نتایج جستجو برای: habitat patches

تعداد نتایج: 75719  

Journal: :محیط شناسی 0
فرود آذری دهکردی استادیار گروه برنامه ریزی و مدیریت دانشکدة محیط زیست، دانشگاه تهران نوشین خزاعی دانشجوی کارشناسی ارشد، دانشکدة محیط زیست دانشگاه تهران

degradation model was introduced as an instrument of environmental impact assessment (eia) in iran. several methods are introduced in rapid environmental assessment, but none of them have evaluated landscape level. thus, the main objective of this research is to introduce a new spatial method for eia by using landscape metrics. a benefit of rapid assessment by using ecological landscape metrics...

Journal: :Journal of mathematical biology 2007
Lionel Roques Radu S Stoica

This paper presents a study of a nonlinear reaction-diffusion population model in fragmented environments. The model is set on R(N), with periodic heterogeneous coefficients obtained using stochastic processes. Using a criterion of species persistence based on the notion of principal eigenvalue of an elliptic operator, we provided a precise numerical analysis of the interactions between habitat...

1997
Timothy H. Keitt

Populations may be regulated by both local density dependent factors and spatial variation in habitat quality I explore the in uence of spatial autocor relation in habitat quality on the survival of model populations Dispersal is modeled as Markov tran sitions between patches A nite rate of population increase was assigned to each patch Total habitat area and mean dispersal distance had strong ...

Journal: :international journal of environmental research 0
s. rasouli graduate faculty of environment, university of tehran, p.o. box 14155-6135, tehran, iran m. makhdoum farkhondeh faculty of natural resources, university of tehran, p.o. box 4111, karaj , iran h.r. jafari graduate faculty of environment, university of tehran, p.o. box 14155-6135, tehran, iran r. suffling faculty of environment, university of waterloo, 200 university avenue west, waterloo, on n2l 3g1, canada b. kiabi faculty of biological science, shahid beheshti university, p.o. box 1983963113, tehran, iran a.r. yavari graduate faculty of environment, university of tehran, p.o. box 14155-6135, tehran, iran

identification of rapid degradation of ecological resources requires effective environmental monitoring including ecological integrity assessment .our first aim is to analyze ecological integrity in a landscape context while developing a method to assess integrity in spite of a dearth of historical data. we used a spatial-temporal reference framework for land cover maps for assessing ecological...

Journal: :Iranian Journal of Applied Ecology 2022

Investigating the Habitat Patches of Baluchistan Black Bear (Ursus thibetanus gedrosianus), Using Landscape Metrics (Case Study: Bahr Asman and Zaryab Areas, Kerman Province)

2000

“TRED-NOTä DEERFLY PATCHES” (6.4 ́ 14.2 cm adhesive strips) affixed to the back and front of nylon mesh solid black and solid white “baseball” caps were evaluated for their ability to trap host-seeking Chrysops celatus Pechuman, C. vittatus Weidemann, and Diachlorus ferrugatus (F.). Trials were conducted in a commercial pine bottomland forest habitat in northwestern Florida during peak seasonal ...

Journal: :Bulletin of mathematical biology 2006
J V Ross

This paper has three primary aims: to establish an effective means for modelling mainland-island metapopulations inhabiting a dynamic landscape; to investigate the effect of immigration and dynamic changes in habitat on metapopulation patch occupancy dynamics; and to illustrate the implications of our results for decision-making and population management. We first extend the mainland-island met...

2015
CARMEN G. MONTAÑA CRAIG A. LAYMAN KIRK O. WINEMILLER

The curvilinear relationship between species richness and habitat area (species–area relationship (SAR)) is a fundamental ecological pattern. The relationship is often viewed from a long-term perspective across relatively large spatial scales, reflecting a balance between immigration and extinction dynamics. We explored whether predictions of SAR also manifest over short time periods (days) in ...

Journal: :The American naturalist 2001
C C Vos J Verboom P F Opdam C J Ter Braak

Nature conservation is increasingly based on a landscape approach rather than a species approach. Landscape planning that includes nature conservation goals requires integrated ecological tools. However, species differ widely in their response to landscape change. We propose a framework of ecologically scaled landscape indices that takes into account this variation. Our approach is based on a c...

Journal: :The Journal of experimental biology 2013
Takeshi Suzuki Takeshi Kojima Makio Takeda Masayuki Sakuma

Non-diapausing spider mites (Tetranychus urticae) live on the undersurface of host leaves during summer, but diapausing mites overwinter in dark hibernacula. The light environments of these habitats differ: visible radiation (VIS) but not ultraviolet radiation (UV) reaches the undersurface of leaves, but neither enters dark hibernacula. Thus, mites of either seasonal form could locate their pre...

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