نتایج جستجو برای: canopy layer

تعداد نتایج: 296597  

2016
Jee Hoon Kim Joon Woo Lee Tae In Ahn Jong Hwa Shin Kyung Sub Park Jung Eek Son

Canopy photosynthesis has typically been estimated using mathematical models that have the following assumptions: the light interception inside the canopy exponentially declines with the canopy depth, and the photosynthetic capacity is affected by light interception as a result of acclimation. However, in actual situations, light interception in the canopy is quite heterogenous depending on env...

2013
Chunbo Jiang Zhengbing Chen Heidi Nepf

Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. The MIT Faculty has made this article openly available. Please share how this access benefits you. Your story matters. [1] This paper describes the transition from open channel flow to flow over submerged vegetation using velocity mea...

Risks assessment of forest project implementation in spatial density changes of forest under canopy vegetation using artificial neural network modeling approach   Nowadays, environmental risk assessment has been defined as one of the effective in environmental planning and policy making. Considering the position and structure of vegetation on the forest floor, the main role of forest under ca...

2015
X. Xu C. Yi E. Kutter

Stably stratified canopy flow in complex terrain has been considered a difficult condition for measuring net ecosystem–atmosphere exchanges of carbon, water vapor, and energy. A long-standing advection error in eddy-flux measurements is caused by stably stratified canopy flow. Such a condition with strong thermal gradient and less turbulent air is also difficult for modeling. To understand the ...

2004
Bo Song Jiquan Chen Janet Silbernagel

In this study, the structurally heterogeneous canopy of a 12-ha plot in an old-growth Douglas-fir forest was analyzed using three-dimensional (3-D) canopy modeling, geographic information system (GIS), and spatial statistics. Using this approach, we were able to depict how species composition and spatial distribution affect the 3-D structure of canopies. We were also able to slice the canopy an...

2007
R. A. Hill

An understorey model is created for an area of broadleaf, deciduous woodland in eastern England using airborne LiDAR data from winter 2003 (leaf-off conditions) and summer 2005 (leaf-on). The woodland is ancient, semi-natural broadleaf and has a heterogeneous structure, with a mostly closed canopy overstorey and a patchy understorey layer beneath. In places, particularly in the centre of the st...

2009
Y. S. Meng Y. H. Lee B. C. Ng

In this paper, rainfall effect on the VHF radio-wave propagation in a tropical forest is further studied in details. Theoretical study and experimental investigations are performed with the help of a four-layered model for forested environment. It is found that the lateral wave traveling along the air-canopy interface, the direct waves, and the ground reflected waves are the main modes for VHF ...

2007
H. Nepf M. Ghisalberti B. White E. Murphy

Citation Nepf, H. et al. " Retention time and dispersion associated with submerged aquatic canopies. Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. The MIT Faculty has made this article openly available. Please share how this access benefits you. Your story matters. [1] The shear ...

Journal: :دانش علف های هرز ایران 0
مجید آقا علیخانی دانشگاه تربیت مدرس فائزه زعفریان کارشناسی ارشد اسکندر زند محقق حمید رحیمیان مشهدی استاد دانشگاه محمد رضوانی دکتری

in order to determine the role of plant leaf area in radiation distribution within the canopy and a better understanding of how crops and weeds intercept light a study of the complexity of plants is necessary. the  effect of intercropping on leaf area distribution and dry matter accumulation in corn, soybean and weeds canopy was studied in a  field experiment at a research field of tehran unive...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید