Browsing by Subject "Sugar maple"

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    Demonstration of Hardwood Trusses in Residential Construction Projects
    (University of Minnesota Duluth, 2002-01) Brashaw, Brian K; Vatalaro, Robert J; Ross, Robert J; Wang, Xiping
    The hardwood lumber industry is a key component of the forest products industry in the Lake States and Northeast regions of the United States. Two of the primary lumber species include sugar maple (Acer saccharum) and red maple (Acer rubrum). High grade lumber from these species has an extremely high value, often exceeding $1,500/thousand board feet (M bdft). Lower grades of maple including pallet lumber usually sell for $200 to $275/M bdft. A cooperative Lake States research team developed the technical and economic background necessary for using low grade maple as structural components in metal-plate trusses and prefabricated wood I-joists. Specific projects that have been completed addressed the following research topics: lumber yield and recovery, lumber properties, acce\erated drying schedules, truss plate fasteners, truss fabrication and testing, I-joist fabrication and testing, and :financial assessments. An important step prior to implementation was the development of several demonstration projects using structurally graded maple lumber. A relationship was established with the Duluth Chapter of Habitat for Humanity International and a demonstration project was developed to use the red maple lumber in trusses for two houses with attached garag~s that were to be built during the summer of 2001. To minimize concerns oflumber length and s_pecies, we chose to use red maple as truss webs with spruce-pine-fir (SPF) chords in the house section and red maple for both the truss chords and webs in the attached garage. Red maple cants were obtained, sawn into 2- by 4-in. dimension lumber and dried using an accelerated kiln schedule. Structural grading was completed using an E-computer with visual overrides for #2 a11d #3 grade lumber. Truss designs were completed and sealed by a professional engineer and the trusses were manufactured by Kylmala Truss in Duluth, Minnesota. Natural Resources Research Institute (NRRI) personnel were involved in the setting of the trusses. There were no specific problems noted from the use of red maple in either the house or garage trusses. A second demonstration project was designed to use sugar maple lumber as web stock in a standard storage truss in a garage built in rural Duluth, Minnesota. Kiln-dried hard maple remaining from earlier projects was graded using a commercial E-computer. The lumber was then provided to Kylmala Truss for use in manufacturing a 6:12 pitch garage truss that spanned 26 ft. The trusses were set by NRRI personnel and covered with oriented strandboard (OSB) sheathing. There were no specific problems or challenges identified from using hard maple in the trusses, although it was difficult to hand nail siding to the hard maple web on the gable end trusses.
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    Impacts of earthworm bioturbation on elemental cycles in soils: An application of a geochemical mass balance to an earthworm invasion chronosequence in a sugar maple forest in Northern Minnesota.
    (2013-06) Resner, Kathryn "Kit" Elizabeth
    Earthworms are arguably the best known soil bioturbator, yet their impacts on soil biogeochemistry are difficult to quantify as a function of their roles in physically mixing soils. In glaciated regions of North America, northern hardwood forests have evolved without native earthworms since the last glacial retreat. However, earthworms have invaded northern hardwood forests owing to agricultural expansion, fishing, recreational, and logging activities. Earthworm consumption of the organic horizon in Minnesota hardwood forests has resulted in dramatically changing forest floor ecology and soil morphology, yet their impacts on soil biogeochemistry remain largely unknown. An earthworm invasion chronosequence near Leech Lake in Northern Minnesota provides an ideal outdoor laboratory to quantify the interactions between biogeochemical and physical processes associated with different earthworm species and biomasses. Across the earthworm invasion transect, the A horizon elemental chemistry profiles show that earthworms have vertically relocated minerals, which is consistent with 210-Pb activity profiles. While soil elemental depth profiles confirm increased mixing with earthworm invasion, the depth profiles cannot be solely explained by mixing. I used a geochemical mass balance model to examine soils' biogeochemical responses to invasive earthworms. Fractional and absolute mass losses/gains of biologically important elements such as Ca, P, K, Fe, and Si, relative to the parent material, are substantially altered by invasive earthworm species. The arrival of A-horizon-mixing, endogeic earthworms most dramatically reduces the level of the elemental enrichments in the A horizons. The declined elemental enrichments are likely derived from the consumption of particulate organic matter by endogeic species, which leads to the mineralization and leaching of Ca, P, K. The dramatic losses of the enrichments also suggest that the newly mineralized nutrients are in excess of the nutrient demand from understory plants. Our results indicate the significant and potentially negative impacts of invasive earthworms on the soil nutrient cycling and consequently the sustainability of the hardwood forests in the Great Lakes Region.
