scholarly journals Prediction of Fuel Loading Following Mastication Treatments in Forest Stands in North Idaho, USA

2020 ◽  
Vol 12 (17) ◽  
pp. 7025
Author(s):  
Ryer Becker ◽  
Robert Keefe
Keyword(s):  
Fire Behavior ◽  
Stand Density ◽  
Post Treatment ◽  
Behavior Modeling ◽  
Fuel Reduction ◽  
Fuel Loading ◽  
Stem Size ◽  
Fuel Loads ◽  
Pre Treatment ◽  
Mean Square Errors

Fuel reduction in forests is a high management priority in the western United States and mechanical mastication treatments are implemented common to achieve that goal. However, quantifying post-treatment fuel loading for use in fire behavior modeling to forecast treatment effectiveness is difficult due to the high cost and labor requirements of field sampling methods and high variability in resultant fuel loading within stands after treatment. We evaluated whether pre-treatment LiDAR-derived stand forest characteristics at 20 m × 20 m resolution could be used to predict post-treatment surface fuel loading following mastication. Plot-based destructive sampling was performed immediately following mastication at three stands in the Nez Perce Clearwater National Forest, Idaho, USA, to correlate post-treatment surface fuel loads and characteristics with pre-treatment LiDAR-derived forest metrics, specifically trees per hectare (TPH) and stand density index (SDI). Surface fuel loads measured in the stand post-treatment were consistent with those reported in previous studies. A significant relationship was found between the pre-treatment SDI and total resultant fuel loading (p = 0.0477), though not between TPH and fuel loading (p = 0.0527). SDI may more accurately predict post-treatment fuel loads by accounting for both tree number per unit area and stem size, while trees per hectare alone does not account for variations of tree size and subsequent volume within a stand. Relatively large root-mean-square errors associated with the random forest models for SDI (36%) and TPH (46%) suggest that increased sampling intensity and modified methods that better account for fine spatial variability in fuels resulting from within-stand conditions, treatment prescriptions and machine operators may be needed. Use of LiDAR to predict fuel loading after mastication is a useful approach for managers to understand the efficacy of fuel reduction treatments by providing information that may be helpful for determining areas where treatments can be most beneficial.

scholarly journals Long-Term Effects of Fuel Reduction Treatments on Surface Fuel Loading in the Blue Mountains of Oregon

Forests ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1306
Author(s):  
Kat E. Morici ◽  
John D. Bailey
Keyword(s):  
Fire Behavior ◽  
Fuel Load ◽  
Fire Season ◽  
Fuel Reduction ◽  
Prescribed Burn ◽  
Long Term Effects ◽  
Fuel Loading ◽  
Fuel Treatments ◽  
Blue Mountains ◽  
Pre Treatment

Fire exclusion and a lengthening fire season has resulted in an era of megafires. Fuel reduction treatments in forested ecosystems are designed to guard against future extreme wildfire behavior. Treatments create a heterogenous landscape and facilitate ecosystem function and resilience in fire-adapted forests of the western United States. Despite widespread recognition that repeated fuel treatments are needed to maintain desired stand characteristics over time, few field studies have evaluated treatment longevity. The Blue Mountains Fire and Fire Surrogate site in northeastern Oregon presented an opportunity to investigate woody fuel loading 15–17 years after four treatments: mechanical thin, prescribed burn, both thin and burn, and no treatment control. The principal findings were: (1) fine fuel load 15 years post-burn remained slightly below pre-treatment values; (2) rotten coarse fuel load was reduced post-burn, but sound coarse fuel was not altered by any active treatment; and (3) total woody fuel load 15–17 years post-treatment was similar to pre-treatment values. Understanding surface fuel loading is essential for predicting fire behavior. Overall, the effects of fuel reduction treatments on woody surface fuels were transitory in dry mixed conifer forests. Frequent maintenance treatments are recommended to protect values at risk in areas with high fire hazards. Quantifying the persistence of changes in forest conditions aids in the planning and analysis of future fuel treatments, along with scheduling maintenance of existing treated areas.

