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Biological Conservation

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Distribution patterns, range size and niche breadth of Austrian endemic plants

Franz Essl a,*, Markus Staudinger b, Oliver Stöhr c, Luise Schratt-Ehrendorfer d,Wolfgang Rabitsch a, Harald Niklfeld d

a Federal Environment Agency, Spittelauer Lände 5, A-1090 Vienna, Austriab AVL – ARGE Vegetation Ecology and Landscape Planning GmbH, Theobaldgasse 16/4, A-1060 Vienna, Austriac Museum Haus der Natur, Museumsplatz 5, A-5020 Salzburg, Austriad Faculty Centre Biodiversity, Department of Biogeography, University Vienna, Rennweg 14, A-1030 Vienna, Austria

a r t i c l e i n f o

Article history:Received 18 August 2008Received in revised form 15 May 2009Accepted 26 May 2009Available online xxxx

Keywords:AltitudeHabitat preferenceHot spotsNiche breadthPleistoceneRange size

0006-3207/$ - see front matter � 2009 Elsevier Ltd. Adoi:10.1016/j.biocon.2009.05.027

* Corresponding author. Tel.: +43 1 31304 3323; faE-mail address: franz.essl@umweltbundesamt.at (

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a b s t r a c t

Endemic species are not a uniform group in terms of range size, habitat preferences, and ecological plas-ticity. Based on a recent inventory of endemic vascular plant species in Austria, we analysed distributionpatterns, altitudinal distribution and habitat preferences of endemic species and analysed the correlationof range size and niche breadth. The inventory includes 103 vascular plant taxa (species and subspecies)endemic to Austria.

Grid cells (cell size ca. 35 km2) with highest taxon numbers (max. 25 taxa) are limited to the Northeast-ern Calcareous Alps, whereas highest numbers of acidophilous endemics occur in the easternmost high-mountain chains of the Central Alps. The majority of endemics (61 taxa; 59.2%) are found on calcareousbedrock, 6 taxa (5.8%) on intermediate substrates, and 29 (28.2%) on siliceous bedrock. The range size ofendemic vascular plant taxa is strongly skewed towards very narrow distributions – 45 taxa are restrictedto <20 grid cells. Average range sizes differ markedly between endemics of different broad habitat types,endemics of habitats with limited and patchy distribution (serpentine vegetation, dry grassland) havingthe smallest ranges.

The altitudinal distribution of endemic plant taxa peaks at high altitudes, in the subalpine and loweralpine altitude belt. Below the tree line, endemics predominantly colonize extra- and azonal dry orwet habitats, whereas above the tree line, zonal alpine grassland and azonal vegetation types (scree,rocks, snowbeds) are equally essential to the endemic flora. Niche breadth of endemics is positively, how-ever moderately, correlated with range size. This correlation is stronger for the altitudinal distributionthan for the number of habitats colonized.

The distribution patterns and ecology of endemics differ considerably from overall biodiversity pat-terns and must be addressed appropriately in conservation strategies. Small niche-breadths and the spe-cific habitat requirements of endemics of very localized distribution render these taxa highly vulnerableto climate change.

� 2009 Elsevier Ltd. All rights reserved.

1. Introduction

Endemism as it is understood here is the restriction of the nat-ural range of a taxon to a defined geographical area (Gaston, 1994).Endemic taxa are not randomly distributed – neither in space, noralong altitudinal gradients or in habitats. An improved understand-ing of patterns of endemism offers insights into the spatialarrangement and the causal factors of species diversity and will in-form conservationists on how and where to prioritize conservationefforts (Myers et al., 2000; Mittermeier et al., 2005; Lamoreuxet al., 2006). It is also a prerequisite for an analysis of the risk ofextinction from climate and land-use change. Endemic species

ll rights reserved.

x: +43 1 31304 3700.F. Essl).

l. Distribution patterns, range

are expected to be especially vulnerable to these pressures dueto their often small population sizes, low genetic diversity and spe-cific habitat requirements (Gilpin and Soulé, 1986; Dirnböck et al.,2003; Thomas et al., 2004; Thuiller et al., 2005; Malcolm et al.,2006; Schwartz et al., 2006).

Extremes in range sizes in endemics range from very narrowlydistributed steno-endemics to relatively widespread and abundantspecies. Ecological plasticity, expressed, e.g. as the number of hab-itats colonized and occurrence in different altitudinal zones, mightbe linked with the range size of endemics and might make steno-endemics even more vulnerable (Gaston, 1994).

Recent environmental factors acting on species stronglycontribute to endemicity patterns. These comprise e.g. climateand edaphic variables, topography, size and spatial arrangementof resulting habitats (Rosenzweig, 1995). Further, inter-specific

size and niche breadth of Austrian endemic plants. Biol. Conserv. (2009),

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interactions as predation, herbivory and symbiosis alter distribu-tion patterns. Besides environmental factors with a current impact,previous studies demonstrated that climate history (i.e. Ice Ages)contributes to the understanding of recent distribution patternsof endemics at a global scale (Hubbell, 2001; Jansson, 2003), andespecially in the alpine region (Taberlet et al., 1998; Tribsch andSchönswetter, 2003). In the Alps, climatic fluctuations in the Pleis-tocene with glaciations of large fractions of the Alps (Van Husen,1987) led to widespread migration, range restrictions, and survivalin disjunct refugia (Hewitt, 1996; Tribsch and Schönswetter, 2003;Schönswetter et al., 2005), from where taxa may have subse-quently spread.

The mountain ranges of the Alps are one of the most importanthot spots of endemic vascular plant species diversity in Europe(Myers et al., 2000; Aeschimann et al., 2004). The Eastern Alps ingeneral (288 endemic vascular plant species, Tribsch and Schöns-wetter, 2003; Tribsch, 2004) and Austria in particular (Pawłowski,1970; Ozenda, 1995) harbour a substantial fraction of these taxa.

In recent years, considerable research has been devoted to theecology, biogeography and phylogeography of endemic plant spe-cies of the Eastern Alps (e.g. Dullinger et al., 2000; Schönswetteret al., 2002; Pauli et al., 2003; Tribsch and Schönswetter, 2003;Tribsch, 2004). Building on this research, an exhaustive inventoryof Austrian endemic plant and animal taxa has recently beenaccomplished (Rabitsch and Essl, 2009). This inventory includesinformation on species ecology and biology with grid-based distri-bution data of all endemic taxa.

Using these data, we are addressing the following questionshere: (1) How are endemic plant taxa in Austria distributed withrespect to altitude, bedrock and habitats? (2) What is the patternof range sizes of endemic species and how is range size linked toniche breadth?

