A snow-covered forest mapping method for optical remote sensing is proposed. The method is based on linear sub-pixel reflectance modelling of the surface components snow, individual tree species and bare ground. Experiments are performed using a 100% snow-covered Landsat TM scene and aerial photos covering spruce, pine and birch forest in the Jotunheimen mountain area of South Norway. The refle...

Height-diameter relationship is one of the most important stature characteristics of trees. It will change with climatic conditions because height and diameter growth displays different sensitivities to climatic factors such as temperature. Detecting and understanding changes in the stature of trees growing along altitudinal gradients up to their upper limits can help us to better understand th...

The mid-altitude zone of the Qinling Mountains in China was once dominated by birch and pine-oak belts but are now mainly covered by secondary growth following large-scale deforestation. Assessing the recovery and sustainability of these forests is essential for their management and restoration. We investigated and compared the tree species composition and community assemblages of secondary for...

BACKGROUND Wild birch trees grow in limited areas in Japan and are not a common aero-allergen. However, many patients who do not live in the area show positive birch pollen Radioallergosorbent Test (RAST). Therefore, being sensitized by another tree pollen which is closely related to birch may result in showing a specific IgE antibody to birch. Alder is a one of these trees and in the past it g...

birch (betula sp.) is considered as extinction species and its natural regeneration in iranian forests ‎is very slow. difficulties in regeneration as well as natural seed germination of birch tree besides ‎high levels of seed contaminations have justified the application in‏ ‏vitro culture with respect to its ‎conservation and genetic improvement. hence, the in vitro culture initiation using se...

Rising interest in using wood in non-residential multi-story building structures opens up new opportunities for utilising low-grade hardwoods. The primary objective of this study was to evaluate the geographic variation in modulus of elasticity (MOE) and modulus of rupture (MOR) of sugar maple and yellow birch wood in relation to stand and tree characteristics for two regions in New Brunswick, ...

The forests of North Mongolia are largely dominated either by larch (Larix sibirica Ledeb.) or birch (Betula platyphylla Sukaczev). The increasing demand for timber and firewood is currently met by removal of wood from these forest stands. Therefore, silvicultural approaches that account for both utilization and protection are needed. Thinning trials were established in the research area Altans...

Silver Birch (Betula pendula Roth), a pioneer tree species, and Scots Pine (Pinus sylvestris L.) used for revegetation are typical tree species in the mine reclamation area of the Sokolov Basin (West Bohemia, the Czech Republic). Chlorophyll content in their foliage can be used as one of the indicators of tree stress caused by adverse soil conditions with heavy metal contamination being the maj...

Object based image classification is applied to assess the upward advance of tree species in Finnish Lapland caused by the current global warming. An automated Feature Extraction Module (Fx) implemented in ENVI is used to extract the tree crowns from a digitized panchromatic aerial photograph acquired in 1947 and a false colour aerial photograph from 2003 of an altitudinal foresttundra ecotone ...

Methods We evaluated subjects from Southern Romania, a Central European region with temperate continental climate with submediterranean and humid subtropical influences, where sensitization to Betulaceae pollen is less important in pollinosis compared with that to grass or weed pollen. We selected adult patients from the region of sylvosteppe with low density forests dominated by deciduous spec...