نتایج جستجو برای: pinus ponderosa
تعداد نتایج: 13623 فیلتر نتایج به سال:
Four levels of vegetative competition wete used to quantify the growth of loblolly and shot-deaf pines (Pinus taeda L. and /? echinatu Mill.) in naturally regenerated, even-aged stands on the Upper Coastal Plain of southeastern Arkansas, USA. Treatments included: (I) no competition control, (2) woody competition control, (3) herbaceous competition control. and (4) total control of nonpine veget...
In this study we examine the distribution of Rhizopogon species in spore banks from five California pine forests. Four of the forest sites were discontinuous populations of Pinus muricata and a fifth was a Pinus ponderosa stand in Sierra National Forest. Rhizopogon species were retrieved by bioassaying the soils with pine seedlings followed by isolation of axenic cultures from individual root t...
The piñon (Pinus edulis Engelm.)-juniper [Juniperus monosperma (Engelm.) Sarg.] woodlands of Bandelier National Monument are experiencing accelerated erosion. Earlier studies suggest that causes of these rapidly eroding woodlands are related to an unprecedented rapid transition of ponderosa pine (Pinus ponderosa C. Lawson) savanna to piñon-juniper woodlands as a result of cumulative historical ...
Fire-dependent pine forests in the Caribbean Basin cover extensive areas in the coastal plain of the Caribbean Sea and Gulf of Mexico and on several islands in the Bahamas Archipelago, Cuba, Hispaniola, and the Honduran Bay islands. These forests are high in conservation value but, unfortunately, remain mostly unprotected. Moreover, even though they are fire dependent, the use of fire for fores...
Although tree-ring-width chronologies have been widely used for temperature reconstructions, there are many sites around the world at which there is little evidence of a clear climate signal in the ring-width chronologies. This is the case with the long-lived conifer Huon pine (Lagarostrobos franklinii (Hook. F.) Quinn), endemic to Tasmania, Australia, when the species grows at low elevation. I...
Distribution Endemic to the six largest Ha-waiian islands. Size Greatly variable, typically reaches 20–24 m (66–79 ft) in height; may be much smaller on lava rock or boggy soils. Habitat Wide range, 1–2500 m (1–8200 ft) elevation with rainfall of 400–10,000 mm (16–400 in). Largest component of lowland and mon-tane wet and mesic forests, dry forests, subal-pine shrublands, and new lava flows. Ve...
Our primary objective was to present and test a new technique for in vitro estimation of respiration of cores taken from old trees to determine respiratory trends in sapwood. Our secondary objective was to quantify effects of tree age and stem position on respiratory potential (rate of CO2 production of woody tissue under standardized laboratory conditions). We extracted cores from one to four ...
We evaluated a smartphone app (TRESTIMATM) for forest sample plot measurements. The app interprets imagery collected from the sample plots using the camera in the smartphone and then estimates forest inventory attributes, including species-specific basal areas (G) as well as the diameter (DgM) and height (HgM) of basal area median trees. The estimates from the smartphone app were compared to fo...
An approach for synthesizing the results of ecological research pertinent to land management is the analysis of the historic range of variability (HRV) for key ecosystem variables that are affected by management activities. This report provides an HRV analysis for the upland vegetation of the Medicine Bow National Forest in southeastern Wyoming. The variables include live tree density, dead tre...
Hylobius warreni Wood, also known as the Warren root collar weevil, is a flightless insect that feeds on conifers throughout the boreal forests of Canada. Mature trees typically can withstand feeding, but larval feeding around the root collar may cause mortality to young trees. Recently, a large outbreak of mountain pine beetle (Dendroctonus ponderosae Hopkins) has killed a high proportion of m...
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