the control of biological, hydrological and geochemical cycles of soil is the key part of the earth system. the objective of this research was to evaluate changes in soil chemical properties due to deforestation occurred in the gazafolya village, merek watershed, kermanshah province, iran. toward this attempt, 35 soil samples were collected from top soil layer using auger in early june, 2013. s...

introduction urban landscape is experiencing rapid changes which put all urban domains under pressures. these processes revolutionize urban landscape into spaces without ecologic values. the sustainability of green patches and corridors has been scathed by lack of ecological approaches in planning and design. therefore, urban green spaces structures and functions have been damaged. green spaces...

introduction forest ecosystems have continuously downgraded due to every environmental pressure including climate change, aerosols deposits, industrial pollutions and other degradation factors. the output soon or late would be a different forest. forest monitoring is a well-regulated and usually long running procedure, which has the ability to detect these phenomena and reactions based on aims ...

the ecological potential assessment of forest sites introduces an index or indices that show the potential of forest site for fulfillment of special different roles of forest. khanikan forest at chalous needs precise investigation for assessment as indicator of lowland forests in forest ecosystems of northern iranwith considering its location position in caspian lowland and different values. th...

a 1993 result of j. llibre, and m. misiurewicz, (theorem a [5]), states that if a continuous map f of a graph into itself has an s-horseshoe, then the topological entropy of f is greater than or equal to logs, that is h( f ) ? logs. also a 1980 result of l.s. block, j. guckenheimer, m. misiurewicz and l.s. young (lemma 1.5 [3]) states that if g is an a-graph of f then h(g) ? h( f ). in this pap...

In large regions of the world, biomass is a very important source of energy. The global bioenergy market based on forest biomass is growing rapidly. About 92 % of the bioenergy in Sweden comes from forests. Biomass from forests is not homogenous. The locations, transport distances, and transport methods, can differ very much and the industries that need biomass as input prefer raw materials wit...

Information on the productivity, costs and applications of the logging system is a key component in the evaluation of management plans for the rehabilitation and utilization of Caspian forests. Skidding and road construction costs are expensive forest operations. Determining the optimum forest road network density is one of the most important factors in sustainable forest management. Logging me...