Disjunct Occurrence of Harpanthus drummondii (Taylor) Grolle (Geocalycaceae, Jungermanniopsida) in the Boreal Forest of West-Central Canada Author(s): Richard T. Caners Source: Evansia, 30(1):24-30. 2013. Published By: The American Bryological and Lichenological Society, Inc. DOI: http://dx.doi.org/10.1639/079.030.0104 URL: http://www.bioone.org/doi/full/10.1639/079.030.0104 BioOne (www.bioone.org) is a nonprofit, online aggregation of core research in the biological, ecological, and environmental sciences. BioOne provides a sustainable online platform for over 170 journals and books published by nonprofit societies, associations, museums, institutions, and presses. Your use of this PDF, the BioOne Web site, and all posted and associated content indicates your acceptance of BioOne’s Terms of Use, available at www.bioone.org/page/ terms_of_use. Usage of BioOne content is strictly limited to personal, educational, and non-commercial use. Commercial inquiries or rights and permissions requests should be directed to the individual publisher as copyright holder. BioOne sees sustainable scholarly publishing as an inherently collaborative enterprise connecting authors, nonprofit publishers, academic institutions, research libraries, and research funders in the common goal of maximizing access to critical research. Evansia 30(1) 24 Disjunct occurrence of Harpanthus drummondii (Taylor) Grolle (Geocalycaceae, Jungermanniopsida) in the boreal forest of west-central Canada Richard T. Caners Alberta Biodiversity Monitoring Institute Royal Alberta Museum, Edmonton, Alberta T5N 0M6, Canada Email: [email protected] Abstract: The liverwort Harpanthus drummondii (Taylor) Grolle (Geocalycaceae, Jungermanniopsida) is known mostly from temperate regions of eastern North America where it is restricted to dead wood in forests. Recently, the species was discovered in the boreal forest of west-central Canada, demonstrating a substantial disjunction from the next closest known occurrence. A distribution map is provided along with features that distinguish it from the closely related H. scutatus (F.Weber & D.Mohr) Spruce. Key Words: Boreal forest, dead wood, epixylic, Harpanthus scutatus, liverwort, phytogeography The liverwort Harpanthus drummondii (Taylor) Grolle (Geocalycaceae, Jungermanniopsida) was recently documented in west-central Canada, in the boreal mixedwood forest of northwestern Alberta. The species is known from a limited number of occurrences in eastern North America where it is restricted to dead wood in forests (Grolle 1965; Schuster 1980; Crum 1991; N. Miller, pers. comm., 8 Feb 2010). The species can be found in both conifer and broadleaf forests, and also in mixed broadleaf-conifer stands such as Acer saccharum Marshall (sugar maple) – Fagus grandifolia Ehrh. (American beech) – Tsuga canadensis (L.) Carrière (eastern hemlock) forest (N. Miller, pers. comm., 8 Feb 2010). Based on collections from a number of North American herbaria, the species has been recorded in Canada from N.B., Ont., and Que., and in the United States from Ky., Mass., Mich., N.C., N.H., N.Y., Pa., Vt., Wis., and W.Va. (Hicks and Davison 1989; Schafale and Weakley 1990; Crum 1991; Faubert 2007; Faubert et al. 2010; Consortium of North American Bryophyte Herbaria 2012; Global Biodiversity Information Facility 2012) (Figure 1). The species has also been recorded in the United States from Conn., S.C., and Va. (Schuster 1980). Schuster (1980) indicated the species had not been reported elsewhere worldwide but suggested that specimens of the closely related H. scutatus (F.Weber & D.Mohr) Spruce in Japan may in fact be H. drummondii. More recently, H. drummondii has been reported from the boreal forest of Russian Siberia (Bakalin et al. 2001). The occurrence of the species in western Canada is an intriguing and notable disjunction from the relatively conterminous distribution in eastern North America. The next closest record of Harpanthus drummondii in relation to the collection from Alberta, is more than 2100 km to the southeast along the southwestern shore of Lake Superior in Michigan (NYBG 254570). This record is from a collection made by L. S. Cheney in 1896. Apart from that historic collection the next closest record was more recently documented by J. Crowe in 1970 (LKHD 79100, 79101) from the Thunder Bay District of Ontario. Given that the species is being reported here for the first time in Alberta (Alberta Conservation Information Management System 2012), and that this represents a substantial range extension, a detailed account of the occurrence is provided. Harpanthus drummondii is closely related to H. scutatus and collections of these two species can be difficult if not impossible to name when lacking diagnostic features (Schuster 