2. Materials and methods

2.1. Study area

Austria is a landlocked country in Central Europe covering anarea of 83, 858 km2 (46�220–49�010 N latitude, 09�330–17�060 E lon-gitude). Two thirds of Austria are dominated by mountainous re-gions of the Alps (Fig. 1A). Limestones and dolomites build upthe lower northern and southern fractions of the Austrian Alps,whereas silicate bedrocks predominate in the higher central parts.Within Austria, elevation ranges from 115 m a.s.l. in the easternlowlands to 3797 m a.s.l. at the highest peak of the Alps (Groß-glockner). About 35% of the Austrian territory are situated above1000 m a.s.l., and 0.5% of the Austrian territory are glaciated. An-nual precipitation varies from 500 to 2500 mm, and the mean an-nual temperature varies from 10 �C in the warmest parts to below�5 �C on the highest peaks.

2.2. Data and analyses

The selection of endemic vascular plant taxa was based on theinventory of Austrian endemic taxa (Rabitsch and Essl, 2009),which included endemics (100% of the range within the politicalborders of Austria) and subendemics (>75% of the range withinAustria, few very narrowly distributed endemics have been in-cluded when >50% of their range or even less lied within Austria).Due to the profound differences found in apomicts (e.g. taxa ingenera Hieracium, Rubus, Sorbus, Taraxacum and Ranunculus aurico-mus group) in terms of reproduction and taxonomic treatment(Hörandl et al., 2007), these were excluded from this study.

For the remaining endemic taxa the following information hasbeen collated: geographical distribution according to the grid of

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the Central European floristic mapping project (5 longitudinal min-utes � 3 latitudinal minutes, ca. 35 km2, Niklfeld, 1998, see TableA1). Data sources include the database of the Austrian floristicmapping project, and a large set of publications, unpublished re-cords and herbarium specimens. These data are available fromthe corresponding author on request.

The range size of endemics was extrapolated by counting thenumber of occupied grid cells. For subendemics we only usedoccurrences in grid cells within Austria, which means that theirrange size is not fully covered; however, as we only includedsubendemics which marginally extend beyond the Austrian bor-ders, we consider this range underestimation tolerable.

Information given in the distribution data set and in additionalliterature (see Rabitsch and Essl, 2009 for data sources) was used todetermine the altitudinal distribution of each endemic using alti-tude classes of 100 m (see Table A1). To test if altitudinal nichebreadth is range size dependent we tested if altitudinal distribu-tion and the numbers of occupied grid cells are correlated.

Data on colonized habitats was extracted from national florasand additional publications (see Rabitsch and Essl, 2009 for details)and assigned to habitats (see Table A1). Habitat classification isbased on a modified version of the Austrian habitat catalogue(Umweltbundesamt, 2008), which closely corresponds to phytoso-ciological units, mainly on the hierarchical level of alliances. To testif niche breadth is range size dependent we tested if the numbersof colonized habitats and numbers of occupied grid cells are corre-lated with each other. In both cases we conducted a univariate lin-ear regression (function: lm) with the log (natural logarithm) of thepredictor. The confidence interval (95%) indicating the reliability ofan estimate was calculated by the function predict for the elementsof the data sets. Statistical analyses were carried out in R, version2.5.1 (2006) (R Development Core Team, 2006).

Further we analysed, if range sizes differ between endemics ofdifferent broad habitat types. The differences between the broadhabitat types were visualized by box-and-whisker plots. Thesebroad habitat types are: forests, dry grassland, wet habitats (fens,vegetation of springs, shorelines), scree and rock vegetation, alpineand subnival grassland (incl. snowbeds), tall herb vegetation, andvegetation on serpentine bedrock (see Table A1). Each endemictaxon was assigned to one bedrock class (calcareous bedrock, sili-ceous bedrock or intermediate substrates as calcareous schists)mainly based on the data of Tribsch and Schönswetter (2003)and updated in a few cases (see Table A1).

The nomenclature of vascular plants follows Fischer et al.(2005).

3. Results

3.1. Species numbers, distribution patterns and hot spots

The inventory of endemics includes 103 endemic vascular planttaxa (species and subspecies). Even recently, new taxonomicdescriptions of endemic taxa occur regularly within this floristi-cally and taxonomically well-known region (e.g. Grulich andHodalova, 1994; Hörandl and Gutermann, 1995). Saxifraga styriaca,a morphologically well-circumscribed species of the NiedereTauern Mountains (Fig. 1B), is the endemic described most recently(Köckinger, 2003).

None of the Austrian endemics are endemic at the genus or ahigher taxonomic level. In absolute terms, large families (Astera-ceae and Brassicaceae: 12 taxa, Poaceae: 11 taxa) dominate,whereas small- to medium-sized families have the highest relativeshare of endemics: Papaveraceae (20% endemics), Saxifragaceae(16%), Primulaceae and Crassulaceae (12%) (Table 1). Large familieswithout endemics are the Cyperaceae and the Lamiaceae. Endemic

size and niche breadth of Austrian endemic plants. Biol. Conserv. (2009),

Fig. 1. Distribution maps of (A) the calciphilous Heracleum austriacum subsp. austriacum, endemic to the Northeastern Calcareous Alps, and (B) of the acidophilous Saxifragastyriaca, endemic to the eastern Central Alps. Background colours mark the 8 main bio-geographical regions of Austria (Sauberer and Grabherr, 1995): regions within the Alps(Northern and Southern Alps, predominantly calcareous substrates; Central Alps, predominantly siliceous substrates; Carinthian basin) and outside the Alps (BohemianMassif; Northern foothills; Southern foothills; Pannonic region) are shown. The morphological boundary of the Alps is further indicated by a green line. (For interpretation ofthe references to colour in this figure legend, the reader is referred to the web version of this article.)

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monocots are only represented by 11 Poaceae taxa (5.1%), andferns (Pteridophyta) and gymnosperms (Gymnospermae) do nothave any endemics at all. At the genus level, the highest numberof endemic taxa is found in species-rich genera with predomi-nantly mountain species (Campanula, Dianthus, Draba, Festuca, Saxi-

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fraga), whereas some large genera of the Austrian flora do not boastany endemics (Allium, Carex, Potentilla, Rosa, Trifolium, Viola).

Grid cells with highest taxa numbers (max. 25 taxa) are limitedto the Northeastern Calcareous Alps (between Mount Schneebergto the east and Totes Gebirge to the west, Fig. 2). High numbers

size and niche breadth of Austrian endemic plants. Biol. Conserv. (2009),

Table 1Taxonomic composition of the endemic flora of Austria at the family level. The tableshows the number of endemic taxa per family, the number of indigenous taxa incl.archaeophytes (based on Fischer et al., 2005) and the percentage of endemics (values>10% are shown in bold letters).

