Knowledge of the distribution and natural history of bats in Southeast Alaska is limited. We conducted capture and acoustic surveys for bats throughout Southeast Alaska in 2005 and continued surveys on Prince of Wales Island in 2006. We documented capture success, relative abundance, morphology, and periods of reproduction for each species. Capture success varied by species, location, and type of capture site. Little brown myotis (Myotis lucifugus; Le Conte 1831) were captured most frequently, followed by California myotis (M. californicus; Audubon and Bachman 1842), Keen's myotis (M. Keenii; Merriam 1895), and long-legged myotis (M. volans; Allen 1866). We captured little brown myotis throughout the region, Keen's and California myotis as far north as Juneau, and long-legged myotis in the southern part of the region. Silver-haired bats (Lasionycteris noctivagans; Le Conte 1831) were not captured, but were sighted on Prince of Wales Island and acoustic data indicate they may occur as far north as Juneau. Based on low rates of detection, all species appear to occur in low densities in Southeast Alaska. Better understanding of population status and trends, habitat ecology, and response to forest management is needed to identify essential habitat elements and prioritize conservation strategies in this region.

The Hanford Reach is one of the few remaining unimpounded sections of the Columbia River. However, because of flow management at upstream dams, there are often large fluctuations in water level. To determine how environmental conditions might affect age-0 resident fishes in the Hanford Reach, we evaluated species composition, distribution, abundance, and standard lengths of larval and juvenile fishes along shoreline habitats during July and August 1998, 1999, and 2000. Catches in beach seine hauls during all three years were highly variable. The four most abundant taxa collected were three cyprinids, peamouth (Mylocheilus caurinus), northern pikeminnow (Ptychocheilus oregonensis), and redside shiner (Richardsonius balteatus); and suckers (Catostomus spp.). Highest overall catches were in sloughs of the Hanford Reach in 1999, a year with high flows, lower water level fluctuations, and more vegetation. Mean shoreline summer water temperatures were higher in 1998 than in 1999 and 2000, and mean lengths of the four most abundant taxa in late August were also greater in 1998, due presumably to enhanced growth or an earlier spawning season. In spite of flow fluctuations, overall catches of age-0 resident fishes were greater in the riverine Hanford Reach compared to past catches in a more lentic Columbia River reservoir. High abundances of age-0 resident fishes in the Hanford Reach could be due to more spawning and rearing habitat in this structurally complex area, and may mitigate for negative effects of variable flow regimes.

This study investigates the influence of parasitic western dwarf mistletoe on prescribed fire behavior and limb flammability of ponderosa pine. Fall season prescribed fires were applied to 14 plots (7 infested and 7 uninfested) in an 81.5 ha mixed-conifer stand at Crater Lake National Park. I measured stand structure variables and surface fuel composition before and after burning and monitored fire behavior during burns. To assess the influence of mistletoe infection on limb flammability in a more controlled setting, I burned infected and uninfected limbs (n = 18 each) in a burn chamber. Results show that plots at Crater Lake infested with mistletoe burned at higher temperatures for shorter periods than uninfested plots. Plots with greater duff biomass recorded higher temperatures, while those with greater accumulations of litter burned longer. All plots experienced a significant reduction in total surface fuel loads following fire, however there was no difference in fuel reduction between uninfested and infested plots, suggesting mistletoe has little influence on fire behavior in this forest type. Infected branches lost a greater proportion of their mass during burn chamber tests, primarily in the form of needles. These results indicate that dwarf mistletoe has little influence on the behavior of low-intensity surface fires, but further research is needed to assess the role of mistletoe in other fire conditions and stand types.

The Pumice Desert is a pumice flat occupying about 640 ha along the northern portion of Crater Lake National Park. It is surrounded by lodgepole pine (Pinus contorta var. murrayana) forest. The purpose of the study was to identify the factors maintaining the open, barren nature of the area and to monitor vegetation changes. The initial vegetation survey on the Pumice Desert was conducted in 1965. Nine 0.04-ha strip plots and one rectangular 40.5-ha plot were marked with iron rods to monitor herbaceous plants and lodgepole pine. The plots were resurveyed in 1977, 1995, 2000, and 2005. Only 14 species were initially found in the 0.04-ha plots; an additional species was found in 2005. Plant numbers varied in the 0.04-ha plots during four surveys spanning 40 years. Vegetation was sparse with about 5% coverage. However, the number of trees in the 40.5-ha plot nearly tripled in the 40 years the area has been monitored. This paper documents the changes that have taken place over 40 years and offers rationale for the slow speed of plant succession. It also documents the predominance of multiple-trunked lodgepole pine within the study area and evaluates possible causes.

