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Ground-layer Bryophyte Communities of Post-adelgid Picea-Abies Forests
Sarah E. Stehn, Christopher R. Webster, Janice M. Glime, and Michael A. Jenkins

Southeastern Naturalist, Volume 9, Issue 3 (2010): 435–452

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2010 SOUTHEASTERN NATURALIST 9(3):435–452 Ground-layer Bryophyte Communities of Post-adelgid Picea-Abies Forests Sarah E. Stehn1, Christopher R. Webster1,*, Janice M. Glime2, and Michael A. Jenkins3 Abstract - Spruce-fir forests of the southern Appalachians are threatened by the widespread death of Abies fraseri (Fraser Fir) caused by the exotic Adelges piceae (Balsam Woolly Adelgid). Subsequent canopy opening, due to decimation of the fir population, has likely affected ground-layer dynamics and diversity. We sampled bryophytes on 60 randomly selected plots within the spruce-fir zone of Great Smoky Mountains National Park (GSMNP) using the line-intercept method (total sampling distance of 1800 m). Our sampling revealed 97 bryophyte species (64 mosses and 33 liverworts) comprising 32 families and 60 genera on ground-layer substrates in spruce-fir forests. Our results suggest that upwards of 20% of the bryoflora of GSMNP can be found on ground-level substrates in the spruce-fir zone. Introduction The southern Appalachians, especially Great Smoky Mountains National Park (GSMNP), are known for their diverse flora (e.g., Whittaker 1956, 1965) and fauna (e.g., Petranka 1998, Watson et al. 1994). The broad elevation range (266–2024 m) of the mountains allows for the existence of many habitats, and the area has historically served as a mixing point for species with affinities to northern coniferous forests (White and Renfro 1984), the eastern Coastal Plain, and even the tropics (Sharp 1939). Occupying the highest peaks, the spruce-fir (Picea-Abies) zone has been noted for its unique flora (White and Renfro 1984). Compared to northern Appalachian spruce-fir, GSMNP’s warmer climate and geographic location allow it to support many exceptional disjuncts and endemic species (White 1984). Additionally, the geologic history of the southern Appalachians as a refuge for species retreating from glaciation, and the status of the spruce-fir zone as a relict boreal system over the past 18,000 years (Delcourt and Delcourt 1984) have contributed to this unique composition. However, over the past 30 years, the overstory of spruce-fir forest in the southern Appalachians has undergone significant change due to the widespread death of Abies fraseri (Pursh) Poir. (Fraser Fir) caused by the invasion of the exotic Adelges piceae Ratz. (Balsam Woolly Adelgid [BWA]) (e.g., 1School of Forest Resources and Environmental Science, Michigan Technological University, Houghton, MI 44931. 2219 Hubbell Street, Houghton, MI 44931. 3Department of Forestry and Natural Resources, Purdue University, West Lafayette, IN 47907. *Corresponding author - cwebster@mtu.edu. 436 Southeastern Naturalist Vol. 9, No. 3 Jenkins 2003, Nicholas et al. 1992, Smith and Nicholas 1998). In addition to adelgid-caused fir mortality, chronic acid deposition (Hain and Arthur 1985), climatic stress (Johnson et al. 1986), and accelerated rates of natural disturbance (Busing and Pauley 1994) have been hypothesized to have negatively affected the survival of both Picea rubens Sarg. (Red Spruce) and remaining Fraser Fir. Change in overstory condition, as well as direct and indirect effects associated with acid deposition and climatic