Have you ever hiked up a mountain and felt frosty wind blowing across your face? You might need to button jacket visit this place, but here, whitebark pine trees are right at home. Whitebark pines thrive in the highest forests of western North America. In these environments, help other, less-hardy species establish, grow, survive. For pine, chilly mountaintops provide refuge from insects, disea...

The western pine beetle, Dendroctonus brevicomis LeConte (Coleoptera: Curculionidae: Scolytinae), is a major cause of ponderosa pine, Pinus ponderosa Dougl. ex Laws., mortality in much of western North America. This study was designed to quantify relationships between western pine beetle trap catches [including those of its primary invertebrate predator Temnochila chlorodia (Mannerheim) (Coleop...

Stand conditions influence the partitioning of biomass to stem, foliage, branch, and root components. Using data from 4 to 6-year old loblolly pine (Pinus taeda L.) trees grown in a miniature-scale spacing trial, this study determined the effect of initial planting density on the biomass partitioning of loblolly pine. An analysis of covariance concluded that density did not have a significant e...

The recent introduction of Sirex noctilio F. (Hymenoptera: Siricidae) into North America has raised interest in native siricids and their parasitoids to better understand the potential impact of S. noctilio. In the southeastern United States, we assessed various techniques to capture native siricids and their parasitoids using traps, lures, and trap trees. During 2009Ð2011, in total, 2,434 wasp...

We tested the hypothesis that the leaf area/sapwood area ratio in Scots pine (Pinus sylvestris L.) is influenced by site differences in water vapor pressure deficit of the air (D). Two stands of the same provenance were selected, one in western Scotland and one in eastern England, so that effects resulting from age, genetic variability, density and fertility were minimized. Compared with the Sc...

Repeatability was estimated for constitutive oleoresin yield measurements in 10 stands of three species of pines native to southeastern United States. Trees of these species that discharge large quantities of oleoresin upon wounding are considered to be most resistant to attack by southern pine beetle (Dendroctonus frontalis Zimmermann). Oleoresin yield is usually measured from one or more smal...

We examined the effect of climate on aboveground biomass allocation of ponderosa pine (Pinus ponderosa) by measuring trees in disjunct forest stands growing on the same substrate at high-elevation montane sites and low-elevation desert sites. Climatic differences between the sites were comparable to the difference between present and future climates of interior North America that is expected to...

The woodwasp Sirex noctilio is a major pest of pine plantations worldwide. Economically significant damage is however limited to outbreak populations. To understand what determines outbreaks dynamics in this species, we developed an individual based model for a wasp population developing within a pine plantation. We show that outbreaks may be the result of the insect's life history. Specificall...

Our objective was to evaluate piperidine alkaloids as potential resistance factors in Sitka spruce, Picea sitchensis (Bong.) Carr, at risk to attack by white pine weevils, Pissodes strobi (Peck). We sampled 72 seedlings in each of two replicated field trials in the Oregon Coast Range. The seedlings were grown from open-pollinated seeds of putatively "resistant" or "susceptible" off-site parenta...

The winter roost-site selection of most North American foliage-roosting bats is relatively unknown. We examined winter roost-site selection of Seminole bats (Lasirrrus seminolus) in the Lower Coastal Plain of South Carolina during January 2004. Seminole bats used a variety of day-roost structures including the canopy of overstory hardwood trees, hanging vines, pine needle clusters suspended fro...