نتایج جستجو برای: vegetation density

تعداد نتایج: 453936  

2015
Gemma Rutten Andreas Ensslin Andreas Hemp Markus Fischer Lucas C.R. Silva

In most habitats, vegetation provides the main structure of the environment. This complexity can facilitate biodiversity and ecosystem services. Therefore, measures of vegetation structure can serve as indicators in ecosystem management. However, many structural measures are laborious and require expert knowledge. Here, we used consistent and convenient measures to assess vegetation structure o...

اشرف زاده, محرم, عرفانزاده, رضا,

This study aimed to investigate the effect of canopy cover of individual woody patches on soil seed bank characteristics viz. density, richness and the similarity between soil seed bank and above ground vegetation. The study was conducted in Mazayjan, Zarindasht, south of Fars province in 2013. Therefore, 40 4m2 plots beneath and outside of Ziziphus spina-christi (dominant woody species) were e...

2008
O. Durán

In this work we present measurements of vegetation cover over parabolic dunes with different degree of activation along the north-eastern Brazilian coast. We are able to extend the local values of the vegetation cover density to the whole dune by correlating measurements with the gray-scale levels of a high resolution satellite image of the dune field. The empirical vegetation distribution is f...

2003
Cem Ünsalan Kim L. Boyer

Vegetation indices have been used extensively to estimate the vegetation density from satellite and airborne images for many years. In this paper we first focus on one of the most popular vegetation indices, the normalized difference vegetation index (NDVI ) [1] and introduce a statistical framework to analyze it. We propose a solution to the saturation problem of this index based on our statis...

Journal: :Journal of vector ecology : journal of the Society for Vector Ecology 2005
Karen J Willems Cameron E Webb Richard C Russell

Using larval Cx. annulirostris mosquitoes, this study compared the predation rate of Pseudomugil signifer and Gambusia holbrooki for four larval instars, three prey densities, and three vegetation densities. There was no significant difference in the quantity of first, second, and third instar larvae consumed by the two fish species after 24 h. There was a significant negative relationship betw...

2017
Haim Weissmann Rafi Kent Yaron Michael Nadav M Shnerb

The process of desertification in the semi-arid climatic zone is considered by many as a catastrophic regime shift, since the positive feedback of vegetation density on growth rates yields a system that admits alternative steady states. Some support to this idea comes from the analysis of static patterns, where peaks of the vegetation density histogram were associated with these alternative sta...

2013
Rosalind B. Renfrew Douglas H. Johnson Gary R. Lingle Douglas Robinson ROSALIND B. RENFREW DOUGLAS H. JOHNSON

Native grassland is one of the most heavily degraded of all North American ecosystems, and restoration of altered grasslands is a tool used to mitigate some of the biological ramifications of past land use practices. Providing habitat for grassland-dependent bird species often is one of the many goals of restoration. We evaluated the efficacy of meadow restoration for breeding birds in the Nebr...

2006
Joanne Chia Min Zhu Peter Caccetta

Multi-temporal Landsat coverages of the entire Australian continent have been assembled under the Australian Greenhouse Office (AGO) National Carbon Accounting System (NCAS) Land Cover Change Program. The major purpose of this program was the production of spatially detailed classifications of the extent and change in area of forest cover for Australia since 1972 for input to carbon modelling. ...

حسینی, سید محسن, سلمان ماهینی, عبدالرسول , صیاد, احسان , غلامی, شایسته , محمدی , جهانگرد,

The spatial distribution of soil organisms is influenced by the plant cover, thus resulting in a horizontal mosaic of areas subjected to gradients of nutrient availability and microclimatic conditions.This study was conducted to investigate the spatial variability of soil macrofauna in relation to vegetation density in the riparian forest landscape of Karkhe. The vegetation density was determin...

2013
Eric M. Wood Anna M. Pidgeon Volker C. Radeloff Nicholas S. Keuler

For decades, ecologists have measured habitat attributes in the field to understand and predict patterns of animal distribution and abundance. However, the scale of inference possible from field measured data is typically limited because large-scale data collection is rarely feasible. This is problematic given that conservation and management typical require data that are fine grained yet broad...

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