scholarly journals Chronosequence of Fuel Loading and Fuel Depth Following Forest Rehabilitation Frill Treatment of Tanoak to Release Douglas-Fir: A Case Study from Northern California

Forests ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 691
Author(s):  
Raven M. Krieger ◽  
Brian E. Wall ◽  
Cody W. Kidd ◽  
John-Pascal Berrill
Keyword(s):  
Woody Debris ◽  
Fire Severity ◽  
Fire Behavior ◽  
Fire Effects ◽  
Behavior Modeling ◽  
Northern California ◽  
Fuel Loading ◽  
Excessive Competition ◽  
Pre Treatment ◽  
Forest Rehabilitation

There is concern that forest management activities such as chemical thinning may increase hazardous fuel loading and therefore increase risk of stand-replacing wildfire. Chemical thinning, often accomplished by frill treatment of unwanted trees, leaves trees standing dead for a time before they fall and become surface fuels. In coastal northern California, frill treatment is used as a forest rehabilitation treatment that removes tanoak (Notholithocarpus densiflorus) to release merchantable conifers from excessive competition. We studied fuel bed depth and fuel loading after frill treatment of tanoak along a 16-year chronosequence that substituted space for time. The total depth of fuel bed was separated into woody fuels, litter, and duff. The height of each layer was variable and greatest on average in post-treatment year 5 after treated tanoak had begun to break apart and fall. Initially, the evergreen tanoak trees retained their foliage for at least a year after treatment. Five years after treatment, many tanoak had fallen and transitioned to become fine- and coarse woody debris. After 11 years, the larger pieces of down wood were mostly classified as rotten. After 16 years, the fuel loading appeared roughly equivalent to pre-treatment levels, however we did not explicitly test for differences due to potential confounding between time and multiple factors such as inter-annual climate variations and site attributes. Nevertheless, our data provide some insight into changes in surface fuel characteristics due to rehabilitation treatments. These data can be used as inputs for fire behavior modeling to generate indicative predictions of fire effects such as fire severity and how these change over time since treatment.

A Simulation Study to Estimate Effects of Wildfire and Forest Management on Hydrology and Sediment in a Forested Watershed, Northwestern U.S.

2018 ◽  
Vol 61 (5) ◽  
pp. 1579-1601 ◽  
Author(s):  
Anurag Srivastava ◽  
Joan Q. Wu ◽  
William J. Elliot ◽  
Erin S. Brooks ◽  
Dennis C. Flanagan
Keyword(s):  
Sediment Yield ◽  
Post Treatment ◽  
Water Yield ◽  
National Forest ◽  
Fuel Reduction ◽  
Fuel Treatments ◽  
Peak Flows ◽  
Treatment Conditions ◽  
Forest Fuel ◽  
Pre Treatment

Abstract. Suitable fuel reduction treatments are needed in the Colville National Forest, Washington, to reduce the risk of severe wildfire. This study aimed to identify high-risk erosion hillslopes following wildfire to aid in forest fuel reduction planning and to evaluate the effects of fuel treatments on the watershed hydrological response. The specific objectives were (1) to assess the soil burn severity associated with wildfires and use that information to identify critical hillslopes for forest fuel treatments, and (2) to evaluate the potential changes in water yield and peak flows from pre-treatment (undisturbed forest) to post-treatment (thinning and prescribed burn) conditions, in the East Deer Creek Watershed (EDCW), a subwatershed of the Colville National Forest. Assessments were made using a modeling approach for hypothetical wildfire and fuel treatment scenarios. FlamMap, a fire behavior model, was used to predict the spatial distribution of wildfire intensity for a hypothetical event under current vegetation conditions. WEPP simulations were subsequently completed to obtain sediment and water yields based on fire intensity and topography. WEPP erosion estimations following a simulated wildfire showed hillslope sediment yield varying from 0 to 49.4 Mg ha-1 year-1 from the 777 hillslopes, which were ranked in descending order of sediment yield to identify critical hillslopes for fuel treatments. The WEPP model calibrated for a nearby gauged watershed was then applied to the EDCW for pre-treatment and post-treatment conditions. At the watershed scale, the increase in water yield from pre-treatment to post-treatment conditions ranged from 0.7% to 5.6% on hillslopes delivering 10% to 50% of the predicted post-fire sediment. Simulated water balance components at the treated hillslopes showed substantial changes. Surface runoff, subsurface lateral flow, and deep percolation increased 150% (5 mm), 50% (9 mm), and 40% (41 mm), respectively, whereas evapotranspiration (ET) decreased 23% (124 mm). The relative differences between pre- and post-harvest peak flows showed no clear trends as treatment area increased. The results suggest that thinning and prescribed burns to treated hillslopes in the EDCW may lead to an increase in water yield and significant alterations in hydrological processes. Keywords: Fuel treatments, Modeling, Peak flows, Sediment, Water yield, Wildfire.

