The relative productivity of even-aged and uneven-aged or multiaged stands is a frequently debated topic in silviculture and forestry. Nearly all previous comparisons have been empirical growth studies, simulations of stand growth, or economic analyses based on differences in stem volume production. Both even-aged and multiaged systems are highly variable and the large number of variables and a...

We analyzed one of the longest-term ecological data sets to evaluate how forest overstory structure is related to herbaceous understory plant strategies in a ponderosa pine forest. Eighty-two permanent 1-m2 chart quadrats that were established as early as 1912 were remeasured in 2007. We reconstructed historical forest structure using dendrochronological techniques. Ponderosa pine basal area in...

Porcupines (Erethizon dorsatum) rely on trees and shrubs for winter food and can cause serious, localized damage to conifers. Twenty-two percent of ponderosa trees (Pinus ponderosa) examined in southeastern Washington were damaged by porcupines. Most damage involved complete girdling of the midto upper boles of the larger trees (12 to 30 cm dbh) in the stand. Preliminary repellent trials with c...

An infectious microorganism, identified as Listeria monocytogenes, has been isolated from the bloodstream of pregnant mice fed a diet containing Pinus ponderosa needles. When the isolate was injected into pregnant mice, reproductive dysfunction and other changes, including speckled livers, spleen atrophy, and hemorrhagic intestines, appeared to mimic the signs of the disease in pregnant mice fe...

Pinus ponderosa and P. resinosa population samples have mean frequencies of enzymatically inactive alleles of 0.0031 and 0.0028 at 29 and 27 enzyme loci, respectively. Such alleles are rare and are apparently maintained by selection-mutation balance. Ponderosa pine have much higher amounts of allozymic and polygenic phenotypic variation than red pine, yet both species have similar frequencies o...