نتایج جستجو برای: tree height

تعداد نتایج: 265995  

بخشنده ناورود, بهزاد, بنیاد, امیراسلام, ترکمن, جواد, میرعبداللهی شمسی, مرتضی,

  Oriental Beech forests have economic and ecological importances in Hyrcanian zone in the north of Iran. Therefore qualitative and quantitative controls of the stands are essential in management of these forests. This study was aimed for determining the effect of age on growing variables of beech trees in Lomir forest in Asalem, Guilan Province. In this study, 179 Beech trees were selected bas...

Journal: :Plant, cell & environment 2006
Michael G Ryan Nathan Phillips Barbara J Bond

We proposed the hydraulic limitation hypothesis (HLH) as a mechanism to explain universal patterns in tree height, and tree and stand biomass growth: height growth slows down as trees grow taller, maximum height is lower for trees of the same species on resource-poor sites and annual wood production declines after canopy closure for even-aged forests. Our review of 51 studies that measured one ...

حاتمی, نیشتمان, حیدری, حشمت الله, معیری, محمدهادی,

It is necessary to calculate the volume increment for estimation of annual allowable cut in forestry plants. In order to compute increment of main species in district one of Dr. Bahramniaʹs forest, firstly, forest divided to four forest zonation based on basal area ratio of tree species including Fageto-Carpinetum, Carpineto-Parroetum, Parrotio- Carpinetum and Mixed types. Then, 140 circular pl...

2007
Don C. Bragg

Most hypsometers apply a mathematical technique that utilizes the tangent of angles and a horizontal distance to deliver the exact height of a tree under idealized circumstances. Unfortunately, these conditions are rarely met for hardwoods in the field. “new” predictor based on sine and slope distance and discussed here does not require the same assumptions for accurate height determination. Ca...

2006
Michael S. Williams

Five instruments were tested for reliability in measuring tree heights under realistic conditions. Four linear models were used to determine if tree height can be measured unbiasedly over all tree sizes and if any of the instruments were more efficient in estimating tree height. The laser height finder was the only instrument o produce unbiased estimates of the true height for all four linear m...

2007
Sorin C. Popescu

Airborne lidar (Light Detection And Ranging) is a proven technology that can be used to accurately assess aboveground forest biomass and bio-energy feedstocks. The overall goal of this study was to develop a method for assessing aboveground biomass and component biomass for individual trees using airborne lidar data in forest settings typical for loblolly pine stands (Pinus taeda L.) in the sou...

1991
FREDRIK MANNE

Finding low elimination trees is important in parallel Cholesky factorization. We look at two orderings for achieving low height, Nested Dissection and Maximal Independent Subset, and show that in general they will not give a minimum height elimination tree. A more general version of Nested Dissection called Minimal Cutset orderings is shown to always contain an ordering that gives a minimum he...

2014
Don C. Bragg

Q uick and accurate tree height measurement has always been a goal of foresters. The techniques and technology to measure height were developed long ago—even the earliest textbooks on mensuration showcased hypsometers (e.g., Schlich 1895, Mlodziansky 1898, Schenck 1905, Graves 1906), and approaches to refine these sometimes remarkable tools appeared in the first issues of Forestry Quarterly, Pr...

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