A New Forest Fire Paradigm: The Need for High-Severity Fires

Forest fires, particularly those that burn at mixed and high severity (collectively called ‘severe’), have been traditionally perceived as catastrophic events, directing public attention and immense forest management budgets toward fire prevention and suppression. These fires may indeed be catastrophic when measured by losses of human lives and property. However, severe fires in wildland areas are both natural and necessary to maintain the integrity of dynamic, disturbance-adapted forest systems. We propose a change in the current paradigm—which holds that severe forest fires are always harmful—to a new one that embraces their ecological necessity

Patterns of woodboring beetle activity following fires and bark beetle outbreaks in montane forests of California, USA

Increasingly frequent and severe drought in the western United States has contributed to more frequent and severe wildfires, longer fire seasons, and more frequent bark beetle outbreaks that kill large numbers of trees. Climate change is expected to perpetuate these trends, especially in montane ecosystems, calling for improved strategies for managing Western forests and conserving the wildlife that they support. Woodboring beetles (e.g., Buprestidae and Cerambycidae) colonize dead and weakened trees and speed succession of habitats altered by fire or bark beetles, while serving as prey for some early-seral habitat specialists, including several woodpecker species. To understand how these ecologically important beetles respond to different sources of tree mortality, we sampled woodborers in 16 sites affected by wildfire or bark beetle outbreak in the previous one to eight years. Study sites were located in the Sierra Nevada, Modoc Plateau, Warner Mountains, and southern Cascades of California, USA. We used generalized linear mixed models to evaluate hypotheses concerning the response of woodboring beetles to disturbance type, severity, and timing; forest stand composition and structure; and tree characteristics.</p

The state of the Martian climate

60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes

Five endometrial cancer risk loci identified through genome-wide association analysis.

We conducted a meta-analysis of three endometrial cancer genome-wide association studies (GWAS) and two follow-up phases totaling 7,737 endometrial cancer cases and 37,144 controls of European ancestry. Genome-wide imputation and meta-analysis identified five new risk loci of genome-wide significance at likely regulatory regions on chromosomes 13q22.1 (rs11841589, near KLF5), 6q22.31 (rs13328298, in LOC643623 and near HEY2 and NCOA7), 8q24.21 (rs4733613, telomeric to MYC), 15q15.1 (rs937213, in EIF2AK4, near BMF) and 14q32.33 (rs2498796, in AKT1, near SIVA1). We also found a second independent 8q24.21 signal (rs17232730). Functional studies of the 13q22.1 locus showed that rs9600103 (pairwise r(2) = 0.98 with rs11841589) is located in a region of active chromatin that interacts with the KLF5 promoter region. The rs9600103[T] allele that is protective in endometrial cancer suppressed gene expression in vitro, suggesting that regulation of the expression of KLF5, a gene linked to uterine development, is implicated in tumorigenesis. These findings provide enhanced insight into the genetic and biological basis of endometrial cancer.I.T. is supported by Cancer Research UK and the Oxford Comprehensive Biomedical Research Centre. T.H.T.C. is supported by the Rhodes Trust and the Nuffield Department of Medicine. Funding for iCOGS infrastructure came from the European Community's Seventh Framework Programme under grant agreement 223175 (HEALTH-F2-2009-223175) (COGS), Cancer Research UK (C1287/A10118, C1287/A10710, C12292/A11174, C1281/A12014, C5047/A8384, C5047/A15007, C5047/A10692 and C8197/A16565), the US National Institutes of Health (R01 CA128978, U19 CA148537, U19 CA148065 and U19 CA148112), the US Department of Defense (W81XWH-10-1-0341), the Canadian Institutes of Health Research (CIHR) for the CIHR Team in Familial Risks of Breast Cancer, the Susan G. Komen Foundation for the Cure, the Breast Cancer Research Foundation and the Ovarian Cancer Research Fund. SEARCH recruitment was funded by a programme grant from Cancer Research UK (C490/A10124). Stage 1 and stage 2 case genotyping was supported by the NHMRC (552402 and 1031333). Control data were generated by the WTCCC, and a full list of the investigators who contributed to the generation of the data is available from the WTCCC website. We acknowledge use of DNA from the British 1958 Birth Cohort collection, funded by UK Medical Research Council grant G0000934 and Wellcome Trust grant 068545/Z/02; funding for this project was provided by the Wellcome Trust under award 085475. NSECG was supported by the European Union's Framework Programme 7 CHIBCHA grant and Wellcome Trust Centre for Human Genetics Core Grant 090532/Z/09Z, and CORGI was funded by Cancer Research UK. BCAC is funded by Cancer Research UK (C1287/A10118 and C1287/A12014). OCAC is supported by a grant from the Ovarian Cancer Research Fund thanks to donations by the family and friends of Kathryn Sladek Smith (PPD/RPCI.07) and the UK National Institute for Health Research Biomedical Research Centres at the University of Cambridge.This is the author accepted manuscript. The final version is available from Nature Publishing Group via http://dx.doi.org/10.1038/ng.356

