106 research outputs found
A Comprehensive Guide to Fuel Management Practices for Dry Mixed Conifer Forests in the Northwestern United States
This guide describes the benefits, opportunities, and trade-offs concerning fuel treatments in the dry mixed conifer forests of northern California and the Klamath Mountains, Pacific Northwest Interior, northern and central Rocky Mountains, and Utah. Multiple interacting disturbances and diverse physical settings have created a forest mosaic with historically low- to mixed-severity fire regimes. Analysis of forest inventory data found nearly 80 percent of these forests rate hazardous by at least one measure and 20 to 30 percent rate hazardous by multiple measures. Modeled mechanical treatments designed to mimic what is typically implemented, such as thinning, are effective on less than 20 percent of the forest in single entry, but can be self-funding more often than not. We provide: (1) exhaustive summaries and links to supporting guides and literature on the mechanics of fuel treatments, including mechanical manipulation, prescribed fire, targeted grazing and chemical use; (2) a decision tree to help managers select the best mechanical method for any situation in these regions; (3) discussion on how to apply prescribed fire to achieve diverse and specific objectives; (4) key principles for developing an effective monitoring plan; (5) economic analysis of mechanical fuel treatments in each region; and (6) discussion on fuel treatment longevity. In the electronic version of the document, we have provided links to electronic copies of cited literature available in TreeSearch online document library (http://www.treesearch.fs.fed.us/
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Deploying initial attack resources for wildfire suppression: spatial coordination, budget constraints, and capacity constraints
We combine a scenario-based, standard-response optimization model with stochastic simulation to improve the efficiency of resource deployment for initial attack on wildland fires in three planning units in California. The optimization model minimizes the expected number of fires that do not receive a standard response-defined as the number of resources by type that must arrive at the fire within a specified time limit-subject to budget and station capacity constraints and uncertainty about the daily number and location of fires. We use the California Fire Economics Simulator to predict the number of fires not contained within initial attack modeling limits. Compared with the current deployment, the deployment obtained with optimization shifts resources from the planning unit with highest fire load to the planning unit with the highest standard response requirements but leaves simulated containment success unchanged. This result suggests that, under the current budget and capacity constraints, a range of deployments may perform equally well in terms of fire containment. Resource deployments that result from relaxing constraints on station capacity achieve greater containment success by encouraging consolidation of resources into stations with high dispatch frequency, thus increasing the probability of resource availability on high fire count days.Nous combinons un modèle d'optimisation de la réponse standard basée sur différents scénarios a` une simulation stochastique pour améliorer l'efficacité du déploiement des ressources lors de l'attaque initiale des feux de forêt dans trois unités de gestion en Californie. Le modèle d'optimisation minimise le nombre attendu de feux qui ne reçoivent pas une réponse standard (définie comme la quantité de ressources de chaque type qui doit être déployée `a l'intérieur d'une certaine limite de temps) a` cause de contraintes de budget et de capacité des stations et de l'incertitude quant au nombre quotidien de feux et `a leur localisation. Nous utilisons le simulateur de l'aspect économique des feux en Californie pour prédire le nombre de feux qui ne sont pas maîtrisés a` l'intérieur des limites déterminées par la modélisation de l'attaque initiale. Comparativement au déploie-ment actuel, le déploiement obtenu par optimisation déplace des ressources de l'unité de gestion qui a le fardeau d'intervention le plus lourd vers l'unité de gestion qui a les exigences de réponse standard les plus élevées mais laisse le succès simulé de la maîtrise des feux inchangé. Ce résultat indique que dans les conditions actuelles de contraintes de budget et de capacité, différents déploiements peuvent avoir une aussi bonne performance en termes de maîtrise du feu. Les déploiements de ressources qui résultent de la réduction des contraintes de capacité des stations ont plus de succès dans la maîtrise des feux en favorisant la consolidation des ressources dans les stations qui ont une fréquence élevée de déploiement, augmentant par conséquent la probabilité que les ressources soient disponibles les jours où le nombre de feux est élevé. [Traduit par la Rédaction]Keywords:
Allocation,
Forest fires,
Airtankers,
Wildland fire suppression,
Management,
California,
Stochastic representation,
Containment,
Protection planning mode
Impact of Experience Corps® Participation on Children’s Academic Achievement and School Behavior
This article reports on the impact of the Experience Corps® (EC) Baltimore program, an intergenerational, school-based program aimed at improving academic achievement and reducing disruptive school behavior in urban, elementary school students in Kindergarten through third grade (K-3). Teams of adult volunteers aged 60 and older were placed in public schools, serving 15 h or more per week, to perform meaningful and important roles to improve the educational outcomes of children and the health and well-being of volunteers. Findings indicate no significant impact of the EC program on standardized reading or mathematical achievement test scores among children in grades 1–3 exposed to the program. K-1st grade students in EC schools had fewer principal office referrals compared to K-1st grade students in matched control schools during their second year in the EC program; second graders in EC schools had fewer suspensions and expulsions than second graders in non-EC schools during their first year in the EC program. In general, both boys and girls appeared to benefit from the EC program in school behavior. The results suggest that a volunteer engagement program for older adults can be modestly effective for improving selective aspects of classroom behavior among elementary school students in under-resourced, urban schools, but there were no significant improvements in academic achievement. More work is needed to identify individual- and school-level factors that may help account for these results
