نتایج جستجو برای: habitat variables

تعداد نتایج: 364517  

2009
Tracey B. Champlin John C. Kilgo Marcia L. Gumpertz Christopher E. Moorman

Microclimate may infl uence use of early successional habitat by birds. We assessed the relationships between avian habitat use and microclimate (temperature, light intensity, and relative humidity) in experimentally created canopy gaps in a bottomland hardwood forest on the Savannah River Site, SC. Gaps were 2to 3-year-old group-selection timber harvest openings of three sizes (0.13, 0.26, 0.5...

2017
Eric Ariel L. Salas Raul Valdez Stefan Michel

We modeled summer and winter habitat suitability of Marco Polo argali in the Pamir Mountains in southeastern Tajikistan using these statistical algorithms: Generalized Linear Model, Random Forest, Boosted Regression Tree, Maxent, and Multivariate Adaptive Regression Splines. Using sheep occurrence data collected from 2009 to 2015 and a set of selected habitat predictors, we produced summer and ...

2009
AlexAndre H. Hirzel

Habitat suitability (HS) modeling relates a species’ potential presence/absence to a set of environmental variables. because of stochastic or demographic population fluctuations, relating abundance to environment is difficult and generally requires time-series of population-density data. Here, I propose an approach to compute relative capacity of a set of habitat classes. I defined relative cap...

Journal: :Molecular ecology 2012
Rose L Andrew Katherine L Ostevik Daniel P Ebert Loren H Rieseberg

Isolation by adaptation increases divergence at neutral loci when natural selection against immigrants reduces the rate of gene flow between different habitats. This can occur early in the process of adaptive divergence and is a key feature of ecological speciation. Despite the ability of isolation by distance (IBD) and other forms of landscape resistance to produce similar patterns of neutral ...

Journal: :Ambio 2003
Holger Dettki Ronny Löfstrand Lars Edenius

Habitat models may provide viable tools for co-management of large ungulates and forest resources, yet their applicability has not been comprehensively evaluated in managed forest. We examined 2 inherently different approaches to model the relative winter habitat suitability for moose (Alces alces) in the coastal area of northern Sweden. An empirical approach based on GPS positions of 15 female...

The Baluchistan Black Bear (BBB), a critically endangered subspecies (CR), is distributed in the southeastern Iran. Modelling of landscape connectivity of the BBBs among habitat patches can be insightful for the conservation managers working in Iran. Our study was designed to identify the potential corridors among 31 habitat patches of the BBBs in Iran using the circuit theory method. Habitat s...

2013
Lenore Fahrig

I challenge (1) the assumption that habitat patches are natural units of measurement for species richness, and (2) the assumption of distinct effects of habitat patch size and isolation on species richness. I propose a simpler view of the relationship between habitat distribution and species richness, the ‘habitat amount hypothesis’, and I suggest ways of testing it. The habitat amount hypothes...

2004
M. J. Genner M. I. Taylor D. F. R. Cleary S. J. Hawkins M. E. Knight G. F. Turner

The rock-restricted cichlid fish assemblages of Lake Malawi exhibit high spatial diversity in their species composition and relative abundance. However the extent to which this is due to the effects of local environmental differences, dispersal limitation of constituent taxa, and the assignment of allopatric populations to species is uncertain. We examined the factors associated with diversity ...

2007
MATTHEW D. JOHNSON

Understanding habitat quality for birds is crucial for ecologists and managers, but few papers have explored the advantages and disadvantages of different ways to measure it. In this review I clarify terminology and distinguish habitat quality from related terms, differentiate habitat quality at the levels of individual birds and populations, and describe different field methods for measuring h...

The climate changes have an important role in distribution of plant species. Statistical species distribution models (SDMs) are widely used to predict the changes in species distribution under climate change scenarios. In the peresent study, the distribution of Alopecurus textilis in the current and future climate condition (2050) under the influence of climate change and two scenarios of RCP 4...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید