نتایج جستجو برای: rangeland and forest
تعداد نتایج: 16850726 فیلتر نتایج به سال:
Registered, multi temporal Landsat data of a study area in central Pennsylvania were analyzed to detect and assess changes in the forest canopy resulting from insect defoliation. Images taken July 19, 1976, and JUne 27, 1977, were chosen specifically to represent forest canopy conditions before and after defoliation, respectively. Several image manipulation and data transformation techniques, d...
Pteridium aquilinum is known as an invasive species in different ecosystems of the world. The spread of this species is increasing in the north of Iran particularly outside of forest ecosystems. In this study, the amount and composition of soil seed banks in the dense pathes of Pteridium were investigated in summer rangelands of Bandpay in the south of Babol city in Mazandaran province, Iran...
This study aimed to compare plant species diversity indices (diversity and richness) and some physico-chemical properties of soil among forest, ecotone and rangeland habitats. Vegetation sampling was done randomly at each habitat. One dominant community was selected in each habitat and one key area was distinguished in each community and 8×1m2 plots were randomly established in each key area. I...
The process of infiltration is one of the most important components of the hydrological cycle. On the other hand, the direct measurement of infiltration process is difficult, time spending and expensive. Infiltration models play a main role in managing water resources. Therefore, different types of models with various degrees of complexity were developed to reach this aim. So, this research ca...
This study was carried out in Bale Eco-Region (BER) which is located in Southeastern Ethiopia with the objective of addressing the cause and effect of ecological damage, particularly rangeland degradation. Both purposive and stratified random sampling approaches were used to select HouseHolds (HH). Individual interview, key informants an...
In order to map the forest canopy density Bivareh Ilam Landsat 8 satellite data of 22 July 2014 and FCD model was used. The FCD of four indicators of vegetation, soil, shade and the heat index by applying a suitable threshold was and the density of vegetation and forest canopy density map based on FCD in percent respectively. Forest density map obtained, according to the classes provided by the...
The South can increase pine productivity on its forest lands as increased timber prices make returns from intensified forest management more profitable. We determined the most likely management intensities on industrial lands resulting in five management intensity classes. They are used to estimate the potential growth and yield levels, and compare these to empirical pine yields, developed as a...
a Center for Forestry, University of California, Berkeley, CA 94720-3114, USA b Department of Global Ecology, Carnegie Institution, Stanford, CA 94305-4101, USA c Department of Environmental Science, Policy, and Management, University of California, Berkeley, CA 94720-3114, USA d Department of Forest, Rangeland, and Watershed Stewardship, Colorado State University, Fort Collins, CO 80523-1472, ...
Today, there are many factors affecting watersheds, consequently changing natural ecosystems succession. The aim of this study was to investigate the effect of drought events on land use changes at Doiraj Watershed of Ilam Province from 1996 to 2015. For this purpose, Landsat satellite images were used for land use change monitoring and Standardized Precipitation Index (SPI) was applied for dro...
Different land uses have various effects on the changes of soil properties. The purpose of this study was to evaluate the effects of natural forest, needle-leaved plantation and rangelands of central Alborz on new indices of soil quality (i.e. organic matter stratification, carbon management index and soil biological activities). For this purpose, eight samples from organic layer (litter) and m...
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