Negation and the functional sequence

There exists a general restriction on admissible functional sequences which prevents adjacent identical heads. We investigate a particular instantiation of this restriction in the domain of negation. Empirically, it manifests itself as a restriction the stacking of multiple negative morphemes. We propose a principled account of this restriction in terms of the general ban on immediately consecutive identical heads in the functional sequence on the one hand, and the presence of a Neg feature inside negative morphemes on the other hand. The account predicts that the stacking of multiple negative morphemes should be possible provided they are separated by intervening levels of structure. We show that this prediction is borne out

Pyrodiversity promotes avian diversity over the decade following forest fire

An emerging hypothesis in fire ecology is that pyrodiversity increases species diversity.We test whether pyrodiversity—defined as the standard deviation of fire severity—increases avian biodiversity at two spatial scales, and whether and how this relationship may change in the decade following fire. We use a dynamic Bayesian community model applied to a multi-year dataset of bird surveys at 1106 points sampled across 97 fires in montane California. Our results provide strong support for a positive relationship between pyrodiversity and bird diversity. This relationship interacts with time since fire, with pyrodiversity having a greater effect on biodiversity at 10 years post-fire than at 1 year post-fire. Immediately after fires, patches of differing burn severities hold similar bird communities, but over the ensuing decade, bird assemblages within patches of contrasting severities differentiate. When evaluated at the scale of individual fires, fires with a greater heterogeneity of burn severities hold substantially more species. High spatial heterogeneity in severity, sometimes called ‘mixed-severity fire’, is a natural part of wildfire regimes in western North America, but may be jeopardized by climate change and a legacy of fire suppression. Forest management that encourages mixed-severity fire may be critical for sustaining biodiversity across fire-prone landscapes

Dynamics of breeding-season site occupancy of the California spotted owl in burned forests. The Condor

Abstract. Understanding how habitat disturbances such as forest fire affect local extinction and probability of colonization-the processes that determine site occupancy-is critical for developing forest management appropriate to conserving the California Spotted Owl (Strix occidentalis occidentalis), a subspecies of management concern. We used 11 years of breeding-season survey data from 41 California Spotted Owl sites burned in six forest fires and 145 sites in unburned areas throughout the Sierra Nevada, California, to compare probabilities of local extinction and colonization at burned and unburned sites while accounting for annual and site-specific variation in detectability. We found no significant effects of fire on these probabilities, suggesting that fire, even fire that burns on average 32% of suitable habitat at high severity within a California Spotted Owl site, does not threaten the persistence of the subspecies on the landscape. We used simulations to examine how different allocations of survey effort over 3 years affect estimability and bias of parameters and power to detect differences in colonization and local extinction between groups of sites. Simulations suggest that to determine whether and how habitat disturbance affects California Spotted Owl occupancy within 3 years, managers should strive to annually survey ≥200 affected and ≥200 unaffected historical owl sites throughout the Sierra Nevada 5 times per year. Given the low probability of detection in one year, we recommend more than one year of surveys be used to determine site occupancy before management that could be detrimental to the Spotted Owl is undertaken in potentially occupied habitat. Key words: California Spotted Owl, colonization, extinction, occupancy, site-occupancy modeling, Strix occidentalis. Dinámicas de la Ocupación de Sitio por Strix occidentalis occidentalis en la Estación Reproductiva en Bosques Quemados Resumen. Entender la manera en que los disturbios de hábitat, como los incendios forestales, afectan la extirpación y la probabilidad de colonización-el proceso que determina la ocupación del sitio-es crucial para desarrollar un manejo forestal adecuado para la conservación de Strix occidentalis occidentalis, una subespecie cuyo manejo es preocupante. Usamos datos de 11 años de monitoreo de la estación reproductiva de 41 sitios de presencia de S. o. occidentalis quemados en seis incendios forestales y 145 sitios en áreas no quemadas a lo largo de Sierra Nevada, California, para comparar las probabilidades de extirpación y colonización en sitios quemados y no quemados tomando en cuenta las variaciones en detectabilidad anuales y específicas de cada sitio. No encontramos efectos significativos de los incendios en estas probabilidades, sugiriendo que los incendios, incluso aquellos que queman en promedio 32% del hábitat adecuado con una alta severidad dentro de un sitio de presencia de S. o. occidentalis, no amenazan la persistencia de la subespecie en el paisaje. Empleamos simulaciones para examinar como diferentes asignaciones de esfuerzo de monitoreo a lo largo de tres años afectan la capacidad de estimación y sesgan los parámetros y el poder para detectar diferencias en colonización y extirpación entre los grupos de sitios. Las simulaciones sugieren que para determinar sí y cómo los disturbios de hábitat afectan la ocupación de S. o. occidentalis a lo largo de tres años, los gestores deberían esforzarse para monitorear anualmente ≥200 sitios históricos de la especies afectados y ≥200 no afectados a lo largo de Sierra Nevada cinco veces por año. Dada la baja probabilidad de detección en un año, recomendamos que se use más de un año de monitoreo para determinar la ocupación antes de aplicar manejos que podrían ser negativos para S. o. occidentalis en sitios potencialmente ocupados