Prelinlinary survey of the mosses ( Bryophytaj from Los Glaciares National Park , Santa Cruz Province , Argentina

The main moss commiii~ities from Los Glaciares National Park, province of Santa Crua, Argentina, occurring in var'ious types of vascular vegetation, are described. The 6iirvey included different cold temperate h'othofogus Coresi types to the west, evergreen, su~nmergreen, and mixed forests, and the shrub steppe to the east. An alphabetical list of the studied spocies, as well as representative specimens and notes on habitat and suhtrata, are presented. Among the material collected, 111 species and two varieties were recognized, 42 of which arc new records for the prorincc oESonta C m z .

A comprehensive moss collection, as well as detailed field observations on distribution and composition of the moss communities were carried out by the authors during three summer seasons, 1987/88!90, within the limits of National Park Los Glaciares (Fig. 1).Survey included dii' ferent cold temperate Nothofkgus fbrest types and the shrub steppe.The Park is situated in the southwest of Santa Cruz province, and extends over ca.600,000 hectares.I t was created in 1937, and it also contains a World Heritage Site since 1981.
In southern Patagonia, Santa Cruz moss vegetation is virtually unknown perhaps with the sole exception of the lands between 51' -62" latitude, which were explored by the authors on previous projects (Matteri, 1985(Matteri, , 1986)).Historically, only three moss species among Per Dusiin's collections fall within this Park (Dusen, 1906), whereas Carl Skottsberg collected a dozen moss species strictly North of the region (Cardot & Rrotherus, 1923).The important contribution of mosses to the forest vegetation in the area has been reported by several botanists, nonbryologists, suchas Skottsberg (1916Skottsberg ( , 1921)), Piirez Moreau (1959Moreau ( ,1962) ) and Pisano & Dimitri (1973), including the incidental mention of some common mosses.
The aim of this study is to provide a preliminary floristic assessment of the moss flora of the area surveyed.Still, a number of moss collections remain unidentified and a complete systcmatic report will be presented elsewhere.Nevertheless, a general account can be anticipated of the major moss habitats recognised so far at the vegetation types referred to above, as well as information on the role played by different moss communities in different habitats.

THE LAND
The area currently studied lies in the southwestern upper corner of Santa Cruz province, between 50Qand 50e 4 0 ' s latitude, within the weilknown Continental Ice Region (Fig. 1).Lago Argentino, a typical Andean lake, running eastward to the Atlantic Ocean through the Santa Cruz River, dominates the landscape.The western end of the lake runs far into the Preandean Mountains by way of' two bigger arms, which in turn, open out into countless channels and small fiordlike inlets receiving extensive glaciers from the western Ice Sheets.The investigated forests fall entirely along the western border of National Park Los Glaciares where high rounded mountains attain 2000-2300 m a.s.l., just East of the main Andean chain.
Due t o the broken nature of t h e terrain Nothofagus trees ("beech"!do not form large forested areas but limited thickets in sheltered valleys and flanking glaciers, on gentle slopes from lake level (185 m a.s.1.)to estimated 1000-1100 m  1. (PBrea Moreau, 19593.Inland vegetation is often split by the occurrence of small glacial lakes with ice-blocks adrift, high cliffs with waterfalls, flooded areas, free morraines and swift-running rivulets.The land is wind-swept by dominant western wet winds and the annual rainfail is roughly estimated around 1500-2000 mm (Pbrez Moreau, 1959, Schwerdtfeger, 1976).
Alongthe eastern limits of the Park, from Mt. Fitz Roy (49V17' 8-73"s' W) southward, to the vicinity of Glacier Frias (50W42' S-T3WW), scattered and open forest stands Dve way to the shrubsteppe district.Low mean annual rainfall (200 -300 mm) and desiccating winds determine the dryness of soil and inlpoverishing of the vegetation on this fringe, mostly situated in lowlands, at 200 -400 m a.s.1.

