نتایج جستجو برای: crown height
تعداد نتایج: 118047 فیلتر نتایج به سال:
Remote sensing is revolutionizing the way we study forests, and recent technological advances mean we are now able - for the first time - to identify and measure the crown dimensions of individual trees from airborne imagery. Yet to make full use of these data for quantifying forest carbon stocks and dynamics, a new generation of allometric tools which have tree height and crown size at their c...
To analyze the main variables affecting crown biomass, we measured crown biomass and a number of variables describing tree size, such as stem diameter at breast height (D), tree height (H), crown width (Cw) and crown length (Cl), from 754 sample trees of four pine species in China, specifically, Pinus massoniana, P. yunnanensis, P. tabulaeformis and P. elliottii. In addition, we developed indiv...
Background and Purpose: Structure of crowns in forest stands is one of the main factors which determines growth and development of trees. Dynamic change occurs with the age of the stand due to silvicultural interventions or natural disturbances during which trees are removed from the stand. The aim of this article is to analyse the structure of the crown shape of pedunculate oak and common horn...
A rapid canopy reflectance model inversion experiment was performed using multi-angle reflectance data from the NASA Multi-angle Imaging Spectro-Radiometer (MISR) on the Earth Observing SystemTerra satellite, with the goal of obtainingmeasures of forest fractional crown cover, mean canopy height, and aboveground woody biomass for large parts of south-eastern Arizona and southern New Mexico (N20...
Topography affects forest canopy height retrieval based on airborne Light Detection and Ranging (LiDAR) data a lot. This paper proposes a method for correcting deviations caused by topography based on individual tree crown segmentation. The point cloud of an individual tree was extracted according to crown boundaries of isolated individual trees from digital orthophoto maps (DOMs). Normalized c...
Detection and Segmentation of Small Trees in the Forest-Tundra Ecotone Using Airborne Laser Scanning
Due to expected climate change and increased focus on forests as a potential carbon sink, it is of interest to map and monitor even marginal forests where trees exist close to their tolerance limits, such as small pioneer trees in the forest-tundra ecotone. Such small trees might indicate tree line migrations and expansion of the forests into treeless areas. Airborne laser scanning (ALS) has be...
The evolution of the 4-variate probability distribution of the diameter at the breast height, total height, crown base height, and crown width against the age in a forest stand is of great interest to forest management and the evaluation of forest resources. This paper focuses on the Vasicek type 4-variate fixed effect stochastic differential equation (SDE) to quantify the dynamic of tree size ...
Virtually all techniques for tree height determination follow one of two principles: similar triangles or the tangent method. Most people apply the latter approach, which uses the tangents of the angles to the top and bottom and a true horizontal distance to the subject tree. However, few adjust this method for ground slope, tree lean, crown shape, and crown configuration, making errors commonp...
The present investigation was aimed to study the qualitative and quantitative characteristics of Lebanon Oak (Quercus libani Olive.) in Marivan city-kordistan. To investigate the effect of altitude on the qualitative and quantitative characteristics of Lebanon Oak, 108 circular plots of 1000 m2 on three elevation classes of 1400-1600, 1600-1800 and 1800-2000 m were designated. Within each plot,...
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