We examined photosynthetic characteristics of two fast- and two slow-growing half-sib families of both loblolly pine (Pinus taeda L.) and slash pine (Pinus elliottii var. elliottii Engelm.) on two sites in northern Florida to: (1) quantify variation in light-saturated net photosynthesis (Amax) associated with vertical crown position and foliage age; (2) quantify the amount and distribution of l...

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 ...

Asymmetry in motor patterns is present in a wide variety of animals. Many lateralized behaviors seem to depend on brain asymmetry, as it is the case of different tasks associated to food handling by several bird and mammal species. Here, we analyzed asymmetry in handling behavior of pine cones by red squirrels (Sciurus vulgaris). Red squirrels devote most of their daily activity to feeding, thu...

Fire injury can increase tree susceptibility to some bark beetles (Curculionidae, Scolytinae), but whether wildfires can trigger outbreaks of species such as mountain pine beetle (Dendroctonus ponderosae Hopkins) is not well understood. We monitored 1173 lodgepole (Pinus contorta var. latifolia Doug.) and 599 ponderosa (Pinus ponderosa Doug. ex Law) pines for three years post-wildfire in the Ui...

On 26 May 2003, intense rainfall from a series of thunderstorms in eastern North Carolina caused flooding that eventually destroyed the concrete dam in Hope Mills, draining Hope Mills Lake, and revealing a formerly submerged and buried structure that was identified as a timber crib dam. Inspection revealed these logs to be old-growth longleaf pines, which are now rare on the coastal plain lands...

In the dry Swiss Rhone Valley, Scots pine forests have experienced increased mortality in recent years. It has commonly been assumed that drought events and bark beetles fostered the decline, however, whether bark beetle outbreaks increased in recent years and whether they can be linked to drought stress or increasing temperature has never been studied. In our study, we correlated time series o...

Using historical General Land Office record as a reference, this study employed a landscape-scale disturbance and succession model to estimate the future cumulative effects of six alternative management plans on the tree species composition for various physiographic settings for the Mark Twain National Forest in Missouri. The results indicate that over a 200-year horizon, the relative abundance...

Whitebark pine is an important component of high elevation ecosystems in the western United States and Canada. Many wildlife species, including grizzly and black bears, squirrels, and birds, forage on the large, wingless seed. Whitebark pine relies heavily upon the Clark's nutcracker for seed dispersal and regeneration. Due to fire exclusion, white pine blister rust, and the mountain pine beetl...

The distribution of extractives, lignin, and carbohydrates in radiata pine and their variation with tree age are reviewed. Extractives, their nature, and amount depend on the heartwood content of the tree, and thus upon wood age. Lignin decreases in the pith-to-bark sequence; pentosans content decreases over the first 10-15 growth rings from the pith, after which it is approximately constant. C...