نتایج جستجو برای: residual trees

تعداد نتایج: 180450  

2017
Miguel Montoro Girona Sergio Rossi Jean-Martin Lussier Denis Walsh Hubert Morin

Forest ecosystem management heads towards the use of partial cuttings. However, the wide variation in growth response of residual trees remains unexplained, preventing a suitable prediction of forest productivity. The aim of the study was to assess individual growth and identify the driving factors involved in the responses of residual trees. Six study blocks in even-aged black spruce [Picea ma...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تبریز - دانشکده ریاضی 1394

در این پایان نامه ابتدا روش های لانکسوز و روش های تکراری را مطرح می کنیم و سپس روش های گرادیان مزدوج و مانده مزدوج را با جهتهای جستجو مطرح کرده و تعمیم می دهیم روش های bi-conjugat gradiant و bi-conjugat residual را مطرح کرده و نتایج عددی حاصل را بیان کرده و نتیجه میگیریم که bi-conjugat residual بهتر از bi-conjugat gradiant می باشند.

  Today, modeling and determination of allometric equations of forest trees, especially Junipers trees, are very important for determination of biological status and carbon storage capacity of forest species. The aim of this study was to determine the most suitable allometric equations for estimating the biomass of leaf, sub branch, main branch, trunk, and biomass of total Juniperus excelsa tr...

Journal: :ecopersia 0
ramin naghdi associate professor, department of forestry, faculty of natural resources, university of guilan, sowmeh sara, iran mehrdad nikooy assistant professor, department of forestry, faculty of natural resources, university of guilan, sowmeh sara, iran ismael ghajar assistant professor, department of forestry, faculty of natural resources, university of guilan, sowmeh sara, iran mona ershadifar m.sc. student, department of forestry, faculty of natural resources, university of guilan, sowmeh sara, iran

directional felling of trees plays a key role in reducing of damages to forest residual trees and can also facilitate skidding. the aim of this study was presents a practical linear model for estimation of tree falling direction error in an uneven-aged mixed stand in northern forests of iran. to conduct the study a number of 95 trees of four species fagus orientalis lipsky, carpinus betulus l.,...

2002
James S. Meadows

Partial cutting in bottomland hardwoods to control stand density and species composition sometimes results in logging damage to the lower bole and/or roots of residual trees. If severe, logging damage may lead to a decline in tree vigor, which may subsequently stimulate the production of epicormic branches, causing a decrease in bole quality and an eventual loss in value of the stand. To invest...

2011
Eric S. Kasischke Merritt R. Turetsky Evan S. Kane

0378-1127/$ see front matter 2011 Elsevier B.V. A doi:10.1016/j.foreco.2011.12.009 ⇑ Corresponding author. Tel.: +1 301 405 2179. E-mail address: [email protected] (E.S. Kasischke We collected data to estimate depth of the remaining (residual) organic layer as well as data to estimate total pre-fire organic layer depth in 99 plots located in mature black spruce (Picea mariana (Mill.) BSP) forest...

2010
Peter J. Waddell Ishita Khan Xi Tan Sunghwan Yoo

Least squares trees, multidimensional scaling and Neighbor Nets are all different and popular ways of visualizing multi-dimensional data. The method of flexi-Weighted Least Squares (fWLS) is a powerful method of fitting phylogenetic trees, when the exact form of errors is unknown. Here, both polynomial and exponential weights are used to model errors. The exact same models are implemented for M...

2003
Eric C. Turnblom

Anecdotal evidence gathered from pruning crew observations indicates that there may be enhanced branch growth at the new crown base in young pruned coastal Douglas-fir (Pseudotsuga menziesii var. menziesii) trees compared to unpruned trees. This has the potential to reduce the quality and value of the stem above the pruned portion of the bole. An analysis of the size of branches in the remainin...

2003
F. Ruano

Differences in pest management of olive orchards may affect the development of olive trees and may be reflected in terms of absolute and relative asymmetry, mass, and quality of the leaves. Leaf mass and residual leaf mass of olive trees were significantly greater under organic management than other pest management regimes. The analysis revealed that leaves from trees under different pest manag...

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