PEAT SURFACE COMPRESSION REDUCES SMOULDERING FIRE POTENTIAL AS A NOVEL FUEL TREATMENT FOR BOREAL PEATLANDS

2021 ◽  
Author(s):  
Patrick Jeffrey Deane ◽  
Sophie Louise Wilkinson ◽  
Gregory Verkaik ◽  
Paul Moore ◽  
Dave Schroeder ◽  
...  
Keyword(s):  
Management Strategies ◽  
Ground Cover ◽  
Fire Danger ◽  
Near Surface ◽  
Human Interface ◽  
Boreal Peatlands ◽  
Proactive Management ◽  
Large Fires ◽  
Surface Compression ◽  
Compression Treatment

The wildfire regime in Canada’s boreal region is changing; extended fire seasons are characterized by more frequent large fires (≥200 ha) burning greater areas of land, whilst climate-mediated drying is increasing the vulnerability of peatlands to deep burning. Proactive management strategies, such as fuel modification treatments, are necessary to reduce fire danger at the wildland-human interface (WHI). Novel approaches to fuel management are especially needed in peatlands where deep smouldering combustion is a challenge to suppression efforts and releases harmful emissions. Here, we integrate surface compression within conventional stand treatments to examine the potential for reducing smouldering of near-surface moss and peat. A linear model (adj. R2=0.62, p=2.2e-16) revealed that ground cover (F(2,101)=60.97, p<0.001) and compression (F(1,101)=56.46, p<0.001) had the greatest effects on smouldering potential, while stand treatment did not have a significant effect (F(3,101)=0.44, p=0.727). On average, compressed Sphagnum and feather moss plots showed 57.1% and 58.7% lower smouldering potential, respectively, when compared to uncompressed analogs. While practical evaluation is warranted to better understand the evolving effectiveness of this strategy, these findings demonstrate that a compression treatment can be successfully incorporated within both managed and unmanaged peatlands to reduce fire danger at the WHI.

scholarly journals Urban inland wintertime N<sub>2</sub>O<sub>5</sub> and ClNO<sub>2</sub> influenced by snow-covered ground, air turbulence, and precipitation

2021 ◽  
Author(s):  
Kathryn D. Kulju ◽  
Stephen M. McNamara ◽  
Qianjie Chen ◽  
Jacinta Edebeli ◽  
Jose D. Fuentes ◽  
...  
Keyword(s):  
Ground Cover ◽  
Atmospheric Particulate Matter ◽  
Ionization Mass ◽  
Bare Ground ◽  
Near Surface ◽  
Dinitrogen Pentoxide ◽  
Nitryl Chloride ◽  
Air Turbulence ◽  
Chlorine Radicals ◽  
Wet Scavenging

Abstract. The atmospheric multiphase reaction of dinitrogen pentoxide (N2O5) with chloride-containing aerosol particles produces nitryl chloride (ClNO2), which has been observed across the globe. The photolysis of ClNO2 produces chlorine radicals and nitrogen dioxide (NO2), which alter pollutant fates and air quality. However, the effects of local meteorology on near-surface ClNO2 production are not yet well understood, as most observational and modeling studies focus on periods of clear conditions. During a field campaign in Kalamazoo, Michigan from January–February 2018, N2O5 and ClNO2 were measured using chemical ionization mass spectrometry, with simultaneous measurements of atmospheric particulate matter and meteorological parameters. We examine the impacts of atmospheric turbulence, precipitation (snow, rain) and fog, and ground cover (snow-covered and bare ground) on the abundances of ClNO2 and N2O5. N2O5 mole ratios were lowest during periods of lower turbulence and were not statistically significantly different between snow-covered and bare ground. In contrast, ClNO2 mole ratios were highest, on average, over snow-covered ground, due to saline snowpack ClNO2 production. Both N2O5 and ClNO2 mole ratios were lowest, on average, during rainfall and fog because of scavenging, with N2O5 scavenging by fog droplets likely contributing to observed increased particulate nitrate concentrations. These observations, specifically those during active precipitation and with snow-covered ground, highlight important processes, including N2O5 and ClNO2 wet scavenging, fog nitrate production, and snowpack ClNO2 production, that govern the variability in observed atmospheric chlorine and nitrogen chemistry and are missed when considering only clear conditions.