scholarly journals Decomposing the Interactions between Fire Severity and Canopy Fuel Structure Using Multi-Temporal, Active, and Passive Remote Sensing Approaches

Fire ◽  
2020 ◽  
Vol 3 (1) ◽  
pp. 7 ◽  
Author(s):  
Nicholas S. Skowronski ◽  
Michael R. Gallagher ◽  
Timothy A. Warner
Keyword(s):  
Laser Scanning ◽  
Treatment Effectiveness ◽  
Fire Severity ◽  
Fire Behavior ◽  
Three Dimensional ◽  
Structural Heterogeneity ◽  
Behavior Modeling ◽  
Fuel Loading ◽  
Subtle Difference ◽  
Multi Temporal

Within the realms of both wildland and prescribed fire, an understanding of how fire severity and forest structure interact is critical for improving fuels treatment effectiveness, quantifying the ramifications of wildfires, and improving fire behavior modeling. We integrated high resolution estimates of fire severity with multi-temporal airborne laser scanning data to examine the role that various fuel loading, canopy shape, and other variables had on predicting fire severity for a complex of prescribed fires and one wildfire and how three-dimensional fuels changed as a result of these fires. Fuel loading characteristics were widely variable, and fires were ignited using a several techniques (heading, flanking, and backing), leading to a large amount of variability in fire behavior and subsequent fire effects. Through our analysis, we found that fire severity was linked explicitly to pre-fire fuel loading and structure, particularly in the three-dimensional distribution of fuels. Fire severity was also correlated with post-fire fuel loading, forest structural heterogeneity, and shifted the diversity and abundance of canopy classes within the landscape. This work demonstrates that the vertical distribution of fuel is an important factor and that subtle difference has defined effects on fire behavior and severity.

Effectiveness of prescribed fire as a fuel treatment in Californian coniferous forests

2009 ◽  
Vol 18 (2) ◽  
pp. 165 ◽  
Author(s):  
Nicole M. Vaillant ◽  
Jo Ann Fites-Kaufman ◽  
Scott L. Stephens
Keyword(s):  
Prescribed Fire ◽  
Forest Structure ◽  
Tree Mortality ◽  
Wildland Fire ◽  
Fire Behavior ◽  
Weather Conditions ◽  
Fire Effects ◽  
The United States ◽  
Behavior Modeling ◽  
Fuel Loads

Effective fire suppression and land use practices over the last century have altered forest structure and increased fuel loads in many forests in the United States, increasing the occurrence of catastrophic wildland fires. The most effective methods to change potential fire behavior are to reduce surface fuels, increase the canopy base height and reduce canopy bulk density. This multi-tiered approach breaks up the continuity of surface, ladder and crown fuels. Effectiveness of fuel treatments is often shown indirectly through fire behavior modeling or directly through monitoring wildland fire effects such as tree mortality. The present study investigates how prescribed fire affected fuel loads, forest structure, potential fire behavior, and modeled tree mortality at 90th and 97.5th percentile fire weather conditions on eight National Forests in California. Prescription burning did not significantly change forest structure at most sites. Total fuel loads (litter, duff, 1, 10, 100, and 1000-h) were reduced by 23 to 78% across the sites. The reduction in fuel loads altered potential fire behavior by reducing fireline intensity and increasing torching index and crowning index at most sites. Predicted tree mortality decreased after treatment as an effect of reduced potential fire behavior and fuel loads. To use limited fuel hazard reduction resources efficiently, more effort could be placed on the evaluation of existing fire hazards because several stands in the present study had little potential for adverse fire effects before prescribed fire was applied.