Family Endemic taxa Indigenous taxa(incl. archaeophytes)

% Endemics

Asteraceae 12 ca. 325 3.7Brassicaceae 12 ca. 145 8.3Poaceae 11 ca. 215 5.1Caryophyllaceae 9 133 6.8Orobanchaceae 7 72 9.7Ranunculaceae 6 ca. 125 4.8Saxifragaceae 6 38 15.8Boraginaceae 4 47 8.5Orchidaceae 4 69 5.8Campanulaceae 4 42 9.5Primulaceae 4 34 11.8Crassulaceae 3 25 12.0Gentianaceae 3 39 7.7Rubiaceae 3 48 6.3Apiaceae 2 97 2.1Dipsacaceae 2 19 10.5Euphorbiaceae 2 27 7.4Fabaceae 2 133 1.5Papaveraceae 2 10 20.0Veronicaceae 2 37 5.4Rosaceae 1 ca. 225 0.4Salicaceae 1 37 2.7Valerianaceae 1 14 7.1

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of calciphilous endemics occur also in the easternmost part of theCentral Alps, in the Grazer Bergland – an isolated area of limestonebedrock north to the city of Graz – and in the Austrian part of theSouthern Alps.

The highest numbers of acidophilous endemics occur in theeasternmost high-mountain chains of the Central Alps beginningwith the Eisenerzer Alpen in the east, and they extend westward

Fig. 2. Distribution pattern of endemic vascular plant taxa in Austria (n = 103). Shown ilatitudinal minutes, approximately 35 km2). Background colours mark the different biog

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to the Stubaier Alpen. Areas with mountain tops within the forestbelt lack high altitude endemics, which leads to a more patchy dis-tribution of hot spots (defined as grid cells >15 endemics). Endem-ics of intermediate substrate are concentrated in the central partsof the Austrian Central Alps (Hohe Tauern), where calcareousschists are widespread. Substrate specialists (e.g. endemics of ser-pentine bedrock) with very limited distribution are restricted tolow to medium altitudes in the eastern parts of the Austrian Cen-tral Alps. Outside the Alps, only a few endemics occur. A fewendemics of the northeastern Alps have outlying populations alongriver valleys in the northern foothills. In the Pannonic region ofeasternmost Austria, a few endemics of very localized distributionoccur in dry grassland, halophilic vegetation, and fens.

The range size of endemic vascular plant taxa is stronglyskewed towards very narrow distributions – 22 taxa occur in>100 grid cells (total area ca. 3500 km2) whereas 45 taxa are re-stricted to <20 grid cells (total area ca. 700 km2), of which 21 taxaare restricted to <5 grid cells (total area ca. 175 km2) (Fig. 3). Themost widespread taxon is Heracleum austriacum subsp. austriacum(258 grid cells), an endemic of the Northeastern Calcareous Alps(Fig. 1A). Average range sizes differ markedly between endemicsof different broad habitat types (Fig. 4). Endemics of habitats withlimited and patchy distribution (serpentine vegetation, dry grass-land) have the smallest, whereas endemics of widespread habitats(alpine and subnival grassland, forests, screes and rocks) have thelargest ranges.

3.2. Habitats, bedrock and altitude

Most endemic taxa in Austria show a clear preference for eithercalcareous bedrock (61 taxa; 59.2%), whereas 29 taxa (28.2%) colo-nize siliceous bedrock and 6 taxa (5.8%) intermediate bedrock; theremaining 7 taxa do not show a close relation to bedrock.

Distribution across habitats is very uneven (Table 2). Below thetree line, the habitats most frequently colonized are extra- and

s the cumulative number of endemic taxa per grid cell (5 longitudinal minutes � 3eographic regions (see Fig. 1A).

size and niche breadth of Austrian endemic plants. Biol. Conserv. (2009),

0

50

100

150

200

250

300

1 7 13 19 25 31 37 43 49 55 61 67 73 79 85 91 97 103

endemic taxa

grid

cel

ls

Fig. 3. Numbers of occupied grid cells of endemic plant taxa in Austria.

Fig. 4. Range size (boxplots of mean numbers of grid cell per taxon) of endemics of different broad habitat types. For attribution to broad habitat types see Table A1. Twospecies which could not be attributed to a single broad habitat type were excluded. For. = forests (4 taxa), D. gr. = dry grassland (15 taxa), W. hab. = wet habitats (6 taxa), Sc.and ro. = screes and rocks (28 taxa), Alp. gr. = alpine and subnival grasslands, snowbeds (39 taxa), Ta. h. veg. = tall herb vegetation (5 taxa), Serp. veg. = serpentine vegetation(4 taxa).

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azonal dry or wet grasslands (semi-dry and dry grassland, rockvegetation), fens, vegetation of springs, dry pine forests or edaph-ically extreme habitats (serpentine grassland). Zonal forest vegeta-tion (e.g. Picea and Picea-Abies forests, Fagus forests) are onlycolonized by a few endemics. Above the tree line, zonal alpinegrassland and azonal vegetation types (screes, rocks, snowbeds)are equally essential to the endemic flora.

The altitudinal distribution of endemic plant taxa peaks at highaltitudes in the subalpine krummholz and dwarf shrub vegetationand the lower part of the alpine grassland (1700–1900 m.s.l.)(Fig. 5). High numbers of endemics occur up to the upper alpinevegetation belt (approximately 2500 m.s.l.) and throughout themontane altitudinal belt, but these numbers strongly decrease inthe lowlands and the highest mountains.

3.3. Range size and ecological plasticity

The ecological plasticity of endemic vascular plants in Austria islinked with range size. Niche breadth, expressed as the number of

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habitats colonized, is positively correlated with range size, with asteep increase for endemics of very localized distribution (<20 gridcells, Fig. 6); however, the correlation is not very close. The altitu-dinal distribution of endemics shows a similar correlation withrange size and the correlation is closer (Fig. 7). The average altitu-dinal distribution of very narrowly distributed endemics (<20 gridcells) is 510 m (SD ±352 m), whereas more widespread endemics(>100 grid cells) occur over an average altitudinal span of1295 m (SD ±381 m).

