LIVERWORTS OF PEATLANDS AND TEPUALIA STIPULARIS (HOOK. & ARN.) GRISEB. SWAMP FORESTS IN ISLA GRANDE DE CHILOÉ (CHILE): KEY FOR IDENTIFICATION Hepáticas de las turberas y bosques pantanosos de Tepualia stipularis (Hook. & Arn.) Griseb. de la Isla Grande de Chiloé (Chile): clave para la identificac

Bryophytes play a key role in peatland ecosystems; they participate directly in the constitution of peat and in the maintenance of these ecosystems. Nevertheless, the knowledge of this group is highly limited, specifically for liverworts. Therefore, we present a key to determine liverworts, restricted to peatland habitats and swamp forests of Tepualia stipularis (Hook. & Arn.) Griseb. of Isla Grande de Chiloé (Chile). This key includes the main reported taxa for these ecosystems and it is based on vegetative characters to facilitate identification. Fifty-two species and 28 genera are included. These taxa belong to 19 families. The best represented families are: Lepidoziaceae, Lophocoleaceae, Plagiochilaceae, and Aneuraceae. Chiloscyphus, Plagiochila, and Riccardia are the richest genera. A separate key for each group with similar characters and alphabetical taxa list are provided.


INTRODUCTION
Bryophytes form an important part of peatland ecosystems.Peat is often made up largely of bryophyte biomass, and 90-100% of the ground layer is usually covered by bryophytes (Vitt & Belland 1995).Nevertheless, this group is poorly known and rarely included in floristic and vegetation studies because they are difficult to sample and identify.The knowledge of Chilean bryophyte flora is highly limited.Normally, this botanical group is not considered in studies of flora and vegetation.Thus, bryophytes are not included in the Red Book of Chilean Terrestrial Flora (Benoit 1989).
Field identification of bryophytes is generally difficult, as it requires the examination of microscopic characters and time-consuming work in the laboratory.Moreover, the identification of Chilean liverwort flora is fraught with difficulty due to the sparseness of recent taxonomic literature.Hässel de Menéndez & Rubies (2009) published a Catalogue of the Marchantiophyta and Anthocerotophyta; nevertheless, Chile does not have a national compilation work of liverwort flora yet.The closest monographic work is Cryptogamic Flora of Tierra del Fuego (Hässel de Menéndez & Solari 1976) but unfortunately it only includes a few orders and families.In addition, there are only a few works that include keys for determination of species, e.g., Hepaticae of Brunswick Peninsula (Engel 1978).An alternative way to determine Chilean specimens is to use exotic works, such as: New Zealand flora (Engel & Glenny 2008), Latin-American floras (Gradstein et al. 2001, Gradstein & Pinheiro da Costa 2003), compilations of Southern Hemisphere species (Schuster 2000, Schuster 2002) or monographic papers (Fulford 1963, Fulford 1966, Fulford 1968, Fulford 1976).However, these works only consider some species and genera.
In Chiloé, peatlands and Tepualia stipularis (Hook.& Arn.) Griseb.forests are closely related by their bryophyte floras (Villagrán & Barrera 2002, Villagrán et al. 2003, Villagrán et al. 2002, Villagrán et al. 2005) and their origins (Díaz et al. 2007, Díaz et al. 2008, Zegers et al. 2006).During the fieldwork of floristic and ecological research in Sphagnum peatlands and Tepualia forests of Isla Grande de Chiloé (Chile), bryophytes were collected and studied.In that work, bryo-lichenic flora was described and compared, finding that these ecosystems are related but have differences in their compositions (León 2012).As a complement of that study, we present a key to determine liverworts, restricted to peatland habitats and swamp forests of Tepualia stipularis (Hook.& Arn.) Griseb. of Isla Grande de Chiloé (Chile).The aims of this work are to increase the knowledge of local bryophyte flora and to facilitate the identification of these plants.

Study area
The study area is located in the Isla Grande de Chiloé, Región de Los Lagos, Chile (42°-43° S and 73°-75°W).The prevailing climate is wet temperate with a strong oceanic influence (di Castri & Hajek 1976).The total annual rainfall is about 2,300 mm (CONAF 2009), reaching 5,000 -6,000 mm in some areas, with a mean summer temperature of 10.2ºC and a mean winter temperature of 6.2ºC (Pérez et al. 2003).
The vegetation of Chiloé Island has a mixed composition of broad-leaved evergreen rain forests and it mainly belongs to the North Patagonian and Valdivian forests.North Patagonian forest type is floristically defined by the dominance of shade-tolerant conifers (Podocarpaceae), in addition to Drimys winteri J.R. Forst.& G. Forst.and Nothofagus nitida (Phil.)Krasser in the main canopy, and together with Tepualia stipularis and other Myrtaceae tree species in the understory.Valdivian forests are generally dominated by a different set of broad-leaved evergreen tree species, such as Eucryphia cordifolia Cav. and Aextoxicon punctatum Ruiz & Pav., and several Myrtaceae species in the main canopy and subcanopy (Armesto et al. 1996, Donoso 1993, Gutiérrez et al. 2009).Nevertheless, the rural landscapes of Chiloé Island are also composed by shrublands, secondary forests, plantations of exotic tree species, anthropogenic grasslands, peatlands, and swamp forests.We studied ten sites located in the northern and central parts of the island.Two kinds of Sphagnum peatlands were studied, which were defined according to their origin and their characteristic vegetation (Díaz et al. 2008).The three study areas representing the glaciogenic peatland (GP) type were: Río Negro, Los Caulles, and Púlpito; and the five study areas representing the anthropogenic peatland (AP) were: Senda Darwin, Lecam, Pumanzano, Río Chepu and Teguel.In addition, two sites of Tepualia forest were sampled, Parque Nacional Chiloé and another area of Senda Darwin.

RESULTS
The key presented below is based on vegetative characters to facilitate the identification.Fifty-two species and 28 genera are included.
In Chiloé, the most abundant peatlands are dominated by lax cushions of Sphagnum moss.In general, these cushions are associated with other bryophytes and lichens, also, with sedges (Carex magellanica Lam. and Oreobolus obtusangulus Gaudich.), rushes (Juncus procerus E. Mey., J. stipulatus