American Hazel (Corylus americana), a native North American shrub, offers valuable wildlife food and habitat, but without fire and grazing this aggressive rhizomatous plant dominates the understory, reduces herbaceous vegetation, and alters savanna fuelbeds. Sherburne National Wildlife Refuge in Zimmerman, MN features a globally endangered habitat type, Prairie-Oak Savanna, that is characterized by old-growth Bur Oak (Quercus macrocarpa) stands and expansive lowland and upland tallgrass prairie habitat. But previous land-use and management have allowed hazel to dominate the understory in many areas of the Refuge, making hazel control a primary objective of fire and grazing management. Conventional woody biomass harvesting is destructive, laborious and time-consuming, while allometric measurements require species-specific calibration, high replication, and can also be time-consuming. Terrestrial laser scanning (TLS) has the potential to non-destructively sample greater areas more efficiently and with finer resolution than traditional sampling techniques. TLS has been used in other ecosystems to estimate woody plant biomass and model vegetation structure, but has not yet been applied in Prairie-Oak Savanna. We compare TLS and allometric measurements (diameter at ground level, length to first stem, diameter at first stem, total stem length and overall standing height) in modelling both hazel biomass and vertical understory structure. Each method is calibrated against harvested biomass data across a gradient of hazel abundance in both burned and grazed areas. We discuss the relative effectiveness and merits of TLS and allometric measurements as non-destructive estimators of woody biomass and understory structure.
Oral presentation and poster titles, abstracts, and authors from the Society for Range Management (SRM) Annual Meetings and Tradeshows, from 2013 forward.