stress, have also likely impacted understory species in these forests (e.g., DeSelm and Boner 1984, Gilliam 2006, Johnson and Smith 2005). Often overlooked in vegetation studies due to their small size and difficultly in identificaton, bryophytes may nonetheless have potential value in assessing ecological condition (Frego 2007, Fritz et al. 2009), biodiversity (Smith et al. 2008), and air pollution levels (Gilbert 1968, Gramatica et al. 2006, Uyar et al. 2007). Bryophytes have previously been shown to respond to changes in light (e.g., Hoddinott and Bain 1979), acid deposition (e.g., Bates 2000, Koranda et al. 2007), substrate availability (e.g., Mills and Macdonald 2004, Rambo and Muir 1998, Shields et al. 2007), and substrate quality (e.g., Söderström 1988); thus, it is probable that bryophytes of the spruce-fir zone have been affected by shifts in canopy, shrub, and herbaceous-layer cover and composition resulting from adelgid-induced overstory mortality, as well as other factors affecting high-elevation southern Appalachian forests. Although significant descriptive works on bryophytes in GSMNP spruce-fir forests do exist (Cain and Sharp 1938, Norris 1964, Schofield 1960, Smith 1984), to our knowledge, only three studies have assessed post-adelgid bryophyte condition. Choberka (1998) quantified bryophyte species occurring on Fraser Fir logs, Smith et al. (1991) surveyed for bryophytes on living fir trees, and Davison et al. (1999) reported on the condition of six bryophyte species of conservation concern. The objective of our study was to comprehensively investigate and quantify the condition of ground-layer bryophytes across multiple substrates in the rapidly changing and imperiled spruce-fir zone. Description of Study Area All study sites were located within Great Smoky Mountains National Park (35°35'N, 83°28'W), a 210,000-ha preserve straddling the border of Tennessee and North Carolina (Fig. 1). The climate is classified as humid subtropical and characterized by uniform precipitation distribution. In the spruce-fir zone, above 1500 m, precipitation is especially high, reaching up to 260 cm per year (NCDC 2005). Winter temperatures can be quite low, with January high temperatures averaging 1 °C. Canopy dominance within spruce-fir forests varies considerably with change in elevation, and our study sites encompassed a range from 1262–1964 m 2010 S.E. Stehn, C.R. Webster, J.M. Glime, and M.A. Jenkins 437 due to the broad ecotone that exists between the spruce-fir forest type and the northern hardwood deciduous type (Schofield 1960). At the lower elevations (<1400 m), Red Spruce is the dominant species, with Betula alleghaniensis Britton (Yellow Birch) and Tsuga canadensis (L.) Carr. (Eastern Hemlock) occasionally interspersed. In the mid-elevations (1400–1600 m), Red Spruce and Fraser Fir tend to co-dominate, with pockets of Yellow Birch and Acer spicatum Lam. (Mountain Maple). At the highest elevations (>1600 m), Fraser Fir is the dominant species, but, due to impacts of the BWA, is largely missing from the overstory, and instead often forms a thick regeneration layer in the understory. Additionally, numerous standing snags and networks of fallen logs covering the forest floor now characterize formerly fir-dominated sites. Fast-growing disturbance-adapted species, including Prunus pensylvanica L.f. (Pin or Fire Cherry), Sorbus americana Marsh. (Mountain Ash), and thickets of Rubus canadensis L. (Smooth Blackberry), were common in stands that have experienced heavy