Cytoprotective Effect of Tocotrienol-Rich Fraction and α-Tocopherol Vitamin E Isoforms Against Glutamate-Induced Cell Death in Neuronal Cells

2014 ◽  
Vol 84 (3-4) ◽  
pp. 0140-0151 ◽  
Author(s):  
Thilaga Rati Selvaraju ◽  
Huzwah Khaza’ai ◽  
Sharmili Vidyadaran ◽  
Mohd Sokhini Abd Mutalib ◽  
Vasudevan Ramachandran ◽  
...  
Keyword(s):  
Vitamin E ◽  
Cell Viability ◽  
Neuronal Cells ◽  
Positive Control ◽  
Post Treatment ◽  
Mitochondrial Activity ◽  
Before And After ◽  
Pre Treatment ◽  
Tocotrienol Rich Fraction ◽  
Major Mediator

Glutamate is the major mediator of excitatory signals in the mammalian central nervous system. Extreme amounts of glutamate in the extracellular spaces can lead to numerous neurodegenerative diseases. We aimed to clarify the potential of the following vitamin E isomers, tocotrienol-rich fraction (TRF) and α-tocopherol (α-TCP), as potent neuroprotective agents against glutamate-induced injury in neuronal SK-N-SH cells. Cells were treated before and after glutamate injury (pre- and post-treatment, respectively) with 100 - 300 ng/ml TRF/α-TCP. Exposure to 120 mM glutamate significantly reduced cell viability to 76 % and 79 % in the pre- and post-treatment studies, respectively; however, pre- and post-treatment with TRF/α-TCP attenuated the cytotoxic effect of glutamate. Compared to the positive control (glutamate-injured cells not treated with TRF/α-TCP), pre-treatment with 100, 200, and 300 ng/ml TRF significantly improved cell viability following glutamate injury to 95.2 %, 95.0 %, and 95.6 %, respectively (p < 0.05).The isomers not only conferred neuroprotection by enhancing mitochondrial activity and depleting free radical production, but also increased cell viability and recovery upon glutamate insult. Our results suggest that vitamin E has potent antioxidant potential for protecting against glutamate injury and recovering glutamate-injured neuronal cells. Our findings also indicate that both TRF and α-TCP could play key roles as anti-apoptotic agents with neuroprotective properties.

CONTRACEPTION BY AN INJECTABLE LONG-ACTING OESTROGEN-PROGESTOGEN AGENT. III

1972 ◽  
Vol 69 (1) ◽  
pp. 67-76
Author(s):  
Rolf Plesner
Keyword(s):  
Treatment Period ◽  
Treatment Cycle ◽  
Post Treatment ◽  
Mixed Phase ◽  
Discontinuation Of Treatment ◽  
Phase Type ◽  
Secretory Type ◽  
Pre Treatment ◽  
Long Acting ◽  
Fertile Women