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    Sugar maple (Acer saccharum) forest community dynamics across an environmental gradient from the prairie-forest border to interior forest biome
    (2013-12) Bapikee, Chaïna
    Forest ecosystems are dynamic entities that are subject to a variety of biotic and abiotic environmental changes. Invariably, climate is one of the principal factors controlling the distribution of ecosystems and past fluctuations in climate are known to have shaped the Midwestern United States forests. The Upper Great Lakes region of North America includes Minnesota, Wisconsin, and Michigan, and is characterized by a gradual south to north climatic gradient that defines the eastern deciduous forests (oak-hickory) to the south, the northern mixed hardwood forests (maple, hemlock, and beech) in northern Michigan and Wisconsin, and the sub-boreal forest (spruce-fir) in the far northern parts of the region. Additionally, the Upper Great Lakes region lies at the intersection of three major contrasting air masses: the cold, dry, polar continental air mass descending from the north; the dry, continental westerlies; and the warm, moist, tropical maritime air mass coming from the Gulf of Mexico. Interactions among these three air masses have created a southwest to northeast climatic gradient across the region resulting in a drier and warmer environment in southwest Minnesota as opposed to wetter and cooler conditions in Upper Michigan. It is in this context that the Upper Great Lakes region ecosystems were formed. They include the prairie-forest border (Zone 1), a transition zone between the tall grass prairies and the northern forests in Minnesota; the forest interior (Zone 2), which extends beyond the prairie-forest border into northern Wisconsin; and the deep forest (Zone 3), which lies in Michigan's Upper Peninsula. In recent years, numerous concerns about global environmental changes and their impact on the Upper Great Lakes northern hardwood forests have emerged. Increases of temperature caused by ongoing climate change, along with the proliferation of white-tailed deer (Odocoileus virginianus) populations and invasive European earthworms are predicted to drastically change the overstory and understory of northern hardwood forests. Sugar maple (Acer saccharum) is a common late successional species in the Great Lakes region and is widespread in dry mesic to mesic northern temperate forests. Sugar maple forests provide habitat for many wildlife species while trees are valued for their products (e.g. timber and syrup). This PhD dissertation aims to advance the understanding of the Upper Great Lakes northern hardwood forests by studying sugar maple forest community dynamics across an environmental gradient from prairie-forest border to interior forest biome and discuss their future in a context of global environmental changes. Rather than adopting a field-based approach, 3515 plots including tree and seedling data from the Forest Inventory and Analysis (FIA) program were studied, with 378 plots in Zone 1, 1823 plots in Zone 2, and 1314 plots in Zone 3. Analyses incorporated a combination of ordinations (Bray-Curtis and successional vector overlay), Ordinary Least Squares (OLS) regression models, and Aikaike's Information Criteria (AIC) provided a means for model selection. Chapter 1 investigated the contemporary overstory and understory forest composition of sugar maple communities and successional dynamics across the Upper Great Lakes region, and considered three hypotheses: (1) hardwood forests form a series of distinct communities via association of sugar maple with other tree species in the overstory across the Upper Great Lakes region; (2) sugar maple dominates the understory and succession to sugar maple is occurring in all of the communities--therefore the overstory communities identified are not stable; and (3) mesophication (which was used as a broad concept to include increasing maple proportion within mixed maple-oak forests) in sugar maple-red oak communities is progressing towards greater dominance of sugar maple. Sugar maple dominated forests were identified in association with red oak, bur oak-aspen, and basswood at the prairie-forest border, red oak-red maple, quaking aspen, and basswood in the forest interior, and quaking aspen, red maple-balsam fir, and hemlock-yellow birch-white cedar in the deep forest of Upper Michigan. Mesophication is occurring in most sugar maple-red oak communities of the prairie-forest border and sugar maple regeneration dominates in combination with white ash, ironwood, and bitternut hickory (Zone 1), red maple, balsam fir, and ironwood (Zone 2), and balsam fir (Zone 3), indicating that the distinct overstory communities may not be stable and that sites are trending towards relative homogeneity. However, despite the regeneration success of sugar maple, some stands had no sugar maple regeneration and we predict a decline in future sugar maple abundance resulting from the long term effects of deer browsing, earthworm invasion, and increased drought effects due to global environmental change. In Chapter 2, tree and seedling richness-site productivity relationships were examined in sugar maple forests of the Upper Great Lakes region. First, the form of the species richness-site productivity relationship of the overstory and understory of sugar maple forests was investigated on three data sets (i.e. whole data set, upper 90th quantile subset, and random sample subset) by testing the null hypothesis that the species richness-site productivity is flat. The alternative hypotheses were that the richness-site productivity relationship is 1) hump-shaped, 2) positive monotonic, 3) negative monotonic, and 4) U-shaped. Second, after noticing that sugar maple abundance approached 100% on some plots, the existence of threshold effects of sugar maple abundance on species richness was investigated by testing the null hypothesis that no threshold effect exists (i.e. species richness decreases linearly with increase sugar maple abundance) against that alternative that there is a threshold effect of sugar maple abundance (i.e. species richness display threshold responses to increase basal area). Results varied across zones and data sets, indicating that sample size might be influencing the results. Overall, there was a significant positive relationship between tree richness and site productivity but a flat seedling richness-site productivity relationship. The addition of sugar maple basal area to the models greatly improved the results. There was no apparent threshold effect but sugar maple abundance had very strong negative effect on species richness, which appeared to increase from the prairie-forest border towards Upper Michigan. Chapter 3 focused on the ecological niche of sugar maple seedlings from the prairie-forest border to the interior of the forest biome. Sugar maple seedling sensitivity to current forest structure and composition (sugar maple basal area and stand age), as well as site level environmental conditions (sand proportion, soil depth, slope, and TRASP - an index related to aspect) was assessed under the hypothesis that sugar maple seedlings respond differently to environment variables across the region and have a broader environmental niche in the Upper Peninsula of Michigan than at the prairie-forest border. As expected, basal area of sugar maple was generally positively related to sugar maple seedling density, while the effects of % sand and soil depth varied across the three zones. TRASP, an index related to aspect, had a strong negative influence on seedling abundance at the prairie-forest border and interior zones (Zones 1 and 2, respectively), but had no influence in the deep interior zone (Zone 3). The overall interpretation of the models and patterns across the climate gradient indicated that sugar maple seedling abundance is currently insensitive to environmental variables (i.e. has a very broad environmental niche) in Upper Michigan, with many stands currently growing on sites with relatively high percent sand content, shallow soils, and southerly slopes. The expected shift in future climate would make the climate of Upper Michigan like that of the prairie-forest border by late 21st century, thereby reducing the probability of seedling establishment on many sites currently with high dominance of sugar maple. Additionally, high deer populations and earthworm invasion will narrow the niche of sugar maple in Upper Michigan even more so than changing climate alone.