نتایج جستجو برای: pine tree
تعداد نتایج: 184804 فیلتر نتایج به سال:
BACKGROUND Previous studies have shown that plants often have species-specific effects on soil properties. In high elevation forests in the Southern Rocky Mountains, North America, areas that are dominated by a single tree species are often adjacent to areas dominated by another tree species. Here, we assessed soil properties beneath adjacent stands of trembling aspen, lodgepole pine, and Engel...
The sustainability of indigenous Monterey pine (Pinus radiata D. Don) at Año Nuevo stands in the central coast of California was examined. The foremost management objective in these stands is to establish and maintain stand structures that ensure a sustainable presence of the species in terms of uneven-aged management. The major threats are the proliferation of shadetolerant tree species and th...
The mistletoe, Viscum album, living on Scots pine (Pinus sylvestris) has been reported barely to regulate its transpiration and thus heavily to affect the gas exchange of its host. The extent of this mistletoe effect and its underlying mechanism has, so far, only been partially analysed. In this study, pine branches with different mistletoe infestation levels were investigated by sap flow gauge...
ract: At four sites in the Gulf Coastal Plain, mechanical whole-tree harvesting (MWT) removed more biomass nutrients than hand-fell bole-only harvesting (HFBO). Soil compaction and loblolly pine (Pinus tae& L.) regeneraion growq varied among sites. At one location, MWT increased soil bulk density by 0.1 ~ g m ~ , from 1.14 to -24 ~ g m ~ , with no effect on kee growth. At a second location, whe...
Mechanical thinning and the application of prescribed fire are commonly used to restore fire-adapted forest ecosystems in the Western United States. During a 10-year period, we monitored the effects of fuel-reduction and forest-restoration treatments on levels of tree mortality in an interior ponderosa pine, Pinus ponderosa Dougl. ex Laws., forest in California. Twelve experimental plots, rangi...
The following brief synthesis of mountain pine beetle epidemiology is based on host-beetle interaction. In the first part I briefly describe the relationship between the dynamics of lodgepole pine and mountain pine beetle. The second part describes the phases in the infestation cycle and their main characteristics. This synthesis is based on published information on infestation behaviour in wes...
Crown structure, absorbed photosynthetically active radiation (APAR) and growth were analyzed in 300 replicated loblolly (Pinus taeda L.) and slash pine (Pinus elliottii Engelm. var. elliotti) clones to: (1) quantify genetic variation in crown structural traits, growth and APAR at the species, family and clonal levels; and (2) estimate within-family genetic and environmental influences on measu...
Effects of canopy ozone (O(3)) exposure and signatures of genetic structure using isozyme markers associated with O(3) tolerance were analyzed in approximately 20-, approximately 80-, and >200-yr-old ponderosa (Pinus ponderosa Dougl. ex Laws.) and Jeffrey pine (Pinus jeffreyi Grev. & Balf.) in Sequoia National Park, California. For both species, the number of alleles and genotypes per loci was ...
Pinus massoniana (Masson's pine) is a widespread tree species in central and southern China and northern Vietnam; it is valued for rosin and paper production. Despite the significant economic value of Masson's pine, little work has been done on its molecular genetics. We developed 318 SSR primers from genome sequences of P. massoniana, and we identified 10 polymorphic markers. The number of all...
Removal of nickel ions from aqueous solutions containing 1-100 mg l(-1), using pine tree (Pinus nigra) materials modified with HCl, was investigated on a laboratory scale. For this purpose, two natural adsorbents such as the modified pine bark (MPB) and the modified pine cone (MPC) materials with HCl solution were studied. At first, the required concentration level of the HCl solution for the m...
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