scholarly journals Predicting future invaders and future invasions

2019 ◽  
Vol 116 (16) ◽  
pp. 7905-7910 ◽  
Author(s):  
Alice Fournier ◽  
Caterina Penone ◽  
Maria Grazia Pennino ◽  
Franck Courchamp
Keyword(s):  
Papua New Guinea ◽  
Ecosystem Functioning ◽  
Species Distribution Models ◽  
Invasive Alien Species ◽  
Management Strategies ◽  
Central Africa ◽  
Invasive Ants ◽  
Distribution Models ◽  
Proactive Management ◽  
Local Extinctions

Invasive alien species are a great threat to biodiversity and human livelihoods worldwide. The most effective way to limit their impacts and costs is to prevent their introduction into new areas. Identifying invaders and invasions before their occurrence would arguably be the most efficient strategy. Here, we provide a profiling method to predict which species—with which particular ecological characteristics—will invade, and where they could invade. We illustrate our approach with ants, which are among the most detrimental invasive species, as they are responsible for declines of numerous taxa, are involved in local extinctions, disturb ecosystem functioning, and impact multiple human activities. Based on statistical profiling of 1,002 ant species from an extensive trait database, we identify 13 native ant species with an ecological profile that matches that of known invasive ants. Even though they are not currently described as such, these species are likely to become the next global invaders. We couple these predictions with species distribution models to identify the regions most at risk from the invasion of these species: Florida and Central America, Brazil, Central Africa and Madagascar, Southeast Asia, Papua New Guinea Northeast Australia, and many islands worldwide. This framework, applicable to any other taxa, represents a remarkable opportunity to implement timely and specifically shaped proactive management strategies against biological invasions.

URANIUM EXPLORATION WITH COMPUTER‐PROCESSED LANDSAT DATA

Geophysics ◽  
1977 ◽  
Vol 42 (3) ◽  
pp. 536-541 ◽  
Author(s):  
Robert K. Vincent
Keyword(s):  
Recognition Rate ◽  
Ground Cover ◽  
Open Pit ◽  
Spectral Signature ◽  
Near Surface ◽  
Wind River Basin ◽  
Uranium Mines ◽  
Porous Sandstone ◽  
Uranium Exploration ◽  
Color Composite

A spectral signature has been constructed for an oxidized topsoil found in the vicinity of near‐surface uranium deposits in porous, arkosic sandstones of the Wind River Basin, Wyoming. A new type of contour map, created from Landsat computer compatible tapes, designed to connect regions of equal percentage of ground area covered by a specified target of interest, was applied to a Landsat frame covering the entire basin. The resulting maps showed relatively high percentages of ground cover by this particular topsoil in regions adjacent to open pit uranium mines in the Gas Hills region, as well as on or near known uranium prospects (as yet undisturbed) in the basin interior. A 10,000-pixel test area west of Lander, Wyoming was found to contain only one pixel (a 0.01 percent recognition rate) identified as the topsoil of interest. However, a whole‐frame recognition map produced a much higher (0.58 percent) recognition rate, indicating that the false alarm rate for this signature is still significantly high, although better than what can be expected from photointerpretation of single ratio images or color composite ratio images. This “signature” has been applied to Landsat frames in other geographical areas with known uranium mines in porous sandstone, and oxidized topsoil has been recognized near these mines.

Implementing Strategic Weed Prevention Programs to Protect Rangeland Ecosystems

2015 ◽  
Vol 8 (2) ◽  
pp. 233-242 ◽  
Author(s):  
Brenda S. Smith ◽  
Roger L. Sheley
Keyword(s):  
Prevention Program ◽  
Invasive Plant ◽  
Flow Model ◽  
Management Strategies ◽  
Cost Effective ◽  
Prevention Programs ◽  
Strategic Decision ◽  
Plant Management ◽  
Invasive Plant Management ◽  
Proactive Management