1980; N. Miller, pers. comm., 8 Feb 2010). Both species are considered uncommon with H. scutatus supposedly being less frequent in eastern North America than H. drummondii (Schuster 1980; N. Miller, pers. comm., 8 Feb 2010). The two species were recognized as taxonomically distinct by Grolle (1965) who was the first to Evansia 30(1) 25 Figure 1. Distribution of Harpanthus drummondii in North America. Specimen locations are based on collections from the following herbaria: ALTA, BH, CANM, DUKE, F, GH, LKHD, MICH, MO, NBM, NYBG, NYS, QFA, QK, TRT, UBC, UNAF, and WIN (herbarium abbreviations based on Thiers 2012), and from Schuster (1980). A few specimens lacked detailed location information and could only be mapped at the county level within a state or province. Map created by SimpleMappr (Shorthouse 2010). publish on this hepatic in North America. The main feature that distinguishes these species is the production of gemmae from the apices of erect, gradually attenuated shoots in H. drummondii that are lacking in H. scutatus. In H. scutatus, gemmae are always produced from short, ventral intercalary branches (Schuster 1980). In addition, Harpanthus drummondii differs in having the following gametophytic characters (Schuster 1980): plants very small (600)800‒1025 μm wide; leaves typically flat, laterally somewhat patent, little concave, and oblong-ovate to ovate, 560‒660(680) μm long × 500 ‒590(630) μm wide, and nearly symmetrical, with antical and postical margins subequal in length and subequally arched; weaker trigones; and oil bodies usually 2‒4 per cell. H. scutatus, in comparison, has larger plants, 1000‒1250 μm wide; leaves laterally patent to more commonly antically secund, somewhat concave, obliquely broadly ovate-orbicular to ovate-oblong, (450)600‒785 μm long × (400)650 ‒765 μm wide; both leaf margins somewhat convex, with the dorsal margin longer than the ventral and decurrent; cells with conspicuous to bulging, large trigones; and oil bodies (2)3‒5(7) to (3)5‒11(12‒14) per cell. Further, H. drummondii is apparently restricted to moist, decorticated logs, and is often found in association with other mesophytic epixylic liverworts (Muhle and LeBlanc 1975; Schuster 1980; N. Miller, pers. comm., 8 Feb 2010). H. scutatus is most frequent at damp-to-wet sites on rocks, or moist peaty soil on poorly drained slopes, and Evansia 30(1) 26 is rarely found on decaying logs (Schuster 1980; N. Miller, pers. comm., 8 Feb 2010). Despite these differences, Schuster (1980, P293) indicates that H. drummondii and H. scutatus may be inseparable as species, with H. drummondii merely representing a weak epixylic form of H. scutatus. In this study, Harpanthus drummondii was collected at the Ecosystem Management Emulating Natural Disturbance (EMEND) research site in northwestern Alberta (Figure 2; centered on 56° 46' 13'' N, 118° 22' 28'' W). The collection was made on 13 July 2005 and then subsequently identified in November 2008. The EMEND experiment is located within the Lower Boreal Highlands Natural Subregion of the Boreal Forest Natural Region in Alberta (Natural Regions Committee 2006) (http://www.emend.rr.ualberta.ca). The subregion covers 55615 km2 in the province (15% of Boreal Forest Natural Region) and ranges in elevation from 400–1050 m a.s.l. (Natural Regions Committee 2006). Climate is continental with cold winters (mean January –20.0 °C) and short, warm summers (mean July 15.0 °C), with a mean annual frost free period of 97 days. Total mean annual precipitation in the subregion is 495 mm, with 334 mm falling as rain. Within the study area forests are variously dominated by Populus tremuloides Michx. (trembling aspen), P. balsamifera L. (balsam poplar), and Picea glauca (Moench) Voss (white spruce), with lower abundances of Picea mariana (Mill.) Britton, Sterns & Poggenb. (black spruce), Abies balsamea (L.) Mill. (balsam fir), Pinus contorta Douglas ex Loudon (lodgepole pine), and Betula papyrifera Marshall (paper birch). Harpanthus drummondii was documented at EMEND within a single forest stand that had been experimentally harvested during the winter of 1998/1999 with 10% of the canopy retained as dispersed green-tree retention (Figure 3). The stand had a mean elevation of 813 m a.s.l. and was classified before harvest as a "white spruce/green alder (Alnus viridis ssp. crispa [Aiton] Turrill)" plant community type within the "white spruce/low-bush cranberry (Viburnum edule [Michx.] Raf.)" ecosite phase (e4.1, Beckingham et al. 1996; EMEND core data). At the time of collection the forest canopy was dominated by white spruce, with lower abundances of trembling aspen, balsam poplar, and paper birch. Within this forest stand a single population of H. Figure 2. Location of the EMEND research site (filled drummondii with