نتایج جستجو برای: forest grass cover

تعداد نتایج: 227128  

Journal: :Journal of environmental management 2012
Kurt H Riitters James D Wickham Timothy G Wade Peter Vogt

The conservation value of natural vegetation is degraded by proximity to anthropogenic land uses. Previous global assessments focused primarily on the amount of land protected or converted to anthropogenic uses, and on forest vegetation. Comparative assessments of extant vegetation in terms of proximity to anthropogenic land uses are needed to better inform conservation planning. We conducted a...

Density and diversity of birds in two different forest zones, namely, Shasta Kalateh Protected Forest and Alangdareh Recreational Forest, were estimated and compared. Birds and environmental variables were recorded within 25 m radius in 100 sampling points. The first axis of Canonical Component Analysis segregated two main groups of birds. The first group consisted of Black Woodpecker, Great Sp...

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...

2017
Kathleen H. Keeler KATHLEEN H. KEELER

The abundance of plants with extrafloral nectaries was determined for a series of temperate habitats in Nebraska. Mean cover of plants with extrafloral nectaries was 1.3% in riparian forest understory, 1.8% in virgin deciduous forest understory, 0.0% in tall-grass prairie, and 8.3% in sandhill prairie. Sandhills prairie contained distinct communities with different mean cover of plants with ext...

2011
Brooke L. Bateman Christopher N. Johnson

Cockatoo grass [Alloteropsis semialata (R.Br.) A. Hitchc.] is considered a keystone species in northern Australian ecosystems as it provides a food resource for many species, including several endangered vertebrates. This study examined both local and regional environmental factors influencing cockatoo grass distribution and abundance in the Wet Tropics of north Queensland, Australia. Local dis...

Journal: :جنگل و فرآورده های چوب 0
سیدمعین الدین زمانی دانشجوی کارشناسی ارشد جنگل داری دانشگاه یاسوج، ‏یاسوج، ایران رقیه ذوالفقاری عضو هیئت علمی ‏‏دانشکدة کشاورزی و پژوهشکدة منابع طبیعی دانشگاه یاسوج، ‏یاسوج، ایران سهراب الوانی نژاد عضو هیئت علمی ‏‏دانشکدة کشاورزی و پژوهشکدة منابع طبیعی دانشگاه یاسوج، ‏یاسوج، ایران

today, determination of the ecological species groups for current and future situation of forest and its relationship with environmental factors is necessary for forest management. for this purpose, 50 plots were established in altitude range of 2091- 2811 meters above sea level and 600 hectare in protected area of western dena. four ecological groups was identified using twinspan analysis that...

2007
Thomas Swetnam

Intensive livestock grazing was an important cause of reduction in surface fire occurrence in many Western forests. This effect occurred primarily during the late 1800s and early decades of the 1900s. Very large herds of sheep, goats, cattle and horses removed the grass cover in under stories of ponderosa pine and mixed conifer forests. In 1890, for example, there were more than 5 million sheep...

Journal: :international journal of environmental research 0

land cover change constitutes one of main way of alteration of soil organic matter in both quantitative and qualitative terms. the goal of this study was to compare the carbon stock and the isotopic signature of the organic matter in the soil of areas with different land use, covered with forest and grass (pasture). the study area is located at sorocaba, sp, brazil. using un-deformed soil sampl...

2004
Tanja N. Williamson Robert C. Graham Peter J. Shouse

Forty years after conversion from chaparral to perennial veldt grass in the San Dimas Experimental Forest, we compared land surface and soil properties between areas of the two vegetation types. Our objective was to evaluate the impact of this vegetation conversion on the soil physical properties likely to impact zero-order watershed hydrology. In three watersheds of each vegetation type, surfa...

Journal: :جنگل و فرآورده های چوب 0
بیت الله محمودی استادیار گروه جنگلداری دانشکدة منابع طبیعی و علوم زمین دانشگاه شهرکرد، شهرکرد، ایران احمد بازگیر دانشجوی دکتری جنگلداری دانشکدة کشاورزی دانشگاه لرستان، خرم آباد، ایران جهانگیر فقهی دانشیار گروه جنگلداری و اقتصاد جنگل دانشکدة منابع طبیعی دانشگاه تهران، کرج، ایران فاطمه جعفری کارشناس ارشد مدیریت کشاورزی دانشکدة منابع طبیعی دانشگاه تهران، کرج، ایران

one of the indicators of management and sustainability control of forest resources is the definition deforestation and degradation types. these factors hazard quantitative and qualitative of the iranian forests. in this study with integrated approach, different forms of forest degradation identified in the forest areas with a reviews of library resources and then investigation the degree of sta...

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