THE VEGETATION
Despite the presence of the sumrnergreen Nothofaguspumilio ("lenga") forests ail over this region, several different ibrest types can be distinguished rrlainly when cryptogamic vegetation is being considered.Following rnost closely the vegetation analysis made by Pisano & Diiiiitri (1973), moss fieldwork was centred around stands of pure summergreen N pumilio, evergreen associations of N betuloides ( " y i n d o " ~ with Drimnys winteri ("canelo") and on mixed stands of snmmergreen-evergreen A70thojagus.Forest stands were selected amongst mature undisturbed communities with no evidence of logging or other human activities.
The shrub steppe, on its north-south course, follows approximately 73'W longitude, and on this ca.300 krn transect it crosses tile western half of both lakes, Viedma on the North, and Argentirio on the South.I t is mostly cbaracteriscd by xerophyte vegetation, together with grassy prairies and mesophyte elements from western sectors.
These forest stands develop from lake level to nearly 600 m as.)., on Iow-lying areas or gently sloping valleys among glaciers.Trees are well developed but the open canopy determines a most iuminous forest with tile floor covered with litter among big boulders and few rotten logs.In the shrub layer Ma.vten~~s magellanica is a common element together with Berberis buxzfolia (Fig. 2) and M.yoschilos oblongam.m e r e a s , Embothrium coccineum is frequent in coastal sites.The forest floor is sparsely covered by Viola macz~lata, Blechnum penna-marina, Acaena oualifolia and in marshy areas by Gunnera magellanica and Escalloniu uirgata (Fig. 3 ) .Empetrum rubrum, in turn, forms continuous bushes on forest floor in  Richest moss habitats in these forests are by Ihr represented by boulders, high cliffs and living tree trunks in this order, with floor con~munities less abundant.A striking saxicolous moss cover, together with filmy ferns and many lichens, forms at times such a thick carpet over everything that it masks the true nature of ilie substratum.This feature was particularly observed in forest stands at Bahia Onelli where the hanging moss carpets are usually dripping water.The communities are mainly composed of showy rriosscs with weft life forms such as Leptodon smithii, Neckera chilensis, Stenomitri~lm pentastichum and tall turfs of Eustichia longirostris, Bartramin halleriana, B. ith.yphyllu~, etc. Elidden and nesting among them, there are smooth mats of the tinyiibbronia ciliaris intcrwoven with Synlrichia anderssonii (Fig. 4), and short turfs of various species of Encalypta, Philonotis nigroflaua, P scabrifolia, Catagonium nitens wr.rn,yurum, Plagiothecium oualifoliunz and Bartramia patens, among others.Curiously, the giant Leptostomum menziesii believed to be a strict epiphyte, is growing abundantly on scattered boulders and even small colonies could also he found on the floor its turfs are often so dense that no other plant grows int,ermixed.
Vertical walls behind waterfalls show a particularly dense moss layer composed of a few hygrophylous species of the large-cushion life form such as Breutelia inlegrifolia, Distichophyllum kraussei, Fissidens rigidulw and Eurhynchium fuegianz~m.A few nieters from t h e main waterspray, tall turfs of Pyrrhobr.yummnioides arid Entosthodon laxus are plentiful.
Epiphytic moss communities in Nothofagus pumilio forests are a180 conspicuous on bark of trees and shrubs.Luxuriant bushy rough mats of Lepyrodon lagurus, L. tomentosus, Acrocladium auriculatum, together with abundant tall turfs of Fruiting Leptoslomum menziesii, small cushions of Ulota spp.and Ca1,yptopogon mnioides carpeted tree trunks to over 1.5 -2 m of their length.Rough mats of Brachythecium paradoxam were only present covering tree bases and roots, at times associated with Leptotheca gaudichaudii.
Nthough considerable litter occurs on the forest floor, moss communities are notably sparse.This forest floor is typically recognised by the presence of two dominant mosses.One is S,yntrichia robusta (Fig 5), a large plant, orangc.green in colour with an intriguing life form.I t grows as an unbroken loose weft, with prostrate and erect stems little attached to the substratum, struggling and intertwining with every other plant or seedling found on i t s way.T h e second one is Rosulabryurnperlimbatum (Fig. 5), a former rarity, less frequent than the other but equally common.It forms definite rounded and tough communities of the tall-turf life form, thickly matted with tomentum.
