doi: 10.1093/wjaf/27.4.C3pmid: N/A
Article PDF first page preview Close This content is only available as a PDF. © 2012 by the Society of American Foresters
doi: 10.1093/wjaf/27.4.164pmid: N/A
Article PDF first page preview Close This content is only available as a PDF. © 2012 by the Society of American Foresters
Affleck, David, L.R.;Keyes, Christopher, R.;Goodburn, John, M.
doi: 10.5849/wjaf.11-039pmid: N/A
Abstract The characterization of crown fuel parameters is a critical element in many fire behavior simulators used for decision support in the fire-prone coniferous forests of western North America. We briefly review the development and limitations of current conifer crown fuel models in this region as they impact the potential utility of fire behavior simulations. We then identify and evaluate conifer crown modeling efforts and techniques that have been advanced outside the fire and fuels domain, including models developed for bio-energy and carbon inventory, wood quality determination, and empirical and process-based growth and yield projections. Whereas the latter models often focus on crown parameters distinct from those traditionally described in fuels studies, we contend that advances in conifer crown fuel modeling can be made by recognizing and extending the results of these parallel lines of research. Such advances are needed to adequately parameterize crown fuels if we are to reap advantages from next-generation fire behavior models and, by extension, to improve our understanding of fuels management and treatment strategies. At the same time, more information must be derived from long-term fuels treatment and silvicultural trials to improve our understanding of how conifer crowns respond to treatments. crown fuels, crown biomass, crown architecture, process-based models, wildland fire This content is only available as a PDF. © 2012 by the Society of American Foresters
Goheen, Donald, J.;Mallams,, Katrina;Betlejewski,, Frank;Hansen,, Everett
doi: 10.5849/wjaf.11-011pmid: N/A
Abstract Two techniques widely recommended for managing Port-Orford-cedar root disease (caused by the introduced pathogen Phytophthora lateralis) are vehicle washing and roadside sanitation. However, their effectiveness has never been tested using a sample-based approach. Vehicle washing effectiveness was evaluated using Port-Orford-cedar seedling baits and a double-washing method. Washing with water can significantly reduce the amount of inoculum adhering to vehicles and boots. Effectiveness of roadside sanitation, the creation of zones along roads with few or no living Port-Orford-cedar hosts, was monitored using seedling baits for up to 12 years along ten infested roadsides that received operational treatments and for 8 years along four that did not. Sanitation treatments greatly reduced the amount of inoculum over time. Inoculum decline became most substantial in years 4 to 12 after treatment, suggesting that this treatment would be most useful in long-term strategies on roads used for many activities rather than in the short-term. Implementation monitoring of 17 roads that were sanitized by contract crews demonstrated that contractors were very thorough in removing all Port-Orford-cedars that met contract specifications. Vehicle washing and sanitation treatments reduce the likelihood of P. lateralis spread and are appropriate for use with other techniques in disease management strategies. Phytophthora lateralis, invasive pathogen, disease management This content is only available as a PDF. © 2012 by the Society of American Foresters
Lynch, Thomas, B.;Budhathoki,, Chakra;Wittwer, Robert, F.
doi: 10.5849/wjaf.11-030pmid: N/A
Abstract Models were developed for tree height and crown characteristics of eastern cottonwood (Populus deltoides Bartr. Ex. Marsh). Equations related cottonwood height to dbh and crown condition category (less than 50% live, at least 50% but less than 100% live, and 100% live). Crown width equations related crown width to dbh, crown condition category, and basal area per hectare. Additional equations related crown length to total height, basal area per hectare, and crown condition category. Data were obtained during a sample of trees located in a riparian area surrounding the Cimarron River on the Cimarron National Grassland. The band of trees on either side of the Cimarron River channel was surrounded by treeless, semiarid grassland typical of southwestern Kansas. Many trees were growing in scattered clumps or nearly open grown. In addition, there was variability in proportions of live crown present, as classified by crown condition category. These factors influence crown dimensions and are typical of cottonwood trees found in Great Plains riparian areas. Since height measurement trees were sampled on plots, mixed-effects models with random effects representing plot effects were developed for the height-diameter relationships (a model developed using ordinary least squares is also presented). Models of crown width and crown length were developed using ordinary least squares. random effects, mixed model, grassland, Cimarron This content is only available as a PDF. © 2012 by the Society of American Foresters
Long, James, N.;Shaw, John, D.