adelgid-related overstory mortality. Methods In order to quantify bryophyte community composition in post-adelgid spruce-fir forests, we randomly located 60 plots within GSMNP using a stratification based on overstory type in an attempt to capture the wide range of canopy conditions representative of the spruce-fir zone and its Figure 1. Location of 60 plots where bryophytes were sampled in Great Smoky Mountains National Park. 438 Southeastern Naturalist Vol. 9, No. 3 ecotone with northern hardwoods (Schofield 1960). Using the NatureServe vegetation model for GSMNP (White et al. 2003), 40 plots were selected in areas with Fraser Fir- or spruce-fir-dominated canopies, and 20 plots were selected in areas of Red Spruce dominance, but still in the spruce-fir zone. Beyond this stratification and a restriction that limited plots to less than 500 but greater than 10 m from roads and trails to ensure safe access, plot locations were random, and the sampling regime at each plot was systematic. We sampled all selected plots over the summers (June–August) of 2007 and 2008. At each plot, bryophyte sampling was conducted along three 20-m transects using the line-intercept method. The line-intercept method has been successfully used for quantitative bryophyte sampling (e.g., Hattaway 1980, Kimmerer 1994), including in spruce-fir forests (e.g., Davis 1964), but it is important to note that due to the extremely small size of some bryophyte species, it is probably impossible to capture the linear cover of every bryophyte shoot that crosses the line, and those small species are likely underrepresented. Transects were systematically positioned at 4 m, 10 m, and 16 m from the higher-elevation end of the plot and laid perpendicular to the slope of the plot to minimize trampling damage. Since transects were placed systematically within randomly located plots, the amount and type of substrate, tree, shrub, and herbaceous canopy cover, and moisture classes encountered were purely by chance. We quantified bryophyte cover by species and substrate along alternate meters of each transect for a total sampling distance of 30 m at each plot. A meter stick was placed on the ground directly under the transect to accurately measure cover when the transect tape lay >10 cm above the ground surface. Our substrate sampling focused on those occurring at ground-level (<50 cm) and was limited to occupied rather than available substrates for most categories. Substrates were assigned to one of 5 classes: (1) rock for stones and boulders (>5 cm diameter); (2) soil for mineral soil, organic soil, and humus; (3) live wood for tree and shrub bases; (4) litter for coniferous litter and fine woody debris (<5 cm diameter); and (5) coarse woody debris (>5 cm diameter). Coarse woody debris (CWD) was further classified as either hard (decay class 1 and 2) or soft (decay class 3, 4, 5) based on Jenkins et al. (2004). We collected bryophyte species which proved difficult to identify in the field, put them in paper envelopes, and brought them to the lab for later identification. Because of the small size of bryophytes, it is common for species identification to involve the use of both dissecting and compound microscopes and thus require significant laboratory time. Specimens were identified by the lead author under guidance of the third author. Particularly difficult specimens and groups were later verified by personnel at the Duke University herbarium and compared with regional collections. Nomenclature follows Stotler and