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Negative consequences of positive feedbacks in US wild-fire management

Forest Ecosystems 2015年第2期2卷 57-66页

作者： David E Calkin Matthew P Thompson Mark A Finney Forestry Sciences Laboratory US Forest Service Rocky Mountain Research Station Fire Sciences Laboratory US Forest Service Rocky Mountain Research Station

Over the last two decades wildfire activity, damage, and management cost within the US have increased substantially. These increases have been associated with a number of factors including climate change and fuel accumulation due to a century of active fire suppression. The increased fire activity has occurred during a time of significant ex-urban development of the Wildland Urban Interface （WUI） along with increased demand on water resources originating on forested landscapes. These increased demands have put substantial pressure on federal agencies charged with wildfire management to continue and expand the century old policy of aggressive wildfire suppression. However, aggressive wildfire suppression is one of the major factors that drive the increased extent, intensity, and damage associated with the small number of large wildfires that are unable to be suppressed. In this paper we discuss the positive feedback loops that lead to demands for increasing suppression response while simultaneously increasing wildfire risk in the future. Despite a wealth of scientific research that demonstrates the limitations of the current management paradigm pressure to maintain the existing system are well entrenched and driven by the existing social systems that have evolved under our current management practice. Interestingly, US federal wildland fire policy provides considerable discretion for managers to pursue a range of management objectives however, societal expectations and existing management incentive structures result in policy implementation that is straining the resilience of fire adapted ecosystems and the communities that reside in and adjacent to them.

关键词： Wildfire suppression Wildfire paradox Wildland urban interface Resilience

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Non-native plant species richness and influence of greenhouses and human populations in the conterminous United States

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Ecological Processes 2023年第1期12卷 388-401页

作者： Brice B.Hanberry USDA Forest Service Rocky Mountain Research StationRapid CitySD 57702USA

Background One issue in invasive plant ecology is identification of the factors related to the invasion process that increase number of non-native *** invasion by non-native species increases,so does the probability that some non-native species will become harmful,or classified as invasive species,which disrupt natural ecosystems with attendant economic and social costs.I quantified patterns of how non-native species richness varied with vegetation types and human *** evaluate the relative importance of different predictor variables for invasion pathways in the conterminous United States,I modeled non-native plant species richness by county compared to current and historical human populations;greenhouses and nurseries;railroads,pipelines,transmission lines,and oil and gas wells;and land covers of impervious surface,development intensity categories,agriculture,and vegetation types.I also modeled these variables within vegetation types,excluding vegetation *** To summarize patterns,non-native plant species richness increased from 72 to 200 with increasing human population density *** and forest land use mosaics had the greatest mean number of non-native plant species,ranging from 121 to 166,whereas grasslands and grassland mosaics had the least number of non-native plant species,about *** modeling variable importance,all combined variables had R^(2)values of 56%(random forests regressor)and 54%(cubist regressor)for predictions of withheld observations of non-native plant species rich-ness,with greenhouse density and percent forestlands as most influential *** variables of greenhouses(R^(2)=29%),historical and current human populations(R^(2)=27%and 23%),impervious surface(25%),and medium intensity development(23%)were most associated with non-native plant species *** vegetation types,greenhouse and historical human population densities were influential variables particularly in forestlands,shrubland

关键词： Agriculture Energy Forest Grassland Invasive Propagule Rural Transport Urban

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Trajectory from beech and oak forests to eastern broadleaf forests in Indiana, USA

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Ecological Processes 2019年第1期8卷 21-28页

作者： Brice B.Hanberry USDA Forest Service Rocky Mountain Research StationRapid CitySD 57702USA

Background:Historical forests(circa 1799 to 1846)of Indiana were predominantly composed of American beech(25%of all trees)and upland oaks(27%of all trees).I compared historical forest composition,using studies of smaller areas to approximate composition for uncommon species or genera(<4.5%of all trees)and forest types,to current forest composition and forest types in Indiana.I also compiled published historical density estimates from small studies and estimated current density for the ***:Current forests are diverse with an even composition of many eastern broadleaf *** addition to upland oaks,which decreased to 13%of all trees,only sugar maple currently comprises greater than 10%of all *** increasing species were yellow-poplar,red maple,black cherry,and eastern *** redcedar increased from no presence to one of the most abundant ten species(≥3.5%of composition),similarly to the pine genus,becoming more common currently than American *** or oak or beech-oak forest types(≥24%of all trees)became eastern broadleaf forests,with no dominant species,and black cherry,red maple,and eastern redcedar forest types now *** of historical oak or beech forests ranged from 28 trees per hectare to 175 trees per hectare,which probably represent savannas and *** mean density of Indiana forests is 385 trees per hectare,ranging from 180 trees per hectare to 450 trees per *** forests likely contain dense layers of woody vegetation,filling the midstory and replacing herbaceous vegetation in the ground ***:Historically dominant beech and oak forests in the eastern United States have transitioned to an alternative state of closed eastern broadleaf forests due to uncontrolled establishment of many tree species.

