Browsing by Subject "BWCAW"

Now showing 1 - 3 of 3
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    Estimated Primary Forest Extents of the Boundary Waters Canoe Area Wilderness (BWCAW)
    (2022-08-29) Johnson, Lane B; lbj@umn.edu; Johnson, Lane B; University of Minnesota Experimental Forests; University of Minnesota Dendroecology Laboratory
    This primary forest coverage was developed in 2014-2015 as an aid to tree-ring fire history investigations in the Boundary Waters Canoe Area Wilderness (Kipfmueller et al. 2021, Larson et al. 2021, Johnson and Kipfmueller 2016). The coverage is generally useful for research and stewardship of the forest communities within the BWCAW. The map is meant as a guide for presence/absence of primary forest and is not a substitute for on-the-ground assessments of forest age, composition, and structure. The coverage is still a work in progress and may be further refined with the help of coverage users. The coverage is best used to visualize primary forest extents and is not meant, at this time, to provide exact measures of remaining old-growth forest. Wildfires from 2015-2021 may have caused slight reductions in old-growth forest extents since this coverage was developed.
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    M-193 Bedrock Geology of the Cavity Lake Fire Area, Boundary Waters Canoe Area Wilderness, Northeastern Minnesota
    (Minnesota Geological Survey, 2017) Jirsa, Mark, A; Starns, Edward, C; Schmitz, Mark, D
    The bedrock geology in this part of the Boundary Waters Canoe Area Wilderness is extremely diverse and unusually well exposed (Fig. 1). Many parts of this area were mapped to varied levels of detail in the 1930s, and more recently in the 1970s and 1980s (see Index Map), with efforts focused primarily along waterways. A severe windstorm in 1999 blew down trees in much of the region, and a delayed result in 2006 was the Cavity Lake forest fire. The fire exposed bedrock and allowed comparatively unencumbered access to interior parts of the map area, creating a unique and time-sensitive opportunity for mapping. Fieldwork and compilation of prior mapping was conducted in 2007 and 2008, and a preliminary map was produced (Jirsa and Starns, 2008). That map is revised here to incorporate subsequent fieldwork and geochronologic analyses, including one new date acquired by coauthor Schmitz. The map portrays bedrock that represents crustal evolution spanning the Neoarchean to Mesoproterozoic Eras (Fig. 2), with an emphasis on structural and stratigraphic relationships in the Neoarchean portion. Neoarchean greenstone-granite terrane of the Wawa subprovince of the Superior Province is represented by a succession of mostly mafic to ultramafic metavolcanic rocks (circa [ca.] 2,700 Ma), unconformably overlain by calc-alkalic volcanic and volcaniclastic rocks (ca. 2,690 Ma), and intruded by the Saganaga Tonalite (also ca. 2,690 Ma).
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    Wilderness Visitor Experience Over Time: Change, Constraints, & Impacts
    (University of Minnesota Department of Forest Resources, 2009) Schroeder, Sierra L.; Schneider, Ingrid E.
    The purpose of this study was to understand changes such as constraints impacting recreational wilderness visitors, & to describe the impact of these constraints among visitors to a U.S. wilderness area: the Boundary Waters Canoe Area Wilderness (BWCAW).