Crandall-Stotler (1977) for liverworts (except for Riccardia jugata Schust., which fol2010 S.E. Stehn, C.R. Webster, J.M. Glime, and M.A. Jenkins 439 lows Hicks 1992) Anderson et al. (1990) for mosses (except for the genus Sphagnum L. which follows Anderson (1990), and Hypnum fauriei Cardot, which follows Schofield et al. [in press]). Bryophyte specimens collected in this study are housed in the Natural History Collection (catalog numbers 104001–104961) of Great Smoky Mountains National Park, Gatlinburg, TN. Results and Discussion Our sampling quantified the distribution of 97 bryophyte species (64 mosses and 33 liverworts) comprising 32 families and 60 genera in sprucefir forests (Appendix 1). The GSMNP species list, which is likely quite comprehensive due to previous descriptive works (Cain and Sharp 1938, Norris 1964, Schofield 1960, Smith 1984) and ongoing All Taxa Biodiversity Inventory (ATBI; Nichols and Langdon 2007) activities, contains 485 species; thus, we can conclude that at least 20% of the bryoflora of GSMNP can be found on ground-level substrates in the spruce-fir zone. Species of note include the globally imperiled liverwort Bazzania nudicaulis A. Evans, which is endemic to spruce-fir forests of the southern Appalachians. We found small amounts of this species at two sites (Appendix 1)—once on a downed dead Fraser Fir and once on rock. However, given that its most frequent habitat is the bark of living Fraser Fir, our sampling design would not necessarily capture its distribution well. The most frequent species were Thuidium delicatulum (Hedw.) Schimp, Tetraphis pellucida Hedw., Brotherella recurvans (Michx.) Fleisch, and Bazzania trilobata (L.) A. Gray found on 58, 54, 53, and 49 of 60 plots, respectively. Our species total is comparable with other studies. Although Cain and Sharp (1938) found 81 mosses and 45 liverworts in their classification of bryophytic unions in GSMNP, the slightly higher number of species in their study can easily be attributed to their inclusion of species throughout the cove hardwood community types. Norris (1964) found 131 mosses and 76 liverworts in a detailed study on the bryoecology of the spruce-fir zone. This high species count likely resulted from his extensive sampling on all substrates (including those on standing live trees) and in all microhabitats, which has been shown to best capture bryophyte diversity (McCune and Lesica 1992, Newmaster et al. 2005). Our sampling inherently included greater sampling distance on the most frequently encountered substrates, but did not make efforts to include all microhabitats. Our species count was higher than the two existing post-adelgid studies, reflective of their focus on single substrates. Smith et al. (1991) found 27 bryophyte species occurring on living Fraser Fir trees, and Choberka (1998) documented 30 bryophytes occurring on downed Fraser Fir logs. Our species list is perhaps best compared to that of Schofield (1960), which focused on variation across the spruce-fir deciduous forest ecotone. 