arid ecology lab - distribution and floristics of bryophytes in ......arid soil crusts comprising...

Aust, J. Bot., 1996,44, 223-247

Distribution and Floristics of Bryophytes in Soil Crusts in Semi-arid and Arid Eastern Australia

D. J. Eldridge and M. E. Tozer

Department of Land and Water Conservation, c/o Graduate School of the Environment, Macquarie University, NSW 2109, Australia.

Abstract A total of 56 bryophyte taxa associated with biological soil crusts was collected from 282 sites in semi- arid and arid eastern Australia. The 41 moss taxa and 15 liverwort taxa found were dominated by the families Pottiaceae and Ricciaceae respectively. Bryophytes were present at 224 of the 282 sites, and their distribution varied widely according to different landscapes. The mean number of taxa per site ranged from 8.9 on plains with red earths to 2.1 on active floodplains. The most common bryophytes found in the survey area were Bryum pachytheca, Didymodon torquatus, Gigaspermum repens, Goniomitrium enerve, Desmatodon convolutus, Stonea oleaginosa, Crossidium davidai, Riccia limbata and Riccia lamellosa. In this paper, the distribution of bryophytes in relation to landscape types, and some strategies for surviving in arid environments and their roles in biodiversity and rangeland condition assessment are discussed. Their distribution is compared with other published and unpublished studies from similar areas of Australia.

Introduction Arid soil crusts comprising bryophytes, lichens, bacteria, fungi and cyanobacteria are a

characteristic feature over much of arid and semi-arid eastern Australia (Rogers and Lange 1972). In Australia, their distribution has been linked to soil type, rainfall distribution and land use (see Eldridge and Greene 1994). In the semi-arid woodlands of eastern Australia where the dominant soils are calcareous earths and red earths, soil crust biota may occupy up to 80% of the soil surface in some areas (Eldridge, unpublished data). Their presence is generally viewed as beneficial in maintaining rangeland stability (West 1990), and during unfavourable times they may provide the only form of biological covering on the surface. Significant changes in soil physical and chemical properties result when soil crusts are removed by either grazing (Andrew and Lange 1986) or fire (Greene et al. 1990).

Bryophytes are important components of biological soil crusts. Whilst not forming true soil crusts like lichens, they nevertheless increase insulation at the soil surface, enhance nutrient cycling and contribute to surface stability by reducing raindrop energy. They also provide food and niches for soil invertebrates (Davidson et al. 1990). Bryophytes promote soil formation by accelerating physical and chemical weathering of soils, by trapping windblown sediments (Danin and Gaynor 1991), and by contributing directly to organic matter in the soil (Longton 1992). Nutrients taken up by bryophytes may be released and made available to other organisms by leaching, upon death and decomposition, following fire, and to a limited extent by herbivory (Longton 1992).

By comparison with mesic areas, the bryophyte flora of semi-arid Australia is poorly known. At a local level, studies have focused on bryophytes in New South Wales (NSW) at Mungo National Park (Downing and Selkirk 1993); in South Australia at Middleback Field Study Centre near Whyalla (Bell 1980; Howarth 1983) and the mid-north region (Hyde 1994); and in Victoria in the Mildura district (Browne, unpublished data), Hattah Lakes


National Park (Willis 1970) and Wyperfeld National Park (Scott 1982). Regional checklists of mosses in arid areas have been compiled using herbarium collections for NSW by Ramsay (1984), the Northern Temotory by Catcheside and Stone (1988), and Western Australia by Stoneburner et al. (1993). None of these regional checklists include liverworts.

This paper reports on a survey of the distribution of bryophytes associated with soil crusts over an area of approximately 500 000 km2 of western NSW, Australia (Fig. la). The aims of this study were to determine the extent of soil crusts in the semi-arid rangelands and to document the bryophyte species composition and their relative abundance on the principal landscapes types in western NSW. The work forms part of a larger study designed to investigate the usefulness of lichen and hryophyte t a x 2s hio-inrlic&rs ef ra~gehx! health.

The Survey Area The survey area includes the arid and semi-arid zones of NSW (as defined by Meigs 1953). It

includes all of the Western and Far Western Plains Botanical Subdivisions (defined by Jacobs and Pickard 1981). It is bounded in the north by the Queensland border (latitude 29"001S), in the west by the South Australian-NSW border (longitude 141°00'E), in the south by the Murray River and in the east by longitude 147"301E (Fig. la). Although these boundaries include small areas of the Central and South Western Slopes Botanical Subdivisions, no collections were made from these areas. The principal land use in the area is sheep and cattle grazing on native pastures, but some areas of permanent and opportunistic cropping are camed out on the eastern and south-western margins.

Climate

Rainfall is spatially and temporally variable, decreasing from 450 mm per year in the north-east to less than 150 mm per year in the far north-west (Fig. lb). Rainfall is predominantly summer-dominant in the north and winter-dominant in the south. Droughts are a regular feature of the climate. Diurnal temperatures are typically hot in summer (> 40°C) and mild in winter (> 10°C). Evaporation increases from south to north and from east to west (Cunningham et al. 1981).

Geomorphology

Most of the survey area lies within the Murray-Darling Basin, and is depositional in origin. The Basin is largely overlain by Quaternary aeolian deposits that are calcareous in nature. The most extensive depositional landscape consists of level to undulating plains of Quaternary aeolian sediments and local colluvial materials on which are superimposed broad sandsheets and linear and subparabolic dunes. Extensive plains of Quaternary alluvium are found on the Riverine Plain in the south-eastern section of the survey area, and along the floodplains of the Darling, Murrumbidgee and Murray Rivers, which drain most of the area. Erosional landscapes are much smaller in extent, and landforms including ranges and hills with rock formations dating from the Precambrian to Tertiary occur in the north of the survey area, particularly around Cobar, White Cliffs and Broken Hill. Water erosion and redistribution of sediments is still active on these landscapes (Cunningham et al. 1981).

Landscape Types

The survey area can be classified into the following seven associations of landform, soils and vegetation. The distribution of these landscape types is shown in Fig. 2.

( I ) Ranges and hills of shallow loams. These are scattered throughout the survey area, supporting sparse mulga (Acacia aneura) and a variable understorey of sparse grasses, forbs and, occasionally, perennial shrubs of the family Chenopodiaceae.

(2) Footslopes and rolling downs of loamy duplex soils. These occur on the margins of the erosional landscapes near White Cliffs, Tibooburra and Broken Hill. The soils are often overlain with a mantle of quartz or silcrete gravel, increasing their resistant to erosion. These landscapes support a shrubland dominated by saltbush (AtripEex spp.) and bluebush (Maireana spp.).

(3) Extensive plains of earthy sands and dunes of deep neutral red earths. These occur in the north- west of the survey area, between Bourke and Tibooburra. They support scattered mulga,

Bryophytes of Soil Crusts

I a. V I C T O R I A

I V I C T O R I A

1

Fig. 1. The survey area, showing (a) the major towns and botanical subdivisions (NWP, North Western Plains; SWP, South Western Plains; NFWP, North Far Western Plains; SFWP, South Far Western Plains), and (b) the rainfall isohyets and distribution of winter and summer rainfall.


Q U E E N S L A N D

V I C T O R I A I

I km 50 0 50 100 150 krn

Fig. 2. Distribution of the seven landscape types in the survey area: 1, ranges and hills; 2, footslopes and rolling downs; 3, plains of earthy sands and dunes of neutral red earths; 4, sandplains and dunefields of calcareous earths; 5, plains, low ridges and flats of loamy red earths; 6, relict floodplains, playas and drainage lines; 7, active floodplains, drainage lines and depressions.


moderately dense shrubs from the genera Eremophila, Dodonaea and Senna, and sparse pastures. The soils are often bare and subject to wind erosion and sand drifting. Sandplains and dunefields of calcareous earths. This is the predominant landscape in the south- west of NSW, and supports a woodland dominated by belah and rosewood (Casuarina cristata and Alectryon oleifolium) and low shrublands dominated by mallees (Eucalyptus spp.). When pasture cover is low these soils are subject to wind and water erosion. Plains, low ridges and flats of loamy red earths. This landscape type occurs over extensive areas in the east of the survey area between Bourke and Griffith. It is dominated by bimble box (Eucalyptus populnea), red box (E. intertexta), white cypress pine (Callitris glaucophylla) and mulga, and typically supports a dense understorey of perennial shrubs (Dodonaea, Eremophila, Senna spp.) and q m s e ~ I S S P S . The wi!s are often severely degraded through water sheeting and gullying. Relict floodplains, playas and drainage lines. Occuring predominantly in the Riverine Plain in the south-east, this landscape is a mosaic of red and brown duplex soils and grey clays. The landscape type supports saltbushes, bluebushes and variable grasses. The duplex soils are susceptible to scalding (Beadle 1948) once the overlying coarser textured topsoil has been removed through erosion, often the result of overgrazing. Active floodplains, drainage lines and depressions. This landscape type consists of cracking grey and brown clays and is part of the drainage system of the Murray-Darling Basin. These soils support an open woodland-grassland dominated by river red gum (Eucalyptus camaldulensis), blackbox (E. largijlorens), coolabah (E. microtheca) and gidgee (Acacia cambagei). The soils are relatively stable.