ABSTRACT Twenty-two fertile women were treated cyclically in from 4–30 cycles (mean 15.5) with a total of 341 injections of Deladroxate®, an injectable, long-acting oestrogen-progestogen. The injections were administered on the 8th (7th–9th) day of each cycle. Before treatment, the last pre-treatment cycle was controlled by means of daily recordings of the basal body temperature (BBT), urinary excretion of pregnanediol and total pituitary gonadotrophins at certain intervals, and by endometrial biopsies obtained late in the cycle. The effects of Deladroxate® on ovulation, on pituitary gonadotrophic function, and on the endometrium were controlled by the above mentioned parameters during cycles 1, 3, and 6, and all assessments were repeated after discontinuation of treatment. During treatment, there was a statistically significant fall in gonadotrophin excretion values (as compared with the pre-treatment values), and the fall was found to be gradually progressive during treatment. After discontinuation of treatment, there seemed to be a tendency towards an increase in the excretion values. Suppression of ovulation as determined by means of the pregnanediol excretion during treatment, was effective in nearly all of the treatment cycles checked. The fall in pregnanediol excretion was also gradually progressive during treatment, while there was a slight increase in excretion values in the post-treatment period. During treatment, 79 BBT curves were recorded. Nearly 50 % were monophasic, indicating anovulatory cycles, 17 curves were biphasic, but with the rise in temperature occurring at non-characteristic times in the cycles, 18 curves were classified as thermogenic because of a rise in temperature occurring within 24 hours after the injection, and 5 curves were not assessable. During the first month after discontinuation of treatment, 8 out of 10 recorded curves were monophasic. Out of 53 endometrial biopsies obtained around the 23rd day of the cycle, 31 were of the mixed phase type, but showing a predominance of proliferative patterns, 15 were of the secretory type, and 7 were purely proliferative. Out of 15 biopsies obtained in the post-treatment period, only two were of the mixed phase type, 12 were proliferative and one was purely secretory.

Pre-treatment and post-treatment visual functions in congenital myopia alone versus congenital myopia complicated by amblyopia

2018 ◽  
Vol 75 (4) ◽  
pp. 44-48
Author(s):  
A. Mukhina ◽  
◽  
I. Boichuk ◽  
L. Zhuravliova ◽  
◽  
...  
Keyword(s):  
Post Treatment ◽  
Visual Functions ◽  
Pre Treatment

scholarly journals Relationship between metamorphopsia and inner retinal microstructure following intravitreal ranibizumab injection for branch retinal vein occlusion

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yoshimi Sugiura ◽  
Fumiki Okamoto ◽  
Tomoya Murakami ◽  
Shohei Morikawa ◽  
Takahiro Hiraoka ◽  
...  
Keyword(s):  
Macular Edema ◽  
Retinal Vein Occlusion ◽  
Branch Retinal Vein Occlusion ◽  
Post Treatment ◽  
Intravitreal Ranibizumab ◽  
Vein Occlusion ◽  
Treatment Naïve ◽  
Pre Treatment ◽  
Number Of Injections

AbstractTo evaluate the effects of intravitreal ranibizumab injection (IVR) on metamorphopsia in patients with branch retinal vein occlusion (BRVO), and to assess the relationship between metamorphopsia and inner retinal microstructure and other factors. Thirty-three treatment-naïve eyes of 33 patients with macular edema caused by BRVO with at least 12 months of follow-up were included. The degree of metamorphopsia was quantified using the M-CHARTS. Retinal microstructure was assessed with spectral-domain optical coherence tomography. Disorganization of the retinal inner layers (DRIL) at the first month after resolution of the macular edema (early DRIL) and at 12 months after treatment (after DRIL) was studied. Central retinal thickness (CRT), and status of the external limiting membrane as well as ellipsoid zone were also evaluated. IVR treatment significantly improved best-corrected visual acuity (BCVA) and CRT, but the mean metamorphopsia score did not improve even after 12 months. Post-treatment metamorphopsia scores showed a significant correlation with pre-treatment metamorphopsia scores (P < 0.005), the extent of early DRIL (P < 0.05) and after DRIL (P < 0.05), and the number of injections (P < 0.05). Multivariate analysis revealed that the post-treatment mean metamorphopsia score was significantly correlated with the pre-treatment mean metamorphopsia score (P < 0.05). IVR treatment significantly improved BCVA and CRT, but not metamorphopsia. Post-treatment metamorphopsia scores were significantly associated with pre-treatment metamorphopsia scores, the extent of DRIL, and the number of injections. Prognostic factor of metamorphopsia was the degree of pre-treatment metamorphopsia.

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