440 Southeastern Naturalist Vol. 9, No. 3 Schofield’s sites captured a variety of canopy conditions due to natural variation with elevation and aspect, whereas we captured this variation as well as that induced by the effects of the BWA. Schofield’s species list included 45 mosses, 11 of which we did not find, though no clear trend in species loss was apparent. We did, however, find several species not reported by Schofield (1960), including some very common mosses such as Hypnum pallescens (Hedw.) P. Beauv. and Rhytidiadelphus triquetrus (Hedw.) Warnst. (found on 27% of our plots) and most notably Dicranodontium denudatum (Brid.) E. Britton, which we found on 65% of our plots. This difference may reflect an increase in dead downed wood availability within spruce-fir forests due to BWA effects since 1960, as we found D. denudatum predominantly on downed wood (68.8% of noted occurrences). Hypnum pallescens was also frequently found on downed wood (85.3% of noted occurrences). Figure 2. Substrate preference of bryophyte groups: a) liverworts and b) mosses. Percent of total group cover found on each substrate is shown. CWD refers to coarse woody debris substrates of any decay class. 2010 S.E. Stehn, C.R. Webster, J.M. Glime, and M.A. Jenkins 441 Although our sampling did not quantify unoccupied substrate availability, our results suggest that bryophytes occupy a variety of substrates along the forest floor in post-adelgid spruce-fir forests. Coniferous litter supported 43.2% of the cover of bryophytes, soil 27.1%, CWD 24.6% (7.5% on decay classes 1 and 2; 17.1% on decay classes 3, 4, and 5), rock 2.8%, and live wood 2.3%. Mosses and liverworts exhibited similar affinities for litter, rock, and live wood, but liverworts displayed a stronger affinity for CWD and mosses displayed a stronger affinity for soil (Fig. 2). Growth form and taxonomic group played a major role in elevation differences among species (Stehn 2009). Substrate availability on the forest floor and substrate preference of individual species (Fig. 3, Appendix 1) may become important drivers of bryophyte community composition and cover as the impacts of BWA-induced canopy opening continue to influence groundlayer conditions. Bryophyte response to another conifer pest, the exotic Adelges tsugae Annand. (Hemlock Woolly Adelgid), which decimates Eastern Hemlock, Figure 3. Individual species substrate preference for all species occurring on ≥100 cm across all sampled substrates. For simplicity, cover on live wood and rock substrates is not included. See Appendix 1 for definitions of species codes. 442 Southeastern Naturalist Vol. 9, No. 3 was catalogued in the northern Appalachians by Cleavitt et al. (2008). The authors conducted pre-infestation surveys and revisited sites 9–11 years after outbreak, documenting a sustained increase in bryophyte species richness and attributing it to an increase of CWD and mineral soil substrate availability. Comparable quantitative pre-BWA ground-layer bryophyte data are unavailable for GSMNP, but we may expect a similar increase in richness to have occurred based on comparisons to Schofield (1960). Given that bryophytes have been positively linked to the regeneration of conifers (McLaren and Janke 1996, Parker et al. 1997, St. Hilaire and Leopold 1995), and that regeneration success of the declining conifers will be important if spruce-fir forests of the southern Appalachians are to persist (e.g., Busing 1996, Johnson and Smith 2005), monitoring the condition of bryophyte communities may be integral to understanding the long-term dynamics of this system. Our results, which quantify ground-layer bryophytes in spruce-fir forests of GSMNP 20–30 years post-adelgid, provide an important baseline for future bryoecology research in this imperiled forest type. Acknowledgments This project was made possible by funding from the Air Resource Division of the National Park Service and the Ecosystem Science Center at Michigan Technological University and by assistance from Student Conservation Association volunteers. 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Science 147:250–260. 2010 S.E. Stehn, C.R. Webster, J.M. Glime, and M.A. Jenkins 447 Appendix 1. Abundance of all species found along ground-layer transects in 60 spruce-fir forest plots within Great Smoky Mountains National Park. Frequency indicates both the number of plots (n = 60) and the number of transect segments (n = 30 at each plot) where the species occurred. CWD = coarse woody debris. % Cover on plot Substrate utilization: when present, Frequency when present % of cover found on each substrate # # (mean CWD CWD Live Phylum/Order/Family Species code Species Plots Seg ± 95% CI) -hard -soft Litter wood Rock Soil Bryophyta Bryales Bryaceae POHLELO Pohlia elongata Hedw. 1 1 0.03 ± 0.00 0 0 0 0 0 100.0 Mniaceae MNIUHOR Mnium hornum Hedw. 2 3 0.18 ± 0.23 18.2 0 0 0 0 81.8 PLAGCIL Plagiomnium ciliare (Müll. Hal.) T. Kop. 7 18 0.37 ± 0.57 3.0 0 1.3 5 0 91.1 RHIZPUN Rhizomnium punctatum (Hedw.) T. Kop. 5 27 0.76 ± 0.70 0 30.4 0 0 0 69.6 Dicranales Dicranaceae DICRHET Dicranella heteromalla (Hedw.) Schimp. 10 20 0.61 ± 0.47 0 21.2 3.8 0 2.2 72.8 DICRASP Dicranodontium asperulum (Mitt.) Broth. 4 16 1.05 ± 1.23 6 0 0 7 65.9 21.4 DICRDEN Dicranodontium denudatum (Brid.) E. Britton 39 182 0.81 ± 0.25 10.8 58 9 1.6 2.4 17.6 DICRFUS Dicranum fuscescens Turner 28 131 0.87 ± 0.43 9.9 29.8 4.6 1.8 1.9 52.0 DICRSCO Dicranum scoparium Hedw. 31 151 1.13 ± 0.49 6.1 22.8 4.7 0.8 2.6 62.9 DICRVIR Dicranum viride (Sull. & Lesq.) Lindb. 1 3 0.60 ± 0. 10 0 0 0 0 0 0 PARALON Paraleucobryum longifolium (Hedw.) Loeske 7 18 0.27 ± 0.16 50.0 17.2 32.8 0 0 0 Leucobryaceae LEUCALB Leucobryum albidum (Brid. ex P. Beauv.) Lindb. 2 6 0.35 ± 0.57 0 0 0 0 0 100.0 LEUCGLA Leucobryum glaucum (Hedw.) Ångstr. 4 12 0.31 ± 0.27 0 0 11 0 0 89.0 Grimmiales Grimmiaceae GRIMMsp Grimmia sp. Hedw. 1 2 0.36 ± 0.0 0 0 0 0 0 0 100.0 Hypnales Brachytheciaceae BRACDIG Brachythecium digastrum Müll. Hal. & Kindb. 1 1 0.13 ± 0.0 0 0 100.0 0 0 0 0 448 Southeastern Naturalist Vol. 9, No. 3 % Cover on plot Substrate utilization: when present, Frequency when present % of cover found on each substrate # # (mean CWD CWD Live Phylum/Order/Family Species code Species Plots Seg ± 95% CI) -hard -soft Litter wood Rock Soil BRACOXY Brachythecium oxycladon (Brid.) A. Jaeger 7 41 1.91 ± 1.78 2.0 0 17.0 0 11.9 69.0 BRACPLU Brachythecium plumosum (Hedw.) Schimp. 3 3 0.34 ± 0.39 0 71.0 0 0 29.0 0 BRACRUT Brachythecium rutabulum (Hedw.) Schimp. 1 1 0.13 ± 0.00 0 0 0 0 100.0 0 BRACHsp Brachythecium sp. Schimp. in B.S.G. 4 17 0.44 ± 0.61 17.0 0 83.0 0 0 0 BRYHGRA Bryhnia graminicolor (Brid.) Grout 1 6 0.90 ± 0.00 0 22.2 77.8 0 0 0 BRYHNOV Bryhnia novae-angliae (Sull. & Lesq.) Grout 10 40 1.23 ± 0.45 0.8 0 40.1 0 0.5 58.5 STEESER Steerecleus serrulatus (Hedw.) H. Rob. 37 163 0.72 ± 0.21 3.9 6.8 82.4 1.6 0.4 5.0 Hylocomiaceae HYLOUMB Hylocomiastrum umbratum (Hedw.) Schimp. 11 34 0.81 ± 0.43 1.5 13.8 32.1 0 0 52.6 HYLOSPL Hylocomium splendens (Hedw.) Schimp. 37 261 3.39 ± 1.13 1.7 0.9 8.6 0 0 88.9 LOESBRE Loeskeobryum brevirostre (Brid.) Fleisch. 11 54 3.08 ± 0.16 2.8 7.1 0.6 0 21.1 68.4 PLEUSCH Pleurozium schreberi (Brid.) Mitt. 7 33 1.97 ± 0.29 0 5.8 1.2 0 0 93.0 RHYTSQU Rhytidiadelphus squarrosus (Hedw.) Warnst. 8 32 1.65 ± 0.06 0 0 19.6 0 17.6 62.8 RHYTTRI Rhytidiadelphus triquetrus (Hedw.) Warnst. 