4. Discussion

4.1. Distribution patterns, hot spots and post-glacial re-colonization

Of the 288 vascular plant species and subspecies endemic to theeastern Alps (Tribsch and Schönswetter, 2003; Tribsch, 2004), 103(36%) are endemic to Austria. However, as the inclusion of endem-ics here is based on the boundaries of a political entity (Austria),several range-restricted species of the Southeastern Calcareous

size and niche breadth of Austrian endemic plants. Biol. Conserv. (2009),

Table 2Habitat preferences of endemic vascular plant taxa in Austria. Note that taxa canoccur in several habitats. For attribution to habitats see Table A1. The codes of thehabitats refer to the Austrian habitat catalogue (Umweltbundesamt, 2008).

code Habitat # taxa % taxa

4 Alpine to subnival grassland, snowbeds4.1 Alpine grassland 40 38.84.2 Subnival cushion vegetation 20 19.44.3 Snowbeds 15 14.69 Forests and subalpine scrubs9.1 Pinus mugo krummholz, subalpine Alnus

alnobetula and Salix Scrub16 15.5

9.2 Floodplain forest, Acer-Tilia forests 3 2.99.7 Sub- to montane Picea-Abies-Fagus forests 5 4.99.9 Ostrya forests 2 1.99.10 Larix und Larix-Pinus cembra forests 2 1.99.11 Picea and Picea-Abies forests 4 3.99.12 Pinus sylvestris and Pinus nigra forests 17 16.58 Thermophilic scrubs 2 1.96.1, 6.3 Tall herb vegetation, forest fringes 14 13.67 Dwarf shrub vegetation 9 8.72.1, 2.2.3 Vegetation of springs, fens 9 8.71.3.5, 1.4.9 Alluvial habitats and riparian pioneer

habitats8 7.8

10 Geomorphological habitats10.4 Rock vegetation 40 38.810.5 Scree vegetation 40 38.83 Grasslands3.1, 3.2.1, 3.2.2 Mesic to wet grassland 6 5.83.3.1 Semi-dry grassland 10 9.73.3.2 Dry grassland 20 19.43.4 Halophilic grassland 1 1.03.5 Serpentine and heavy metal grassland 7 6.8

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Alps do not fulfil the inclusion criteria, as their range predomi-nantly lies in adjacent Slovenia or Italy. Therefore, the number ofendemics would increase substantially in the Austrian SouthernAlps, if these species would be included (Niklfeld et al., 2008).

The observed pattern of geographic distribution of endemicswithin Austria closely resembles the one presented by Tribschand Schönswetter (2003), Tribsch (2004) for mountain ranges inthe Eastern Alps. But, as the grid cells used here – as well as by Eng-lisch et al. (2005) and Niklfeld et al. (2008) – are smaller by a factorof 10–20 than mountain ranges, the picture is more detailed. In

Fig. 5. Altitudinal distribution of endemic vascular plant taxa shown as a number of eneach endemic species is given in Table A1. The share of the total Austrian area in each a

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peripheral regions of the Austrian Alps where the highest moun-tain tops only marginally protrude into the alpine altitudinal belt,hot spots of endemics are confined to the highest mountain ridges.At the convergence of two bio-geographical regions (e.g. Northernand Central Alps), local hot spots are due to the combined presenceof different bedrocks within small areas, resulting in an overlap ofspecies distributions. In the northern foothills, the few endemicsfound here are limited to large river valleys, which offer suitablehabitats locally (e.g. conglomerate rock precipices) for endemicswhose distribution is concentrated in the northeastern Alps. Inthe Pannonic lowlands of eastern Austria, the few localized ste-no-endemics are restricted to areas with extra- or azonal habitats(halophilic grassland, fens, dry grasslands). Taxonomic composi-tion in different hot spots is very distinct, e.g. there is no taxon en-demic to Austria that occurs in both the Southern and theNortheastern Calcareous Alps. This is in contrast to several ende-mic species of the entire Alps showing, e.g. North–South disjunc-tions (Merxmüller, 1952–1954).

The range size of Austrian endemic vascular plant taxa isstrongly skewed towards very narrow distributions. The overridingrole that climatic fluctuations during the Pleistocene seem to haveplayed for the current distribution patterns of endemics is con-firmed, as all hot spots (>15 endemics per grid cell) lie withinnot – or only moderately – glaciated potential refugia (reviewedby Tribsch and Schönswetter, 2003; Tribsch, 2004; Schönswetteret al., 2005). However, high numbers of endemics extend substan-tially into areas (especially of the Central Alps, e.g. Hohe Tauern)which were heavily glaciated during the Last Glacial Maximum(Van Husen, 1987). Thus, current ecological factors as climaticgradients and habitat availability significantly modify the distribu-tion patterns of endemic species (Pils, 1995), and post-glacialre-colonization, nunatak survival within the ice shield or, in fewcases, post-glacial speciation must have taken place (Tribsch andSchönswetter, 2003).

4.2. Altitudinal distribution, habitats, and bedrock

Range sizes of endemics of broad habitat types differ markedly,endemics restricted to rare and patchy habitats in low to mediumaltitudes (serpentine vegetation, dry grassland, wet habitats)

demics occurring in a 100 m altitudinal belt (grey bars). Altitudinal distribution forltitudinal belt is shown as a black line.

size and niche breadth of Austrian endemic plants. Biol. Conserv. (2009),

Fig. 6. Correlation between range size (shown as the number of occupied grid cells per endemic taxon) and niche breadth (expressed as the number of habitats colonized) ofendemic vascular plants in Austria (r2 = 0.28; y = 0.4231Ln (x) + 1.4642, p < 0.001). The solid line shows the estimated values for the elements of the data set on the base of thefitted regression equation. The slashed lines show the confidence interval (95%) of the estimated values. For attribution to habitats see Table A1.

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having the smallest ranges. We argue that patches of these habitatsoffer favourable conditions for speciation and long-term survival:extreme abiotic conditions give rise to high selection pressure,populations are effectively separated from each other and popula-tion sizes are usually small. Further, during climatic fluctuations ofthe Ice Ages, these lowland habitats might have offered favourableconditions for in situ-survival (Tribsch and Schönswetter, 2003).

The altitudinal distribution of endemics peaks in the subalpineand lower alpine belt, confirming regional analyses of endemics ofthe Alps (Médail and Verlaque, 1997; Dullinger et al., 2000; Casaz-za et al., 2005), and seems to be valid for the entire alpine region(Pawłowski, 1970; Tribsch and Schönswetter, 2003). Endemics ofEuropean mountain ranges are generally concentrated in mid tohigh altitudes, e.g. the Carpathians (Kliment, 1999), the Corsicanmountains (Médail and Verlaque, 1997) and the Caucasian range(Agakhanjanz and Breckle, 2002). Endemics of low-lying regionsin Europe are mostly confined to the Mediterranean, which mightreflect the warmer climate there during the Ice Ages, allowing spe-cies adapted to warmer climates to survive (García-Barros et al.,2002).

