نتایج جستجو برای: soil disturbance area

تعداد نتایج: 783833  

Journal: :مرتع و آبخیزداری 0
مقداد جورغلامی دانشکده منابع طبیعی دانشگاه تهران، دکترای جنگلداری وحید ریزوندی دانشکده منابع طبیعی دانشگاه تهران، کارشناسی ارشد جنگلداری باریس مجنونیان قراقز دانشکده منابع طبیعی دانشگاه تهران، دکترای جنگلداری

assessment and management of the environmental impacts of forest harvesting operations have become increasingly critical factors in practicing commercial forestry. this study investigated soil disturbance from a forest logging system operation on an 8-hectare mixed broadleaved stand in compartment no. 309 in gorazbon district in kheyrud educational and research forest. the objective of this stu...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شیراز - دانشکده علوم 1392

gol-e-gohar iron ore mine of sirjan in southern part of iran is a large open pit that operates below the groundwater table and during mining operation, dewatering is required to prevent operation processes from flooding. current operation is going on by digging wells in or out of the pit and pumping to prevent flooding. as a result of the former dewatering operation a vast deep cone of depressi...

A. Najafi, H. Sam Daliri

Skidding operations can cause considerable and wide spread soil disturbance. The objective of this study was to evaluate the effects of ground skidding operations on soil compaction, moisture content, and total porosity at different levels of slope and traffic frequency. Four levels of traffic intensity (3, 8, 13, and >13 passes of a Crawler Tractor Onezhets ? 110) and three levels of slope ( ...

Journal: :caspian journal of environmental sciences 2013
a. najafi h. sam daliri

skidding operations can cause considerable and wide spread soil disturbance. the objective of this study was to evaluate the effects of ground skidding operations on soil compaction, moisture content, and total porosity at different levels of slope and traffic frequency. four levels of traffic intensity (3, 8, 13, and >13 passes of a crawler tractor onezhets ? 110) and three levels of slope ( 2...

Journal: :Environmental management 2005
Sherry A Leis David M Engle David M Leslie Jeffrey S Fehmi

Loss of grassland species resulting from activities such as off-road vehicle use increases the need for models that predict effects of anthropogenic disturbance. The relationship of disturbance by military training to plant species richness and composition on two soils (Foard and Lawton) in a mixed prairie area was investigated. Track cover (cover of vehicle disturbance to the soil) and soil or...

1998
Emily Carter Bob Rummer Robert Rummer Bryce Stokes

A study was installed in an upland hardwood forest to evaluate the site impacts associated with three alternative prescriptions clearcut, deferment cut, and strip cut. Two methods of site impact assessment were employed: 1) assignment of disturbance classes to selected points within each treatment area and 2) measurement of soil bulk density, gravimetric water content, and soil strength at poin...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تربیت مدرس - دانشکده منابع طبیعی و علوم دریایی 1388

this research was conducted in two protect and destroy region in the middle zagros, in illam province. in order to identification of ecological species group and evaluate density of regeneration, effect of many factors such as protection, vegetation, physiographic factors, physical and chemical properties of soil in study locations were studied. to achieve these purpose number of 54 plots using...

2012
Junichi Fujinuma Rhett D. Harrison

Edge-effects greatly extend the area of tropical forests degraded through human activities. At Pasoh, Peninsular Malaysia, it has been suggested that soil disturbance by highly abundant wild pigs (Sus scrofa), which feed in adjacent Oil Palm plantations, may have mediated the invasion of Clidemia hirta (Melastomataceae) into the diverse tropical lowland rain forest. To investigate this hypothes...

2013
E. Lobo

Treefall gaps are the major source of disturbance in most tropical forests. The frequency and size of these gaps have important implications for forest ecosystem processes as they can influence the functional trait distribution of tree communities, stand-level aboveground biomass and productivity. However, we still know little about the relative importance of environmental drivers of gap distur...

2003
Daniel G. Gavin

Forest soil disturbance intervals are usually too long to measure using plot-based studies, and thus they are poorly understood. The mean soil disturbance interval (MSDI) in an old-growth forest on the west coast of Vancouver Island was estimated from radiocarbon dates of charcoal from organic and mineral soil horizons. Two assumptions are required to estimate the MSDI: (1) charcoal from forest...

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