Methods The main roads and tracks were followed in order to obtain a comprehensive coverage of the survey

area. The routes were selected to form a grid of sites across the area. Sites were selected at intervals of 10-30 km along these routes. Some areas of special interest were also sampled. These included national parks and long-term grazing exclosures, railway corridors and regeneration areas. In total, 282 sites were assessed. At each site, transects were established perpendicular to, and commencing 100-200 m away from, the edge of the road. Along each transect 10 quadrats (0.5 m2) were laid down to form the basis for data and soil crust collection.

As the relationship between soil surface condition, vascular plants and soil crust biota was of interest, all field data were collected within a quadrat. Data included descriptions of soil surface condition; microtopography; landscape element; slope; type and degree of erosion; estimations of the cover and relative composition of lichens, bryophytes and cyanobacteria; cover and type of vascular plants; and cover and type of plant litter. Relationships between surface morphology, vascular plants and lichen and bryophyte taxa are presented elsewhere. Separate samples of the soil crust were collected from up to four, but usually two, quadrats within each transect, and transported to the laboratory to enable the bryophytes present in the crusts to be identified. Material was collected to provide voucher specimens for lodgement in various herbaria. A supplementary sample of soil crust was also collected from the surrounding soil surface in an attempt to collect taxa that were not represented in the quadrat samples.

Soil samples were sieved in the laboratory using a 2 mm sieve. Mosses and liverworts were identified using keys and descriptions in the southern Australian bryophyte regional flora treatments in Scott and Stone (1976), Catcheside (1980) and Scott (1985), as well as some more recent generic revisions. Many specimens were sent to Australian bryologists for positive determinations. Nomenclature follows Streimann and Curnow (1989) for mosses and Scott (1985) for liverworts, or more recently published taxonomic revisions.

Problems in Identification

Most bryophytes were identified to species level, but some could be identified only to family or genus level due to identification problems. These problems arose from the reliance upon vegetative characters for identifications. Very little fertile material was found. Some genera and species can be identified accurately only using reproductive characters (capsules and spores). In these cases, plants were keyed out as far as could be certain using available vegetative characters. Environmental stress affecting vegetative characters and the presence of vegetatively similar plants meant that dependance upon vegetative characters did not always lead to reliable identifications.


Those family and genera where identification essentially requires observations of reproductive structures included: most genera within the Funariaceae, some of the species within the genera Acaulon, Phascum and Pottia (Pottiaceae), and the liverwort genus Fossombronia. Within the genus Pottia, specimens were determined only as Pottia sp. except for P. brevicaulis (which is distinguishable by the expansion of its costa towards the apex) or when a determination was obtained from a bryologist. Therefore individual Pottia species probably occur more commonly than our data show.

Harsh environmental conditions experienced within the study area can lead to weathering of the leaves and differential expression of identifying characters. Leaves of Bryum spp. were often found weathered, making observation of the critical leaf characters difficult. These leaf characters include leaf areolation, leaf margin and projection of the costa beyond the lamina, as defined by Spence and Ramsay (1997). Similarly the apices of !eaves in the genera ACGLLICX and Phasciiiii (P~t thceaej were easily damaged in situ or during transport of collected material. Thus the discrimination between some species based upon the length of the excurrent costa (Stone 1989) was not always possible. Differences in light and moisture have been found to have significant impact on the expression of thallus characters in the liverwort genus Riccia (including colour, width, thickness, number and size of cilia and scales: Na- Thalang 1980). This caused problems most particularly in distinguishing between Riccia lamellosa and R. sorocarpa.

A number of species formed groups of vegetatively similar plants. It was necessary to develop criteria, based on published material but not included in keys, with which to separate them. Crossidium davidai, Desmatodon convolutus and Pottia brevicaulis have similar leaf shape, recurved margins and papillose lamina1 cells. In this study, they were distinguished by the presence and length of filaments overlying the costa. This criterion has been used previously by Downing and Selkirk (1993) to distinguish between Crossidium and Desmatodon. Plants with filaments consisting of more than one cell were assigned to C. davidai, those with filaments of one cell to D. convolutus and those with the cells of the costa clearly visible (i.e. no filaments) were assigned to P. brevicaulis. The latter is also recognised by the expansion of the nerve towards the apex. Barbula homschuchiana and Didymodon torquatus are also very similar plants with comparable habits and leaf shape. Specimens with highly papillose cells were determined as B. hornschuchiana and those with smooth cells (although they may be projecting) were determined as D. torquatus. Zander (1993) agrees with the use of these characters as discriminating features. In some cases, it was not possible to distinguish between different groups because no reliable way of separating them could be found. Didymodon torquatus, D. subtorquatus and D. luehmanni are all included in D. torquatus. Other workers (Downing and Selkirk 1993) have also combined these species.

Results and Discussion Distribution of Bryophyte Taxa

In all, 56 taxa were collected from the survey area, representing 12 families. These included 41 taxa of mosses and 15 taxa of liverworts (mainly Riccia spp.). Of the mosses, 76% (32 taxa) were represented by the families Pottiaceae and Bryaceae.

Bryophytes were present at 224 of the 282 sites on all soil types. About 9% of sites had only a single species present, and 58% of sites contained five or less taxa (Table 1). The most common mosses in order of occurrence at individual sites were Bryum pachytheca (182 sites), Didymodon torquatus (122), Gigaspermum repens (94), Goniomitrium enewe (92),

Table 1. Frequency distribution of the number of taxa found at the 282 sites in the survey area

No. of taxa per site No. of sites Percentage of sites


Desmatodon convolutus (87), Stonea oleaginosa (86) and Crossidium davidai (63). The most common liverworts were Riccia limbata (83 sites) and Riccia lamellosa (52).

Comparisons with Other Semi-arid Regions of Australia Comparisons of the bryoflora of other arid and semi-arid zones within Australia are given

in Table 2. For those studies undertaken on a broad regional basis, only zones or sites with a semi-arid or arid climate similar to that experienced in western NSW were examined in this study. This included the Eremaean Botanical Province for the Western Australian census (Stoneburner et al. 1993), the Central Northern and Central Southern regions of the Northern 7 l'erritory [Catcheside and Stone i988j, the Western and Far Vesteix B~tmica! Snbdivisinns of NSW (Ramsay 1984), and those sites in Hyde's (1994) South Australian study, where rainfall was less than 450 mm per year.

The census of NSW mosses recorded the highest number of species (48), followed by the census of Western Australian mosses (47), this study (41) and the mosses of the Northern Territory (40). Hyde (1994) described 31 mosses from comparable sites in South Australia. Western Australia had 21 mosses (51%) in common with this study, and South Australia, the Northern Territory and NSW had 16 (39%), 14 (34%) and 23 (56%) respectively.

Whilst taxonomic changes, problems of scale between the various studies (e.g. broad regional cf. local landform scale) and difficulties in identifying some specimens to species level make direct comparisons between the studies difficult, a few generalisations can be made. Only one species, Desmatodon convolutus, occurred in all studies, and Aloinia bifrons (= A, sullivaniana), Bryum pachytheca and Gigaspermum repens occurred in 9 of the 10 studies. Riccia lamellosa occurred in all five of the nine studies that recorded liverworts. Many studies failed to record genera such as Pottia probably due to problems of identification.

