نتایج جستجو برای: forest density

تعداد نتایج: 509797  

2011
BRIAN F. ALLAN RICHARD S. OSTFELD FELICIA KEESING

Unknown to the United States three decades ago, Lyme disease is now the most prevalent vectorborne disease in the country. Caused by the bacterium Borrelia burgdorferi, Lyme disease is typically transmitted to humans by the bite of a blacklegged tick (Ixodes scapularis) in the nymph stage. For this reason the density of infected nymphs is considered the most precise ecological indicator of Lyme...

2003
SAMUEL A. CUSHMAN KEVIN MCGARIGAL

We used a comparative mensurative landscape-level experiment to quantify the relative importance of mature forest area and fragmentation and differences among watersheds in influencing avian community diversity in the Oregon Coast Range, USA. Our study design included three large hydrological basins, two levels of fragmentation, and six levels of mature forest area. We recorded 82 species of bi...

Natural regeneration is one of the key aspects of forest sustainability and a tool to decide on restoration programs in forest areas. The purpose of this study was to investigate the quantity of natural regeneration of Acer campestre L. as one of the most important tree species in Arasbaran forests and its relationship with elevation changes and structural characteristics in the natural stands....

2001
Joop Schaye

It is shown that many properties of Lyα forest absorbers can be derived using simple physical arguments. Analytical expressions are derived for the density and the size of an absorber as a function of its neutral hydrogen column density, which agree well with both observations and hydrodynamical simulations. An expression is presented to compute ΩIGM from the observed column density distributio...

2009
Huabing Huang Peng Gong Xiao Cheng Nick Clinton Zengyuan Li

Forest structural parameters, such as tree height and crown width, are indispensable for evaluating forest biomass or forest volume. LiDAR is a revolutionary technology for measurement of forest structural parameters, however, the accuracy of crown width extraction is not satisfactory when using a low density LiDAR, especially in high canopy cover forest. We used high resolution aerial imagery ...

2005
G. Geoff Wang David H. Van Lear William L. Bauerle

Effects of prescribed fires on the 1-year establishment of white oak seedlings were investigated on the Clemson Experimental Forest, South Carolina, USA. Three stands, each consisting of a burn and a control treatment of about 1 ha in size, were examined in the study. On each burn and control treatment, six to eight dominant white oak trees were randomly selected along the slope and four 2-m ra...

2014
ANDERS JARNEMO JEROEN MINDERMAN NILS BUNNEFELD JOSEFINA ZIDAR JOHAN MÅNSSON

Deer (Cervidae) cause considerable damage to forest plantations, crops, and protected habitats. The most common response to this damage is to implement strategies to lower population densities. However, lowering deer density may not always be desirable from hunting, recreational, or conservation perspectives. Therefore, knowledge is needed about additional factors beyond deer density that affec...

2015
Weiwei Cong Tusheng Ren Baoguo Li

Afforestation is a prevalent practice carried out for soil recovery and carbon sequestration. Improved understanding of the effects of afforestation on soil organic carbon (SOC) content and dynamics is necessary to identify the particular processes of soil organic matter (SOM) formation and/or decomposition that result from afforestation. To elucidate these mechanisms, we have used a sequential...

Journal: :Folia primatologica; international journal of primatology 2013
Bright O Kankam Pascale Sicotte

We explore the factors influencing the abundance of Colobus vellerosus in 11 forest fragments [Boabeng-Fiema Monkey Sanctuary and 9 surrounding forest fragments (range: 3.2-190 ha)] in the forest-savanna transition zone of Ghana. We used a 'complete' count for the colobus census in the fragments. We determined the fragment sizes using geographic information system methods and assessed forest fr...

Journal: :Remote Sensing 2015
Mathias Neumann Maosheng Zhao Georg Kindermann Hubert Hasenauer

The mission of this study is to compare Net Primary Productivity (NPP) estimates using (i) forest inventory data and (ii) spatio-temporally continuous MODIS (MODerate resolution Imaging Spectroradiometer) remote sensing data for Austria. While forest inventories assess the change in forest growth based on repeated individual tree measurements (DBH, height etc.), the MODIS NPP estimates are base...

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