Upland Hardwood Woodland and Forest Landscape Endpoint Ecological Assessment

Upland hardwood woodland and forest in the Ozark Highlands is one of the nine priority habitat types identified in the Integrated Science Agenda Draft V4 (ISA) established by the Adaptation Management Science Team (AMST) of the Gulf Coastal Plains and Ozarks Landscape Conservation Cooperative (GCPO LCC). The desired ecological state for the upland hardwood priority habitat system is described as “large blocks of oak forest and woodland in appropriately distributed successional stages in predominately forested landscapes, with woodlands characterized by moderate canopy cover and tree densities that allow ample light to reach the ground, supporting a variety of grasses and forbs, and with forests characterized by nearly closed overstory canopy with well-developed subcanopy, shrub, and understory strata comprised of shade-tolerant species.” The ISA presents draft metrics for the configuration and condition of the broadly defined habitat, including forest patches >5,000 ac (revised to >3,000 ac for this assessment), >70% woodland and forest habitat in the 10 km radius landscape, adequate connectivity, 20-80% and >80% overstory canopy cover for woodlands and forests, respectively, >14" average tree diameter, ~40 and ~80 trees/acre tree density for woodlands and forests, respectively, one large snag per every five acres, one six foot downed log >8" dbh per acre, midstory cover <20%, oak hickory basal area >90% and >70% for woodlands and forests, respectively, and fire return interval of 3 years for woodland and 10 years for forest habitats. We applied these thresholds to the available geospatial data to generate a draft condition index for upland hardwoods in the geographical boundary of the Gulf Coastal Plains and Ozarks Landscape Conservation Cooperative (GCPO LCC).
 
Our method first identifies forests where hardwood woodlands and forests either are or have the potential to be dominant by selecting ecological classes from a composite of the Oklahoma Vegetation Classification, Texas Ecological Systems, Florida Cooperative Land Cover, and the 2011 National GAP Land Cover Data layer. This step generated a base layer describing where upland hardwood woodlands and forests are in any condition throughout the GCPO geography, which we refer to as the “Mask.” Outside the woodland and forest Mask, a raster representing potential habitat was generated using a combination of the Central Hardwoods Joint Venture Ecological Potential layer and the LANDFIRE Biophysical Settings (BpS) data layer, which represents vegetation that may have been dominant on the landscape at the time of European Settlement. Individual pixels within the Mask raster layer were classified according to the two configuration metrics (forest patch size, >70% forest cover). The process then assessed eight measurable forest condition endpoints  within each of the four configuration bins using a set of data layer estimates of each condition. Basal Area estimates were obtained from the USFS live tree species basal area data product. Canopy Cover estimates were obtained from the 2011 National Land Cover Database (NLCD) U.S. Forest Service Tree Canopy (analytical) product. All other data layers associated with condition endpoints (average tree diameter per acre, tree density, midstory density, snag density, and down wood) were obtained from unpublished data layers shared with GCPO staff by scientists at the USFS Remote Sensing Applications Center. The individual data endpoints were run through a decision matrix that outputted a Condition Index Value score, ranging from 0 -  37, that indicated current condition of upland hardwood systems on the landscape.  Condition Index Values were then used as a foundational data input layer for development of the GCPO LCC Conservation Blueprint version 1.0.