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Displaying 11,311 - 11,320 of 64,721 Publications- Two lightning stroke data sets for the same time period from a 7854 sq.km. area in the Black Hills, South Dakota USA , one from Vaisala and the other from WSI (Weather Services International now The Weather Company) were compared with respect to number of events, number of positive and negative strokes, amplitude and number of subevents. There was also an attempt to match strokes between the two data sets. The first stroke recorded for each data set took place on June 15 2012 at 3:49 PM MDT and the last stroke for each data set occurred on June 26 2012 at 2:58 PM MDT. The WSI data set has...AuthorsKathy Gray, Don Latham, Paul A. SopkoSourceIn: 25th International Lightning Detection Conference & 7th International Lightning Meteorology Conference; March 12-15, 2018; Ft. Lauderdale, Fl. Vaisala. 7 p.Year2018
- The measurement and characterization of wildland fuel matrices in ways that are relevant to both fire managers and scientists remains challenging. Wildland fuel characterization differs markedly from the characterization of fuels in the built environment, as these fuels are comprised of the components of dynamic ecosystems where change is a constant. This problem is confounded by the spatial and temporal extents and resolutions at which fuels are to be measured. Additionally, the number of variables that must be considered can make fuel characterization efforts seem intractable. However,...AuthorsNicholas Skowronski, Michael R. GallagherKeywordsSourceIn: Manzello, S., ed. Encyclopedia of wildfires and wildland-urban interface (WUI) fires. Cham: Springer. 10 p.Year2018
- The occurrence (probability) and extent (proportion) of tree internal stem decay are important attributes influencing potential wood quality and value, but variation in decay by species, tree size and geographic range are rarely evaluated and modelled. In this analysis, we used 1246 destructively sampled trees across 33 species in the northeastern United States and New Brunswick, Canada to determine the factors influencing the combined probability and proportion of decay. In the process, we evaluated three modelling approaches including a two-part conditional model, multinomial model and...AuthorsJereme Frank, Mark Castle, Jim Westfall, Aaron Weiskittel, David MacFarlane, Sharad Baral, Philip Radtke, Gaetan PelletierSourceForestryYear2018
- We used an experimental design to analyze factors affecting participation rates for family forest owner outreach campaigns. Through logistic regression, we assessed the participation rates as a function of campaign and landowner attributes. Participation rates ranged from 3% to 14%. Owners offered a publication were on average 4.3 times more likely to participate than those offered a forester visit. Owners with a college degree were on average 1.5 times more likely to participate than those with lower levels of formal education. Extension and other outreach professionals can use knowledge...AuthorsBrett J. Butler, Sarah M. Butler, Kelley Dennings, Tricia Gorby. KnootSourceJournal of Extension. 56(7): 7RIB3. 26 p.Year2018
- Our ability to predict the identity of future invasive alien species is largely based upon knowledge of prior invasion history. Emerging alien species—those never encountered as aliens before—therefore pose a significant challenge to biosecurity interventions worldwide. Understanding their temporal trends, origins, and the drivers of their spread is pivotal to improving prevention and risk assessment tools. Here, we use a database of 45,984 first records of 16,019 established alien species to investigate the temporal dynamics of occurrences of emerging alien species worldwide. Even after...AuthorsHanno Seebens, Tim M. Blackburn, Ellie E. Dyer, Piero Genovesi, Philip E. Hulme, Jonathan M. Jeschke, Shyama Pagad, Petr Pyšek, Mark van Kleunen, Marten Winter, Michael Ansong, Margarita Arianoutsou, Sven Bacher, Bernd Blasius, Eckehard G. Brockerhoff, Giuseppe Brundu, César Capinha, Charlotte E. Causton, Laura Celesti-Grapow, Wayne Dawson, Stefan Dullinger, Evan P. Economo, Nicol Fuentes, Benoit Guénard, Heinke Jäger, John Kartesz, Marc Kenis, Ingolf Kühn, Bernd Lenzner, Andrew M. Liebhold, Alexander Mosena, Dietmar Moser, Wolfgang Nentwig, Misako Nishino, David Pearman, Jan Pergl, Wolfgang Rabitsch, Julissa Rojas-Sandoval, Alain Roques, Stephanie Rorke, Silvia Rossinelli, Helen E. Roy, Riccardo Scalera, Stefan Schindler, Kateřina Štajerová, Barbara Tokarska-Guzik, Kevin Walker, Darren F. Ward, Takehiko Yamanaka, Franz EsslKeywordsSourceProceedings of the National Academy of SciencesYear2018