We studied litter sizes, den characteristics, and den site selection by wolves (Canis lupus ligoni) on Prince of Wales and adjacent islands in Southeast Alaska, USA. The study area was extensively logged and roaded enabling us to examine effects of those factors on den site selection. We counted pups in dens during May using an infrared video camera with a flexible-shaft. We recorded habitat features at dens and used logistic regression to compare den site characteristics within 100-m and 1000-m circular buffers around dens with randomly matched unused locations. Litter size averaged 4.1 (SD = 1.7) pups, however, average litter sizes of six first-time breeding females were smaller ( = 3.0, SD = 2.5). Dens were located in root wads of large living or dead trees within old-growth forest stands <150m from freshwater. Within 100-m and 1000-m buffers, wolves selected coarse-canopy old-growth forest stands and muskegs adjacent to lakes, ponds or streams, on gentle slopes, that were farther from logged stands and roads than unused locations. Landscape features such as elevation and slope, and proximity of fresh water had the greatest effects on den site selection. Covariates tabulated within 100-m buffers had much greater influence on den site selection than variables tabulated within 1000-m buffers indicating that wolves mostly responded to features within the immediate vicinity of dens. Wolves generally avoided clearcuts and roads but they tolerated intense disturbances of short duration during our den visits. We suggest wolves prefer locations away from roads and clearcuts but will select them if suitable alternative locations do not exist. Once established at den sites, wolves will tolerate some human disturbance at least of short duration.

We calculated monthly soil moisture deficits from historical meteorological data from the south coast of mainland British Columbia to quantify warm and dry conditions at monthly and seasonal scales. Our main objective was to determine if climatic conditions antecedent to recorded outbreaks of western hemlock looper (Lambdina fiscellaria lugubrosa Hulst) may have triggered population growth. Periods of soil moisture deficits during the month of June were associated with the onset western hemlock looper outbreaks in the study area, as were warmer and drier conditions during the growing season two years prior to the first year of visible defoliation. Models of climate change predict that future summers in the Pacific Northwest will be warmer and potentially drier than present, and although other factors besides climate influence western hemlock looper population dynamics, the combined effects of more frequent droughts, changes in forest cover, and expanded range of western hemlock due to climate change may result in increased frequency, size and severity of outbreaks in the future.

In temperate rainforests of western North America, some second-growth forests are managed to promote development of the multi-dimensional structures observed in old-growth forests. Information about tree architecture from across a range of growing conditions is needed to support this goal. Accordingly, branch and crown dimensions associated with tree age, site index, and stand basal area are reported for 854 Douglas-fir trees, which were harvested from old-growth forests in Washington, Oregon, and northern California in the 1960s. Sample trees ranged from 38–647 years old. The average diameter and the relative height of the first live and dead branch increased with tree age. In contrast, only weak relations existed between live crown ratio, which was highly variable, and tree age or site index. Differences between old Douglas-fir trees and younger trees with an equivalent breast-height diameter (dbh) were greatest in the dimensions of their first branches. Between ages 100 to 500 yr, for example, the mean first live branch on a 127cm dbh tree was estimated to more than double in diameter—from 3.1 to 6.6 cm—at a basal area of 114 m²/ha. Despite the limitations associated with inherited data, study results have silvicultural implications for managed Douglas-fir forests because they indicate that crown morphologies of large, young trees were not the same as their similarly sized, older counterparts on sites spanning a range of average natural stand density conditions within the Douglas-fir region.

In British Columbia, foresters use the height-age models for trembling aspen (Populus tremuloides Michx.) from the neighbouring province of Alberta to predict height and site index for paper birch (Betula papyrifera Marsh.) because height-age models for paper birch in British Columbia do not exist. The aspen model has not been extensively tested for local use on paper birch trees. Consequently, it is not known how well they predict the height growth of site trees. We rectified this situation by developing paper birch height-age models from locally collected stem analysis data for paper birch. Data from 61 plots in the Interior Douglas-Fir, Interior Cedar and Hemlock, and Sub-Boreal Spruce biogeoclimatic zones were fit to a model based on the log-logistic function. Differences in growth patterns between the zones were detected using indicator variables. This height-age model should be used for paper birch in the sampled biogeoclimatic zones in British Columbia because it is the best fitting model. An alternative model is available for sites not in the sampled zones. A comparison of the trembling aspen model and the paper birch model indicates that the difference between the models is small over most of the management age range of paper birch. The exception to this is at young ages and high site indexes, where paper birch is predicted to be taller than trembling aspen.