Weed prevention is recognized as one of the most cost-effective management strategies for invasive plants. In the field of invasive plant management increasing emphasis is being directed toward proactive management. However, land managers are still somewhat reluctant to aggressively employ prevention programs. Part of this reluctance could be due to lack of understanding of what a comprehensive prevention program entails. The purpose of this paper is to improve strategic decision-making for site-specific prevention programs, such as those on ranches or in watersheds. Our interest is in advancing prevention planning for land managers—the people who are faced with the constant pressure of potential invasive species infestations on a day-to-day basis. To facilitate more widespread use of prevention programs we are proposing definitions for key terminology to standardize and facilitate communication about prevention programs. Additionally, we present a flow model with the steps necessary to successfully implement such programs. The model has three categories from which specific prevention planning occurs: (1) education, (2) early detection and eradication, and (3) interruption of movement. The flow model directs users through a series of interlinked steps. Finally, we provide a case study in which a ranch manager implemented a prevention program using this framework. By using this model, managers are poised to conduct more strategic planning. This model also has applications in outreach and education programs to assist land managers in prevention planning.

scholarly journals Weather Factors Associated with Extremely Large Fires and Fire Growth Days

2021 ◽  
pp. 1-53
Author(s):  
Brian E. Potter ◽  
Daniel McEvoy
Keyword(s):  
Wind Speed ◽  
Growth Response ◽  
Health Management ◽  
Fire Growth ◽  
Weather Factors ◽  
Evaporative Demand ◽  
Fire Weather Index ◽  
Near Surface ◽  
Daily Weather ◽  
Large Fires

Abstract“Megafires” are of scientific interest and concern for fire management, public safety planning, and smoke-related public health management. There is a need to predict them on time scales from days to decades. Understanding is limited, however, of the role of daily weather in determining their extreme size. This study examines differences in the daily weather during these and other, smaller fires, and in the two sets of fires’ responses to daily weather and antecedent atmospheric dryness. Twenty fires of unusual size (over 36 400 ha), were each paired with a nearby large fire (10 100 to 30 300 ha). Antecedent dryness and daily near-surface weather were compared for each set of fires. Growth response to daily weather was also examined for differences between the two sets of fires. Antecedent dryness measured as the Evaporative Demand Drought Index was greater for most of the fires of unusual size than it was for smaller fires. There were small differences in daily weather, with those differences indicating weather less conducive to fire growth for the unusually large fires than the smaller fires. Growth response was similar for the two sets of fires when weather properties were between 40th and 60th percentiles for each fire pair, but the unusually large fires’ growth was observably greater than the smaller fires’ growth for weather properties between the 80th to 100th percentiles. Response differences were greatest for wind speed, and for the Fosberg Fire Weather Index and variants of the Hot-Dry-Windy Index, which combine wind speed with atmospheric moisture.

scholarly journals A bias corrected WRF mesoscale fire weather dataset for Victoria, Australia 1972-2012

2016 ◽  
Vol 66 (3) ◽  
pp. 281
Author(s):  
Timothy Brown ◽  
Graham Mills ◽  
Sarah Harris ◽  
Domagoj Podnar ◽  
Hauss Reinbold ◽  
...  
Keyword(s):  
Wind Speed ◽  
Relative Humidity ◽  
Fire Danger ◽  
Management Decision ◽  
Fire Weather ◽  
Near Surface ◽  
Australian Water ◽  
Hourly Temperature ◽  
Extensive Evaluation ◽  
Correction Technique

Climatology data of fire weather across the landscape can provide science-based evidence for informing strategic decisions to ameliorate the impacts (at times extreme) of bushfires on community socio-economic wellbeing and to sustain ecosystem health and functions. A long-term climatology requires spatial and temporal data that are consistent to represent the landscape in sufficient detail to be useful for fire weather studies and management purposes. To address this inhomogeneity problem for analyses of a variety of fire weather interests and to provide a dataset for management decision-support, a homogeneous 41-year (1972-2012), hourly interval, 4 km gridded climate dataset for Victoria has been generated using a combination of mesoscale modelling, global reanalysis data, surface observations, and historic observed rainfall analyses. Hourly near-surface forecast fields were combined with Drought Factor (DF) fields calculated from the Australian Water Availability Project (AWAP) rainfall analyses to generate fields of hourly fire danger indices for each hour of the 41-year period. A quantile mapping (QM) bias correction technique utilizing available observations during 1996-2012 was used to ameliorate any model biases in wind speed, temperature and relative humidity. Extensive evaluation was undertaken including both quantitative and case study qualitative assessments. The final dataset includes 4-km surface hourly temperature, relative humidity, wind speed, wind direction, Forest Fire Danger Index (FFDI), and daily DF and Keetch-Byram Drought Index (KBDI), and a 32-level full three-dimensional volume atmosphere.