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Predicting the effect of climate change on wildfire behavior and initial attack success
This study focused on how climate change-induced effects on weather will translate into changes in wildland fire severity and outcomes in California, particularly on the effectiveness of initial attack at limiting the number of fires that escape initial attack. The results indicate that subtle shifts in fire behavior of the sort that might be induced by the climate changes anticipated for the next century are of sufficient magnitude to generate an appreciable increase in the number of fires that escape initial attack. Such escapes are of considerable importance in wildland fire protection planning, given the high cost to society of a catastrophic escape like those experienced in recent decades in the Berkeley-Oakland, Santa Barbara, San Diego, or Los Angeles areas. However, at least for the three study areas considered, it would appear that relatively modest augmentations to existing firefighting resources might be sufficient to compensate for change-induced changes in wildland fire outcomes
Estimates of live-tree carbon stores in the Pacific Northwest are sensitive to model selection
<p>Abstract</p> <p>Background</p> <p>Estimates of live-tree carbon stores are influenced by numerous uncertainties. One of them is model-selection uncertainty: one has to choose among multiple empirical equations and conversion factors that can be plausibly justified as locally applicable to calculate the carbon store from inventory measurements such as tree height and diameter at breast height (DBH). Here we quantify the model-selection uncertainty for the five most numerous tree species in six counties of northwest Oregon, USA.</p> <p>Results</p> <p>The results of our study demonstrate that model-selection error may introduce 20 to 40% uncertainty into a live-tree carbon estimate, possibly making this form of error the largest source of uncertainty in estimation of live-tree carbon stores. The effect of model selection could be even greater if models are applied beyond the height and DBH ranges for which they were developed.</p> <p>Conclusions</p> <p>Model-selection uncertainty is potentially large enough that it could limit the ability to track forest carbon with the precision and accuracy required by carbon accounting protocols. Without local validation based on detailed measurements of usually destructively sampled trees, it is very difficult to choose the best model when there are several available. Our analysis suggests that considering tree form in equation selection may better match trees to existing equations and that substantial gaps exist, in terms of both species and diameter ranges, that are ripe for new model-building effort.</p
Reasons for Transfer and Subsequent Outcomes Among Patients Undergoing Elective Spine Surgery at an Orthopedic Specialty Hospital
Objective:
To evaluate the reasons for transfer as well as the 90-day outcomes of patients who were transferred from a high-volume orthopedic specialty hospital (OSH) following elective spine surgery. Materials and Methods:
All patients admitted to a single OSH for elective spine surgery from 2014 to 2021 were retrospectively identified. Ninety-day complications, readmissions, revisions, and mortality events were collected and a 3:1 propensity match was conducted. Results:
Thirty-five (1.5%) of 2351 spine patients were transferred, most commonly for arrhythmia (n = 7; 20%). Thirty-three transferred patients were matched to 99 who were not transferred, and groups had similar rates of complications (18.2% vs. 10.1%; P = 0.228), readmissions (3.0% vs. 4.0%; P = 1.000), and mortality (6.1% vs. 0%; P = 0.061). Conclusion:
Overall, this study demonstrates a low transfer rate following spine surgery. Risk factors should continue to be optimized in order to decrease patient risks in the postoperative period at an OSH
Dying well with reduced agency: a scoping review and thematic synthesis of the decision-making process in dementia, traumatic brain injury and frailty
Background
In most Anglophone nations, policy and law increasingly foster an autonomy-based model, raising issues for large numbers of people who fail to fit the paradigm, and indicating problems in translating practical and theoretical understandings of ‘good death’ to policy. Three exemplar populations are frail older people, people with dementia and people with severe traumatic brain injury. We hypothesise that these groups face some over-lapping challenges in securing good end-of-life care linked to their limited agency. To better understand these challenges, we conducted a scoping review and thematic synthesis.
Methods
To capture a range of literature, we followed established scoping review methods. We then used thematic synthesis to describe the broad themes emerging from this literature.
Results
Initial searches generated 22,375 references, and screening yielded 49, highly heterogeneous, studies that met inclusion criteria, encompassing 12 countries and a variety of settings. The thematic synthesis identified three themes: the first concerned the processes of end-of-life decision-making, highlighting the ambiguity of the dominant shared decision-making process, wherein decisions are determined by families or doctors, sometimes explicitly marginalising the antecedent decisions of patients. Despite this marginalisation, however, the patient does play a role both as a social presence and as an active agent, by whose actions the decisions of those with authority are influenced. The second theme examined the tension between predominant notions of a good death as ‘natural’ and the drive to medicalise death through the lens of the experiences and actions of those faced with the actuality of death. The final theme considered the concept of antecedent end-of-life decision-making (in all its forms), its influence on policy and decision-making, and some caveats that arise from the studies.
Conclusions
Together these three themes indicate a number of directions for future research, which are likely to be applicable to other conditions that result in reduced agency. Above all, this review emphasises the need for new concepts and fresh approaches to end of life decision-making that address the needs of the growing population of frail older people, people with dementia and those with severe traumatic brain injury
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