نتایج جستجو برای: pine cones
تعداد نتایج: 28479 فیلتر نتایج به سال:
Coevolution is increasingly recognized as an important process structuring geographic variation in the form of selection for many populations. Here we consider the importance of a geographic mosaic of coevolution to patterns of crossbill (Loxia) diversity in the northern boreal forests of North America. We examine the relationships between geographic variation in cone morphology, bill morpholog...
The use of pine nuts, the seeds of Pinus pinea, is on the increasing in the modern Mediterranean diet. Little more than 20 cases of allergy to this tree nut have been published, and cross-reactivity with pine pollen, peanut and almond has already been reported. We describe the case of a young boy with several episodes of anaphylaxis after pine nut ingestion. Specific IgE to pine nut and Artemis...
-Since the 1950s the existence of natural hybrids between shortleaf pine and loblolly pine has been recognized and reported in the literature. In a range-wide study of isoenzyme diversity in shortleaf pine. we found 16 percent of the trees from western populations were hybrids. based on the isocitrate dehydrogenase (IDH) locus. In stands thought to be pure shortleaf pine in west central Arkansa...
Studies of forest declines are important, because they both reduce timber production and affect successional trajectories of landscapes and ecosystems. Of particular interest is the decline of red pines which is characterized by expanding areas of dead and chlorotic trees in plantations throughout the Great Lakes Region. Here we examine the impact of two bark beetle groups, namely red turpentin...
In this study, we assessed the effects of chronic defoliation on radial, height and volume growth of Crimean pine (Pinus nigra Arnold) trees of the pine processionary moth [Thaumetopoea wilkinsoni Tams (Lepidoptera:Thaumetopoeidae)] in western Turkey Crimean pine tree ring chronologies were analyzed for evidence of the pine processionary moth (PPM). Tree ring widths from non-defoliated Crimean ...
Pine tar is the end product of pine wood carbonisation following distillation using extreme heat. An extensive literature search was conducted back to the 1950s for this review. Pine tar has been used in medicine for more than 2000 years to treat a range of skin conditions because of its soothing and antiseptic properties. Pine tar should not be confused with coal tar, which has been produced f...
This study investigates the capacity of neuronal growth cones to synthesize protein locally and independently of their cell body. Isolated growth cones were prepared from cultures of neurons from the snail Helisoma by transecting neurites proximal to the growth cone. The capacity for protein synthesis was tested by radiolabeling cultures with 3H-leucine and analyzing the resultant autoradiogram...
ABSTRACT Trees which lack obvious fire-adaptive traits such as serotinous seed-bearing structures or vegetative resprouting are assumed to be at a dramatic disadvantage in recolonization via sexual recruitment after fire, because seed dispersal is invariably quite constrained. We propose an alternative strategy in masting tree species with woody cones or cone-like structures: that the large clu...
0378-1127/$ see front matter 2012 Elsevier B.V. A http://dx.doi.org/10.1016/j.foreco.2012.02.017 ⇑ Corresponding author. Tel.: +1 334 844 1040; fax E-mail address: [email protected] (L.J. Samuels Longleaf pine (Pinus palustris Mill.), a species that once dominated the southeastern USA, is considered to be more drought tolerant than the principle plantation species in the South, loblolly pine (...
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