Distribution in Relation to Landscape Types The greatest diversity of bryophytes (mean number of taxa per site) occurred in the plains

of red earths (8.9) and sandplains of calcareous earths (6.8). Active floodplains and drainage lines had the lowest diversity (2.1 per site) closely followed by footslopes (2.2), and plains of earthy sands and dunefields of deep neutral red earths (2.2) (Table 3).

Whilst many bryophytes were ubiquitous in the survey area, some were restricted almost exclusively to certain landform types, possibly in response to amount and seasonality of rainfall or calcium carbonate. In this survey, Aloina bifrons, Bryobartramia novae-valesiae and Crossidium geheebii were restricted exclusively to calcareous soils. The presence of carbonate in the fine fraction of the soils has been shown to strongly influence the cover and composition of bryophytes in eastern Australia (Downing 1992; Downing and Selkirk 1993). Fossombronia spp., Barbula calycina, Riccia crinita, Eccremidium pulchellum, Asterella drummondii and Bryum argenteum were restricted predominantly to plains with non- calcareous soils. Additionally, these areas tended to occur in the eastern fringe of the survey area where rainfall exceeds 400 mm per year and is evenly distributed in summer and winter. Bryum campylothecium, Barbula crinita, Ceratodon purpureus and Fissidens taylorii were all restricted to relict floodplains dominated by clays and duplex soils. More data are needed, however, before definitive statements can be made about the preference of certain species for certain soil types and climatic regimes.

A total of 28 taxa was found on the hills and ranges of shallow loams. Whilst the mosses Bryum pachytheca and Stonea oleaginosa occurred at more than 12 sites (i.e. > 70% of this landscape type), most taxa occurred at fewer than five sites (i.e. < 30% of sites). Bryophytes were generally restricted to areas of deeper soils around the sparse vegetation or in sheltered microsites below rock outcrops, and predominantly occurred as scattered individuals rather than associated with well-developed soil crusts.


Table 2. Comparison of species composition between the present study and other bryophyte surveys in arid and semi-arid zones within Australia +, species found; -, species not found. Blank spaces in the liverwort section indicates that liverworts were not included in study. Numbers in parentheses are the number of sites in the current study from which each species was collected. WA, Western Australia; SA, South Australia; NT, Northern Territory; Vic., Victoria; NSW, New South Wales. Sources: 1, Stoneburner et al. (1993); 2, Howarth (1983); 3, Hyde (1994); 4, Catcheside and Stone (1988); 5, Willis (1970); 6, Scott (1982); 7, Browne (unpublished data); 8, Ramsay (1984); 9, Downing and Selkirk (1993); 10, this study

Taxon WA S A NT Vic. NSW

Source: 1 2 3 4 5 6 7 8 9 1 0

Mosses ARCHIDIACEAE Archidium rothii A. stellatum

BRY ACEAE Brachymenium preissianum Bryum argenteum B. billardieri B. caespiticium B. campylothecium B. capillare B. chrysoneuron B. dichotomum B. pachytheca B. radiculosum B. torquescens B. sp. C B. sp. kptobryum pyriforme

BRYOBARTRAMIACEAE Bryobartramia novae-valesiae - DICRANACEAE Campylopus perauriculatus Dicranella sp.

DITRICHACEAE Ceratodon purpureus Eccremidium arcuatum E. minutum E. pulchellum E. sp. Pleuridium nervosum

EPHEMERACEAE Ephemerum cristatum

FISSIDENTACEAE Fissidens asplenioides F. gillianus F. hurnilis F. leptocladus F. megalotis F. perobtusus


Table 2. continued

Taxon - - - - - - -

WA S A NT Vic. NSW

F. taylorii F. vittatus F. aff. dietrichiae

FUNARIACEAE Funariaceae spp. Funaria acaule F. apophysata F, gracilis F. helmsii F, hygrometrica F. muhlenbergii F. phymatodea F. radians F. salsicola F. subnuda Goniomitrium acuminatum G. enerve Physcomitrella readeri

GIGASPERMACEAE Gigaspermum repens

HYPNACEAE Hypnum cupressifonne

LEPTOSTOMACEAE Lqtostomum inclinans

POTTIACEAE Acaulon chrysacanthum A. granulosum A. leucochaete A. muticum complex: A. eremicola A. integrifolium A. triquetrurn A. sp. Aloina bifions A, aloides var. ambigua Barbula calycina B. crinita B. homschuchiana B. subcalycina B. sp. aff. unguiculata B. sp. Crossidium davidai C. geheebii C. sp. aff. davidai c. sp. Desmatodon convolutus D, recurvatus


Table 2. continued

D. sp. - - + - - - - - - - Didymodon torquatus + - + - - + + - + + ( 1 2 2 ) D. wildii - - - - - - - + - - D. sp. - - + - - - - + - Gymnostomum sp. + - + - - - - - - Phascopsis rubicunda - - + - - - - - - Phascum laticosturn - - - - - - - - - P. longipilum + - - - - - - - - P. robustum var. robusturn - - - - - - - + - P. robustum var. crassinervium + - - - - - - + - Pottia brevicaulis + - - - - - - - - P. davalliana - - - - - - - - - P. drummondii + - - - - - - - - P. globosa P. latzii P. scabrifolia P. starckeana P. sp. Pterygoneurum kelmseyi + - - - + - - + - - P. ovaturn + + + - - - - + + + ( I ) Stonea oleaginosa + - + - - - - + - +(86) Tetrapterum cylindricum - - - - - + + + - - Tortella cirrhata + - - - - - - - - - Tortula deserta - + - - - - - - - - T. laevipila - - - - - - - + - - T. panduraefolia - - - - - - - + - - T. papillosa - + - - - - + - + - T. princeps - + + - + - - + - - Trichostomopsis australasiae + - + - - - - - - - Trichostomumbrachydontium + - + + - - - - + +(9) T. crispulum - - - + - - - - - Triquetrella papillata + - + - + + + - - - T. richardsiae - - - - - - - + - - Weissia controversa - - + - - - - + - - W. willisiana - - - + - - - - - - w. sp. - - + - - - - - - - PTY CHOMITRIACEAE Ptychomitrium australe - - - - - - - + - -

Liverworts ACROBOLB ACEAE LRthocolea squamata

AYTONIACEAE Asterella drummondii

CEPHALOZIELLACEAE Cephaloziella arctica Cephaloziella exiliflora

CODONIACEAE


Table 2. continued

Taxon WA S A NT Vic. NSW

1 2 3 4 5 6 7 8 9 1 0

Fossombronia alt-ilamellosa F. cf. intestinalis F. leucoxantha F. wondraczekii F. sp.

MONOCARPACEAE Monocarpus sphaerocarpus

RICCIACEAE Riccia albida R. asprella R. bifurca R. cartilaginosa R. cavernosa R. crinita R. crozalsii R. crystallina R. larnellosa R. limbata R. marginata R. nigrella R. papulosa R. rorida R. sorocarpa R. vesiculosa R. cf. vesiculosa

Footslopes and rolling downs of loamy duplex soils supported a depauperate bryophyte flora of 19 taxa, of which Bryum pachytheca and Riccia limbata were dominant. These plants usually occurred as scattered individuals, often associated with the lichen Heppia despreauxii.

A total of 25 taxa was found in plains of earthy sands and dunes of deep neutral red earths. Goniomitrium enerve, Bryum pachytheca and Riccia limbata were dominant. Mosses were found in association with soil crust lichens, particularly Collema coccophorum and Heppia despreauxii in sheltered sites under shrubs or as scattered individuals.

Sandplains and dunefields of calcareous earths supported a rich flora of 38 bryophyte taxa. Dominant species included Bryum pachytheca, Gigaspermum repens, Stonea oleaginosa, Didymodon torquatus, Crossidium davidai, Goniomitrium enerve, Desmatodon convolutus and Aloina bifrons. Other common taxa included the Acaulon muticum complex, Crossidium geheebii, Phascum robustum var. robustum, Riccia limbata and R. lamellosa. Crossidium sp. aff. davidai (possibly an undescribed species) was found at nine sites in this landscape type. Plains, low ridges and flats of loamy red earths had the same number of taxa (38) as that of the calcareous earths, but taxa were generally found at fewer sites (i.e. did not occur as commonly). Dominant species included Bryum pachytheca, Didymodon torquatus, Goniomitrium enewe, Gigaspermum repens, Riccia larnellosa and R, limbata. Other less common species included Bryum argenteum, Eccremidium pulchellum, Desmatodon


Table 3. Total number of taxa and the average number of taxa per site in each of the seven landscape types in semi-arid and arid New South Wales

- - -

Landscape type No. of sites Total no. of taxa Average no. of in landscape type taxa per site

1. Ranges and hills 18 28 5.8 2. Footslopes 39 19 2.2 3. Plains and dunefields of earthy sands and

neutral red earths 56 25 2.2 4. Plains and dunefields of calcareous earths 6 1 38 6.8 5. Plains and dunefields of red earths 43 38 8.9 6. Relict Floodplains 16 34 5.3 7. Active Floodplain 49 13 2.1

convolutus, Fossombronia spp., Riccia crinita and Phascum robustum var. robustum. On both of these landscape types bryophytes were closely associated with soil crust lichens, particularly Psora decipiens, Catapyrenium spp., Endocarpon pusillum, E. rogersii and Peltula patellata ssp. australiensis.'Other mosses such as Barbula calycina, Gigaspermurn repens and Goniomitrium enewe occurred in small monospecific tufts independent of the soil lichen crust.

Relict floodplains, playas and drainage lines also supported a rich suite of bryophytes (34 taxa). The dominant species were Bryum pachytheca, Didymodon torquatus, Desmatodon convolutus. Other common taxa included Riccia limbata, Gigaspermum repens and Phascum robustum var. robustum. Some species were commonly found growing under shrubs. Species showing a preference for clay soils included Bryum campylothecium, Barbula crinita, Ceratodon purpureus, Fissidens taylorii and to a lesser extent Fissidens vittatus and Bryum argenteum. Most bryophytes occurred in small mats associated with other mosses and liverworts as lichen crusts were generally poorly developed on these soils. Active floodplains, drainage lines and depressions, however, had the poorest representation of bryophytes with only 13 taxa being found and only Riccia limbata and Bryum pachytheca occurring at more than five sites. This is attributed to the seasonally cracking clay soils, which are frequently gilgaid and often bare.

Adaptive Strategies of Bryophytes in Arid and Semi-arid Environments

Many of the mosses and liverworts found within the survey area display mechanisms that may assist them in coping with the stresses of growing in arid or semi-arid environments and, most particularly, coping with desiccation. These mechanisms include short life spans, niche preference, specialised leaves, distinctive leaf movements, plant habit, and thermoregulatory and hygroscopic leaf constituents.

Some bryophytes such as Goniomitrium enewe Rave a high reproductive effort with a short life span (< 1 year) and produce a few large spores (> 20 p,m) that remain dormant during periods of drought and fall into During's (1992) 'annual shuttle' strategy. Along with ephemeral mosses such as Ephemerum cristatum, these species exist only in favourable niches such as road drains or ephemeral watercourses where soil moisture is abundant for short periods. Riccia species have been found to occur in distinct species bands around water courses in response to soil moisture (Rogers 1994). Perennial species (R. limbata, R. blackii) were found to occur on the driest edge of the ecotone, whereas the ephemeral species (R. multifida, R. vesiculosa) occurred in the wettest spots and died upon dessication, producing sporophytes before death.


Most arid-zone species are small plants, with small leaves. Additionally, the leaves are often composed of small, square shaped cells that decrease the ratio of cell surface area to volume, thereby reducing moisture loss for individual cells (Bell 1982). Specialised leaf structures are also common in the plants that were found during this study. The mosses, Aloina bifrons, Crossidium geheebii, C. davidai and Desmatodon convolutus, possess filaments and lamellae on the adaxial surface of the costa. Apart from increasing photosynthetic ability, these outgrowths probably act as sun-shades offering protection when curled in over the stem apex, or over the developing sporophyte (Scott 1982). Lamellae, filaments and papillae may also serve to soak up small amounts of dew, acting as foci for condensation and enabling the moss to 'wet out' within seconds of being moistened. Fine hair points, narrowly revolute or involute leaf margins, channelled or grooved ieaves and papillae can act as fine channels directing water towards the centre of the plant (Catcheside 1980). The marginal bristles in Riccia crinita could plausibly operate in the same way. The hyaline or semi-hyaline leaves of Gigaspermun repens and Bryum argenteum may act also as protective sheaths for the photosynthetic parts of the plants, protecting them against insolation, desiccation and possibly mechanical damage (Scott 1982). The marginal hyaline scales of Riccia lamellosa, R. vesiculosa and R. sorocarpa may act similarly.

Many mosses in the semi-arid zone, and most particularly those in the family Pottiaceae, appear to tolerate desiccation by distinctive leaf movements such as twisting and rolling when dry (Scott 1982). Didymodon torquatus, Barbula hornschuchiana and B. calycina have long leaves that twist helically around the stem on drying. This twisting encases the plant, protecting the adaxial side of the leaf (Scott 1982). The effect is to greatly reduce plant volume, and the dense packing may protect the delicate photosynthetic cells underneath (Catcheside 1980). Perennial liverworts such as Asterella drurnmondii, Riccia limbata and R. nigrella possess black ventral scales that are high in anthocyanin. When the soil dries up, these plants fold along the midline, protecting the dorsal photosynthetic suxface with a row of black plates. Upon re-wetting, the scales retract within 30 min, allowing photosynthesis to proceed. The dorsal surface is densely porous, and on hydration may retain moisture within the cells for long periods. Some bryophytes can tolerate burial by dust and sand grains because of these leaf movements. Stonea oleaginosa and Riccia lamellosa tolerate burial of their stems and thalli in the soil surface. Eventually all that is exposed is a thin surface area on the abaxial side of the leaves. After rainfall the leaves rapidly rehydrate and may roll out within seconds or minutes. Moore (1980) showed that Barbula calycina, which is common on sandy soils, is able to grow through layers of accreting sand by flexing its leaves back strongly when moistened. Not only is it well adapted to survive in unstable soils, but it is an important soil stabiliser (Scott 1982).

The habit of mosses may also assist survival in these harsh conditions. Mosses growing in dense tufts or cushions are tightly packed, increasing their boundary layer resistance (Sveinbjornsson and Oechel 1992). This boundary layer resistance my be further increased by the presence of long leaf tips such as in Barbula crinita (Proctor 1982).

The leaves of Stonea oleaginosa contain unusually high amounts of lipid (Stone 1978); which may assist in thermoregulation. Similarly the anthocyanin present in the leaf fronds of Fossombronia spp. is probably also related to thermoregulation. Thick deposits of calcium carbonate crystals on the thallus of Riccia albida may have a protective effect, or the white encrustation may be hygroscopic (Scott 1982).

Biodiversity and Conservation Value of Bryophytes As there have been few comprehensive studies of terricolous bryophytes in Australia,

their conservation status is difficult to assess. Apart from the current study, there have been no systematic field-based attempts to document the soil-borne bryoflora of semi-arid regions over extensive areas. Other site-specific studies are listed in the Introduction and in Table 2.


Most mosses are small, inconspicuous and often even cryptic in the usual low-rainfall seasons that prevail in arid and semi-arid areas. Further, they can often be identified only using a microscope in the laboratory. Thus their presence or absence in certain landform types may be an artefact of the collection procedure, or the season or time of year when collections were made, rather than a true reflection of habitat preference. The value of this survey, however, is that it serves as a basis on which future surveys of the biodiversity of non-vascular plants can be assessed.

Although little is known about the extent to which Australian bryophytes are endangered or vulnerable (Scott 1996), some species have been identified as being rare or endangered (Scott and Stone 1980; Catcheside 1982; Scott 1985; Hyde 1994). For similar environments in South Australia, Catcheside (1980), Scott (1985) and Stone (1977) list Riccia crinita, Bryobartramia novae-valesiae, Desmatodon recurvatus and Trichostomum brachydontium as being rare or uncommon in South Australia. Apart from Riccia crinita, which is relatively common on the eastern margins of the survey area, B. novae-valesiae and T. brachydontium were found infrequently in the area. B. novae-valesiae was collected at five sites in the survey area. Its present status is unknown, but the fact that it was found on an abandoned cultivation paddock may suggest that it is not threatened by cultivation.

