Southern Blue Ridge: An Analysis of Matrix Forests - Conservation ...

The Southern Blue Ridge is a forested landscape of steeps slopes, high mountains, deep ravines, andwide valleys. The combination of intact temperate forest over a diversity of landforms, elevation zones,and bedrock geologies, makes it one of the most biologically diverse areas in North America. “The regionsupports the highest diversity of salamanders in the world, extremely rich forests with a tremendousdiversity of tree and herbaceous species, and very high densities of breeding birds” (Hunter et al. 1999).Five broad forest types, characteristic of the region, form the dominant matrix (Appalachian oakhardwoods, dry oak pine, cove forests, northern hardwoods, andspruce-fir), and their distribution tracks change with elevation. Otherforest types (such as riparian forests) occur at a smaller scale, usually inconjunction with a landform or specific setting. At the scale of largeintact forest areas (5,000 – 50,000 acres), the individual forest typesblend and intermix to form a larger functioning unit that shares manyprocesses and exhibits structural and compositional heterogeneity. Eachforest type will display a range of successional classes, given the abilityof various processes and disturbances to play out across the landscape.From a global perspective, the temperate deciduous and mixed forest ofthe Southern Blue Ridge is a huge and irreplaceable ecosystemrecovering from regional-scale deforestation. The great majority of thecurrent forest is mid-to-late successional; however much of its speciesand structural composition has been altered by past land uses andpractices such as agriculture, pasturing, fire suppression, and logging.Photo by Hugh MortonConcurrent with forest re-establishment, the human population hasincreased exponentially, leading to increased densities of roads and other urban environments whichhave led to greater forest fragmentation. Other stresses have expanded to include and compoundhabitat fragmentation, and threats such as increased pests and pathogens, soil acidification and globalclimate change continue to increase.In 2000, The Nature Conservancy (TNC) and its partners (Southern Appalachian Forest Coalition andAssociation for Biodiversity Information) conducted an Ecoregional Assessment for the Southern BlueRidge, identifying priority conservation locations (portfolio sites) known to harbor conservation targets(i.e., globally-rare plants, animals, and natural communities) (TNC & SAFC 2000). The EcoregionalAssessment, however, did not include identification and evaluation of large contiguous forested habitatsthemselves for conservation priorities, which form the very matrix supporting embedded conservationtargets. The scope and magnitude of today’s conservation challenges mean that we can no longerafford to limit our strategies to protecting a network of preserves, but must consider strategies andlandscapes large enough to maintain key ecosystem processes and services, resilience, and movementof organisms. TNC has recognized the need for this new “whole system” approach that involves workingat multiple scales, with an increasing emphasis on managing for connectivity and a permeable matrix oflands and waters that vary in quality, surrounding portfolio sites of high ecological integrity. In theSouthern Blue Ridge, this means looking across the landscape at large blocks of native habitat that cansupport the species, communities, and ecosystem processes and functions that will protect biodiversityand support people’s well-being now and into the future.The first iteration of the Southern Blue Ridge Ecoregional Assessment in 2000 (TNC & SAFC 2000)focused largely on rare species and communities or elements of biodiversity that occurred at the scale3