Development of a common definition approach for multi-event attribution of fire weather extremes

2021 ◽  
Author(s):  
Zhongwei Liu ◽  
Jonathan Eden ◽  
Bastien Dieppois ◽  
Matthew Blackett
Keyword(s):  
Climate Model ◽  
Grid Point ◽  
Management Strategies ◽  
Fire Danger ◽  
Fire Weather ◽  
Weather Extremes ◽  
Fire Weather Index ◽  
Fire Emissions ◽  
Common Definition ◽  
Extreme Fire

&lt;p&gt;In response to the occurrence of large wildfire events across both hemispheres in recent years, the effort to understand the extent to which climate change may be altering the frequency of fire-conducive meteorological conditions has become an emerging subfield of attribution science. However, to date, the relative paucity of wildfire attribution studies, coupled with limited observational records, makes it difficult to draw solid and collective conclusions to better inform forest management strategies. The inter-study differences that emerge due to the choice of methodology and event definition are common to many attribution studies; for wildfire attribution in particular, the lack of consensus on how fire danger should be defined in a meteorological context presents an additional challenge.&lt;/p&gt;&lt;p&gt;Here, we present a framework for the simultaneous attribution of multiple extreme fire weather episodes of using an empirical-statistical methodology. Key to this framework is the development of a common spatiotemporal definition for extreme fire weather events. With reference to the fourth version of Global Fire Emissions Dataset (GFED4), we focus on all parts of the world that have experienced fires during the period 1995-2016. At each target grid point, we fit a Generalized Extreme Value (GEV) distribution, scaled by global mean surface temperature (smoothed over 4 years), to the annual maxima of a series of reanalysis-derived fire danger indicators (including the fire weather index) for the period 1980-2018. Using global maps of risk ratios and percentage of changes, we quantify the influence of recent global warming on the frequency and magnitude of fire weather extremes according to a common &amp;#8216;event type&amp;#8217; definition, irrespective of their spatiotemporal occurrence. We subsequently conduct a collective attribution analysis of a series of recent exceptional events. We conclude with suggestions for further application to climate model ensembles and a discussion of the potential of our findings to inform decision-makers and practitioners.&lt;/p&gt;

Yellow Nutsedge (Cyperus esculentus) Growth and Reproduction in Response to Nitrogen and Irrigation

Weed Science ◽  
2009 ◽  
Vol 57 (1) ◽  
pp. 21-25 ◽  
Author(s):  
Corey V. Ransom ◽  
Charles A. Rice ◽  
Clinton C. Shock
Keyword(s):  
Soil Water ◽  
Control Strategies ◽  
Management Strategies ◽  
Soil Water Potential ◽  
Reproductive Potential ◽  
Ground Cover ◽  
Irrigation Level ◽  
Nitrogen Levels ◽  
Yellow Nutsedge ◽  
Extensive Growth

Growth and reproductive potential of individual yellow nutsedge plants were examined under two nitrogen levels and three soil moisture regimes. Irrigation levels were selected on the basis of irrigating at soil water potentials of −20, −50, and −80 kPa. Yellow nutsedge patch expansion was measured using digital images to determine ground cover, while plots were subsampled to estimate total shoot and tuber production. High nitrogen increased shoot production in 2004. When plots were irrigated at a soil water potential of −20 kPa, a single yellow nutsedge plant produced 3,000 and 1,700 shoots and 19,000 and 20,000 tubers in 2003 and 2004, respectively. Patch expansion at −20 kPa was exponential, with the greatest expansion occurring between the middle of July and mid to late August. This research demonstrates that the vegetative and reproductive potential of yellow nutsedge is greatly influenced by irrigation level. With such extensive growth and reproductive potential, management strategies for yellow nutsedge should focus on prevention, early detection and containment, early treatment, and integration of control strategies to reduce its competitiveness and spread.

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