Women and Black, Indigenous, and People of Color (BIPOC) employees are underrepresented in science and natural resource management institutions. Student and recent graduate trainee and internship ...programs have been used to try to address this in United States federal agencies over the last few decades. Our study evaluates how effective such programs are at improving U.S. federal workforce diversity. We used a comprehensive employee dataset from the United States Department of Agriculture (USDA) Forest Service-which has the largest natural resource management workforce in the country-to analyze the demographic characteristics and career paths of paid interns from 1996-2017. We found that a majority of employees who started as interns later converted to permanent employment with the USDA Forest Service. In addition, Black and Hispanic interns were, respectively, 5 and 3 times more likely than White interns to work for the agency in permanent positions after their internships. However, people who started as interns had significantly shorter USDA Forest Service careers than those who started in permanent positions. White women entering directly into permanent positions typically advanced to higher pay grades through promotion faster than White women who entered as interns. Finally, male BIPOC interns involuntarily separated (i.e., were fired) at significantly higher rates than all other employees. Our study suggests that while internship employment programs can be an effective tool for hiring a diverse workforce, they are not sufficient to close the overall workforce diversity gap. In addition, only a small percentage of new hires every year are interns. To achieve a level of representation that mirrors the civilian labor force, our study suggests that internship programs need to focus on long-term employee retention and be of significantly larger scale.
Despite the importance of financial outcomes to stand-level forest management decision-making, long-term assessments are rare. We compared the quality and value of mixed, northern conifer ...(Picea–Abies–Tsuga) stands in Maine, USA, treated with a range of silvicultural systems and exploitive cuttings for 65 years. Ten replicated treatments — single-tree selection and uniform shelterwood systems, commercial clearcutting, fixed and guiding diameter-limit cutting, and no cutting — were assessed for quality and value of standing and harvested trees. Selection systems resulted in good tree quality and high stand value, particularly when applied on a short cutting cycle, but small harvest volumes were not always commercially operable. Shelterwood system resulted in good tree quality, but changes in species values over time influenced financial outcomes. In contrast, commercial clearcutting and fixed diameter-limit cutting resulted in poor tree quality and low residual stand value after multiple harvests. Guiding diameter-limit cutting resulted in high stand value and is more appropriately characterized as a silvicultural system than exploitive harvesting when applied with harvest volume limits and seed tree retention. Overall, treatments focused on short-term financial gain led to degraded stand conditions, while those that sought to grow high-quality trees resulted in desirable outcomes over the long term.
Rehabilitation of cutover stands is often a management objective of landowners who desire improved stand conditions and increased value from future harvest revenues. We evaluated crop tree growth ...response and quality following precommercial rehabilitation treatments in mixedwood stands degraded through repeated exploitive cutting in Maine, USA. Treatments included control (no rehabilitation), moderate rehabilitation (crop tree release), and intensive rehabilitation (crop tree release plus timber stand improvement). Paper birch (Betula papyrifera Marsh.), red spruce (Picea rubens Sarg.), and eastern hemlock (Tsuga canadensis (L.) Carriere) crop tree diameter increments 0 to 9 years after treatment were greater following rehabilitation than in the control. Diameter increment did not differ between intensities of rehabilitation for any species. For conifers in the lower strata, crop tree height growth and change in crown length were negatively correlated with basal area in larger trees. The occurrence of epicormic branches on paper birches was greater in the rehabilitation treatments than the control. However, most epicormic branches occurred above the height corresponding to the first sawlog. These findings indicate that rehabilitation of mixedwood stands with similar characteristics can result in improved growth of crop trees without jeopardizing the quality of the lower bole in paper birches.
Understanding forest structural changes resulting from postdisturbance management practices such as salvage logging is critical for predicting forest recovery and developing appropriate management ...strategies. In 2013, a tornado and subsequent salvage operations in northern Maine, USA, created three conditions (i.e., treatments) with contrasting forest structure: blowdown, blowdown + salvage, and control (undisturbed). We sampled forest structure in five stands representing each of these three treatments. Our results document obvious and predictable changes to forest structure caused by the blowdown and salvage operations; however, they also include unexpected findings: downed coarse woody debris volume remained quite high in the salvaged areas, although its vertical distribution was markedly reduced; salvage operations did not reduce fine woody debris volume; and the salvage operation itself reduced the abundance of upturned root masses. Our study contributes to a growing body of literature highlighting the fact that outcomes of salvage operations vary considerably from situation to situation. Nevertheless, they suggest that salvage logging has important implications for residual stand structure and regeneration potential and that these implications should be considered carefully when weighing postdisturbance management options.
Although northern white-cedar ( Thuja occidentalis; henceforth cedar) is thought to have few insect pests, arborvitae leafminers (primarily Argyresthia thuiella) have been known to cause leaf ...necrosis. Yet, historical evidence for leafminer outbreaks is limited. We combined leafminer larval surveys conducted between 1950 and 1992 with tree-ring analyses from eight cedar stands to reconstruct a history of leafminer outbreaks in Maine, USA. Our tree-ring data show distinctive 2- to 3-year growth reductions that we attribute to leafminers. Several such growth reductions correspond to peak leafminer larval abundances, providing evidence that the reductions are reliable indicators of leafminer activity. Outbreak severity within a site was unrelated to cedar abundance. Outbreak periods thus identified (beginning ca. 1919, 1937, 1950, 1962, mid-1970s, but not at all sites) suggest that leafminer damage may have been more prevalent (albeit patchy) than previously thought. This historical information is relevant given current outbreaks in Maine and elsewhere.
Bridging the Gender Gap KERN, CHRISTEL C.; KENEFIC, LAURA S.; STOUT, SUSAN L.