Bryophytes as Indicators of Rangeland Health Although bryophytes are small, and damaged by intensive overstocking and trampling,

they are less susceptible to short-term fluctuations that might occur as a result of burning or dry periods and droughts. This makes bryophytes useful indicators of rangeland health and, during periods such as droughts, they may be more useful than vascular plants. Management decisions on pastoral properties such as destocking or moving of animals to alternative paddocks are frequently based on the condition of the herbaceous layer or on the condition of the grazing animals. However, there is often a lag period between the point at which vascular plants begin to decline in condition and a degeneration of the soil surface and its associated microbiota such as bryophytes and lichens.

During droughts or dry times, when the herbaceous layer is sparse, rangeland condition can be assessed by monitoring the soil surface and the biological crust component, provided that the crust has not be destroyed by overgrazing (Tongway 1994). The composition of bryophytes and lichens in soil crusts is an integral component of rangeland condition assessment (Eldridge and Koen, unpublished data). Preliminary work has suggested that the mosses Barbula crinita, Bryum campylothecium and Fissidens vittatus tend to be associated with surfaces in good condition, whereas Crossidium geheebii and Desmatodon convolutus tend to be associated with surfaces in poor condition (Eldridge et al. 1995).

Annotated List of Bryophytes Associated with Soil Crusts This list includes a frequency score, distributional information and any relevant notes.

Undescribed and infrequently found taxa have specimen citation and these specimens will be lodged at the National Herbarium of NSW (NSW). The frequency of a species is defined as follows: infrequent, less than five occurrences; relatively infrequent, 6-20 occurrences; common, 21-100 occurrences; and abundant, more than 100 occurrences. Distributional data consists of occurrences within the Botanical Subdivision of NSW (Jacobs and Pickard 1981) (NWP, SWP, North and South Western Plains; NFWP, SFWP, North and South Far Western Plains); and occurrence within the previously described landscape types, with their abbreviations as follows: FtNGHL, (1) scattered ranges and hills of shallow loams; FTSLO, (2) footslopes and rolling downs of loamy duplex soil soils; PLSND, (3) extensive plains of earthy sands and dunes of deep neutral red earths; PLCAL, (4) sandplains and dunefields of calcareous earths; PLRED, (5) plains, low ridges and flats of loamy red earths; FLREL, (6) relict floodplains, playas and drainage lines; and FLACT, (7) active floodplains, drainage


lines and depressions. Taxa thought to be endemic to Australia are marked with an asterisk (*) (sources: Catcheside (1980) for mosses and Scott (1985) for liverworts).

Mosses Archidiaceae * Archidium stellatum Stone

Infrequent. NFWP. Landscape type: PLSND. Found in drain along road. First dncurr?ented record for the arid and semi-arid zone.

Specimen Examined

Eldridge BSCS 310 and Tozer, 16 Mar. 1994,30 km W of Yantabulla.

Bryaceae Bryum argenteum Hedw.

Common. NWP, SWP, NFWP, SFWP. Landscape type: RNGHL, FOOT, PLSND, PLCAL, PLRED, FLREL. Cosmopolitan. Found on all soil-landforms except active floodplains, and more dominantly occurring on PLRED. Not documented in semi-arid and arid South Australia and Western Australia.

Bryum caespiticium Hedw.

Infrequent. SWP. Landscape type: PLRED. First documented record for western NSW

Specimen Examined

Eldridge BSCS 61,31 July 1993, 15 km W of Euabalong West.

Bryum campylothecium Tayl.

Relatively infrequent. SWP, SFWP. Landscape type: PLCAL, FLREL. It character- istically occupies bare ground under Atriplex vesicaria and other shrubs. Catcheside (1980) and Howarth (1983) both found this species to be common.

Bryum sp. C (sensu Catcheside 1980)

Infrequent. N W . Landscape type: PLCAL, PLSND, FTSLO.

Specimens Examined Eldridge BSCS 281, 15 Oct. 1993, 70 km N of White Cliffs; Eldridge BSCS 450, 10 Sept. 1993,

9 km E of Emrndale; Eldridge BSCS 451,14 Oct. 1993,12 km E of 'Coona Coona' Homestead.

Bryum dichotomum (Hedw.)

Relatively infrequent. NFWP, SWP, SFWP. Landscape type: RNGHL, FTSLO, PLSND, PLCAL, FLREL. Cosmopolitan.

Bryum pachytheca C.Muel1.

Abundant. NWP, SWP, NFWP, SFWP. Landscape type: all. Cosmopolitan. The most commonly recorded moss throughout the survey area, found on all soil and vegetation communities often in association with Didymodon torquatus, Gigaspermum repens, Stonea oleaginosa, Acaulon spp. and other Bryum spp.


Bryobartramiaceae Bryobartramia novae-valesiae (Broth. ex Roth) Stone & Scott

Infrequent. SWP, SFWP. Landscape type: PLCAL, FLREL. Most frequently found in PLCAL landscapes. Not previously documented for western NSW.

Specimens Examined Eldridge BSCS 406 and Tozer, 13 July 1994, 100 km N of Wentworth; Eldridge BSCS 407 and

Tozer, 14 July 1994, 59 km NW of Wentworth; Eldridge BSCS 412, 5 Aug. 1993, 100 km N of Balranald. Eldridge BSCS 416 and Tozer, 14 July 1994,30 km SE of 'Belmore' Homestead.

Ditrichaceae Ceratodon purpureus (Hedw.) Brid.

Infrequent. SWP. Landscape type: FLREL. Cosmopolitan. Found at only two sites in long-term experimental areas from which grazing by domestic animals has been excluded since 1954. Both sites are bryophyte-rich.

Specimens Examined Eldridge BSCS 15,8 June 1993, c. 70 km SW of Hay; Eldridge BSCS 440,7 June 1993,8 km SE of

Oxley.

* Eccremidium arcuatum (Hook. & Wils.) C.Muel1.

Relatively infrequent. NWP, SWP, SFWP. Landscape type: FTSLO, PLCAL, PLRED. It is probable that its distribution is limited to higher rainfall areas. Most samples were growing on the soil surface but a few were found in soil accumulating in cracks on small rocks on the soil surface.

Eccremidium pulchellum (Hook. & Wils.) C.Muel1.

Relatively infrequent. NWP, SWP. Landscape type: PLSND, PLRED. Most frequently found in PLRED landscapes.

Ephemeraceae * Ephemerum cristatum (I3ook.f. & Wils.) C.Muel1.

Relatively infrequent. SWP. Landscape type: PLRED. An ephemeral species found only after recent rain. It is common during good seasons in areas subject to seasonal inundation (Catcheside 1980); in this survey it was present at only six sites.

Fissidentaceae Fissidens taylorii C.Muel1.

Infrequent. SWP. Landscape type: FLREL. Found at only three sites on clay soils and commonly on accumulated soil beneath perennial shrubs.

Specimens Examined Eldridge BSCS 50, 8 June 1993, c. 70 km SW of Hay; Eldridge BSCS 397,9 June 1993,7.5 km N

of 'Lochinvar' Homestead turnoff; Eldridge BSCS 396,9 June 1993, 10 km E of Moulamein.


Fissidens vittatus H0ok.f. & Wils.

Relatively infrequent. NWP, SWP, SFWP. Landscape type: RNGHL, PLCAL, PLRED, FLREL. It is often a dominant species in the bryophyte community where it occurs. It is generally restricted to duplex soils and clays in the Riverina, and red earths on the eastern fringe of the survey area.

Funariaceae Funariaceae spp.

Relatively infrequent. NWP, SWP, NFWP, SFWP. Landscape type: PLSND, PLCAL, PLRED, FLREL. Unidentifiable beyond family. Species identified by other workers in this region include F. apophysata, F. glabra and F. hygrometrica (Ramsay 1984; Downing and Selkirk 1993). Most species are annual or biennial (Catcheside 1980).

* Goniomitrium enewe Hook. & Wils.

Common. NWP, SWP, NFWP, SFWP. Landscape type: all. Most often found on calcareous loams and red earths. Mainly as scattered plants, though

occasionally forming dense tufts. Catcheside (1980) regards this species as rare, which is contradictory to our findings.

Gigaspermaceae Gigaspermum repens (Hook.) Lindb.

Common. NWP, SWP, NFWP, SFWP. Landscape type: PLCAL, PLRED, FLACT, FLREL. Most common on plains with calcareous soils and red earth soils. Occurs as scattered plants or monospecific clumps. Its occurrence has been documented in all the other bryophyte surveys.

Pottiaceae Acaulon muticum complex (sensu Stone 1989)

Common. NWP, SWP, NFWP, SFWP. Landscape type: all. This complex includes those species of Acaulon that are not triquetrous in habit and have a costa subpercurrent to percurrent (rarely to 200 pm) (Stone 1989). It includes the species A. eremicola, A. mediterraneum, A. integrifolium and A. granulosum, distinguishable on spore morphology.

Aloina bifrons (De Not.) Delgadillo

Common. SWP, SFWP. Landscape type: RNGHL, PLCAL, PLRED. Occurring in predominantly winter rainfall areas, and generally restricted to plains with calcareous earths. Although thought to occur commonly with Crossidium geheebii, which it resembles superficially (Catcheside 1980), only 23% of sites containing C. geheebii contained A. bifrons as well. Its occurrence has been documented (as a synonym, A. sullivaniana) in all the other bryophyte surveys.

Barbula calycina Schwaegr.

Relatively infrequent. SWP. Landscape type: PLSND, PLRED. It is locally abundant within its geographic range. It grows in small cushions to 5 cm across. Usually found on dunes and


sandplains with mallee (Eucalyptus spp.) and cypress pine (Callitris glaucophylla) and generally occurring in the spaces between trees. Laboratory studies have shown that the species is able to continue sprouting upwards to avoid being buried by successive layers of sand.

Barbula crinita Schultz

Relatively infrequent. SWP. Landscape type: FLREL. All specimens were collected from the riverine plain. Plants were restricted to sheltered microsites on accumulated soil and litter under bladder saltbush (Atriplen vesicaria) and dillon bush (Nitraria billardieri) shrubs. Whilst this species is known to occur on sandplains with mallee (Catcheside 1980), it was EQ+ r em... rvuud iii ihcse environments in tine current study. Howarth (1983) found this species to

be very common in the chenopod shrublands of Middleback Station.

Barbula homschuchiana Schultz

Common. NWP, SWP, NFWP, SFWP. Landscape type: RNGHL, FTSLO, PLSND, PLCAL, PLRED, FLRFiL. Found more commonly associated with woodlands of poplar box and pine (Eucalyptus populnea and Callitris glaucophylla) with red earths. Generally found on bare soil with other mosses including Didymodon torquatus, Stonea oleaginosa, Bryum pachytheca and Goniomitrium enerve.

Barbula sp. aff. unguiculata Infrequent. SEWP. Landscape type: RNGHL, PLCAL. An uncommon moss found near Ivanhoe, and in the south-westem comer of NSW on

plains of calcareous earths. Differs from B. unguiculata in that the margins are recurved towards the apex, and from B. hornschuchiana by the rounded apex of the leaf as opposed to a tapering apex.

Specimens Examined Eldridge BSCS 361 and Tozer, 12 July 1994, 30 km W of Silver City Highway on 'Buckalow'

Homestead road; Eldridge BSCS 442 and Dryden, 4 Aug. 1993, c. 70 km SW of Ivanhoe.

* Crossidium davidai Catches.

Common. NWP, SWP, NFWP, SFWP. Landscape type: all. A ubiquitous moss found at 63 sites on all soil types and vegetation communities, but more abundant on calcareous soils. Generally associated with other mosses such as Didymodon torquatus and Desmatodon convolutus.

Crossidium sp. aff. davidai Relatively infrequent. NWP, SWP, NFWP, SFWP. Landscape type: RNGHL, FTSLO,

PLCAL, PLRED. This taxon is possibly an undescribed new species that is similar to Crossidium davidai in that it has multi-celled filaments (> 4 cells long), but different in that the filaments extend more than three-quarters of the way down the costa on the adaxial surface rather than just in the upper (apical) half of the leaf.

Specimens Examined Eldridge BSCS 443 and Dryden, 4 Aug. 1993, 90 km SW of Ivanhoe; Eldridge BSCS 444 and

Dryden, 5 Aug. 1993,s km E of Lake Mungo turnoff; Eldridge BSCS 448 and Tozer, 21 Mar. 1994, c. 1 1 km NW of Silverton; Eldridge BSCS 449 and Tozer, 20 Mar. 1994, Fowlers Gap Research Station.

Crossidium geheebii (Broth.) Broth.

Common. NWP, SWP, N W , SFWP. Landscape type: all. This moss was present on all


landscape types, particularly plains with calcareous earths, where it is found in association with a range of other mosses such as Didymodon torquatus, Desmatodon convolutus and Stonea oleaginosa.

Desmatodon convolutus (Brid.) Grout Common. NWP, SWP, NFWP, SFWP. Landscape type: all. Desmatodon convolutus is one of the most common mosses of the arid and semi-arid

zones. Generally in winter rainfall areas, on all landscape types, particularly, plains with calcareous loams. It occurs in dense tufts on bare soil and under shrubs and trees with Didymndm torpatus, Stonea oleaginosa and Bryum pachytheca. Howarth (1983) also found this to be a common component of the Middleback Station bryoflora, and it is documented in all of the bryophyte surveys.

Didymodon torquatus (Tayl.) Catches. Abundant. NWP, SWP, N W , SFWP. Landscape type: all. One of the most common

mosses found in semi-arid and arid landscapes. It was found at 122 sites in most landscapes, except the sandplains and dunefields of sandy red earths in the north-west. It occurred frequently with Desmatodon convolutus, Bryum pachytheca, Gigasperrnun repens and Crossidium davidai, often in dense tufts. Catcheside (1980) notes the role of this species in soil stabilisation.

Phascum readeranum Stone Infrequent. SFWP. Landscape type: FTSLO. Found at only one site on degraded desert

loam soils between Broken Hill and Menindee.

Specimen Examined Eldridge BSCS 394,9 Sept. 1993,40 krn S of Broken Hill.

Phascurn robustum (Broth. ex Roth) Stone var. robusturn Common. NWP, SWP, NFWP, SFWP. Landscape type: RNGHL, FTSLO, PLCAL,

PLRED, FLREL, FLACT. A moderately widely distributed moss found at 42 sites in the southern half of the survey area south of the Barrier Highway. It appears to favour woodlands with calcareous earths and red earths, and often grows in association with other common mosses such as Didymodon torquatus and Bryum pachytheca.

Phascum robustum (Broth. ex Roth) Stone var. crassinervium (C.Muel1. Roth.) Stone Relatively infrequent. NWP, SWP, SFWP. Landscape type: PLCAL, PLRED, FLREL.

Found at six sites in the survey area on a range of soil types from clays in the Riverina to calcareous earths near Wentworth in the south-west.

Phascum laticostum Stone Infrequent. SWP, SFWP. Landscape type: FLREL. On eroded duplex soils with exposed

clay subsoils near Hay and Pooncarie.

Specimen Examined Eldridge BSCS 148,6 Aug. 1993, c. 100 km NE of Mildura.

Pottia brevicaulis (Tayl.) C.Muel1.

Common. NWP, SWP, NFWP, SFWP. Landscape type: all. Catcheside (1980) describes this species as a common ephemeral in semi-desert areas.


Pottia davalliana (Sm.) C.Jens.

Infrequent. SWP. Landscape type: PLRED. Found inside and adjacent to a long-term grazing exclosure west of Condobolin.

Specimen Examined

Eldridge 41 1 ,3 1 July 1993, 15 km W of Euabalong West.

Pottia drummondii (Wils.) Willis

Infrequent. SFWP. Landscape type: FLACT, PLCAL. It has been noted to occur on saline muds (Catcheside 1980). One of our specimens (Eldridge BSCS 415) most certainly occurred on a saline floodplain. In this area, tufts of mosses were restricted to areas of accumulated soil below lignum (Meuhlenbeckia florulenta) shrubs. The other specimen (Eldridge 402), although from the same geographic area, occurred on speargrass plains, not usually expected to have saline 'soil.

Specimens Examined Eldridge BSCS 402 and Tozer, 13 July 1994, 4.3 km S of turnoff to 'Warakoo' Homestead;

Eldridge BSCS 415 and Tozer, 13 July 1994,3.8 km E of Rufus R.