Polytrichaceous mosses in this region are less abundant as compared to Fuegian moss vegetation (Matteri & Schiavone, 1988).However, as ground dwellers they are often found in medium sized colonies on fiat forest floor or gentle eroded slopes.In this situation Polytrichnmjuniperinum and P piliferum (Fig. 6 ) a r e common while Polyirichadelphus magellanicus is rarer, all of which form tall hard turfs.Associated with them we find Platyneurumpraealtum and rough mats of Brach.ytheciumsubpilosum.
In places where the low lying terrain becomes wet and marshy Nothofagus pumilio almost disappears and gives way to scattered stunted and crooked N. antarctica, the rustic "fiire."However, not strictly a forest habitat these marshes contain a rich hygrophylous moss flora intermixed with Cyperaceae and Gunnera magellanica, Blechum penna-marina and Berberis buxifolia.Here, we find lax tall turfs of the pearl colour Racoinitrium lanuginosum (Fig 7 ) and the golden Codriophorus Laeuigatus (Fig. 8) growing a t their best, together with Orthotheciella varia on small stumps, Pohlia wahlenhergii, Bryum laeuigatum, Dicranella cardotii, and the bushy Breutelia angustiretis (Fig. 10).

ii. Evergreen Forest Moss Communities
Pure stands of evergreen trees such as t,hose of Southeastern Fuegia or western Magallanes, are infrequent in this region.Some limited stands may be found on western inlets ofthe central part of Lago Argentina, extending over gentle slopes for 200 m above the lake level.Well developed copses were investigated mainly a t the southern end of Seno Mayo (50' 22' S, 73Ql6'W), just facing Mayo Glacier and to a less extent, in the vicinity of Bahia Canario (50' 26' S, 73V2'W) on the western shore of Canal de 10s Ternpanos (Fig. 1).The dominating tree is Nothofigus betuloides, associated with I1rim.y~winteri as a lower element.The understory contains as predominant members Pseudopanax laeteuirens and Maytenus magellanica.The littoral fringe of this association shows a thick shrub layer mainly composed of Berberis buxifolia and PeFnett,ya mucronata, often mixed with Escallonia ruhra and Fuch,sia magellanica.The fbrest floor is densely littered, with many rotten logs and sparsely distributed are i,uzuriaga marginata, Blechnum penna-man n a an$l,ebeta~zthz~s myrsiniles.mossco communities are sparsely distributed on thi's s h a e forest floor, densely on rotten logs, and also up, to 2 m on livirig trees.A particularly iriteresting moss habitat is represented by clearings in the forest canopy with a thick graminaceous floor layer.In this situation, the most common floor colonies in the forest are of the loose weft 1iEe form as inPtychomnion cygniselum and of the rounded tall lax turfs such as Dicranoloma robustam, D. hariotii, (2oniobryum subbasilare, 131at.yneurumpraealtum, and a couple of species of Tayloria.Extensive patches of the handsome Pol.~trichastrum longisetum (Fig. 9) grow intermixed with Le]~lodontium longicaule var.microruncinatum, Breuteliaplicata and again, hut infrequently, S.yntrichia robusta (Fig. 5).
Still solid rotten logs in tile forest are colonised by thick carpets of liverworts, licheris and mosses.Among the latter there are short loose wefts of Pt,ychomnion c.ygniseturn, a common ground dweller, Ulota spp., Orthodontium lineare, the little and former rarity Sauloma tenella, with rough m a t s of t h e weedy Acrocladium auriculatum.
From tree bases upward, to almost 2 m high, moss colonies are very well developed on living trees.Huge carpets of Lepyrodon lagurus, L. tomentosus and Leptostomum menziesii wrap tightly the Nothofogus bark, continuing unbroken into t h e t r e e roots with soft m a t s of Catagonium nitens, rough mats of Sanionia uncin a t a , thick t u r f s of 2,ygodon hookeri and Bartramia hallerianu, together with large patches of fruiting Leptotheca gaudiclzaudii.