16 74 0.98 ± 0.47 0 0 13.6 0 0 86.4 Hypnaceae CALLHAL Callicladium haldanianum (Grev.) H.A. Crum 1 1 0.30 ± 0.00 0 0 100 0 0 0 HYPNCUR Hypnum curvifolium Hedw. 15 49 1.16 ± 0.49 26.9 44.8 18.9 0.6 7.1 1.7 HYPNFAU Hypnum fauriei Cardot 9 25 0.59 ± 0.33 7.5 26.7 65.8 0 0 0 HYPNIMP Hypnum imponens Hedw. 27 215 2.90 ± 1.16 12.4 33.0 48.2 4.9 1.4 0.1 HYPNPAL Hypnum pallescens (Hedw.) P. Beauv. 16 31 0.42 ± 0.37 31.4 53.9 2 6.9 5.9 0 HYPNPRA Hypnum pratense (Rabenh.) Koch ex Spruce 1 1 0.90 ± 0.00 0 100.0 0 0 0 0 HYPNUsp Hypnum sp. Hedw. 1 3 0.26 ± 0.00 0 0 0 100.0 0 0 ISOPMUE Isopterygiopsis muelleriana Schimp.) Z. Iwats. 1 1 0.10 ± 0.00 0 0 0 0 100 0 ISOPTEN Isopterygium tenerum (Sw.) Mitt. 7 16 0.49 ± 0.18 10.6 14.4 22.1 21.2 12.5 19.2 PLATREP Platygyrium repens (Brid.) Schimp. 6 13 0.37 ± 0.14 50.7 29.9 0 4.5 14.9 0 PSEUELE Pseudotaxiphyllum elegans (Brid.) Z. Iwats. 6 18 0.52 ± 0.27 0 14.9 39.4 0 25.5 20.2 PTILCRI Ptilium crista-castrensis (Hedw.) De Not. 15 40 1.14 ± 0.96 0 6.2 4.3 0 5.4 84.1 PYLAPOL Pylaisiella polyantha (Hedw.) Grout 12 14 0.24 ± 0.10 64 11.2 24.7 0 0 0 PYLASEL Pylaisiella selwynii (Kindb.) H.A. Crum, Steere 1 1 0.20 ± 0.00 0 0 100.0 0 0 0 & L.E. Anderson 2010 S.E. Stehn, C.R. Webster, J.M. Glime, and M.A. Jenkins 449 % Cover on plot Substrate utilization: when present, Frequency when present % of cover found on each substrate # # (mean CWD CWD Live Phylum/Order/Family Species code Species Plots Seg ± 95% CI) -hard -soft Litter wood Rock Soil Plagiotheciaceae PLAGCAV Plagiothecium cavifolium (Brid.) Z. Iwats. 11 49 0.68 ± 0.39 0 4.0 67.0 3.5 12.0 12.8 PLAGDEN Plagiothecium denticulatum (Hedw.) Schimp. 1 2 0.13 ± 0.00 0 100.0 0 0 0 0 PLAGLAE Plagiothecium laetum Schimp. 20 50 0.28 ± 0.12 1.2 7.1 69.6 10.1 6.5 5.4 Sematophyllaceae BROTREC Brotherella recurvans (Michx.) Fleisch. 53 789 5.65 ± 1.02 9.5 21.7 62.7 4.6 1.3 0.2 HETEAFF Heterophyllium affine (Hook.) Fleisch. 12 24 0.59 ± 0.45 53.3 31.3 11.2 0 0 4.2 PYLATEN Pylaisiadelpha tenuirostris (Bruch & Schimp.) 8 19 0.42 ± 0.23 4.0 18.0 59.4 9 10 0 W.R. Buck SEMAADN Sematophyllum adnatum (Michx.) E. Britton 1 4 0.66 ± 0.00 70.0 30.0 0 0 0 0 SEMADEM Sematophyllum demissum (Wilson) Mitt. 2 2 0.48 ± 0.16 0 0 0 0 100.0 0 Thuidiaceae THUIDEL Thuidium delicatulum (Hedw.) Schimp. 58 665 4.62 ± 1.21 3.9 3.4 86.5 1.8 2.0 2.3 Leucodontales Anomodontaceae ANOMROS Anomodon rostratus (Hedw.) Schimp. 1 1 0.30 ± 0.00 0 0 0 0 100 0 Leucodontaceae LEUCBRA Leucodon brachypus Brid. 1 4 2.16 ± 0 10 0 0 0 0 0 0 Orthotrichales Orthotrichaceae ORTHOsp Orthotrichum sp. Hedw. 1 1 0.13 ± 0 10 0 0 0 0 0 0 ORTHSTE Orthotrichum stellatum Brid. 1 1 0.20 ± 0.00 0 100.0 0 0 0 0 Polytrichales Polytrichaceae ATRICRI Atrichum crispum (James) Sull. 7 14 0.19 ± 0.21 0 2.4 4.9 0 0 92.7 ATRIOER Atrichum oerstedianum (Mull. Hal.) Mitt. 12 30 0.68 ± 0.35 0 0 16.2 0 0 83.8 POLYPAL Polytrichum pallidisetum Funck 41 226 2.49 ± 1.17 0.8 6.9 1.7 1.4 0 89.1 450 Southeastern Naturalist Vol. 9, No. 3 % Cover on plot Substrate utilization: when present, Frequency when present % of cover found on each substrate # # (mean CWD CWD Live Phylum/Order/Family Species code Species Plots Seg ± 95% CI) -hard -soft Litter wood Rock Soil Sphagnales Sphagnaceae SPHACAP Sphagnum capillifolium (Ehrh.) Hedw. 1 5 0.86 ± 0.00 0 0 0 0 0 100.0 SPHAGIR Sphagnum girgensohnii Russow 4 34 8.40 ± 12.07 0 0 0 0 0 100.0 SPHAQUI Sphagnum quinquefarium (Lindb. ex Braithw.) 