- Imputation models were developed to predict seedling regeneration density and composition on National Forest System (NFS) lands in Oregon and Washington. The models were based on Forest Inventory and Analysis and Pacific Northwest Regional NFS Monitoring data. Individual models were developed based on broad forest plant association groups (FPAGs) with all model development and analysis conducted in R using a most similar neighbor-like imputation approach. Model performance was evaluated based on bias, mean absolute deviation, root mean-squared error (RMSE), and error rate in correctly...AuthorsKarin Kralicek, Andrew J. Sánchez Meador, Leah C. RathbunKeywordsSourceForest Ecology and Management. 409: 667-682.Year2018
- Cost-effective strategic management of aerial forest fire suppression resources involves decisions about fleet location, in order to efficiently match supply and demand. In this study, we explore the flexible design of such a system, pooling the demand of several bases into a “zone”, and analyzing alternative partitions of the territory into zones. Feasible partitions consider an upper limit on the distance between bases, and require their adjacency, within the same zone. Then, we classify the feasible partitions according to a set of six criteria and explore the non-dominated partitions....AuthorsHugo Torres, Abilio Pereira Pacheco, Joao Claro, Michele Salis, Matthew P. Thompson, Crystal S. Stonesifer, Gavino Diana, Silvio CoccoKeywordsSourceIn: Viegas, Domingos Xavier, ed. Advances in Forest Fire Research 2018. Coimbra, Portugal: University of Coimbra, ADAI/CEIF. https://doi.org/10.14195/978-989-26-16-506_158.Year2018
- Large air tankers (LATs) - fixed wing aircraft used for wildfire suppression - are an integral but costly tool for wildfire management. But little evidence is available indicating whether the deployment of LATs is effective at containing fire ignitions during initial attack. Using data on USDA Forest Service wildfire ignitions and LAT deployments from 2010-2012 this paper estimates the effect of deploying a LAT on the likelihood that the fire ignition is contained during initial attack. Results suggest that LATs may be effective for a subset of ignitions with moderate growth potential, but...AuthorsHari Katuwal, Michael Hand, Matthew P. Thompson, Crystal S. Stonesifer, Dave E. CalkinSourcePaper No. 274304 for presentation at the 2018 Annual Meeting; August 5-7; Washington, D.C. Milwaukee, WI: Agricultural and Applied Economics Association. Online: https://EconPapers.repec.org/RePEc:ags:aaea18:274304.Year2018
- Statistically downscaled climate data have been widely used to explore possible impacts of climate change in various fields of study. Although many studies have focused on characterizing differences in the downscaling methods, few studies have evaluated actual downscaled datasets being distributed publicly. Spatially focusing on the Pacific Northwest, we compare five statistically downscaled climate datasets distributed publicly in the US: ClimateNA, NASA NEX-DCP30, MACAv2-METDATA, MACAv2-LIVNEH and WorldClim. We compare the downscaled projections of climate change, and the associated...AuthorsYueyang Jiang, John B. Kim, Christopher J. Still, Becky K. Kerns, Jeffrey D. Kline, Pat CunninghamKeywordsSourceScientific Data. 5(1): 180016.Year2018
- Individual tree crown (ITC) segmentation is an approach to isolate individual tree from the background vegetation and delineate precisely the crown boundaries for forest management and inventory purposes. ITC detection and delineation have been commonly generated from canopy height model (CHM) derived from light detection and ranging (LiDAR) data. Existing ITC segmentation methods, however, are limited in their efficiency for characterizing closed canopies, especially in tropical forests, due to the overlapping structure and irregular shape of tree crowns. Furthermore, the potential of...AuthorsWan Shafrina Wan Mohd Jaafar, Iain Hector Woodhouse, Carlos Alberto Silva, Hamdan Omar, Khairul Nizam Abdul Maulud, Andrew T. Hudak, Carine Klauberg, Adrian Cardil, Midhun MohanKeywordsSourceForests. 9: 759.Year2018