iii. Mixed Forest Moss Communities
An interesting association of evergreen and summergreenNothofagus forests was surveyed at Bahia Toro (50"17'S, 73Ql16' W) on the northernmost corner of Seno Mayo and at the so named Refuge Bay (50"4'S, 73Ql5' W) ca. 2 km N of Bahia Ameghino.There, very old Nothofbgus betuloides and Drimys winteri thrive associated with equally old N pumilio.They grow at lake level, on a very rugged terrain siirrounded by high cliffs with waterfalls and streamlets, creating an adequate shady and extremely wet environment for lower cryptogams.
Under these vascular conditions, mosses are more abundant on the so to speak "floor", because flat open floor is not seen anywhere.Cracked and crumpled soil banks, wet pockets, streamheds and strongly putrid logs and stumps are the domiilwit moss substrata.Dendroid life forms suck1 a? those of Dendroligotrichum dendroides and Hypopterjg.8 iuzn didictyon are common ground elemeiits together with tali turfs of the almost weedy Pyrri~obiyum mnwide,?.Clayish wet banks are carpeted by loose tallturfs ofBarmUnia@eris, B. I d f i n , , Goniobvum subbasilare, Polylrichadelphus magellanicus, Notoligolrichurn minimum., and large wefts of Ptychomnion cygnisetum.Uartramia ilhyphylla, Dendriiligotrichum squamosunz and Philonotis scabrifolia are present on low vertical drier banks.
Stones arid stumps partially submerged in streambeds are colonised by open turfs of Brei~teliaplicata, Phihilonotis uagans and soft mats of the rarer Sauloma tenella, Calyptrochaela apiculala andrlchrophyllum magellanicum.Vittia pachylonza is plenty in fmit submerged in these streams.
The lower 0 1 1 s rnetre of tree trunks are loosely covered by rough mats ofthe common Lepyrodon lagurus and L, tomentosus, to which might be added lax wefts of Lembophyllum orbiculatum, Rzgodium adpressum and R, brach.ypodium.From tree bases to the green ground cover tliere are soft mats of Catagonium nitens, C. nitens var.myurum, H.ypnum shottsbergii and Brachylheciurn paradoxum.Whereas, in definite rou~ided turfs on the ground we find the coprophilous Tayloria magellanica, T mirahilis and T dubyi.Also in these forest stands the waterfall spray zone offers many rock pockets, hollovis and rock crevices for Breutelia plicata, U. integrifolia, Eurh.ynchium fuegiaraum, Philonotis vagans and Cladomniopsis crenato-oblusa, among other strongly hygrophylous moss communities.

iv. Shrub Steppe
As might be expected, the moss flora of the shrub-steppe is less rich in number of species than farther to the west.Though, mosses together with lichens are the dominant and frequently the only visible green cover of most rock habitats in the district.Watercourses or seepage areas yield also important habitats for moss vegetation.The shrub steppe district lies between the eastern grassy steppe and the westerri summergreen forests.East and West limits of tho transect are in many cases indistinct due to the intrusion of elements from  both adjacent districts.Distinctive vegetation of the shrub vteppe is characterised by mostly scattereq communities of pricking xerophytic and some mesbphytic vascular elements.Most common shrubs are Mulinum spinosum ("neneo"), Dismria chacaye Yespino blanco"), and the weed Be]-beris huxifolia ("calafate") (Fig. 2).
