Daniel A. Yaussy

The national Fire and Fire Surrogate study: effects of fuel reduction methods on forest vegetation structure and fuels

Changes in vegetation and fuels were evaluated from measurements taken before and after fuel reduction treatments (prescribed fire, mechanical treatments, and the combination of the two) at 12 Fire and Fire Surrogate (FFS) sites located in forests with a surface fire regime across the conterminous United States. To test the relative effectiveness of fuel reduction treatments and their effect on ecological parameters we used an information-theoretic approach on a suite of 12 variables representing the overstory (basal area and live tree, sapling, and snag density), the understory (seedling density, shrub cover, and native and alien herbaceous species richness), and the most relevant fuel parameters for wildfire damage (height to live crown, total fuel bed mass, forest floor mass, and woody fuel mass). In the short term (one year after treatment), mechanical treatments were more effective at reducing overstory tree density and basal area and at increasing quadratic mean tree diameter. Prescribed fire treatments were more effective at creating snags, killing seedlings, elevating height to live crown, and reducing surface woody fuels. Overall, the response to fuel reduction treatments of the ecological variables presented in this paper was generally maximized by the combined mechanical plus burning treatment. If the management goal is to quickly produce stands with fewer and larger diameter trees, less surface fuel mass, and greater herbaceous species richness, the combined treatment gave the most desirable results. However, because mechanical plus burning treatments also favored alien species invasion at some sites, monitoring and control need to be part of the prescription when using this treatment.

Ecological effects of alternative fuel-reduction treatments: Highlights of the National Fire and Fire Surrogate study (FFS)

The 12-site National Fire and Fire Surrogate study (FFS) was a multivariate experiment that evaluated ecological consequences of alternative fuel-reduction treatments in seasonally dry forests of the US. Each site was a replicated experiment with a common design that compared an un-manipulated control, prescribed fire, mechanical and mechanical + fire treatments. Variables within the vegetation, fuelbed, forest floor and soil, bark beetles, tree diseases and wildlife were measured in 10-ha stands, and ecological response was compared among treatments at the site level, and across sites, to better understand the influence of differential site conditions. For most sites, treated stands were predicted to be more resilient to wildfire if it occurred shortly after treatment, but for most ecological variables, short-term response to treatments was subtle and transient. Strong site-specificity was observed in the response of most ecosystem variables, suggesting that practitioners employ adaptive management at the local scale. Because ecosystem components were tightly linked, adaptive management would need to include monitoring of a carefully chosen set of key variables. Mechanical treatments did not serve as surrogates for fire for most variables, suggesting that fire be maintained whenever possible. Restoration to pre-settlement conditions will require repeated treatments over time, with eastern forests requiring more frequent applications.

Comparison of an empirical forest growth and yield simulator and a forest gap simulator using actual 30-year growth from two even-aged forests in Kentucky

Two individual-tree growth simulators are used to predict the growth and mortality on a 30-year-old forest site and an 80-year-old forest site in eastern Kentucky. The empirical growth and yield model (NE-TWIGS) was developed to simulate short-term (<50 year) forest growth from an industrial perspective. The gap model (ZELIG) is based on the theory of growth processes and has been used to simulate long-term (100 years and greater) forest succession. Based on comparisons of species specific diameter distributions, biomass, and board-foot and cubic-meter volumes, NE-TWIGS performed better for both sites than did ZELIG.

Shoot biomass of turfgrass cultivars grown on composted waste

Various cultivars of four cool-season grass types (tall fescue, fine fescue, perennial ryegrass, and Kentucky bluegrass) were seeded in 0.34-liter plastic pots containing either composted sewage sludge [Com-Til2 (CT), Soil Magic2 (SM)] or composted yard mulch (YM). Plants were grown in the greenhouse for four weeks prior to measuring shoot biomass. White most tall fescue cultivars showed more shoot growth on YM, perennial ryegrass cultivars generally grew better on SM. Cultivars of fine fescue and bluegrass grew about the same on YM or SM, and slightly less on CT. With very few exceptions, shoot biomass of individual cultivars was greater on either YM or SM than it was on CT. Within individual grass types, Pennlawn (fine fescue), Pennant (perennial ryegrass), and Victa (Kentucky bluegrass) averaged consistently better growth on all three composted media. For tall fescue, Aquara, Rebel II, and Monarch performed best on YM, SM, and CT, respectively. Bioaccumulation of heavy metals did not occur in selective samples of shoot tissues collected from the grass types used.

Establishment and characterization of American elm cell suspension cultures

Cell suspension cultures of Dutch elm disease (DED)-tolerant and DED-susceptible American elms clones have been established and characterized as prerequisites for contrasts of cellular responses to pathogen-derived elicitors. Characteristics of cultured elm cell growth were monitored by A700 and media conductivity. Combined cell growth data for all experiments within a genotype showed relatively low variances and between-genotype contrasts during repeated passages showed no significant differences. Subculturing exponentially growing cells at 8–14 day intervals, within readily measured parameters of media conductivity (4.95–4.2 mmhos) and cell concentration (≥ 1.4 A700), consistently resulted in repeatable profiles of elm cell growth and minimized lag phase. Culture cells were essentially homogeneous after 5 subculture passages and their overall appearance was stable. We conclude that the described procedure resulted in consistent cultures suitable for elicitor treatment experiments.

Race to the Future: Integrating 21st Century Skills into Science Instruction

ABSTRACT Race to the Future is an exciting and dynamic activity modeled after the reality television show The Amazing Race. It exemplifies how 21st century skills can be incorporated into core subject instruction and at the same time positively enhance student engagement. In this activity, students work quickly and cooperatively with their teammates and use 21st century skills to successfully decipher five clues related to science content. We have used this activity with excellent results with different groups of students (middle school, high school, and university students), for different purposes (ice-breaker, team-building, course assessment, and evaluation), and in broad curriculum areas (science and math). However, the activity is especially powerful when introduced during the first day or week of class. The meaningful and enjoyable student collaboration, the upbeat class environment, and the enhanced student engagement achieved at the conclusion of this challenging activity set an optimal teaching and learning environment for the entire quarter/semester.

William L. Baker: Fire ecology in rocky mountain landscapes: Island Press, Washington, DC, 2009, 605 pp

Every so often, we need something to make us question our beliefs and views of the natural order of things, to open our minds to different versions of reality so that we become better informed and open to new avenues of thought. The author comes across as slightly antagonistic in his attempt to set the record straight concerning fires in the Rocky Mountains.

William L. Baker: Fire ecology in rocky mountain landscapes

Every so often, we need something to make us question our beliefs and views of the natural order of things, to open our minds to different versions of reality so that we become better informed and open to new avenues of thought. The author comes across as slightly antagonistic in his attempt to set the record straight concerning fires in the Rocky Mountains.