1 5 1.50 ± 0.00 0 0 0 0 0 100.0 Warnst. SPHAGsp Sphagnum sp. L. 1 3 0.70 ± 0.00 0 0 0 0 0 100.0 SPHASQU Sphagnum squarrosum Crome 1 2 0.16 ± 0.00 0 0 0 0 0 100.0 Tetraphidales Tetraphidaceae TETRPEL Tetraphis pellucida Hedw. 54 280 0.86 ± 0.18 9.3 54.8 22.9 4.0 2.9 6.1 Hepatophyta Jungermanniales Calypogeiaceae CALYMUE Calypogeia muelleriana (Schiffn.) Müll. Frib. 11 20 0.46 ± 0.35 1.9 4.5 56.1 1.9 7.1 28.4 CALYNEE Calypogeia neesiana (C. Massal. & Carestia) 1 1 0.030± 0.00 0 100.0 0 0 0 0 Müll. Frib. CEPHBIC Cephalozia bicuspidata (L.) Dum. 4 5 0.18 ± 0.12 0 31.8 59.1 0 0 9.1 CEPHLUN Cephalozia lunulifolia (Dum.) Dum. 16 33 0.29 ± 0.14 13.0 41.8 30.5 4.0 5.7 5.0 CEPHAsp Cephalozia sp. (Dum. emend. Schiffn.) Dum. 9 17 0.25 ± 0.12 0 75.0 16.2 0 4.0 4.4 NOWECUR Nowellia curvifolia (Dicks.) Mitt. 45 196 1.12 ± 0.29 35.4 63.7 0.6 0 0.3 0.1 Cephaloziellaceae CEPHRUB Cephaloziella rubella (Nees) Warnst. 1 2 0.13 ± 0.00 0 0 100 0 0 0 Geocalycaceae CHILPOL Chiloscyphus polyanthos (L.) Corda 1 1 0.16 ± 0.00 0 0 0 0 0 100.0 LOPHHET Lophocolea heterophylla (= Chiloscyphus 2 2 0.05 ± 0.02 0 0 100.0 0 0 0 profundus) (Schrad.) Dumort. Herbertaceae HERBADU Herbertus aduncus (Dicks.) A. Gray 2 2 0.08 ± 0.02 0 0 40.0 0 60.0 0 2010 S.E. Stehn, C.R. Webster, J.M. Glime, and M.A. Jenkins 451 % Cover on plot Substrate utilization: when present, Frequency when present % of cover found on each substrate # # (mean CWD CWD Live Phylum/Order/Family Species code Species Plots Seg ± 95% CI) -hard -soft Litter wood Rock Soil Jubulaceae FRULTAM Frullania tamarisci (Linnaeus) Dum. Dum. 9 12 0.21 ± 0.12 80.7 7.0 1.8 10.5 0 0 Jungermanniaceae ANASHEL Anastrophyllum hellerianum (Nees) R.M. Schust. 2 5 0.18 ± 0.02 45.5 45.5 9.1 0 0 0 ANASMIC Anastrophyllum michauxii (F. Weber) H. Buch ex 7 21 0.73 ± 0.76 37.0 45.5 0 0 0 17.5 A. Evans ANASSAX Anastrophyllum saxicola (Schrad.) R.M. Schust. 1 2 0.60 ± 0.00 0 0 0 0 100.0 0 JAMEAUT Jamesoniella autumnalis (DC.) Steph. 10 24 0.35 ± 0.16 23.6 43.4 17.9 7.5 1.9 5.7 LOPHINC Lophozia incisa (Schrad.) Dum. 4 5 0.11 ± 0.08 14.3 85.7 0 0 0 0 LOPHOsp Lophozia sp. (Dum.) Dum. 2 2 0.08 ± 0.10 0 100.0 0 0 0 0 TRITEXS Tritomaria exsecta (Schrad.) Loeske 4 6 0.35 ± 0.45 0 81.0 7.1 11.9 0 0 Lejeuneaceae LEJELAM Lejeunea lamacerina (Steph.) Schiffn. 2 3 0.08 ± 0.10 0 0 20.0 0 80.0 0 Lepidoziaceae BAZZDEN Bazzania denudata (Torr. ex Gottsche. & Lindenb. 4 6 0.22 ± 0.16 0 0 37.0 48.0 14.8 0 & Nees) Trevis BAZZNUD Bazzania nudicaulis A. Evans 2 3 0.31 ± 0.10 42.1 15.8 0 0 42.1 0 BAZTRIC Bazzania tricrenata (Wahlenb.) Lindb. 2 2 0.20 ± 0.27 0 0 0 0 100.0 0 BAZTRIL Bazzania trilobata (L.) A. Gray 49 333 2.99 ± 1.64 4.2 13.2 74.2 1.3 0.1 7 LEPIREP Lepidozia reptans (L.) Dum. 36 120 0.55 ± 0.27 7.7 28.5 48.5 5.4 1.9 8.1 Pseudolepicoleaceae BLEPTRI Blepharostoma trichophyllum (L.) Dum. 11 24 0.29 ± 0.18 11.2 20.4 23.5 25.5 13.3 6.1 Radulaceae RADUTEN Radula tenax Lindb. 1 1 0.10 ± 0.00 0 0 0 0 100.0 0 Scapaniaceae SCAPNEM Scapania nemorea (L.) Dum. 11 30 0.54 ± 0.23 5.6 7.3 8.4 0 62.6 16.2 SCAPUND Scapania undulata (L.) Dum. 1 1 0.23 ± 0.00 0 0 0 0 0 100.0 Metzgeriales Aneuraceae RICCJUG Riccardia jugata R.M. Schust. 1 1 0.23 ± 0.00 0 100.0 0 0 0 0 452 Southeastern Naturalist Vol. 9, No. 3 % Cover on plot Substrate utilization: when present, Frequency when present % of cover found on each substrate # # (mean CWD CWD Live Phylum/Order/Family Species code Species Plots Seg ± 95% CI) -hard -soft Litter wood Rock Soil RICCPAL Riccardia palmata (Hedw.) Carruth. 2 2 0.05 ± 0.02 0 66.7 33.3 0 0 0 Metzgeriaceae METZCRA Metzgeria crassipilis (Lindb.) A. Evans 1 1 0.06 ± 0.00 100.0 0 0 0 0 0 METZFUR Metzgeria furcata (L.) Dum. 1 1 0.13 ± 0.00 0 0 0 0 100.0 0 Pallaviciniaceae PALLLYE Pallavicinia lyellii (Hook.) Carruth. 1 1 0.10 ± 0.00 0 0 100.0 0 0 0