Ecological Zones of the Nantahala and Pisgah National Forests
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March 5, 2014 Ecological Zones of the Nantahala and Pisgah National Forests 1 March 5, 2014 Contents Overview of Ecological Zones ...................................................................................................................... 3 Spruce-Fir Forest Ecological Zone ............................................................................................................. 10 Spruce-Fir Ecozone Vegetation Structure ............................................................................................... 14 Spruce-Fir Terrestrial Wildlife................................................................................................................ 21 Northern Hardwood Ecological Zone ......................................................................................................... 27 Northern Hardwood Vegetation Structure .............................................................................................. 32 Northern Hardwood and High Elevation Oak Terrestrial Wildlife ......................................................... 40 Oak Ecological Zone ................................................................................................................................... 45 Oak Ecozones Vegetation Structure ....................................................................................................... 60 Oak Terrestrial Wildlife .......................................................................................................................... 87 Acidic Cove and Rich Cove Ecological Zones ......................................................................................... 107 Cove Ecozones Vegetation Structure .................................................................................................... 114 Cove Terrestrial Wildlife ...................................................................................................................... 125 Pine-Oak/Heath Ecological Zone.............................................................................................................. 130 Pine-Oak/Heath Vegetation Structure ................................................................................................... 134 Shortleaf Pine Ecological Zone............................................................................................................. 142 Shortleaf Pine Terrestrial Wildlife ........................................................................................................ 154 Floodplain Ecological Zone .................................................................................................................. 158 Floodplain Terrestrial Wildlife ............................................................................................................. 161 2 March 5, 2014 Overview of Ecological Zones The Nantahala and Pisgah National Forests are distributed across 18 counties in western North Carolina providing the largest amount of public lands available in the region. They are located in the Blue Ridge Physiographic Province of the Southern Appalachian Mountains. The Blue Ridge forms a southwest to northeast mountain range through western North Carolina with many areas over 4,000 feet in elevation. Elevations in the Nantahala and Pisgah NFs range from less than 1,050 feet to greater than 6,200 feet. Geologic processes (fluvial, mass wasting, groundwater movement, etc.), materials (bedrock and surficial deposits), structures (fracture systems, folds, faults), and landforms control or influence a host of ecological factors, such as slope aspect (solar radiation); slope steepness; the distribution and composition of soil parent material and associated vegetation; the characteristics of floodplains, wetlands, riparian areas, and streams; the quantity and quality of surface water and groundwater; natural disturbance regimes; and the nature and condition of watersheds. Geological diversity is the foundation of ecosystem diversity and biological diversity. The relationship of geology to site fertility is a basis for the Ecological Zones in the Southern Appalachians: first approximation by Simon and others (2001). Ecological zones are defined as units of land that can support a specific plant community or plant community group based upon environmental factors such as geology, temperature, moisture, fertility, and solar radiation (Simon 2011). Ecological zones were modeled as multivariate logistic functions of climatic, topographic, and geologic variables. Results of this model suggest that bedrock geology is an important factor affecting the distribution of vegetation. The presence or absence of the plant communities typically associated with an ecological zone is a reflection of past disturbance events including land use changes. Absence of the expected plant communities may serve as an indicator for potential restoration. A combination of geology and past and current land use has shaped the present vegetative composition and abundance of habitats across the forests. Table 1 identifies the 11 ecological zones that include the majority of the lands across the Nantahala and Pisgah NFs. The final number of ecological zones (ecozones) was derived by analyzing the diversity of types and combining those with similar abiotic environments and ecological functions. A diversity of plant communities may be represented in any single ecozone. All the applicable plant communities are listed in Table 1 and were derived from either Natureserve.org, from the Guide to the Natural Communities of North Carolina, 4th Approximation, or from the Ecological Zones in the Southern Blue Ridge, 3rd Approximation. These plant communities or associations are described in the online edition of the natural community publications at the NC Natural Heritage Program web site (http://portal.ncdenr.org/web/nhp/nhp-publications#natural-communities) or the NatureServe Explorer web database (http://www.natureserve.org/explorer/). 3 March 5, 2014 Table 1. Plant communities represented within the 11 ecological zones. Ecological Zones Plant Communities Spruce-Fir Fraser Fir Forest (Rhododendron and Herb Subtypes), Red Spruce – Fraser Fir Forest (Herb, Rhododendron, Birch Transition Herb, & Low Rhododendron Subtypes) Northern Hardwood Northern Hardwood Cove Forest (Typic & Rich Subtypes), Blue Ridge Hemlock Northern Hardwood Forest (acidic subtype) High Elevation Red High Elevation Red Oak Forest (Typic Herb, Rich, Heath, Orchard, & Stunted Oak Woodland Subtypes) Acidic Cove Acidic Cove Forest (Typic Subtype), Canada Hemlock Forest (Typic & White Pine Subtypes), Chestnut Oak Forest (Rhododendron Subtype) Rich Cove Rich Cove Forest (Montane Rich, Montane Intermediate, Foothills Intermediate, Foothills Rich, Red Oak, & Boulderfield Subtypes) Mesic Oak Montane Oak-Hickory Forest (Acidic, Basic, Low Dry, & White Pine Subtypes) Dry-Mesic Oak Dry-Mesic Oak Hickory Forest, Low Montane Red Oak (?), Montane Oak- Hickory Forest (Low Dry Subtypes) Dry Oak Chestnut Oak Forest (Dry Heath, Herb, & White Pine Subtypes) Pine-Oak Heath Pine-Oak /Heath (Typic & High Elevation Subtypes) Shortleaf Pine-Oak Low Mountain Pine Forest (Shortleaf Pine & Montane Subtypes), Southern Heath Mountain Pine-Oak Forest Floodplains Montane Alluvial Forest (Small River & Large River Subtypes) Each of the ecozones have been modeled and mapped based on data collected from more than 5,000 plots recorded across the Southern Blue Ridge. For the purpose of assessing the current condition of ecosystems on the Nantahala and Pisgah NFs the Ecological Zones model was applied spatially to the forest. Descriptions of each ecological zone include the composition of species, the vegetative structure of the forest, general disturbance patterns, and wildlife diversity. In addition to the Ecological Zones model, other data including FSVeg data, the LANDFIRE BioPhysical Settings model, LiDAR (light detection and ranging; a remote sensing technology), and Forest Inventory and Analysis data were used to describe the existing composition and structure of the Nantahala and Pisgah NFs. 4 March 5, 2014 The Field Sampled Vegetation database (FSVeg) is the National Forest inventory information for individual sections of the forest called stands. It also includes data about stand ages, tree species and size, and stand descriptors including fuels, down woody material, surface cover, overstory cover and understory vegetation. More information may be found at: http://www.fs.fed.us/nrm/fsveg/index.shtml. FSVeg spatial data was used in this assessment for the generation of silvicultural and structural age class descriptions by ecozone. FSVeg data (spatial/tabular) was intersected with the Ecological Zones model. Age class distributions for each ecozone were derived using ten-year increments for the silvicultural age class distributions and structural age class grouping based on the BioPhysical Settings Models generated by LANDFIRE (http://www.landfire.gov/index.php). Table 2. Strengths and limitations of FSVeg spatial data used in the assessment of current ecozone conditions. Silvicultural Age Class Distribution Data Structural Age Class Distribution Data ---------------------------------------------------Strengths------------------------------------------------------ 1. Easily identifies changes in land use history. 1. Presents age class data within an ecological context 2. Ten-year age class breaks make trends in 2. When compared to LANDFIRE model structure young forest habitat creation easy to identify by comparisons,