Sumter National Forest Final Report - NatureServe

protrusa, Grammitis nimbata (= Micropolypodium nimbatum), Hymenophyllum tayloriae, Polypodium virginianum, Trichomanesboschianum, Trichomanes intricatum, Vittaria appalachiana); and other vascular species (Galax urceolata, Heuchera parviflora var.parviflora, Houstonia serpyllifolia, Huperzia porophila, Hydrocotyle americana, Impatiens capensis, Phegopteris connectilis,Saxifraga careyana, Saxifraga caroliniana, Carex biltmoreana). This community varies in composition with no consistent dominantspecies. Nominal species are either constant or regional endemics. South and west of the Blue Ridge Escarpment, this association isless diverse than those occurrences in the central portion of the range.Environment: The hydrology of this community is supplied by constant spray from waterfalls. The community consists of nearlyvertical rock surfaces and ledges, slopes, and crevices with shallow soils which are constantly saturated by spray from adjacentwaterfalls. Freezing occurs very rarely, and flooding damage very seldom or never. Small pockets or mats of mineral or organicmatter are interspersed with bare rock, and may or may not have seepage as well.Vegetation: This association consists of a variable collection of mosses, liverworts, algae, vascular herbs, and occasional shrubs(generally less than 10%), most of them requiring constantly moist substrate and very high relative humidity. Many of the typicalspecies of this community are bryophytes and ferns disjunct from tropical regions, endemic bryophytes, and ferns disjunct from borealregions. Shrubs include Rhododendron maximum and Kalmia latifolia. Herb species include Huperzia porophila, Aspleniummontanum, Asplenium trichomanes, Asplenium rhizophyllum, Asplenium monanthes, Cystopteris protrusa, Polypodiumappalachianum, Trichomanes boschianum, Grammitis nimbata, Vittaria appalachiana, Hymenophyllum tayloriae, Trichomanesintricatum, Phegopteris connectilis, Adiantum pedatum, Saxifraga careyana, Saxifraga caroliniana, Heuchera parviflora var.parviflora, Circaea alpina ssp. alpina, Impatiens capensis, Houstonia serpyllifolia, Hydrocotyle americana, Thalictrum spp., Oxalismontana, Carex biltmoreana, and Galax urceolata. Bryophyte species, many of them nearly or entirely limited to this community,include Sphagnum quinquefarium, Sphagnum girgensohnii, Plagiomnium carolinianum, Plagiomnium affine (= Mnium affine),Mnium marginatum, Pseudotaxiphyllum distichaceum (= Isopterygium distichaceum), Bryocrumia vivicolor, Flakea papillosa,Hookeria acutifolia, Thamnobryum alleghaniense, Oncophorus raui, Hyophila involuta, Dichodontium pellucidum, Radula spp.,Plagiochila sharpii, Plagiochila caduciloba, Plagiochila sullivantii, Plagiochila austini, Fissidens osmundioides, Bazzania denudata,Conocephalum conicum, Pellia epiphylla, Pellia neesiana, and Riccardia multifida.Dynamics: These communities occur in unusually stable and equitable environments. The humidity is high and moisture supply isessentially constant. Temperatures are moderated by water, rock, and sheltering from sun and wind, resulting in only rare freezes orhigh temperatures. Potential disturbances include extreme droughts or freezes that may result in some die-off of sensitive species.Floods or rock falls may damage some parts, but in general this community is well sheltered from physical disturbance.Similar Associations:Related Concepts:• IID5a. Wet Acidic Cliff (Allard 1990) B• Spray Cliff (Schafale 1998b) ?Classification Comments: Zartman and Pittillo (1998) found Thuidium delicatulum, Atrichum oerstedianum, Houstoniaserpyllifolia, and Plagiomnium ciliare to be the most constant species in spray cliff communities sampled from the Chattooga RiverWatershed, in northern Georgia, western North Carolina, and northwestern South Carolina.CONSERVATION RANKING & RARE SPECIESGRank: G2 (1998-4-30): This community is very limited, known only from a few dozen occurrences, most of which are less thanone acre in size; the largest are only about two acres in size. Most examples are in rugged montane areas and have escaped directdisturbance, though many may have been affected by logging or development on surrounding lands. Water-quality declines may havedetrimental impacts on this very delicate and easily impacted community. Even limited human visitation has degraded someoccurrences.High-ranked species: Acrobolbus ciliatus (G3?), Aneura sharpii (G1G2), Bryocrumia vivicolor (G1G2), Carex biltmoreana (G3),Hymenophyllum tayloriae (G2), Krigia montana (G3), Oncophorus raui (G3), Plagiochila austinii (G3), Plagiochila caduciloba(G2), Plagiochila sullivantii (G2), Plagiomnium carolinianum (G3), Saxifraga careyana (G3), Saxifraga caroliniana (G2),Trichomanes intricatum (G3G4)ELEMENT DISTRIBUTIONRange: It is found in southwestern North Carolina, northwestern South Carolina, and northeastern Georgia, in the escarpment gorgesof the Southern Blue Ridge and west of the escarpment in eastern Tennessee.Subnations: GA, NC, SC, TNTNC Ecoregions: 51:C, 52:CUSFS Ecoregions: M221Dc:CCC, M221Dd:CCCFederal Lands: NPS (Great Smoky Mountains); USFS (Chattahoochee, Cherokee, Nantahala, Pisgah, Sumter)ELEMENT SOURCESReferences: Allard 1990, Anderson et al. 1990, Dellinger unpubl. data 1992, Farrar 1998, Nelson 1986, Peet et al. unpubl. data2002, Schafale 1998b, Schafale and Weakley 1990, Southeastern Ecology Working Group n.d., Stotler and Crandall-Stotler 1977,Weakley 1993, Weakley and Schafale 1994, Wharton 1978, Zartman and Pittillo 1998Vegetation of Sumter National Forest April 30 2004Copyright © 2004 NatureServe85