We used video cameras to observe the activity patterns and behavior of three female red tree voles (Arborimus longicaudus) and their young in arboreal nests in western Oregon. Observation periods at the three nests were 63, 103 and 148 days. All three voles were primarily nocturnal, but occasionally foraged for brief periods during the day when they had large young in the nest. The median time when voles began and ended activity was 95 min after sunset and 168 min before sunrise, respectively. The median amount of time spent outside the nest at night was 27 min (range = 0–712 min), and most of this time was spent foraging. Nocturnal activity consisted primarily of long periods inside the nest interspersed with short periods of intensive foraging, during which voles ran out of the nest, harvested cuttings and hauled them back to the nest. Cuttings were stored inside the nest or on top of the nest. The mean number of foraging bouts per night was 3.4 ± 0.1 (range = 1–13), and the mean number of cuttings harvested per night was 20.4 ± 3.5 (range = 0–75). Females harvested more cuttings when they had large young in the nest and there was no evidence that they ate anything but the needles and bark of the cuttings that they brought to their nests. All three females produced litters while we observed them (1, 2, and 3 litters, respectively). Juveniles first began to explore outside the nest when they were 30–35 days old and dispersed when they were 47–54 days old. During the last two weeks before they dispersed the juveniles spent considerable time outside the nest at night, becoming increasingly adept climbers and gradually beginning to harvest their own food. Dispersal of siblings occurred on the same night and appeared to be precipitated by female aggression towards the young.

We radiocollared 45 red tree voles (Arborimus longicaudus) in western Oregon and monitored their movements during July 2002–September 2003. We predicted that home range areas would be larger in young forests than in old forests and that males would have larger home ranges and use more nests than females. We tracked individual voles for 82 ± 9 days (mean ± SE; range = 24–307 days). Voles were active primarily at night, although we did see voles outside their nests during the day on two occasions. Of the 45 voles, 18 (4 males, 14 females) occupied a single nest tree and adjacent foraging trees that had interconnecting branch pathways with the nest tree. The other 27 voles (11 males, 16 females) used ≥2 nest trees (range = 2–6). Average distance between alternate nests use by individuals was 45 ± 5 m (range = 4–162 m). Estimates of mean (± SE) and median home range size were 1,732 ± 366 m² and 760 m², respectively (range = 36–10,308 m²). Little variation in home range size was explained by gender or age of voles, or by forest age. However, females occupied fewer nests and made fewer movements between nest trees than males. Male home ranges were larger than females during late winter and spring during the peak breeding period (2,475 ± 1,076 m² and 790 ± 239 m², respectively). We did not detect use of ground nests by radiocollared voles, but we did document occasional cases where voles moved on the ground between nest trees.

Lepidium papilliferum (Brassicaceae) is a rare mustard endemic to sagebrush-steppe habitat in southwestern Idaho. The species, commonly known as slickspot peppergrass, has been described as having two life history patterns with respect to flowering — annual and biennial. Annuals germinate, flower, and die all within their first year, whereas biennials exist as vegetative rosettes in their first year, overwinter, and then reproduce and die in their second year. In this article we identify a third, albeit uncommon, pattern of flowering for L. papilliferum whereby individuals engage in limited flowering and seed production late in their first year, and then, if they survive the winter, flower and set seed again in their second year. In a study conducted at two L. papilliferum populations from June 2007 to June 2008, we found that individuals that flowered late in their first season (N = 34) suffered 59% overwinter mortality, whereas biennials that put off all reproduction until their second year (N = 200) suffered significantly less overwinter mortality at 24% (χ² = 17.094, P < 0.001). We discuss various possibilities for the adaptive significance of multiple flowering in L. papilliferum given the higher overwinter mortality for individuals that exhibit this life history strategy.

Naturalness in biology and natural resources can be defined in different ways—entire courses are taught on the topic, and entire books are devoted to it. This is not an esoteric issue when it comes to managing terrestrial and aquatic resources, because of implications for both biotic and human systems. Value judgments inevitably enter into decision making and policy, ultimately affecting how effort and resources are expended to produce goods and services that meet administrative, social, cultural, and economic goals. This occurs across all spatial and temporal scales.

In this Forum, Robert Lackey cautions that a scientific focus on “natural” constructs can lead to biases that negatively affect decision making and policy about natural resources. James Karr counters that a focus on “natural” can provide an important scientific context that leads to appropriate inferences for environmental protection and policy. Whether or not these articles help you make up your mind about this topic, they will stimulate you to think more consciously about it in the future. —David L. Peterson