نتایج جستجو برای: canopy

تعداد نتایج: 14776  

2004
Timothy E. Link Mike Unsworth Danny Marks

Net canopy interception (Inet) during rainfall in an old-growth Douglas-fir–western hemlock ecosystem was 22.8 and 25.0% of the gross rainfall (PG) for 1999 and 2000, respectively. The average direct throughfall proportion (p) and canopy storage capacity (S) derived from high-temporal resolution throughfall measurements were 0.36 and 3.3 mm, respectively. Derived values of S were very sensitive...

2008
Sean M. Schaeffer Dean E. Anderson Sean P. Burns Russell K. Monson Jielun Sun David R. Bowling

Stable isotopes provide insight into ecosystem carbon cycling, plant physiological processes, atmospheric boundary-layer dynamics, and are useful for the integration of processes over multiple scales. Of particular interest is the carbon isotope content (dC) of nocturnal ecosystem-respired CO2 (dR). Recent advances in technology have made it possible to continuously examine the variation in dR ...

2012
DAN WANG MICHAEL C. DIETZE

Nitrogen (N) addition typically increases overall plant growth, but the nature of this response depends upon patterns of plant nitrogen allocation that vary throughout the growing season and depend upon canopy position. In this study seasonal variations in leaf traits were investigated across a canopy profile in Miscanthus (Miscanthus 9 giganteus) under two N treatments (0 and 224 kg ha ) to de...

2008
Raita Säynäjoki Petteri Packalén Matti Maltamo Mikko Vehmas Kalle Eerikäinen

The aim was to use high resolution Aerial Laser Scanning (ALS) data and aerial images to detect European aspen (Populus tremula L.) from among other deciduous trees. The field data consisted of 14 sample plots of 30 m × 30 m size located in the Koli National Park in the North Karelia, Eastern Finland. A Canopy Height Model (CHM) was interpolated from the ALS data with a pulse density of 3.86/m2...

2017
Alvaro Promis Robert B Allen

Seedlings of co-occurring species vary in their response to resource availability and this has implications for the conservation and management of forests. Differential shade-tolerance is thought to influence seedling performance in mixed Nothofagus betuloides-Nothofagus pumilio forests of Patagonia. However, these species also vary in their soil nutrient requirements. To determine the effects ...

2006
Dong Huang Yuri Knyazikhin Weile Wang Donald W. Deering Pauline Stenberg Nikolay Shabanov Bin Tan Ranga B. Myneni

Radiation reflected from vegetation canopies exhibits high spatial variation. Satellite-borne sensors measure the mean intensities emanating from heterogeneous vegetated pixels. The theory of radiative transfer in stochastic media provides the most logical linkage between satellite observations and the three-dimensional canopy structure through a closed system of simple equations which contains...

Journal: :Global change biology 2017
Jin Wu Shawn P Serbin Xiangtao Xu Loren P Albert Min Chen Ran Meng Scott R Saleska Alistair Rogers

Leaf quantity (i.e., canopy leaf area index, LAI), quality (i.e., per-area photosynthetic capacity), and longevity all influence the photosynthetic seasonality of tropical evergreen forests. However, these components of tropical leaf phenology are poorly represented in most terrestrial biosphere models (TBMs). Here, we explored alternative options for the representation of leaf phenology effect...

2015
Bill Buffum Thomas J. McGreevy Amy E. Gottfried Mary E. Sullivan Thomas P. Husband Stephanie S. Romanach

The New England cottontail (Sylvilagus transitionalis) is a high conservation priority in the Northeastern United States and has been listed as a candidate species under the Endangered Species Act. Loss of early successional habitat is the most common explanation for the decline of the species, which is considered to require habitat with dense low vegetation and limited overstory tree canopy. F...

Journal: :Remote Sensing 2017
Yi Peng Anthony L. Nguy-Robertson Timothy J. Arkebauer Anatoly A. Gitelson

Canopy chlorophyll content (Chl) closely relates to plant photosynthetic capacity, nitrogen status and productivity. The goal of this study is to develop remote sensing techniques for accurate estimation of canopy Chl during the entire growing season without re-parameterization of algorithms for two contrasting crop species, maize and soybean. These two crops represent different biochemical mec...

2004
T. Nakashizuka

As the most basic knowledge of remote sensing, spectral radiances that are reflected from the surface and received by the sensor are under the influence of various physical factors. One of the most important factors is the reflectance properties of the surface such as spatial, spectral and biophysical conditions. On the other hand, Tropical Rainforest is known as the most important for us to su...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید