نتایج جستجو برای: forest trees
تعداد نتایج: 184211 فیلتر نتایج به سال:
In recent years, fundamental changes in the ecosystems of Zagros forest structure have occurred, including the decline of brant’s oak (Quercus bratii Lindl.) that is main species in this region. So this research intends to study trees decline in relation to sylviculture, topography, and soil characteristics. For this purpose, first, parts of forest that showed oak decline were identified by fie...
The conversion of forest to agriculture across the world's tropics, and the limited space for protected areas, has increased the need to identify effective conservation strategies in human-modified landscapes. Isolated trees are believed to conserve elements of ecological structure, providing micro-sites for conservation in matrix landscapes, and facilitating seed dispersal and forest restorati...
this study aims at assessing the impact of land use change (from forest areas to forest parks) on some silvicultural characteristics of stands under recreational land use in boloran natural forest park, kuhdasht. for this purpose, three zones including non-recreation, extensive recreation and intensive recreation regions were chosen. in each zone 30 sample plots in a systematic random design (1...
سابقه و هدف: کبد مهمترین ارگان داخلی بدن میباشد که نقش اصلی در متابولیسم بدن دارد. بیماری کبد را نمیتوان به راحتی در مراحل اولیه کشف کرد زیرا کبد حتی زمانی که قسمتی از آن نیز آسیبدیده باشد به درستی کار میکند و این خود تشخیص این بیماری را مشکل میکند. ابزارهای طبقهبندی اتوماتیک به عنوان یک ابزار کمک تشخیص باعث کاهش بار کاری پزشکان میگردد. طبقهبندیهایی که به منظور تشخیص هوشمند بیم...
langbour p, gérard J, roda Jm, ahmad fauzi p & guibal d. 2011. Comparison of wood properties of planted big-leaf mahogany (Swietenia macrophylla) in martinique island with naturally grown mahogany from brazil, mexico and peru. Big-leaf mahogany (Swietenia macrophylla) has been harvested and traded since the 16th century. It is highly valued and is used to craft luxury furniture and items. Its n...
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...
Assessment of forest structure and their spatial patterns are essential for managing and evaluation of forest ecosystems. This study was conducted at the Zagros forests in Kermanshah to evaluate the forest structural characteristics and their spatial distribution. Data was collected from 25 plots (400 m2) in a 100 m × 100 m systematic sampling grid. The spacing between plots was 50 m. In each p...
Relative to crop plants, the domestication of forest trees is still in its infancy. For example, the domestication of many crop plants was initiated some 10,000 years ago in the so-called 'Fertile Crescent' of the Middle East. By contrast, the domestication of forest trees for the purposes of producing more fibre began in earnest in the last half century. The application of biotechnology to for...
Iran's northern forests, which are mainly located on the northern slopes of Alborz Mountains, are important due to their excellent features. Accordingly, studying the dynamic of forest communities and their growth status can help planners and executive managers. One of the basic information for the management and sustainable use of forests is forest stand volume (volume and number). In fact, th...
Natural forest succession on human-disturbed lands is often slow because the resources necessary for succession are depleted. In such landscapes, forest succession may be dependent on arrival of seeds from off-site, many of which are dispersed by fruiteating animals. We studied bat and bird seed dispersal in a deforested agricultural area adjacent to Kibale National Park, Uganda. Seed rain was ...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید