Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 4 of 4
Full-Text Articles in Physical Sciences and Mathematics
A Buried Spruce Forest Provides Evidence At The Stand And Landscape Scale For The Effects Of Environment On Vegetation At The Pleistocene/Holocene Boundary, Douglas D. Stokke
A Buried Spruce Forest Provides Evidence At The Stand And Landscape Scale For The Effects Of Environment On Vegetation At The Pleistocene/Holocene Boundary, Douglas D. Stokke
Douglas D. Stokke
Due to a unique set of circumstances, we were able to excavate an entire spruce (Picea) forest in Michigan's Upper Peninsula, USA, which was buried in the early Holocene (9928 ± 133 uncalibrated 14C years bp). Trees ranged from < 5 cm to > 50 cm in diameter, and dominants were approximately 9 m tall. The stand was multi-aged, with a maximum tree age of 145 years. Well-preserved stem cross-sections (n = 140) were recovered and the entire stand was mapped. Stand reconstruction combined with pollen and sediment analysis revealed a pure spruce forest in the sandy lowlands surrounded by hills dominated by pine, oak …
Variation In Cell Dimensions And Fibril Angle For Two Fertilized Even-Aged Loblolly Pine Plantations, Douglas D. Stokke, Todd F. Shupe, Elvin T. Choong, Mark D. Gibson
Variation In Cell Dimensions And Fibril Angle For Two Fertilized Even-Aged Loblolly Pine Plantations, Douglas D. Stokke, Todd F. Shupe, Elvin T. Choong, Mark D. Gibson
Douglas D. Stokke
Increment core samples were obtained from randomly selected, nine-year-old lohlolly pine (Pinus faeda L.) in two even-aged plantations in Louisiana in order to determine the variation in cell dimensions and fibril angle of the sites. The Homer site is representative of the growing conditions in north Louisiana, and the Bogalusa site is typical of the conditions in southeastern Louisiana. Both sites were subjected to similar site preparation and weed control and were fertilized in the juvenile period. The anatomical properties that were measured include: fiber length, cell-wall thickness, and microfibril angle (MFA). Observations were made in order to compare corewood …
Variation In Lightness Of White Oak Dimension Stock, Douglas D. Stokke, Anton D. Pugel, John E. Phelps
Variation In Lightness Of White Oak Dimension Stock, Douglas D. Stokke, Anton D. Pugel, John E. Phelps
Douglas D. Stokke
The objectives of this research were to generate a set of sample parameters for the lightness of planed white oak dimension stock, to investigate the effect of grain angle on lightness values, and to determine the level of sampling needed to color match white oak dimension stock on the basis of lightness or darkness as quantified by the parameter L* (psychometric lightness). This information is important when used to determine the feasibility of low-cost portable instruments for evaluating color in an edge-glued hardwood panel production setting. Color measurements were obtained with a portable spectrophotometer interfaced with a notebook computer. The …
Micro And Macromorphology Of Recycled Fiber And Wood, Douglas D. Stokke
Micro And Macromorphology Of Recycled Fiber And Wood, Douglas D. Stokke
Douglas D. Stokke
Wood is a major industrial raw material, with U.S. consumption approaching that of aluminum, plastics, cement, and steel combined. Partially as a result of the magnitude of wood and wood products in use, these products constitute a substantial portion of the solid waste stream. In order to reduce the amount of wood and wood fiber disposed in landfills, efforts to recycle these materials into useful products such as structural composites are needed. The success of such conversion depends in part on knowledge of the morphological characteristics of various sources of secondary wood and wood fibers, and the influence of wood …