The general altitudinal distribution pattern of vascular plants inthe Alps is in sharp contrast to that of endemics, as it is strongly dri-ven by energy availability and thus culminates in low-lying regionswith a mild climate (Wohlgemuth, 1998; Körner, 2002; Moser et al.,2005). On the landscape scale, intermediate altitudes show highestspecies richness in the Swiss Alps (Wohlgemuth et al., 2008). Thiscontrasting altitudinal pattern can be partly attributed to the stronginfluence of climatic fluctuations (Tribsch and Schönswetter, 2003;

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Tribsch, 2004). During the Last Glacial Maximum of the Ice Ages,important refugia for cold adapted taxa were situated in the periph-eral ice-free areas. Vicariance in the Ice Age refugia (Hewitt, 1996;Taberlet et al., 1998), strong geomorphologic and habitat differenti-ations at high altitudes and the existence of effective barriers tospread between high altitude mountain ranges might have furthercontributed to the altitudinal pattern. The well-known preponder-ance of calciphilous endemics might be attributed to the predomi-nance of calcareous glacial refugia (Tribsch and Schönswetter,2003), and it is in line with the higher species-richness found ingeneral on calcareous bedrock in the Alps (e.g. Wohlgemuth,1998; Moser et al., 2005), which seems to be also related to the Cen-tral European climate history (Ewald, 2003). However, the share ofacidophilous endemics in Austria is considerably higher than in theEastern Alps overall (Tribsch and Schönswetter, 2003) and reflectsthe over-proportionally large areas of acidophilous bedrock withinputative glacial refugia.

The observed preponderance of endemic taxa in extreme habi-tats with low competition is a known feature of the Alps (Pawłows-ki, 1970; Ozenda, 1988; Tribsch and Schönswetter, 2003). Thehabitat preferences of the Austrian endemics, however, changealong an altitudinal gradient (Niklfeld, 1973). Endemics distributedin low- to mid-altitudes mostly occur in dry and wet azonal habi-tats, whereas climax forests are poor in endemics. At and above thetree line, this pattern is much less accentuated. Although scree,snowbed and rock vegetation still are the most important habitatsfor endemics, alpine grassland, which form the climax vegetation,are also colonized by a large number of endemics.

size and niche breadth of Austrian endemic plants. Biol. Conserv. (2009),

Fig. 7. Correlation of range size (shown as the number of occupied grid cells per endemic taxon) and the altitudinal distribution (defined as the difference between upper andlower altitudinal distribution limit) of endemic vascular plants in Austria (r2 = 0.46; y = 222.54Ln(x) + 184.59, p < 0.001). The solid line shows the estimated values for theelements of the data set on the base of the fitted regression equation. The slashed lines show the confidence interval (95%) of the estimated values. For number of colonizedgrid cells per endemic see Table A1.

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4.3. Ecological plasticity in relation to range size

Niche breadth of Austrian endemic vascular plants is positivelycorrelated with range size, and more so for the altitudinal distribu-tion than for the number of habitats colonized. The ability to colo-nize several habitats or a wide range of altitude increaseslandscape permeability and thus enhances dispersal. However,more widespread endemics are likely to exist under different re-gional climatic and orographic conditions – e.g. in higher as wellas in lower mountain ranges with different altitudinal positionsof corresponding vegetation belts. Thus, the altitudinal span of aspecies’ occurrence, in such cases, will not necessarily reflect itsecological niche breadth.

In contrast to alien plants in Central Europe (Kühn et al., 2004),the rather weak relation of range size to the tested niche breadthvariables indicates that the numbers of habitats colonized and alti-tudinal distribution only cover a moderate fraction of the featuresresponsible for an endemic taxon’s range size. We argue that spe-cies’ age and traits, population dynamics (Rosenzweig, 1995), his-torical events (e.g. range size during the Last Glacial Maximum,Schönswetter et al., 2005) and the total area and distribution ofthe habitats colonized (Pils, 1995) all contribute to explaining therange size.

4.4. Implications for nature conservation

The distribution and ecology of endemics differ considerablyfrom overall biodiversity patterns and must be addressed appro-

Please cite this article in press as: Essl, F., et al. Distribution patterns, rangedoi:10.1016/j.biocon.2009.05.027

priately in conservation strategies. Currently, 72% of endemicsare not endangered (Niklfeld and Schratt-Ehrendorfer, 1999). Tentaxa are considered to be critically endangered (CR) (see TableA1), most of them have undergone a strong decline during the lastdecades. Eight taxa are endangered (EN) and eleven taxa are vul-nerable (VU). The threat status strongly increases towards taxa re-stricted to low altitudes, and towards endemics restricted topatchy and rare habitats. Further, there are marked differences inthe threat status of endemics of different broad habitat types:endemics of serpentine habitats (50%), dry grassland (60%), andwet habitats (83%) are highly endangered (CR or EN). In contrast,most endemics of widespread habitats as scree and rock vegetation(14%) and alpine grassland (15%) are less (VU) or not threatened.

The smaller altitudinal distribution and the fewer number ofcolonized habitats of very narrowly distributed endemics makethese species especially vulnerable to climate change (Ohlemülleret al., 2008). Dirnböck et al. (2003) predict that several endemicsof the Northeastern Calcareous Alps are highly sensitive to climatechange, and range-restricted alpine endemics may face strong hab-itat reductions, as the tree line is only a few hundred meters belowthe isolated mountains tops. Therefore, the currently low extinc-tion risk of endemics of high-mountain areas in Austria might in-crease considerably in the future.

Urgently needed for all critically endangered and endangeredendemics is the implementation of species action plans whichshould be based on experience gained e.g. in Great Britain (Biodi-versity Action Plan, UK BAP, 2008) or in Bavaria (Berg, 2002). Inthese countries, species action plans have led to significant

size and niche breadth of Austrian endemic plants. Biol. Conserv. (2009),

Table A1Data on distribution, habitat preference, date of scientific description, altitudinal distribution and red list categories of Austrian endemic plant species. Taxon = scientific name (Fischer et al., 2005), # rec = number of records, # grcells = number of colonized grid cells, bedr = bedrock (1 = not classified, 2 = calcareous bedrock, 3 = intermediate bedrock, 4 = siliceous bedrock), (sub)end = taxon endemic (E) or subendemic (S) to Austria, yr sc descr = year of scientificdescription, habitat = codes of colonized habitats (see Table 2), # hab = number of colonized habitats, br ha. = broad habitat types to which the endemic taxon is restricted or in which it predominantly occurs (F = forests, D = drygrassland, W = wet habitats, R = rocks & screes, A. = alpine & subnival grasslands, snowbeds, T = tall herb vegetation, S = serpentine vegetation, N = not classified), alt_min = lower altitudinal distribution limit (in m), alt_max = upperaltitudinal distribution limit (in m), alt_dist = altitudinal distribution (in m), Red l cat = Austrian Red list category (based on Niklfeld and Schratt-Ehrendorfer, 1999).

