersal, establishment, biotic interactions, extinction and evolution. Classical approaches in island biogeography focused on species richness as the deterministic outcome of these processes. This has proved fruitful, but species traits can potentially offer new biological insights into the processes by which island life assembles and why some species perform better at colonising and persisting on islands. Functional traits refer to morphological and phenological characteristics of an organism or species that can be linked to its ecological strategy and that scale up from individual plants to properties of communities and ecosystems. A baseline hypothesis is for traits and ecological strategies of island species to show similar patterns as a matched mainland environment. However, strong dispersal, environmental and biotic-interaction filters as well as stochasticity associated with insularity modify this baseline. Clades that do colonise often embark on distinct ecological and evolutionary pathways, some because of distinctive evolutionary forces on islands, and some because of the opportunities offered by freedom from competitors or herbivores or the absence of mutualists. Functional traits are expected to be shaped by these processes. Here, we review and discuss the potential for integrating functional traits into island biogeography. While we focus on plants, the general considerations and concepts may be extended to other groups of organisms. We evaluate how functional traits on islands relate to core principles of species dispersal, establishment, extinction, reproduction, biotic interactions, evolution and conservation. We formulate existing knowledge as 33 working hypotheses. Some of these are grounded on firm empirical evidence, others provide opportunities for future research. We organise our hypotheses under five overarching sections. Section A focuses on plant functional traits enabling species dispersal to islands. Section B discusses how traits help to predict species establishment, successional trajectories and natural extinctions on islands. Section C reviews how traits indicate species biotic interactions and reproduction strategies and which traits promote intra-island dispersal. Section D discusses how evolution on islands leads to predictable changes in trait values and which traits are most susceptible to change. Section E debates how functional ecology can be used to study multiple drivers of global change on islands and to formulate effective conservation measures. Islands have a justified reputation as research models. They illuminate the forces operating within mainland communities by showing what happens when those forces are released or changed. We believe that the lens of functional ecology can shed more light on these forces than research approaches that do not consider functional differences among species. 相似文献
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外来种入侵的生物学与生态学基础的若干问题 总被引：62，自引：0，他引：62
外来物种的入侵及其所造成的危害已越来越为人们所认识。一个外来物种入侵一个新的生境无疑要具备一定的条件 ,尽管目前对这种条件的研究还只是初步的。首先从其自身来说 ,需要有足够的入侵性 ,这可以认为是入侵种的生物学基础 ,可能表现为具有多倍性、一定的遗传变异、杂合性或表型可塑性 ,以及不同的交配系统等 ;其次一个物种的入侵成功还取决于入侵生境的可入侵性 ,这可以认为是入侵种的生态学基础 ,而新的种间关系的形成 ,尤其是入侵种与其他种类的互惠共生关系的建成是关键。本文主要介绍了有关入侵种的生物学和生态学基础中的一些最新进展 ,希望有助于我国学者对相关研究内容的开展以及对有害外来种入侵的防治 相似文献
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Ling&#x;Ying Shuai Shu&#x;Ping Xiao Yan&#x;Ping Xie Xing&#x;Min Chen Xiang&#x;Rong Song Tian&#x;Qiao Fan Yun&#x;Hua Xie Wei Liu 《Ecology and evolution》2022,12(8)
Understanding the roles of ecological drivers in shaping biodiversity is fundamental for conservation practice. In this study, we explored the effects of elevation, conservation status, primary productivity, habitat diversity and anthropogenic disturbance (represented by human population density and birding history) on taxonomic, phylogenetic and functional avian diversity in a subtropical landscape in southeastern China. We conducted bird surveys using 1‐km transects across a total of 30 sites, of which 10 sites were located within a natural reserve. Metrics of functional diversity were calculated based on six functional traits (body mass, clutch size, dispersal ratio, sociality, diet and foraging stratum). We built simultaneous autoregression models to assess the association between the ecological factors and diversity of the local avian communities. Local avian diversity generally increased with increasing habitat diversity, human population density and primary productivity. We also detected phylogenetic and functional clustering in these communities, suggesting that the avian assemblages were structured mainly by environmental filtering, rather than interspecific competition. Compared with sites outside the natural reserve, sites within the natural reserve had relatively lower avian diversity but a higher level of phylogenetic heterogeneity. 相似文献
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