Full ecoregional plan - Conservation Gateway

PLANNING METHODS FOR ECOREGIONAL TARGETS: MATRIX-FORMING ECOSYSTEMS *One of the goals of ecoregional planning is to identify viable examples of all types ofecosystems at appropriate scale to conserve their component species and processes.Natural terrestrial vegetation communities vary greatly in terms of their sizes andecological specificity; some types cover large areas of varying topography, geology, andhydrology, while others occur only in small patches under very specific environmentalconditions.Matrix-forming (or dominant) ecosystems may extend over very large areas of 1000 tomany millions of acres, often covering 80% or more of the undeveloped landscape.Matrix systems are generally forests in the Eastern United States; the terms matrix forest,matrix community, matrix-forming community, and matrix site are used interchangeablyin the Northeast ecoregional plans. Matrix community types are often influenced byregional-scale disturbances such as hurricanes, insect outbreaks, or fire. They areimportant as “coarse filters” 1 for the conservation of most common species, wide-rangingfauna such as large herbivores, predators, and forest interior birds. The size and naturalcondition of the matrix forest allow for the maintenance of dynamic ecological processesand meet the breeding requirements of species associated with forest interior conditions.Nested within the matrix forests are the smaller patch-forming ecosystems, 2 with morespecific ecological tolerances and often more restricted species.Although differing in size and scale, matrix-forming systems were considered a specialcase of terrestrial ecosystem in the Northeast ecoregional plans. Most of the approachesand assumptions discussed under the terrestrial ecosystem chapter are directly applicableto matrix systems. However, the Natural Heritage Programs that provided the basis foridentifying examples of patch-forming ecosystems had not, to date, developed acomprehensive method of identifying viable examples of the dominant forestcommunities that constitute the background “matrix” within which all other biodiversityis found.Matrix forest assessment within ecoregional planning was developed in conjunction withthe New England Natural Heritage programs to fulfill this need. The methodology hasevolved significantly during the past several years, and has been applied to a broad range* Anderson, M.G. and S.L. Bernstein (editors). 2003. Planning methods for ecoregional targets: Matrixformingecosystems. The Nature Conservancy, Conservation Science Support, Northeast & CaribbeanDivision, Boston, MA.The standard methodologies sections created for this and all Northeast ecoregional assessment reports wereadapted from material originally written by team leaders and other scientists and analysts who served onecoregional planning teams in the Northeast and Mid-Atlantic regions. The sections have been reviewed byseveral planners and scientists within the Conservancy. Team leaders included Mark Anderson, HenryBarbour, Andrew Beers, Steve Buttrick, Sara Davison, Jarel Hilton, Doug Samson, Elizabeth Thompson, JimThorne, and Robert Zaremba. Arlene Olivero was the primary author of freshwater aquatic methods. MarkAnderson substantially wrote or reworked all other methodologies sections. Susan Bernstein edited andcompiled all sections.1 The concept of coarse filter is discussed in the chapter on Terrestrial Ecosystems and Communities.2 Patch-forming ecosystems are discussed in the chapter on Terrestrial Ecosystems and Communities.7/2003 – REVIEWER COMMENTS INCORPORATED MATRIX-1