Bioscience,
12/2015, Letnik:
65, Številka:
12
Journal Article
Recenzirano
Past research has established that diverse scientific communities foster innovation and problem solving more effectively than communities with a narrow range of knowledge, skills, and experience. ...However, gender diversity among scientists is limited, particularly in natural-resource fields. We compared data on scientist gender and rank from the US Department of Agriculture Forest Service Research and Development (FSR&D, a hierarchical organization) with data on faculty gender and tenure status from universities (loosely coupled systems) with comparable areas of study. We found that the representation of women was greater among FSR&D scientists than among university faculty but declined with seniority in both institutions. Within FSR&D, data showed demographic inertia, suggesting that the representation of women in senior scientist positions will increase. Although many mechanisms affect gender representation, our findings suggest that organizational structure affects the diversity of the scientific workforce.
Selection cutting is defined as a tool for uneven-aged silviculture. Dependence on diameter distribution by forestry practitioners for identifying stand conditions has led to misuse of selection-like ...cuttings in even-aged northern hardwood stands. Our study used several long-term data sets to investigate the temporal stability in numbers of trees per diameter class in uneven-aged northern hardwood stands treated with single-tree selection and in 45-year-old second-growth stands treated with selection-like cuttings. We analyzed data from New York, Michigan, and Wisconsin to determine changes through time in number of trees across 2.5 cm diameter classes, shifts in the shape and scale of the three-parameter Weibull function used to describe the diameter distributions, and dynamics of associated stand attributes. Findings showed that single-tree selection cutting created and sustained stable diameter distributions and uniformity of conditions through consecutive entries in uneven-aged stands. By contrast, these characteristics varied through time in the second-growth stands that had been treated with selection-like cuttings. Analysis also showed that the Weibull shape and scale parameters for stands under selection system migrated towards those of the recommended target diameter distribution in the uneven-aged stands. These parameters diverged from the target with repeated use of selection-like cuttings in the second-growth even-aged stands.
Understanding the complexity of forest community dynamics is essential in forest management planning and stewardship, yet lowland northern white-cedar (
Thuja occidentalis
L.) are often managed as ...homogenous communities. Through this study, we defined lowland white-cedar forest community types in unharvested and harvested forest stands within the State of Michigan and examined community type associations with ecological variables. Data collected in unharvested stands revealed three white-cedar community subtypes: (1) cedar-deciduous, (2) cedar-conifer, and (3) cedar-shrub. These unharvested subtypes were dominated by white-cedar, yet characterized by different soils, hydrology, geochemical gradients, and associated tree species. In harvested stands, six community types were identified: (1) aspen-fir, (2) winterberry-willow, (3) balsam fir, (4) cedar-red maple, (5) cedar-black spruce, and (6) alder-tamarack. These harvested community types were located along ecological gradients, including soil type (organic or mineral) and soil water pH. Using community types in unharvested and harvested stands, and associated ecological gradients, potential pathways of compositional transition were theorized. Findings suggest that cedar community subtype affects the likelihood of cedar regeneration and dictates the alternative species replacing cedar after harvest. These findings and potential pathways are useful to forestry practitioners, as they highlight potential changes in tree species dominance following harvest across a range of lowland white-cedar community types, allowing refinement of silvicultural prescriptions to ensure desired outcomes.
Forest management practices designed to meet varied landowner objectives affect wildlife habitat and may interrupt the life-cycle stages of disease vectors, including the black-legged tick, Ixodes ...scapularis Say (Acari: Ixodidae). Ixodes scapularis transmits multiple pathogens including Borrelia burgdorferi, the causative agent of Lyme disease, which is the most common tick-borne disease in the United States. There is evidence that a range of active forest management practices (e.g., invasive plant removal, prescribed burning) can alter tick densities and pathogen transmission. However, few studies have investigated relationships between forest stand structural variables commonly manipulated by timber harvesting and tick ecology. Foresters may harvest timber to create certain forest structural conditions like the mean number of trees, or basal area, per hectare. This study used a spatially replicated experiment in a blocked design to compare forest stands with a range of overstory structures and document variations in the midstory, understory, and forest floor, as well as microclimate conditions within tick off-host habitat. Greater numbers of trees or basal area per hectare correlated with greater canopy closure but less understory cover, stabilized microclimate temperature, higher microclimate humidity, and greater I. scapularis nymph densities. A random forest model identified understory forest structure as the strongest predictor of nymph densities. There was no relationship between the number of trees or basal area per hectare and daily deer (Odocoileus virginianus Zimmermann) activity or nymphal infection prevalence. These findings provide a deeper understanding of tick-habitat associations within a forest stand and have the potential to inform forest management decisions.
Silvicultural thinning can lead to rapid microclimatic changes for residual trees. Despite the benefits of decreased competition, thinning may induce "thinning shock"--temporary negative ...physiological responses as trees acclimate to new conditions. We examined the impact of thinning on the microclimate and physiology of residual, previously shaded red spruce (Picea rubens Sarg.) trees relative to non-thinned controls. Both daily maximum temperature and vapor pressure deficit increased post thinning, with larger increases observed on hotter and drier days. In response to these environmental changes, we found clear evidence of physiological declines. At 1.7 weeks post thinning, we found a 0.59 MPa reduction in average midday water potential relative to control trees, which lasted for an additional 1.4 weeks. Thus, the trees in the thinning treatment were at or beyond published estimates of needle turgor loss. Thinning decreased the photosynthetic efficiency of current-year needles by 3.8% after 2 weeks, and it declined by 1.3% per week for the remainder of the growing season. These results suggest that thinning shock occurs in red spruce, a shade-adapted, climate-sensitive species. Thinning shock may contribute to the lagged growth responses commonly observed post thinning, and these effects may be more extreme in novel future climates.
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