Taxon # rec # grcells

bedr (sub)end yr scdescr

Habitats # hab br hab alt_min alt_ max alt_dist Red l cat

Hab1 Hab2 Hab3 Hab4 Hab5 Hab6

Achillea clusiana 207 74 2 S 1821 4.3 10.5 2 A 1400 2100 700 LCAlchemilla anisiaca 408 111 2 E 1891 4.3 4.1 10.5 3 A 1200 2200 1000 LCAlyssum wulfenianum 10 5 2 S 1814 1.3.5 1 R 500 700 200 CRAndrosace wulfeniana 38 18 4 S 1855 4.2 10.4 2 A 1800 2600 800 LCArtemisia pancicii 22 7 2 S 1881 3.3.2 1 D 100 400 300 ENAvenula adsurgens subsp. ausserdorferi 21 16 4 S 1976 4.1 7.2 9.10 3 A 1000 2000 1000 LCBiscutella laevigata subsp. austriaca 350 176 2 E 1864 3.3.1 3.3.2 4.1 9.12 10.5 9.1.1 5 N 200 2100 1900 LCBiscutella laevigata subsp. kerneri 60 18 1 S 1926 3.3.2 9.12 3.5 3 D 100 700 600 VUBraya alpina 27 18 3 S 1815 4.1 4.2 10.5 1.3.5 4 A 2000 3000 1000 LCCallianthemum anemonoides 92 60 2 E 1823 9.12 10.5 10.4 3 R 400 1700 1300 LCCampanula beckiana 71 40 2 E 1912 3.3.1 6.3 9.7 3 D 200 1200 1000 LCCampanula praesignis 46 35 2 E 1893 10.4 1 R 500 1600 1100 LCCampanula pulla 516 173 2 E 1753 10.4 4.3 4.1 10.5 4 R 1000 2200 1200 LCCochlearia excelsa 10 3 4 E 1908 10.4 10.5 2 R 2000 2400 400 LCCochlearia macrorhiza 4 3 2 E 1971 2.1 2.2.3 2 W 100 200 100 CRComastoma nanum 107 65 3 S 1779 4.2 10.5 2 R 2200 2800 600 LCDelphinium elatum subsp. austriacum 81 28 1 E 1933 9.1.2 6.1 9.10 9.11 4 T 1100 2200 1100 VUDianthus alpinus 413 106 2 E 1753 4.1 10.4 10.5 7.2 4 A 700 2300 1600 LCDianthus carthusianorum subsp. capillifrons 10 8 4 E 1888 3.5 9.12 2 S 400 800 400 DDDianthus lumnitzeri 1 1 2 S 1886 3.3.2 1 D 200 400 200 LCDianthus plumarius subsp. blandus 47 18 2 E 1844 3.3.2 9.12 10.5 9.1.1 4 R 300 1800 1500 LCDianthus plumarius subsp. hoppei 46 31 2 S 1911 3.3.2 10.4 9.12 9.9 4 R 500 1900 1400 LCDianthus plumarius subsp. neilreichii 6 2 2 E 1851 3.3.2 9.12 2 D 200 500 300 ENDoronicum cataractarum 12 4 4 E 1925 9.1.2 6.1 2.1 3 T 1300 2000 700 LCDoronicum glaciale subsp. calcareum 89 28 2 E 1900 4.1 4.3 2 A 1400 2200 800 LCDoronicum glaciale subsp. glaciale 414 235 3 S 1855 10.4 10.5 4.2 4.3 9.1.1 5 R 1700 2600 900 LCDraba aizoides subsp. beckeri 20 20 2 S 1995 3.3.2 10.4 2 R 200 1700 1500 LCDraba pacheri 11 9 4 S 1855 4.3 10.4 10.5 4.3 4 A 1800 2700 900 VUDraba sauteri 61 27 2 S 1823 10.4 10.5 4.2 3 R 1800 2900 1100 LCDraba stellata 154 76 2 E 1762 10.4 10.5 4.3 3 R 1900 2500 600 LCErigeron glabratus subsp. candidus 4 2 2 E 1932 4.1 1 A 1700 2000 300 VUEuphorbia austriaca 359 154 2 E 1875 6.1 9.11 9.7 3.2.2 9.2 5 F 500 2100 1600 LCEuphorbia saxatilis 38 26 2 E 1776 9.12 3.3.2 2 F 300 1100 800 LCEuphrasia inopinata 3 2 4 E 1984 4.1 1 A 1800 2500 700 VUEuphrasia sinuata 2 2 2 E 1984 4.1 1 A 1700 2000 300 VUFestuca eggleri 17 12 4 E 1977 9.12 3.5 3.3.2 3 S 600 900 300 VUFestuca pseudodura 297 202 4 S 1854 4.1 10.5 4.2 10.4 4 A 1700 2900 1200 LCFestuca stricta 63 29 2 E 1970 3.3.2 9.12 3.5 3 D 200 600 400 LCFestuca varia subsp. varia 82 78 4 E 1999 4.1 7.2 10.4 3 A 1400 2300 900 LCFestuca varia subsp. winnebachensis 9 5 4 S 1999 4.1 7.2 10.4 3 A 1600 2400 800 LCFestuca versicolor subsp. brachystachys 243 46 2 E 1882 4.1 10.5 10.4 3 A 900 2200 1300 LCFestuca versicolor subsp. pallidula 81 46 2 E 1882 10.5 10.4 3.3.2 3 R 500 1700 1200 LCGalium meliodorum 78 39 2 E 1909 10.5 10.4 4.1 3 R 1300 1800 500 LCGalium noricum 269 119 2 S 1953 4.1 4.2 4.3 10.5 4 A 900 2500 1600 LCGalium truniacum 189 93 2 S 1913 10.5 10.4 9.12 3 R 400 2000 1600 LCGentiana froelichii subsp. froelichii 16 10 2 S 1832 4.1 4.2 2 A 1400 2400 1000 LCGentianella praecox 42 28 4 S 1968 3.2.1 3.3.1 2.2.3 3.1 4 D 400 1100 700 CRHelictotrichon petzense 8 4 2 S 1967 10.4 1 R 1200 2000 800 LCHeliosperma veselskyi subsp. widderi 2 1 4 S 1979 10.3.2 10.4 2 R 700 800 100 ENHeracleum austriacum subsp. austriacum 898 258 2 S 1753 4.1 6.1 9.1.1 7.2 4 A 600 2100 1500 LCJovibarba globifera subsp. arenaria 248 167 4 S 1837 4.1 10.4 10.5 3 R 900 2500 1600 LC

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Table A1 (continued)