Pottia globosa Catches.

Infrequent. SWP, SFWP. Landscape type: PLCAL. Recorded as rare by Catcheside (1980) in South Australia.

Specimens Examined Eldridge BSCS 409,7 Sept. 1993,20 km W of Ivanhoe; Eldridge BSCS 410,4 Aug. 1993, 70 km

SW of Ivanhoe.

Pottia scabrifolia Bartr.

Infrequent. SWP, SFWP. Landscape type: RNGHL, PLCAL, FLREL. A relatively rare moss found in small clumps in a variety of landscapes including woodlands with calcareous earths between Broken Hill and Wentworth, and clay soils south of Hay.

Specimens Examined Eldridge BSCS 7 , 7 June 1993,s km SE of Oxley; Eldridge BSCS 403 and Tozer, 12 July 1994,30

km W of Silver City Highway on the 'Buckalow' road; Eldridge BSCS 408 and Tozer, 13 July 1994, 4.3 km S of turnoff to 'Warakoo'; Eldridge BSCS 414, 6 Aug. 1993, 100 km NE of Mildura; Eldridge BSCS 417, 10 June 1993,30 km S of Hay.

Pottia starckeana (Hedw.) C.Muel1.

Infrequent. NWP, SWP. Landscape type: PLRED. A relatively common, almost cosmopolitan moss found in eastern Australia.

Specimens Examined Eldridge BSCS 65, 1 Aug. 1993, Yathong Nature Reserve; Eldridge BSCS 418,3 Aug. 1993, 10 km

S of Cobar. Also on specimen of Pterygoneurum ovatum (Eldridge BSCS 413).

Pottia spp.

Common. SWP, NWP, SFWP, NFWP. Landscape type: all. This includes all the undeter- mined Pottia specimens.


Pterygoneurum ovatum Hedwig. Infrequent. SWP. Landscape type: PLCAL. A reputedly common moss on arid-zone soils

in South Australia (Catcheside 1980). This species was found at only one site in the survey area on calcareous earth woodlands east of Ivanhoe.

Specimen Examined Eldridge BSCS 413,7 Sept. 1993,39 km W of Trida.

* Stonea oleaginosa (Stone) Zand. Common. NW?, SW?, NFW?, SI;wP. Lafidscape type: ALL. This moss was found on

most soil types except clays and unstable sands. Stone (1978) and Catcheside (1980) report that it is not uncommon in semi-arid to arid soil crusts associated with other common mosses. S. oleaginosa is a minute moss that is often difficult to see as it may be half buried under the soil surface and the red apices of the leaves often resemble the iron-stained sand grains on which it grows.

Trichostomum brachydontium Bruch Relatively infrequent. NWP, SWP. Landscape type: RNGHL, PLSND, PLCAL, PLRED.

It appears to favour semi-arid woodlands with lightly textured red earths, where it grows in small cushions to a few centimetres across.

Liverworts Aytoniaceae Asterella drummondii (H0ok.f. & Tayl.) R.M.Schuster

Infrequent. NWP. Landscape type: PLRED. Despite the view that this is one of the more common components of arid soil crusts (Scott 1985), specimens were found at only five locations, in semi-arid woodlands with red earths near Cobar.

Specimens Examined Eldridge BSCS 239, 9 Oct. 1993, 20 km W of Nyngan; Eldridge BSCS 291 and Tozer, 14 Mar.

1994, 14 km N of Nyngan; Eldridge BSCS 360,9 Oct. 1993,80 km W of Nyngan; Eldridge BSCS 437 and Tozer, 8 July 1994, Cobar Regeneration Area; Eldridge BSCS 439 and Tozer, 9 July 1994,60 km N of Cobar.

Codoniaceae Fossombronia spp. Raddi.

Common. NWP, SWP, NFWP. Landscape type: RNGHL, PLSND, PLCAL, PLRED, FLREL. Unidentifiable beyond genus, our Fossombronia species most probably belong to Group 3 (sensu Scott 1985). These were most frequently found in PLRED landscapes.

Ricciaceae Riccia albida Sull ex Austin

Infrequent. N M , SFWP. Landscape type: PLCAL. This species is common on gypsum- rich soils (Scott 1985).

Specimen Examined Eldridge BSCS 438 and Tozer, 13 July 1994,4.3 km S of turnoff to 'Warakoo'


Riccia bzfurca Hoffm. Infrequent. NWP, SWP. Landscape type: PLRED, FLREL.

Specimens Examined Eldridge BSCS 44, 8 June 1993,85 km SW of Hay; Eldridge BSCS 73, 1 Aug. 1993,55 km N of

Roto; Eldridge BSCS 395, 8 June 1993, c. 70 km SW of Hay; Eldridge BSCS 230 and Tozer, 9 July 1994,62.8 km S of Bourke.

Riccia billardieri Mont. et Nees ex Gottsche Infrequent. NWW. kndscape type: FTSLC!, PLSND. Its distribution has previously been thought to be restricted to the Northern Territory

(Na-Thalang 1980).

Specimens Examined Eldridge BSCS 389, 10 Sept. 1993,39 km E of Broken Hill; Eldridge BSCS 445 and Tozer, 16 Mar.

1994,4 krn E of Yantabulla; Eldridge BSCS 447,9 June 1993, Paradise Experimental Area.

Riccia cartilaginosa Stephani Infrequent. SWP, NFWP. Landscape type: PLSND, PLRED.

Specimens Examined Eldridge BSCS 398 and Tozer, 8 July 1994,4.3 km SW of Nymagee; Eldridge BSCS 404, 16 Mar.

1994,30 km W of Yantabulla.

* Riccia crinita Tayl. Common. NWP, SWP, NFWP. Landscape type: RNGHL, PLSND, PLRED, FLREL.

It occurred with other mosses and lichens in soil crusts at 23 locations in the survey area. It most frequently occurred on PLRED landscapes, and often occurred in association with R. lamellosa. Scott (1985) describes this species as rare.

Riccia crozalsii Levier Infrequent. NWP. Landscape type: PLSND. This liverwort was found on sandplains with

earthy sands in mulga shrubland. Scott (1985) records that it is most common in open short grassland.

Specimen Examined Eldridge BSCS 405 and Tozer, 16 Mar. 1994, 14 km S of Yantabulla.

Riccia crystallina L. Infrequent. NWP. Landscape type: FLACT. Reportedly common after rain in water lakes

and dams (Scott 1985).

Specimen Examined Eldridge BSCS 400 and Dryden, 8 Nov. 1994, 'Eangawina' Homestead.

Riccia lamellosa Raddi. Common. NWP, SWP, NFWP, SFWP. Landscape type: RNGHL, FTSLO, PLSND,

PLCAL, PLRED, FLREL. Annual. Introduced. A common component of soil crusts, often in association with R, limbata and R. crinita.

Riccia limbata Bisch.

Common. NWP, S W , NFWP, SFWP. Landscape type: all. A ubiquitous liverwort, found


on all soil types, but less commonly on sandy soils in the north-west. The plants commonly occurred as scattered individuals in the soil surface or sometimes with various mosses.

Riccia nigrella DC.

Common. NWP, SWP, NFWP, SFWP. Landscape type: all. Less common than R. limbata. This liverwort was found on clays and red earths throughout the survey area.

Riccia rorida Na-Thalang

Infrequent. SFWP. Landscape type: PLCAL.

Specimen Examined Eldridge BSCS 401,6 Aug. 1993,70 km N of 'Euston'

Riccia sorocaipa Bisch.

Infrequent. NWP, SWP, NFWP. Landscape type: FLREL, PLSND.

Specimens Examined Eldridge BSCS 54, 11 June 1993, c. 65 km W of Booligal; Eldridge BSCS 392 and Tozer, 14 Mar.

1994, 101 km N of Nyngan; Eldridge BSCS 441 and Dryden, 1 Aug. 1993, Yathong Nature Reserve; Eldridge BSCS 446,23 Apr. 1993, 'Bloodwood' Station, W of Bourke.

Riccia vesiculosa (Camng. & Pears.) Stephani

Infrequent. NWP. Landscape type: PLRED. Found at only one site in a table drain along the road. This is an ephemera1 species.

Specimen Examined Eldridge BSCS 288 and Tozer, 14 Mar. 1994,41.2 km N of Nyngan.