关键词： Fire Historical Range of variability Transition

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Recent shifts in shade tolerance and disturbance traits in forests of the eastern United States

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Ecological Processes 2019年第1期8卷 391-401页

作者： Brice B.Hanberry rocky mountain Research Station USDA Forest ServiceRapid CitySD 57702USA

Background:Current forests of the eastern USA have the potential to succeed in composition to more shade-tolerant ***,long-term processes of transition from fire-tolerant tree species to fire-sensitive species and effects of current land use on forests may interfere with successional ***:I examined if forests in three regions have increased in shade tolerance and if life history strategy groups that represent response to disturbance(i.e.,fire-tolerance,early-successional species based on low shade tolerance,mid-successional species,late-successional species,and trees valued for traits related to short harvest rotations)have changed,using Forest Inventory and Analysis surveys,adjusted for comparison,and generalized linear mixed models to assess approximately 30 year trends,with adjustments to equalize different survey ***:Although statistically significant,a slight increase of 2 to 4%in regional mean shade tolerance may not be ecologically *** the central East,mid-successional species replaced early-successional species and early-successional species replaced fire-tolerant oaks,resulting in an overall shift from fire-tolerant oaks to mid-successional *** fire-tolerant pine species and increased planted pine species were the major changes in the northern Southeast and Coastal ***:The successional process of increased composition by shade-tolerant species over time was overshadowed by land use changes that resulted in decreased fire-tolerant species and increased planted ***,frequent land use disturbance may continue to prevent the slow progress of compositional succession to very shade-tolerant species.

关键词： Disturbance Eastern United States Fire Land use Mesophication Oak Pine Succession Traits

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AN INSIDE LOOK AT LEED:EXPERIENCED PRACTITIONERS REVEAL THE INNER WORKINGS OF LEED

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Journal of Green Building 2006年第1期1卷 3-8页

作者： Ashley Muse Josette M.Plaut rocky mountain Institute Colorado State University

INTRODUCTION LEED is leading the building industry towards a greener future.A clever acronym for Leadership in Energy and Environmental Design,the LEED Rating System is a voluntary,consensus-based,national standard for developing high-performance,sustainable *** *** Building Council(USGBC),a non-profit organization,developed the LEED Rating System in the late 1990s,and it has quickly grown to be the most recognized green building assessment tool in the United *** there are over 20,000 LEED Accredited Professionals nationwide,only a small percent have worked closely on a LEED *** this reason,the inner-workings of LEED remain somewhat *** paper seeks to demystify the LEED process by outlining it in a systematic *** information herein will serve as a good tool and reference for individuals who are,or intend to,work on a project pursuing LEED in the near future.

关键词： LEED nationwide herein

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Opinion: the use of natural hazard modeling for decision making under uncertainty

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Forest Ecosystems 2015年第2期2卷 139-142页

作者： David E Calkin Mike Mentis Forestry Sciences Laboratory US Forest Service Rocky Mountain Research Station Business & the environment Postnet Suite

Decision making to mitigate the effects of natural hazards is a complex undertaking fraught with uncertainty. Models to describe risks associated with natural hazards have proliferated in recent years. Concurrently, there is a growing body of work focused on developing best practices for natural hazard modeling and to create structured evaluation criteria for complex environmental models. However, to our knowledge there has been less focus on the conditions where decision makers can confidently rely on results from these models. In this review we propose a preliminary set of conditions necessary for the appropriate application of modeled results to natural hazard decision making and provide relevant examples within US wildfire management programs.

关键词： the use of natural hazard modeling for decision making under uncertainty

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Twenty years of drought-mediated change in snag populations in mixed-conifer and ponderosa pine forests in Northern Arizona

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Forest Ecosystems 2021年第2期8卷 265-277页

作者： Joseph L.Ganey Jose M.Iniguez Scott C.Vojta Amy R.Iniguez US Forest Service Rocky Mountain Research Station2500 S.Pine KnollAZ 86001 FlagstaffUSA

Background:Snags(standing dead trees)are important biological legacies in forest systems,providing numerous resources as well as a record of recent tree *** 1997 to 2017,we monitored snag populations in drought-influenced mixed-conifer and ponderosa pine(Pinus ponderosa)forests in northern ***:Snag density increased significantly in both forest *** increase was driven largely by a pulse in snag recruitment that occurred between 2002 and 2007,fol owing an extreme drought year in 2002,with snag recruitment returning to pre-pulse levels in subsequent time *** later years during the study also were warmer and/or drier than average,but these years were not as extreme as 2002 and did not trigger the same level of snag *** recruitment was not equal across tree species and size classes,resulting in significant changes in species composition and size-class distributions of snag populations in both forest *** trees were far more abundant than snags in these forests,the effect of this mortality pulse on tree populations was far smal er than its effect on snag *** loss rates increased over time during the study,even though many snags were newly *** may reflect the increasing prevalence of white fir snags and/or snags in the smal er size classes,which general y decay faster than snags of other species or larger ***,although total numbers of snags increased,many of the newly recruited snags may not persist long enough to be valuable as nesting substrates for native ***:Increases in snag abundance appeared to be due to a short-term tree mortality"event"rather than a longerterm pattern of elevated tree *** mortality event fol owed a dry and extremely warm year(2002)embedded within a longer-term *** models suggest that years like 2002 may occur with increasing frequency in the southwestern *** years may result in additional mortality pulses,wh

