Ecography
1600-0587
0906-7590
Anh Quốc
Cơ quản chủ quản: Wiley-Blackwell Publishing Ltd , WILEY
Lĩnh vực:
Ecology, Evolution, Behavior and Systematics
Phân tích ảnh hưởng
Thông tin về tạp chí
ECOGRAPHY publishes exciting, novel, and important articles that significantly advance understanding of ecological or biodiversity patterns in space or time. Papers focusing on conservation or restoration are welcomed, provided they are anchored in ecological theory and convey a general message that goes beyond a single case study. We encourage papers that seek advancing the field through the development and testing of theory or methodology, or by proposing new tools for analysis or interpretation of ecological phenomena. Manuscripts are expected to address general principles in ecology, though they may do so using a specific model system if they adequately frame the problem relative to a generalized ecological question or problem.
Các bài báo tiêu biểu
A practical guide to MaxEnt for modeling species' distributions: what it does, and why inputs and settings matter The MaxEnt software package is one of the most popular tools for species distribution and environmental niche modeling, with over 1000 published applications since 2006. Its popularity is likely for two reasons: 1) MaxEnt typically outperforms other methods based on predictive accuracy and 2) the software is particularly easy to use. MaxEnt users must make a number of decisions about how they should select their input data and choose from a wide variety of settings in the software package to build models from these data. The underlying basis for making these decisions is unclear in many studies, and default settings are apparently chosen, even though alternative settings are often more appropriate. In this paper, we provide a detailed explanation of how MaxEnt works and a prospectus on modeling options to enable users to make informed decisions when preparing data, choosing settings and interpreting output. We explain how the choice of background samples reflects prior assumptions, how nonlinear functions of environmental variables (features) are created and selected, how to account for environmentally biased sampling, the interpretation of the various types of model output and the challenges for model evaluation. We demonstrate MaxEnt's calculations using both simplified simulated data and occurrence data from South Africa on species of the flowering plant family Proteaceae. Throughout, we show how MaxEnt's outputs vary in response to different settings to highlight the need for making biologically motivated modeling decisions.
Tập 36 Số 10 - Trang 1058-1069 - 2013
Opening the black box: an open‐source release of Maxent This software note announces a new open‐source release of the Maxent software for modeling species distributions from occurrence records and environmental data, and describes a new R package for fitting such models. The new release (ver. 3.4.0) will be hosted online by the American Museum of Natural History, along with future versions. It contains small functional changes, most notably use of a complementary log‐log (cloglog) transform to produce an estimate of occurrence probability. The cloglog transform derives from the recently‐published interpretation of Maxent as an inhomogeneous Poisson process (IPP), giving it a stronger theoretical justification than the logistic transform which it replaces by default. In addition, the new R package, maxnet, fits Maxent models using the glmnet package for regularized generalized linear models. We discuss the implications of the IPP formulation in terms of model inputs and outputs, treating occurrence records as points rather than grid cells and interpreting the exponential Maxent model (raw output) as as an estimate of relative abundance. With these two open‐source developments, we invite others to freely use and contribute to the software.
Tập 40 Số 7 - Trang 887-893 - 2017
U‐CARE: Utilities for performing goodness of fit tests and manipulating CApture–REcapture data
Tập 32 Số 6 - Trang 1071-1074 - 2009
Habitat selection as a mechanism of resource partitioning in two cryptic bat species <i>Pipistrellus pipistrellus</i> and <i>Pipistrellus pygmaeus</i> Ecomorphological studies of bat communities often reveal the spatial and temporal coexistence of morphologically similar species, leading to suggestions that these communities are structured by non‐deterministic processes. However, the diversification of echolocation call structure in bats allows for considerable morphological similarity while still permitting niche differentiation based on specialisation for prey type and habitat structure. The recent separation of a common Palaearctic bat, the pipistrelle, into Pipistrellus pipistrellus and P. pygmaeus, which are sympatrically distributed throughout their range, raises the question as to whether these two morphologically similar species partition resources in time and space. To test the hypothesis that the coexistence of these cryptic species is facilitated by differential habitat use, 14 P . pipistrellus , and 12 P. pygmaeus were radio‐tracked from adjacent maternity roosts, in northeast Scotland, from May to September 2002/2003. The two species showed distinct habitat partitioning with P. pygmaeus foraging predominantly in riparian woodland and over water, and P. pipistrellus foraging along woodland edges and short isolated tree lines. Inter‐specific overlap in habitat use was low and consequently foraging ranges were segregated spatially. The degree of habitat partitioning revealed in these species, which show considerable overlap in echolocation call parameters and functional morphology, suggests that morphological features, whilst useful in separating chiropteran species into coarse‐grained foraging guilds, may not predict fine‐grained ecological segregation.