Taxon # rec # grcells

bedr (sub)end yr scdescr

Habitats # hab br hab alt_min alt_ max alt_dist Red l cat

Hab1 Hab2 Hab3 Hab4 Hab5 Hab6

Knautia carinthiaca 4 3 2 E 1962 3.3.2 9.12 3.3.1 9.9 4 D 600 800 200 LCKnautia norica 23 17 2 E 1962 3.3.2 9.12 3.5 3.3.1 4 D 600 900 300 VULeucanthemum atratum 527 144 2 E 1966 4.1 10.5 4.2 7.2 4 A 400 2300 1900 LCLeucanthemum lithopolitanicum 5 1 2 S 1960 4.1 4.2 10.5 3 A 1800 2400 600 LCMelampyrum subalpinum 62 44 2 S 1857 9.12 3.3.1 3.3.2 9.11 6.3 5 D 300 1200 900 LCMoehringia diversifolia 86 68 4 E 1839 10.4 10.5 2 R 400 1800 1400 LCMyosotis decumbens subsp. kerneri 56 46 1 E 1912 9.2 9.1.2 6.1 9.1.1 4 T 1000 2000 1000 LCMyosotis rehsteineri 18 4 1 S 1854 1.4.9 1 W 300 400 100 ENNigritella archiducis-joannis 8 7 2 E 1985 4.1 1 A 1700 2000 300 ENNigritella lithopolitanica 30 13 2 S 1978 4.1 1 A 1500 2100 600 LCNigritella nigra subsp. austriaca 95 70 2 S 1990 4.1 3.2.1 2 A 900 2500 1600 LCNigritella stiriaca 16 11 2 E 1985 4.1 1 A 1200 1900 700 ENNoccaea crantzii 433 104 2 E 1762 4.1 10.4 10.5 4.3 9.1.1 5 A 600 2300 1700 LCNoccaea rotundifolia subsp. cepaeifolia 12 3 2 S 1833 1.3.5 1 R 500 700 200 CROnobrychis arenaria subsp. taurerica 9 9 4 E 1938 3.3.2 10.4 10.5 8.7 8.5.3 5 D 700 1900 1200 LCOnosma helvetica subsp. austriaca 13 2 4 E 1891 3.3.2 3.3.1 2 D 200 400 200 CROxytropis triflora 89 58 3 E 1827 4.1 4.2 10.5 3 A 1800 2700 900 LCPapaver alpinum subsp. alpinum 123 59 2 E 1903 10.5 4.2 10.4 1.3.5 4 R 600 2500 1900 LCPapaver alpinum subsp. sendtneri 59 40 2 S 1903 10.5 4.2 10.4 1.3.5 4 R 1000 2700 1700 LCPedicularis aspleniifolia 264 177 4 S 1800 4.2 10.5 4.1 3 A 1900 2800 900 LCPedicularis portenschlagii 107 60 1 E 1827 4.1 10.5 2 A 1500 2800 1300 LCPedicularis rostratospicata subsp. rostratospicata 251 184 2 S 1769 4.1 10.5 2 A 1500 2500 1000 LCPhyteuma globulariifolium subsp. globulariifolium 354 218 4 S 1904 4.1 4.2 2 A 2300 3200 900 LCPrimula clusiana 784 227 2 S 1821 4.1 10.4 4.3 3 A 500 2500 2000 LCPrimula villosa 68 33 4 S 1778 4.1 10.4 4.2 3 A 400 2400 2000 LCPuccinellia peisonis 18 14 2 S 1890 3.4 1 W 100 200 100 VUPulmonaria carnica 16 11 2 S 1973 9.7 9.1.1 6.1 3 F 900 1600 700 LCPulmonaria kerneri 96 58 2 E 1888 6.3 9.7 9.1.1 6.1 4 F 600 1600 1000 LCPulsatilla alpina subsp. schneebergensis 191 141 2 E 2003 4.1 9.1.1 7.2 3 A 1000 1900 900 LCPulsatilla oenipontana 11 4 2 E 1909 3.3.1 6.3 2 D 600 800 200 CRPulsatilla styriaca 65 23 2 E 1841 3.3.2 3.3.1 9.12 3 D 400 1500 1100 VURhinanthus carinthiacus 7 5 4 E 1957 4.1 1 A 1200 2000 800 LCSalix mielichhoferi 201 144 4 S 1849 9.1.2 1.3.5 9.1.2 10.5 4 N 1300 2200 900 LCSaponaria pumila 443 205 4 S 1767 4.1 4.2 10.5 7.2 4 A 1600 2800 1200 LCSaxifraga blepharophylla 93 61 4 E 1902 4.2 10.4 10.5 3 R 1800 3300 1500 LCSaxifraga hohenwartii 28 14 2 S 1808 4.3 10.5 10.4 9.1.1 4 R 1600 2600 1000 LCSaxifraga paradoxa 38 26 4 S 1810 10.4 10.3.2 2 R 400 1600 1200 ENSaxifraga rudolphiana 181 92 3 S 1835 4.3 4.2 10.4 10.5 4 R 2300 3100 800 LCSaxifraga stellaris subsp. prolifera 74 47 4 S 1922 1.3.5 2.1 2.2.3 3 W 1000 2400 1400 LCSaxifraga styriaca 19 16 3 E 2003 4.1 4.2 2 A 1800 2400 600 LCScorzoneroides montaniformis 21 13 2 E 1950 4.3 10.5 2 A 1700 1900 200 LCSempervivum pittonii 5 2 4 E 1854 3.5 9.12 10.4 3 S 600 800 200 CRSempervivum stiriacum 419 203 4 E 1909 10.4 10.5 4.1 3 R 1600 2600 1000 LCSenecio fontanicola 19 18 2 S 1994 2.1 2.2.3 2 W 400 900 500 ENSeseli austriacum 246 160 2 S 1891 10.4 3.3.2 2 R 300 1300 1000 LCSoldanella austriaca 133 82 2 S 1904 4.3 10.5 10.4 4.1 4 A 1300 2300 1000 LCStipa styriaca 15 3 2 E 1970 3.3.1 3.3.2 2 D 800 1100 300 CRTephroseris helenitis subsp. salisburgensis 61 27 1 S 1933 2.2.3 3.1 2 W 400 800 400 ENTephroseris integrifolia subsp. serpentini 4 2 2 E 1929 3.5 9.12 2 S 600 900 300 CRValeriana celtica subsp. norica 316 140 4 E 1925 4.1 7.2 10.4 3 A 1800 2800 1000 LCVeronica chamaedrys subsp. micans 111 95 1 S 1973 6.1 6.3 9.7 9.11 9.1.1 9.5 6 T 800 1900 1100 LCWulfenia carinthiaca 9 2 2 S 1781 6.1 3.2.2 2 T 1000 2000 1000 VUTotal 12638 5948

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improvements in the legal protection status of species, they haveimproved the quality of management in nature reserves, and thusresulted in increases of the population sizes of threatened endem-ics. On a supra-national level, a stronger recognition of endemictaxa should be implemented, e.g. only four Austrian endemicsare listed in the Annex II of the Fauna-Flora-Habitats-directive,which forms the legal basis for the most important European con-servation network.

Acknowledgements

We are obliged to numerous colleagues for contributing to theunderlying inventory of endemic taxa in Austria. We also thankall the enthusiastic field botanists who collected the underlyingdistribution data. We thank J. Kobler for statistical advice. Linguis-tic revision was done by B. Read (Federal Environment Agency Aus-tria). We thank three anonymous reviewers and R. Primack forvaluable comments.

