نتایج جستجو برای: 26 forest cover types

تعداد نتایج: 833058  

Journal: :Environmental management 2013
Urs Gimmi Volker C Radeloff

The concept of naturalness was developed to assess to what degree landscapes represent a natural state. Protected areas are often regarded as the remnants of untouched landscapes although many landscapes commonly perceived as pristine have a long history of human impact. Here, we introduced a historical perspective into the concept of naturalness and the analysis of the effectiveness of protect...

2010
Robert C. Harriss David L. Skole G. Arturo Sánchez-Azofeifa

Accurate estimates of forest cover and forest fragmentation are critical for developing countries such as Costa Rica, which holds four to five percent of the world’s plant and bird species. We estimated forest cover for Costa Rica using Landsat 5 Thematic Mapper satellite scenes acquired between 1986 and 1991. In 1991, 29 percent (ca 14,000 km2) of the land cover of Costa Rica was closed forest...

2002
T. Barata P. Pina

In this paper novel algorithms developed to automatically segment forest cover types are presented. The digital image analysis followed is mainly based on mathematical morphology operators and exploits the textural features in high spatial resolution images. These input images consist of true colour digital orthophotos and the studied forest covers consist of the main occurrences in Portugal: o...

Journal: :international journal of advanced biological and biomedical research 2013
kimia pourmoghadam kamran pourmoghadam esmaiel khosropour maziar haidari

physiological factors have effects on most forest parameters such as forest classification so that understanding knowledge about this subject is important to manage forests. the forests of sorkhake-sanjabi village with area of 1645 ha located in eslam abad city, kermanshah province, iran were selected. 23 sample plots with rectangular shape (40m*50m) were selected and the species, origin of spe...

Journal: :Remote Sensing 2013
Namita Giree Stephen V. Stehman Peter Potapov Matthew C. Hansen

Insular Southeast Asia is a hotspot of humid tropical forest cover loss. A sample-based monitoring approach quantifying forest cover loss from Landsat imagery was implemented to estimate gross forest cover loss for two eras, 1990–2000 and 2000–2005. For each time interval, a probability sample of 18.5 km × 18.5 km blocks was selected, and pairs of Landsat images acquired per sample block were i...

Journal: :Nature 1993

2007
K. Price C. R. Jackson

Basin forest cover is understood to influence stream baseflow in a variety of ways, most significantly via increased soil infiltration and increased evapotranspiration (ET). Extensive forestry experimentation has consistently demonstrated a negative relationship between forest cover and baseflow, attributed to ET losses associated with greater forest cover. However, it is unclear whether this r...

Journal: :environmental resources research 2014
hossein varasteh moradi mohamed zakaria scott . k. robinson

forest fragmentation results in a loss of forest interior and an increase in edge habitat. we studied how understorey bird community composition and habitat variables changed along an edge-to-interior gradient in a 1248-ha lowland rainforest patch in peninsular malaysia. birds and environmental variables such as vegetation structure and litter depth were detected within a 25-m radius of each of...

2017
Cyril Campana Stéphanie Gauvin Jean-François Ponge

Micro-scale changes in earthworm communities and ground cover types were studied along five transect lines in an unmanaged beech forest (Fontainebleau forest, France). Spatial patterns were interpreted to the light of interactions between earthworm species and forest architecture, ground vegetation and quantity as well as quality of litter. The anecic Lumbricus terrestris was associated with pa...

2012
Marion Pfeifer Neil D. Burgess Ruth D. Swetnam Philip J. Platts Simon Willcock Robert Marchant

In East Africa, human population growth and demands for natural resources cause forest loss contributing to increased carbon emissions and reduced biodiversity. Protected Areas (PAs) are intended to conserve habitats and species. Variability in PA effectiveness and 'leakage' (here defined as displacement of deforestation) may lead to different trends in forest loss within, and adjacent to, exis...

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