نتایج جستجو برای: oak trees decline
تعداد نتایج: 187710 فیلتر نتایج به سال:
Foliar infections in California bay (Umbellularia californica) are the most important known source of inoculum contributing to Phytophthora ramorum canker in coast live oak (Quercus agrifolia). This research addressed the question whether there is a “safe” distance between California bay and coast live oak beyond which the risk of disease is acceptably low. We quantitatively evaluated bay cover...
The main purpose of this study is to investigate the quantitative and qualitative characteristics of dominant tree species and their regeneration status in the Arasbaran forests. Data were collected by transect sampling and regeneration was assessed by plot with an area 100 m2. In the sample plots, we recorded information on species type, diameter at breast height, height, quality of seedlings ...
In coppice-with-standards, once a common type of management in Central European lowland forests, selected trees (standards) were left to grow mature among the regularly harvested coppice stools to obtain construction wood. After the underwood was harvested, the forest canopy opened rapidly, giving standard trees an opportunity to benefit from reduced competition. Although this silvicultural sys...
--Sweetgum and water oak trees samp~ed from a plantation over 7 years were used to test whether primary tree component (bole wood, bole bark, limb wood, timb bark, and leaves) predictions could be summed to estima~e total bole. total limb. and total tree values. Estimattons by summing primary component predictions were not significantly different from predictions for the totals, but pr~diction ...
acorn production plays a fundamental role in the organization and dynamics of oak forest ecosystems. regarding acorn importance, visual survey methods have been used to estimate acorn production of oak species throughout the world. in this study, the mast indices of brant`s oak (quercus brantii lindl.) were determined in a section of northern zagros forests, almost 36 ha area, near baneh, kurdi...
the present survey was carried out in oak (quercus brantii lindl.) woodlands of arghvan valley protected area, in ilam province, western iran. the main aim of this study was to survey the understory vegetation of oak in different classes of altitude (1400-1600, 1600-1800 and >1800 m) in the southern aspects, and their relationship with physical and chemical properties of soil. four transects, w...
British Journal of General Practice, August 2015 435 InTroduCTIon Although a native of southern Europe, the thermophilic oak processionary moth (OPM, Thaumetopoea processionea) is expanding its prevalence to encompass Central and Northern Europe. Roughly, over the past decade, the moth’s range has spread northwards and the species has now became established in the warmer regions of Northern Fra...
Old veteran trees function as biodiversity hotspots in both forests and open landscapes, protecting such is an important measure to halt loss of biodiversity. Nevertheless, the number continues decline worldwide, although estimates this mainly stem from geographically restricted case studies. In Norway, oak have received special protection since 2011 through Norwegian Biodiversity Act, however,...
Investigation and Comparison of Slenderness Coefficient Old Persian Oak Wild Pistachio Trees in Different Site Conditions the Middle Zagros
In this paper novel algorithms developed to automatically segment forest cover types are presented. The digital image analysis followed is mainly based on mathematical morphology operators and exploits the textural features in high spatial resolution images. These input images consist of true colour digital orthophotos and the studied forest covers consist of the main occurrences in Portugal: o...
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