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An Integrated Geoecosystem-Remote Sensing Approach To Aspen Ecosystem Management In Northern Lower Michigan School of Natural Resources & Environment McIntire-Stennis Program Burt Barnes, Kathleen Bergen Graduate Students: Ephraim Zimmerman Kara Moore, Catherine Yanca October 28, 2002 Collaborator Tom Crow USFS North Central Research Station Rationale • Following massive logging and post-logging fires in northern Lower Michigan in the mid-to-late 19th Century, the original pine and hemlock-northern hardwood forests were changed to stands primarily dominated by bigtooth and trembling aspens. • Now, 80-100 years later, aspens are declining and are being replaced by other species in patterns determined by site conditions and forest history. • These changes are not well understood, yet have profound ecological, social, and economic implications. Goal • Demonstrate the applicability of the landscape ecosystem approach coupled with remote sensing/GIS methods to develop a model of the spatial and successional status of the aspen resource for ecosystem management. Objectives •Determine the successional pathways for selected ecosystems at the 4000-ha University of Michigan biological Station (UMBS), northern Lower Michigan •Characterize the role of red maple, northern red oak, and eastern white pine in forming 21st Century forest communities for selected landforms and ecosystems. •Model the decline of the aspen resource using an ecosystem approach at multiple spatial scales coupled with remote sensing and GIS methods. Approach • An ecosystem map of the area and permanent sample plots were used to determine successional change at multiple spatial scales. • The composition, structure, and successional trends were determined for 7 aspen- dominated ecosystem types • The occurrence and successional role of species replacing aspen (red maple, northern red oak, and eastern white pine) in diverse ecosystems were determined Results Aspen • On moraine landforms, aspens are being replaced by northern-hardwood species. • In contrast, aspens on outwash plain landforms are being replaced by white and red pines and red maple, depending on ecosystem type. • Different trends of occurrence and succession for red maple, northern red oak, and white pine for a diverse set of ecosystem types was observed and described. Different Landscape Ecosystems Types, Different Successional Pathways Dry Mesic Wet-Mesic Red Maple • Success of red maple is highly ecosystem-dependent • Contrary to the prevailing view, red maple will not become dominant in the long run on dry and dry-mesic ecosystems at UMBS although many of its clones may persist indefinitely. 90.0 Dominant Overstory Dominant Overstory 80.0 Subdominant Overstory SubdominantOverstory Understory Understory 70.0 60.0 Relative Density (%) 50.0 40.0 30.0 20.0 10.0 0.0 1 4 24 25 36 37 41 42 44 45 Low-elevation outwash Low-elevation outwash High-elevation severely High-elevation banded High-elevation calcareous (Pellston Plain) wetlands (Pellston Plain) burned outwash plain outwash plain outwash plain Ecosystem Type Comparison of red maple relative density in three forest layers for selected ecosystem types, outwash physiographic system, UMBS, Cheboygan and Emmet Co., northern Lower Michigan. Northern Red Oak • Red oak understory density was considerably lower than overstory density in most ecosystems types due to: – limited light under dense northern hardwood canopy in mesic ecosystems – severe site conditions, lack of fire, and heavy deer browsing in dry ecosystem types • Higher red oak density in outwash-over moraine ecosystem type – open, patchy aspen canopy – sandy-loam bands in C horizon 450 400 Overstory 350 Understory 300 Density (stems/ha) 250 200 150 100 50 0 1 36 37 74 44 45 40 59 60 76 77 96+97 Ecosystem Type Comparison of northern red oak density in three forest layers for selected ecosystem types, outwash physiographic system, UMBS, Cheboygan and Emmet Co., northern Lower Michigan. Remote Sensing • In combination with field data, GIS and Landsat data are being used to identify the patterns of ecosystem change among the selected landforms and ecosystem types. • The 14 test stands were mapped and combined with other UMBS GIS and Landsat data layers Spectral-Temporal Remote Sensing A combination of Landsat spectral and temporal (deciduous leaf-on/leaf-off) analysis provides information on a) aspen dominated overstory and b) deciduous vs. coniferous understory and successional pathway over the entire spatial extent of UMBS and region. Creating an SNRE UMBS GIS •Many other ArcGIS “layers” were created as a result of this project - a few are shown here overlaid on one Landsat band. •The entire UMBS GIS will eventually be hosted on the ESA Lab website. Hydrology Transportation Landform Level Ecosystems Conclusions • Due to accelerating succession, aspen stands will be replaced by later successional species depending upon the site-specific ecosystem of their occurrence. • Successional models based on the landscape ecosystem framework will prove useful in determining the spatial occurrence of the aspen resource, rate of decline, and succession to other species at the regional landscape scale.
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