Tập 29 Số 5 - Trang 697-708 - 2006
Why the world's vegetation is not totally dominated by resprouting plants; because resprouters are shorter than reseeders
Tập 19 Số 1 - Trang 92-95 - 1996
Numerical and dietary responses of a predator community in a temperate zone of Europe The generalist predation hypothesis predicts that the functional responses of generalist predator species should be quicker than those of specialist predators and have a regulating effect on vole populations. New interpretations of their role in temperate ecosystems have, however, reactivated a debate suggesting generalist predators may have a destabilizing effect under certain conditions (e.g. landscape homogeneity, low prey diversity, temporary dominance of 1 prey species associated with a high degree of dietary specialization). We studied a rich predator community dominated by generalist carnivores (Martes spp., Vulpes vulpes, Felis catus ) over a 6 yr period in farmland and woodland in France. The most frequent prey were small rodents (mostly Microtus arvalis , a grassland species, and Apodemus spp., a woodland species). Alternative prey were diverse and dominated by lagomorphs (Oryctolagus cuniculus, Lepus europeus ). We detected a numerical response among specialist carnivores but not among generalist predators. The dietary responses of generalist predators were fairly complex and most often dependent on variation in density of at least 1 prey species. These results support the generalist predation hypothesis. We document a switch to alternative prey, an increase of diet diversity, and a decrease of diet overlap between small and medium‐sized generalists during the low density phase of M. arvalis . In this ecosystem, the high density phases of small mammal species are synchronous and cause a temporary specializing of several generalist predator species. This rapid functional response may indicate the predominant role of generalists in low amplitude population cycles of voles observed in some temperate areas.
Tập 32 Số 2 - Trang 277-290 - 2009
Experimental evidence for the use of density based interspecific social information in forest birds Reproductive success and habitat preference are generally assumed to be negatively associated with densities of con‐ and heterospecific competitors. However, recent theoretical studies have suggested that in some cases habitat preference may have a nonlinear unimodal function in relation to con‐ or heterospecific competitor densities – intermediate densities being preferred. Such a pattern is expected if con‐ or heterospecific densities are used as a proximate cue in habitat selection, which may produce benefits by reducing searching costs and providing information about current habitat quality and costs of competition. At low density the use of such cues, and hence habitat selection, are hampered, whereas at high density costs of competition exceed the benefits of using cues, leading to avoidance. Here, we tested this hypothesis by examining whether arboreal migratory birds use the density of resident titmice (Parus spp.) in habitat selection decisions. Many migrants and titmice species share similar resource needs making titmice density a reliable source of information for migrants. At the scale of habitat patches, we experimentally created a range of titmice densities from low to very high and subsequently measured the density response of migrants. In contrast to the unimodal habitat preference hypothesis, the average species number and total density of migratory birds were positively and linearly correlated with manipulated titmice density. Thus, migrants probably use titmice density as a relative indicator of habitat quality (abundance or quality of food) because foliage gleaners that share similar food resource with titmice, but not ground foragers, showed a positive association with manipulated titmice density. These results emphasize the positive effect of interspecific social information on habitat choice decisions and diversity of migratory bird community.
Tập 32 Số 3 - Trang 539-545 - 2009
Extinction risk under coloured environmental noise Positively autocorrelated red environmental noise is characterized by a strong dependence of expected sample variance on sample length. This dependence has to be taken into account when assessing extinction risk under red and white uncorrelated environmental noise. To facilitate a comparison between red and white noise, their expected variances can be scaled to be equal, but only at a chosen time scale. We show with a simple one‐dimensional population dynamics model that the different but equally reasonable choices of the time scale yield qualitatively different results on the dependence of extinction risk on the colour of environmental noise: extinction risk might increase as well as decrease when the temporal correlation of noise increases.
Tập 23 Số 2 - Trang 177-184 - 2000
Determinism of bacterial metacommunity dynamics in the southern East China Sea varies depending on hydrography Spatial variation of communities composition (metacommunities) results from multiple assembly mechanisms, including environmental filtering and dispersal; however, whether and why the relative importance of the assembly mechanisms in shaping bacterial metacommunity changes through time in marine pelagic systems remains poorly studied. Here, we applied the elements of metacommunity structure framework and the variation partitioning framework to examine whether temporal variation of hydrographic conditions influences bacterioplankton metacommunity dynamics in the southern East China Sea (ECS). The spatiotemporal variation of bacterial communities composition was revealed using 454 pyrosequencing of 16S rDNA. In addition to the whole bacterial community, we analyzed four dominant taxonomic groups (Cyanobacteria, Alphaproteobacteria, Gammaproteobacteria, and Actinobacteria) separately. Our analyses indicate that, considering the whole community level, the determinism of metacommunity structure varied among seasons. When the degree of connectivity was low (December), the metacommunity exhibited random distribution and was explained mainly by the environmental component. However, Clementsian metacommunity was found at intermediate connectivity (May), during which the environmental and spatial predictors were both significant. When connectivity was high (August), a random distribution pattern was found and no significant effect of environmental filtering or dispersal limitation was detected. Nevertheless, when considering different taxonomic groups, the differences in metacommunity dynamics among groups were found. Our results suggest that the driving forces of metacommunity dynamics varied depending on hydrography, as the degrees of environmental heterogeneity and connectivity among habitat patches were determined by circulation pattern. Moreover, mechanisms varied among different taxonomic groups, suggesting that differential dispersal capacity among taxonomic groups should be integrated into community assembly studies.
Tập 38 Số 2 - Trang 198-212 - 2015
Spatial dynamics in a metapopulation network: recovery of a rare grasshopper Stauroderus scalaris from population refuges
Tập 24 Số 4 - Trang 452-460 - 2001