doi: 10.5849/wjaf.11-036pmid: N/A
Abstract We have developed a density management diagram (DMD) for even-aged mixed-conifer stands in the Sierra Nevada Mountains using forest inventory and analysis (FIA) data. Analysis plots were drawn from FIA plots in California, southern Oregon, and western Nevada which included those conifer species associated with the mixed-conifer forest type. A total of 204 plots met the selection criteria for analysis, which were for even-agedness and species composition. Even-agedness was characterized by a ratio between two calculations of stand density index. Species composition included admixtures of the species characterizing the Sierra Nevada mixed-conifer type with up to 80% of stand basal area contributed by ponderosa and Jeffrey pines. The DMD is unbiased with respect to species composition and therefore should be broadly applicable to the mixed-conifer type. The DMD is intended for use in even-aged stands, but may be used for uneven-aged management where a large-group selection system is used. Examples of density management regimes are illustrated, and guidelines for use are provided. silviculture, maximum stand density index, stocking diagram, mixed species This content is only available as a PDF. © 2012 by the Society of American Foresters
Kitzmiller, Jay, H.;Lunak,, Glenn
doi: 10.5849/wjaf.11-029pmid: N/A
Abstract Giant sequoia (Sequoiadendron giganteum, SEGI) is a Sierra Nevada conifer famous for its supreme size, longevity, decay resistance, and visual appeal. A restricted natural range endangers SEGI to catastrophic wildfire and adverse climate change. Conservation aims to protect and restore extant native groves and to create new groves in promising forest environments. SEGI was compared to the best local conifer, usually ponderosa pine (PIPO), planted on 107 productive sites along western slopes of the Sierra Nevada and southern Cascades. SEGI had greater or similar ht and dbh as PIPO in more than 90% of the plantations. Best development and growth superiority of SEGI occurred in the southern latitudes (< 38.6° lat.), on high quality sites, and middle slopes with southwest aspects at low stand densities. SEGI increased in dbh superiority over PIPO linearly with stand age. On the southern latitude high quality sites, SEGI averaged 2.6 m taller and 22 cm larger in dbh than PIPO at age 50. SEGI incurred greater loss in dbh (compared to PIPO) from higher stand densities on southeastern aspects and high sites. Site elevation did not affect species comparisons. Warmer temperatures and higher precipitation differentially favored dbh of SEGI. sequoiadendron giganteum, tree density, competition, paired-comparisons This content is only available as a PDF. © 2012 by the Society of American Foresters
Coble, Adam, P.;Kolb, Thomas, E.
doi: 10.5849/wjaf.12-001pmid: N/A
Abstract In the western United States, management to sustain riparian forests along regulated rivers will be challenged by future increases in drought and human water use. This study investigated influences of streamflow regulation by McPhee Dam on the Lower Dolores River, Colorado, on the growth response of three riparian tree species (Populus angustifolia, Populus deltoides subsp. wislizenii, and Acer negundo). Standardized indices of radial growth were developed at multiple reaches along the Lower Dolores for a predam canal-diverted period (1961–1984) and a postdam regulated period (1985–2008), and at the unregulated Upper Dolores and San Miguel Rivers during the same time periods. Our results strongly suggest that diversions of the Lower Dolores River into irrigation canals and reservoir storage predisposed Populus species to drought-induced growth declines. Tree growth along the Lower Dolores River was low during severe drought years with low streamflow, and growth decreased sharply when annual streamflow was less than 2.0 × 108 m3 year−1. Our results provide guidelines for flow releases from McPhee Dam to mitigate drought impacts on riparian tree growth along the Lower Dolores River. Acer negundo, dendrochronology, Populus angustifolia, Populus deltoides, river regulation This content is only available as a PDF. © 2012 by the Society of American Foresters
Long, James, N.;Kurtzman, Judith, A.
doi: 10.5849/wjaf.11-008pmid: N/A
Abstract For any proposed vegetation management, there are considerable benefits to exploring a broad range of alternatives that might accomplish the management goals. We outline a practical and defensible process that silviculturists can use when developing and documenting a reasonable range of silvicultural alternatives for accomplishing stand management objectives. goals, objectives, silviculture This content is only available as a PDF. © 2012 by the Society of American Foresters
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