introduction - Pennsylvania Natural Heritage Program

APPENDIX IVCLASSIFICATION OF NATURAL COMMUNITIES IN PENNSYLVANIACNHIs and the status of natural community classification in Pennsylvania:Terrestrial & Palustrine Plant Communities of Pennsylvania (Fike 1999) is the most currentcommunity classification system for Pennsylvania’s palustrine and terrestrial plant communities.This report was developed by the Pennsylvania Natural Diversity Inventory (PNDI) to updateand refine Smith’s 1991 report Classification of natural communities in Pennsylvania (draft), thefirst effort dedicated specifically to the classification of natural communities in Pennsylvania.Work is ongoing to improve the current classification system. Future editions may define newcommunity types or alter currently defined types. Aquatic communities (lakes, streams, andrivers), communities where vegetation is absent or not a definitive characteristic (caves, screeslopes), and communities resulting from extensive human disturbance (early stages of forestregrowth, old agricultural fields, manmade wetlands, etc.), are not addressed in thisclassification. Until more extensive classification work can be completed to define these typesof communities and incorporate them into a single state-wide framework, the County NaturalHeritage Inventory reports will provisionally refer to features of ecological interest that falloutside the Fike 1999 system using categories described in Smith 1991.Community RanksAs with species that are of concern, ranks have been assigned to rate the rarity of each naturalcommunity type identified for Pennsylvania. Appendices Vc and Vd list criteria for global andstate ranks. In most cases, the global extent of these communities has yet to be fully evaluated,and no global rarity rank has been assigned. Work is ongoing to refine these ranks and to furtherdevelop the ranking system to rate the relative quality of communities within a type.FIKE 1999 TYPESGLOBAL STATECOMMUNITY NAME RANK RANKTERRESTRIAL FORESTS:Hemlock (white pine) forest G5 S4Serpentine pitch pine – oak forest G2 S1Serpentine Virginia pine – oak forest G2 S1Pitch Pine – mixed oak forest G? S4Virginia pine – mixed hardwood forest G? S5Dry white pine (hemlock) – oak forest G? S4Hemlock (white pine) – northern hardwood forest G? S5Hemlock (white pine) – red oak – mixed hardwood forest G? S4156