نتایج جستجو برای: forest types

تعداد نتایج: 587788  

2009
Mark D. Nelson Kathleen T. Ward Marvin E. Bauer

—RADARSAT-1 synthetic aperture radar data, speckle reduction, and texture measures provided for separation among forest types within the Twin Cities metropolitan area, MN, USA. The highest transformed divergence values for 16-bit data resulted from speckle filtering while the highest values for 8-bit data resulted from the orthorectified image, before and after performing a histogram stretch. F...

2014
Katharine R. E. Sims

Conservation policies influence both the amount of habitat loss and patterns of habitat fragmentation. This paper develops a “microlandscapes” approach that combines fragmentation measures with quasi-experimental evaluation methods in order to assess the effects of policy on habitat fragmentation. As an application, the paper estimates whether and to what extent wildlife sanctuaries and nationa...

2005
Kevin L. O’Hara

A general premise of forest managers is that modern silviculture should be based, in large part, on natural disturbance patterns and species' adaptations to these disturbances. An understanding of forest stand dynamics is therefore a prerequisite to sound forest management. This paper provides a brief overview of forest stand development, stand structures, and disturbance regimes and discusses ...

2016
Rodrigo B. Ferreira Karen H. Beard Martha L. Crump

Understanding the response of species with differing life-history traits to habitat edges and habitat conversion helps predict their likelihood of persistence across changing landscape. In Brazil's Atlantic Forest, we evaluated frog richness and abundance by breeding guild at four distances from the edge of a reserve: i) 200 m inside the forest, ii) 50 m inside the forest, iii) at the forest ed...

2000
WILLIAM B. KROHN WILLIAM J. ZIELINSKI RANDALL B. BOONE

A recent publication hypothesized that deep snowfall can limit fisher (Martes pennanti) populations, and high fisher populations limit marten populations (M. americana). These hypotheses were evaluated by comparing the historic (1919-1924) and current (1989-1994) distributions of both Martes species in California to current snowfall distributions and forest types presumed to be habitats for eac...

2011
Steven J. Presley Michael R. Willig Christopher P. Bloch Ivan Castro-Arellano Christopher L. Higgins Brian T. Klingbeil

The metacommunity framework integrates species-specific responses to environmental gradients to detect emergent patterns of mesoscale organization. Abiotic characteristics (temperature, precipitation) and associated vegetation types change with elevation in a predictable fashion, providing opportunities to decouple effects of environmental gradients per se from those of biogeographical or histo...

Journal: Desert 2006
A. Kelarestaghi, H. Ahmadi M. Jafari

Land use change may influence many natural phenomena and ecological processes, including runoff, soil erosion, sedimentation and soil conditions. Decreasing of forest area in the North of Iran is one of the critical problems in recent years. The aims of this study are to detect land use changes between 1967 to 2002 using satellite images of Land Sat 7 ETM+ (2002), aerial photos and digital topo...

Journal: :Remote Sensing 2012
Paul M. Treitz Kevin Lim Murray Woods Doug Pitt Dave Nesbitt Dave Etheridge

Over the past two decades there has been an abundance of research demonstrating the utility of airborne light detection and ranging (LiDAR) for predicting forest biophysical/inventory variables at the plot and stand levels. However, to date there has been little effort to develop a set of protocols for data acquisition and processing that would move governments or the forest industry towards co...

2015
Lei Yu Yujie Wang Yunqi Wang Suqi Sun Liziyuan Liu

Separating the components of soil respiration and understanding the roles of abiotic factors at a temporal scale among different forest types are critical issues in forest ecosystem carbon cycling. This study quantified the proportions of autotrophic (RA) and heterotrophic (RH) in total soil (RT) respiration using trenching and litter removal. Field studies were conducted in two typical subtrop...

2003
James D. Wickham

Fragmentation of forest types is an indicator of biodiversity in the Montreal Process, but the available national data permit assessment of only overall forestland fragmentation, not forest type fragmentation. Here we illustrate how to localize national statistics from the 2003 National Report on Sustainable Forests by combining state vegetation maps with national forestland fragmentation maps....

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