关键词： Climate change Drought Monitoring Snag abundance Snag creation Snag dynamics Species composition Tree mortality

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Using our mini-brains: cerebral organoids as an improved cellular model for human prion disease

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Neural Regeneration Research 2020年第6期15卷 1019-1020页

作者： Bradley R.Groveman Ryan walters Cathryn L.Haigh Laboratory of Persistent Viral Diseases National Institute of Allergy and Infectious Diseases Division of Intramural ResearchRocky Mountain Laboratories National Institutes of Health

Neurodegenerative diseases are an ever-increasing burden in an aging *** no cure is available for any of these diseases and treatment is based on managing *** many candidate therapeutics demonstrating promise in animal models,none has yet shown efficacy in human *** is self-evident that humans are different from the animals used to model our diseases,especially models that have been highly manipulated to generate a disease in an animal that does not naturally have such a *** differences are likely the reason for the failures of drug candidates in human trials but,until recently,human models of neurodegenerative diseases were *** development of the human cerebral organoid model,by differentiating three-dimensional human neuronal tissue from pluripotent stem cells,represents a significant advance in studying human brain *** organoids have been used to model Alzheimer’s disease,Parkinson’s disease,Down’s syndrome dementia and we have now shown they can be infected with human prions creating a new model of human prion diseases.

关键词： cerebral likely spite

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TAKING THE“LEED”IN INDOOR AIR QUALITY:DOES CERTIFICATION RESULT IN HEALTHIER BUILDINGS?

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Journal of Green Building 2020年第3期15卷 55-66页

作者： Hannah Phillips Rod Handy Darrah Sleeth Matthew S.Thiese Camie Schaefer James Stubbs rocky mountain Center for Occupational and Environmental Health University of Utah391 Chipeta WaySuite CSLCUT 84108.

Indoor Air Quality(IAQ)has been an area of growing concern with the increasing knowledge of health hazards associated with contaminants,particularly in high occupancy buildings where residents may be exposed to high levels of nuisance dust and other *** and Energy in Environmental Design(LEED®)certification,which is awarded to buildings that prioritize sustainability and efficient resource use,has been increasingly sought in new *** LEED-certified buildings become more commonplace,it is worthwhile to consider whether these new building practices improve IAQ for its *** study compares particulate matter(PM)concentrations in 12 LEED-certified buildings to 12 analogous non-LEED certified buildings on the University of Utah ***-time air sampling was conducted in each building for PM measurements and a Wilcoxon signed rank test was conducted to compare PM levels.A statistically significant difference was found between LEED certification and PM concentrations,with LEED-certified buildings containing,on average,approximately half the PM of their non-LEED *** findings suggest that LEED certification is worth the financial investment,as it may lead to improved IAQ for ***,further research on other contaminants is warranted,including the characterization and comparison of formaldehyde and carbon dioxide levels.

关键词： Indoor Air Quality(IAQ) Particulate Matter Concentrations(PM) LEED-Certified Buildings Sick Building Syndrome(SBS)

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Experimental and Modeling Study of Forest Fire Effect on Soil Thermal Conductivity

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Pedosphere 2016年第4期26卷 462-473页

作者： Kathleen M.SMITS Elizabeth KIRBY William J.MASSMAN Larry Scott BAGGETT Center for the Experimental Study of Subsurface Environmental Processes Department of Civil and Environmental EngineeringColorado School of Mines USDA Forest Service Rocky Mountain Research Station

An understanding of soil thermal conductivity after a wildfire or controlled burn is important to land management and post-fire recovery efforts. Although soil thermal conductivity has been well studied for non-fire heated soils, comprehensive data that evaluate the long-term effect of extreme heating from a fire on the soil thermal conductivity are limited. The purpose of this study was to evaluate the long-term impact of fire on the effective thermal conductivity of soils by directly comparing fire-heated and no-fire control soils through a series of laboratory studies. The thermal conductivity was measured for ten soil samples from two sites within the Manitou Experimental Forest, Colorado, USA, for a range of water contents from saturation to the residual degree of saturation. The thermal conductivity measured was compared with independent estimates made using three empirical models from literature, including the Campbell et al. （1994）, CSt~ and Konrad （2005）, and Massman et al. （2008） models. Results demonstrate that for the test soils studied, the thermal conductivity of the fire-heated soils was slightly lower than that of the control soils for all observed water contents. Modeling results show that the Campbell et al. （1994） model gave the best agreement over the full range of water contents when proper fitting parameters were employed. Further studies are needed to evaluate the significance of including the influence of fire burn on the thermal properties of soils in modeling studies.

关键词： controlled burn degree of saturation empirical model water content wildfire

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