نتایج جستجو برای: beech
تعداد نتایج: 3311 فیلتر نتایج به سال:
Fagus grandifolia (American Beech) is uncommon along the coast of southern New England, but occasionally forms unusual monodominant stands with higher beech abundance than is typical for inland areas. This study documents the distribution of beech on Cape Cod and nearby coastal islands, and evaluates environmental and historical factors that are likely to infl uence its distribution. Tree-ring ...
Beech scale (Cryptococcus fagisuga Lindinger) (Hemiptera: Eriococcidae) is an invasive forest insect established in the eastern United States and Canada. It predisposes American beech (Fagus grandifolia Ehrhart) trees to infection by Neonectria spp. Fungi causing beech bark disease. White wax secreted by the diminutive scales obscures individual insects, making it difficult to accurately quanti...
Beech bark disease (BBD) has affected the composition, structure, and function of forests containing a significant proportion of American beech (Fagus grandifolia Ehrh.) across North America. BBD spread has been investigated at landscape and regional scales, but few studies have examined spatial patterns of disease severity and spread within stands where forest managementmitigationmeasures can ...
Beech forests play an important role in temperate and north Mediterranean ecosystems in Greece since they occupy infertile montane soils. In the last glacial maximum, Fagus sylvatica (beech) was confined to Southern Europe where it was dominant and in the last thousand years has expanded its range to dominate central Europe. We sampled four different beech forest types. We found 298 insect spec...
Relict forests within tussock grassland and abundant subsoil charcoal indicate that prior to Polynesian conflagrations, conifer forests dominated by kaikawaka covered the upper montane plateaux in Moawhango Ecological Region. Much forest remains in peripheral districts where the plateaux border the encircling Kaimanawa, Kaweka and Ruahine greywacke uplands; in these districts, beech forest of t...
American beech (Fagus grandifolia), now a centerpiece species of the eastern deciduous forest, has had a continually changing historical biogeography. This paper reviews the paleoecology, the presettlement occurrence, the modern range, and the current abundance pattern of beech. It synthesizes these four databases into maps representing the distribution and abundance of beech at specific period...
BACKGROUND Beech and oak pollen are potential allergen sources with a world-wide distribution. OBJECTIVE We aimed to characterize the allergen profile of beech and oak pollen and to study cross-reactivities with birch and grass pollen allergens. METHODS Sera from tree pollen-allergic patients with evidence for beech and oak pollen sensitization from Basel, Switzerland, (n=23) and sera from ...
The sooty beech scale insect (Ultracoelostoma sp.) (Hemiptera: Margarodidae) exhibits a highly patchy distribution at local and regional scales. A major factor driving this common distributional phenomenon in other phloem-feeding insects is aggregation and local adaptation. The aim of this study was to determine if Ultracoelostoma was locally adapted to its natal host trees, by contrasting the ...
The annual diet of possums (Trichosurus vulpecula) during both a beech (Nothofagus) mast fruiting year and a non-mast year in the simple beech forests of the North Branch of the Hurunui Catchment, eastern South Island, New Zealand, was determined by sorting the contents of 270 possum stomachs, collected between December 1999 and December 2001. Beech flowers and seeds contributed 46.1% to annual...
The present study aimed to detect sensitivity of beech trees (Fagus sylvatica L.) to meteorological parameters and air pollution by acidifying species as well as to surface ozone outside their north-eastern distribution range. Data set since 1981 of Preila EMEP station enabled to establish that hot Summers, cold dormant, and dry and cold first-half of vegetation periods resulted in beech tree g...
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