Acknowledgments Many people assisted with the identification of bryophytes, from general assistance at the

early stages to more specific identification of difficult specimens. For this we thank Graham Bell (South Australian Herbarium), Elizabeth Brown (National Herbarium of NSW), Robert Coveny (National Herbarium of NSW), Judith Curnow (Australian National Herbarium), Alison Downing (Macquarie University), Helen Ramsay (National Herbarium of NSW) and George Scott (University of Melbourne). George Scott commented on an earlier version of this paper. Sabine Slangen and Melissa Dryden assisted with fieldwork, and Howard McNeill (GIs Operations, Department of Conservation and Land Management) drafted the figures. This research would not have been possible without the financial and logistical support of the Land and Water Resources Research and Development Corporation and the NSW Department of Land and Water Conservation (Soil Conservation Service). Material was collected under a permit from the NSW National Parks and Wildlife Service.

References Andrew, M. H., and Lange, R. T. (1986). Developments of a new piosphere in arid chenopod shrubland

grazed by sheep. I. Changes to the soil surface. Australian Journal of Ecology 11,395-410. Beadle, N. C. W. (1948). 'The Vegetation and Pastures of Western New South Wales with Special

Reference to Soil Erosion.' (Government Printer: Sydney.) Bell, G. (1980). Arid zone mosses of South Australia: a morphological perspective. BSc Honours

Thesis, University of Adelaide. Bell, G. (1982). Leaf morphology of arid-zone moss species from South Australia. Journal o f The

Hattori Botanical Laboratory 53, 147-151.


Catcheside, D. G. (1980). 'Mosses of South Australia.' (Government Printer: South Australia.) Catcheside, D. G., and Stone, I. G. (1988). The mosses of the Northern Territory, Australia. Journal of

Adelaide Botanic Gardens 11, 1-17. Cunningham, G. M., Mulham, W. E., Milthorpe, P. L., and Leigh, J. H. (1981). 'Plants of Western New

South Wales.' (Government Printer: Sydney.) Danin, A., and Gaynor, E. (1991). Trapping of airborne dust by mosses in the Negev Desert, Israel.

Earth Surface Processes and Landforms 16,153-162. Davidson, A. J., Harborne, J. B., and Longton, R. E. (1990). The acceptability of mosses as food for

generalist herbivores, slugs in the Arionidae. Botanical Journal of the Linnean Society 104, 99-1 13. Downing, A. J. (1992). Distribution of mosses on limestones in eastern Australia. Bryologist 95,5-14. Downing, -4. .!., 2nd Sdkirk, P. M. (!993). Bryophybs on !be ca!czeous soils of Mungo National Park,

and arid area of southern central Australia. Great Basin Naturalist 53, 13-23. During, H. (1992). Ecological classifications of bryophytes and lichens. In 'Bryophytes and Lichens in

a Changing Environment'. (Eds J. W. Bates and A. M. Farmer.) pp. 1-31. (Cambridge Press: Oxford.)

Eldridge, D. J., and Greene, R. S. B. (1994). Microphytic soil crusts: a review of their roles in soil and ecological processes in the range!ands of Australia. Australian Journal of Soil Research 32, 389-415.

Eldridge, D. J., Tozer, M. E., and Koen, T. B. (1995). Bryophytes in arid soil crusts: what do they tell us about rangeland condition? In 'Proceedings of the Fifth International Rangelands Congress, Salt Lake City, Utah, July 1995'. (Ed. N. E. West.) pp. 130-131. (Society for Range Management: Denver, Colorado.)

Greene, R. S. B., Chartres, C. J., and Hodgkinson, K. H. (1990). The effect of fire on the soil in a degraded semi-arid woodland. I. Physical and micromorphological properties. Australian Journal of Soil Research 28,755-777.

Hyde, M. K. (1994). 'A Vegetation Survey of Disused Railway Corridors in the Mid-North Region of South Australia, July-November 1992.' (Nature Conservation Society of South Australia: Adelaide.)

Howarth, L. (1983). The ecology of perennial moss species in chenopod shrublands of Middleback Station, South Australia. BSc Honours Thesis, University of Adelaide.

Jacobs, S. W. L., and Pickard, J. (1981). 'Plants of New South Wales.' (Government Printer: Sydney.) Longton, R. E. (1992). The role of bryophytes and lichens in terrestrial ecosystems. In 'Bryophytes and

Lichens in a Changing Environment'. (Eds J. W. Bates and A. M. Farmer.) pp. 32-76. (Cambridge Press: Oxford.)

Meigs, P. (1953). World distribution of arid and semi-arid homoclines. In 'Reviews of Research in Arid Zone Hydrology'. pp. 203-210. (UNESCO: Paris.)

Moore, C. 5.41980). Factors determining the spatial distribution of some coastal sand dune mosses. PhD Thesis, Monash University, Melbourne.

Na-Thalang, 0. (1980). A revision of the Genus Riccia (Hepaticae) in Australia. Brunonia 3,61-140. Proctor, M. C. F. (1982). Physiological ecology: water relations, light and temperature responses,

carbon balance. In 'Bryophyte Ecology'. (Ed. A. J. E. Smith.) pp. 333-381. (Chapman and Hall: London.)

Ramsay, H. P. (1984). Census of New South Wales mosses. Telopea 2,455-534. Rogers, R. W. (1994). Zonation of the liverwort Riccia in a temporary water course in subtropical,

semi-arid Australia. Australian Journal of Botany 42, 659-662. Rogers, R. W., and Lange, R. T. (1972). Soil surface lichens in arid and subarid south-eastern Australia.

I. Introduction and floristics. Australian Journal of Botany 20, 197-213. Scott, G. A. M. (1982). Desert bryophytes. In 'Bryophyte Ecology'. (Ed. A. J. E. Smith.) pp. 105-122.

(Chapman and Hall: London.) Scott, G. A. M. (1985). 'Southern Australian Liverworts.' (Australian Government Publishing Service:

Canberra.) Scott, G. A. M. (Ed.) (1996). 'Overview of the Conservation of Non-marine Lichens, Bryophytes,

Algae and Fungi in Australia.' (Australian Nature Conservation Association: Canberra.) (in press). Scott, G. A. M., and Stone, I. G. (1976). 'The Mosses of Southern Australia.' (Academic Press:

London.) Spence, J. R., and Ramsay, H. P. (1997). Bryaceae. In 'Flora of Australia'. (Ed. A. S. George.)

(Australian Government Printing Service: Canberra.) (in press).


Stone, I. G. (1977). Some morphological and anatomical features of the monotypic genus Bryobartramia Sainsbury (Musci). Australian Journal of Botany 25, 141-157.

Stone, I. G. (1978). Tortula oleaginosa, a new moss from Australia. Journal of Bryology 10, 117-124. Stone, I. G. (1989). Revision of Phascum and Acaulon in Australia. Journal of Bryology 15,745-777. Stoneburner, A., Wyatt, R., Catcheside, D. G., and Stone, I. G. (1993). Census of the Mosses of

Western Australia. The Bryologist 96, 86-101. Streimann, H., and Curnow, J. (1989). 'Catalogue of Mosses of Australia and its External Territories.'

(Australian Government Publishing Service: Canberra.) Sveinbjornsson, B., and Oechel, W. C. (1992). Controls on growth and productivity of bryophytes:

environmental limitations under current and anticipated conditions. In 'Bryophytes and Lichens in a Changing Environment'. (Eds .I. W. Bates and A. M. Farmer.) pp. 77-102. (Cambridge Press: Oxford.)

Tongway, D. J. (1994). 'Rangeland Soil Condition Assessment Manual.' (CSIRO Division of Wildlife and Ecology: Canberra.)

West, N. E. (1990). Structure and function of microphytic soil crusts in wildland ecosystems of arid and semi-arid regions. Advances in Ecological Research 20, 179-223.

Willis, J. H. (1970). 'The Vegetation of Hattah Lakes National Park.' (National Parks Authority: Victoria.)

Zander, R. H. (1993). Genera of the Pottiaceae: mosses of harsh environments. Bulletin of the Buflalo Society of Natural Sciences 32, 1-378.

Manuscript received 12 July 1995, accepted 20 March 1996

arid ecology lab - distribution and floristics of bryophytes in ......arid soil crusts comprising...

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