Rock banks of temporary or seasonal shallow watercourses create a moister environment for more fragile flowering herbs such as Calceolaria hiflora, C. uniflora, Erodiurn cicutarium, Acaena ovalifblia, Gentianella mogellanica or either Osmorrhiza chilensis and various Senecio spp., @owing everywhere Most mosses on this sector are tiny, dusty and blackish cushions or short turfs.Across the shrubsteppe rock habitats are very common.Hollows, rock crevices, small pockets or irregular slits where some ground and iitter retain moisture are good habitats for mosses of the cushion-forming life form.Sarconeuramglaczale, a Pottiaceae Cormerly a Fuegian-Antarctic endemic, is plenty and fruiting.Northernmost plants were found around Chalten population (4YQO'S).Together with it, cushions of 2-3 cm wide of Schistidium apocarpum, Weissia patagonica, tile weed Ceratodonpurpureus, reddish Bryoerytrophyllum recuruirostre, and Psudocrossidium crinitum, Did.ymodon ampliretis, and stunted turfs of Bartrarnia stricta are similarly frequent.
The genus Eizcalypta, with two species, is equally common, fully i n fruit all along the transect as a rock or ground dweller.
Exposed rocky surfaces across the shrubsteppe more often than not, are Sully covered by big Polytrichaceae, Polytrichumjuniperinum and P piliferum (Fig. 6 ) .The latter is the most fiequent Polytrichaceae of desiccated habitats in Patagonia.They thrive intermixed with Hennediella densifolia, Bartramia patens and this widespread species are not krlown on this part of the world (Mattori, 1988).I n between ~l l e Ai~lacomnium turfs, marshy areas are occupied by other interesting species not fourid elsewhere in the shrub-steppe, such as Plagiomniilm ellipticum, Campylium polygamum, and Bryuin laeuigatnm.
The occurrence of slow running rivulets with earth-hanks fringed by grasses, crumpled trees, bushes and Escallonia uirgota (Fig. 3) are not uncommon in the shrub-steppe.There, one can find huge colonies of almost subaquatic mosses of the open wefts type such a s the bright yellow Brachythecium subpilosum, ti-uiting Orthotheciella uaria, Drepanocladus longifolius and Pohlia wahlenbergii.

THE MOSSES
This is an alphabetical list of the mosses so far identified within the boundaries of National Park Los Glacizres.We recognized 74 genera, 111 species and 2 varieties among which there are 42 new records for the province of Santa Cruz ('*).Two additions recently nlade by Miiller (2002) from within the Park are als.lsoincluded.Several of these new records fill in the former gap between north Patagonia and the Fuegianregion, east to the Andes, e.g.J~ptotheca gaudichaudii, Calyptrochaeta odontoloma, Breutelia plicoia, B. subplicata, Notoligotrichum minimum, Tayloria dubyi T mirabilis, etc.
Afewothers, such asRosulahryum macmphvllum, Blindiu mcyiellanica, Entosthodon bus, Goniob~yum subbasilare, and Dicranella cardntii, extend their lmgefrom the Fuegian region northward, into southern Patagonia.Summing up all these additions, the actual figure of mosses recorded from Santa Cruz plavince is raised from 132 taxa (,Mattmi, 2003) to 174 taxa.Additionally, if we include Racomitrium rivulets on western limits of the shrub-steppe ren-Ochyra & Ochyra, 2003), the actual figure for Santa dered interesting bryological results.In between Cruz is 175 kxa.Oribkal collections are deposited stones and on gravelly soil at water level, large in BA, and most of them have been distributed as populations of Philonotis nigroflava, Dicranella series I of Musci Patagonici Exiccati to CIIR, K a M , hookeri and Pohlia wahlenbergii are abu~ldant.
MO and S. The list includes voucher specimens and Narrow courses of melting waters descendinp d a k on substrata.age areas, shallow lagoons and "vegas".Amongst Matteri t h e cyperaceous vegetation of these areas, Vouchers: CM 5084,5668 (BA).xerophytic mosses give way to more mesic com-Subslr.Stream-banks.munities.Impressive golden lax turfs of the rare Aulacomnium palustre (Fig. 11) are abundant.AcroeZudium auriculutum (Mont.)Mitt.When observed closely, they reveal the presence Vouchers: CM 4871,4900a (&A). of masses of brown propagulae.Sporophytes of Suhstr.Rotten logs and bark.