Appendix A

See Table A1.

References

Aeschimann, P., Lauber, K., Moser, D.M., Theurillat, J.P., 2004. Flora Alpina. Bd. 1-3.Haupt Verlag, Bern.

Agakhanjanz, O., Breckle, S.-W., 2002. Plant diversity and endemism in highmountains of Central Asia, the Caucasus and Siberia. In: Körner, C., Spehn, E.M.(Eds.), Mountain Biodiversity – A Global Assessment. Parthenon Publishing,New York, pp. 117–128.

Berg, M., 2002. Das Artenhilfsprogramm für endemische und stark bedrohtePflanzenarten Bayerns. Schriftenreihe für Vegetationskunde 36, 15–21.

Casazza, C., Barberis, G., Minuto, L., 2005. Ecological characteristics and rarity ofendemic plants of the Italian Maritime Alps. Biological Conservation 123, 361–371.

Dirnböck, T., Dullinger, S., Grabherr, G., 2003. A regional impact assessment ofclimate and land-use change on alpine vegetation. Journal of Biogeography 30,401–417.

Dullinger, S., Dirnböck, T., Grabherr, G., 2000. Reconsidering endemism in theNortheastern Limestone Alps. Acta Botanica Croatica 59, 55–82.

Englisch, T., Tribsch, A., Niklfeld, H., 2005. Besonderheiten der Artenvielfalt – selteneund endemische Arten in der Flora Österreichs. In: Borsdorf, A. (Ed.), Das neueBild Österreichs. Verlag der österreichischen Akademie der Wissenschaften,Wien, pp. 33–34.

Ewald, J., 2003. The calcareous riddle. Why are there so many calciphilous species?Folia Geobotanica 38, 357–366.

Fischer, M.A., Adler, W., Oswald, K., 2005. Exkursionsflora für Österreich,Liechtenstein und Südtirol. Biologiezentrum Oberösterreich, Linz.

Gaston, K.J., 1994. Rarity. Chapman & Hall, London.García-Barros, E., Gurrea, P., Luciáñez, M.J., Cano, J.M., Munguira, M.L., Moreno, J.C.,

Sainz, H., Sanz, M.J., Simón, J.C., 2002. Parsimony analysis of endemicityand its application to animal and plant geographical distributions in theIbero-Balearic region (western Mediterranean). Journal of Biogeography 29,109–124.

Gilpin, M.E., Soulé, M.E., 1986. Minimum viable populations: processes of speciesextinction. In: Soulé, M.E. (Ed.), Conservation Biology: The Science of Scarcityand Diversity. Sinauer Ass. Inc., Sunderland, pp. 19–34.

Grulich, V., Hodalova, I., 1994. The Senecio doria group (Asteraceae–Senecioneae) inCentral and Southeastern Europe. Phyton 34, 247–265.

Hewitt, G.M., 1996. Some genetic consequences of ice ages, and their role indivergence and speciation. Biological Journal of the Linnean Society 58, 247–276.

Hörandl, E., Gutermann, W., 1995. Draba aizoides subsp. beckeri (Brassicaceae), einesubendemische Sippe der östlichsten Alpen. Phyton 35, 83–101.

Hörandl, E., Grossniklaus, U., Sharbel, T., Van Dijk, P. (Eds.), 2007. Apomixis:Evolution Mechanisms and Perspectives. Gantner Verlag, Ruggell, Liechtenstein.

Hubbell, S.P., 2001. A Unified Theory of Biogeography and Biodiversity. PrincetonUniversity Press, New York.

Jansson, R., 2003. Global patterns in endemism explained by past climatic change.Proceedings of the Royal Society London, Series B 270, 583–590.

Kliment, J., 1999. Komentovany prehl’ad vyšších rastlín flóry Slovenska, uvádzanychv literatúre ako endemické taxony. Bulletin Slovenskej Botanickej Spolocnosti21 (Suppl. 4).

Köckinger, H., 2003. Saxifraga styriaca Köckinger spec. nova (Saxifragaceae) – einEndemit der östlichen Niederen Tauern (Steiermark, Österreich). Phyton 43, 79–108.

Please cite this article in press as: Essl, F., et al. Distribution patterns, rangedoi:10.1016/j.biocon.2009.05.027

Körner, C., 2002. Mountain biodiversity, its causes and function: an overview. In:Körner, C., Spehn, E.M. (Eds.), Mountain Biodiversity – A Global Assessment.Parthenon Publishing, New York, pp. 3–20.

Kühn, I., Brandenburg, M., Klotz, S., 2004. Why do alien plant species that reproducein natural habitats occur more frequently? Diversity and Distributions 10, 417–425.

Lamoreux, J.F., Morrison, J.C., Ricketts, T.H., Olson, D.M., Dinerstein, E., Knight, M.W.,Shugart, H.H., 2006. Global test of biodiversity concordance and the importanceof endemism. Nature 440, 212–214.

Malcolm, J.R., Liu, C., Neilson, R.P., Hansen, L., Hannah, L., 2006. Global warming andextinctions of endemic species from biodiversity hotspots. Conservation Biology20, 538–548.

Médail, F., Verlaque, R., 1997. Ecological characteristics and rarity of endemic plantsfrom southeastern France and Corsica: implications for biodiversityconservation. Biological Conservation 80, 269–281.

Merxmüller, H., 1952–1954. Untersuchungen zur Sippengliederung undArealbildung in den Alpen Teil 1-3. Jahrbuch des Vereins zum Schutze derAlpenpflanzen und -tiere 17, 96–133Merxmüller, H., . Untersuchungenzur Sippengliederung und Arealbildung in den Alpen Teil 1-3. Jahrbuchdes Vereins zum Schutze der Alpenpflanzen und -tiere 18, 135–158Merxmüller, H., . Untersuchungen zur Sippengliederung und Arealbildungin den Alpen Teil 1-3. Jahrbuch des Vereins zum Schutze der Alpenpflanzen und-tiere 19, 97–133.

Mittermeier, R.A., Gil, P.R., Hoffman, M., Pilgrim, J., Brooks, T., Mittermeier, C.G.,Lamoreux, J., Fonseca, G.A.B., 2005. Hotspots revisited: earth’s biologicallyrichest and most endangered terrestrial ecoregions. Conservation International,392.

Moser, D., Dullinger, S., Englisch, T., Niklfeld, H., Plutzar, C., Sauberer, N.,Zechmeister, H.G., Grabherr, G., 2005. Environmental determinants of vascularplant species richness in the Austrian Alps. Journal of Biogeography 32, 1117–1127.

Myers, N., Mittermeier, R.A., Mittermeier, C.G., De Fonseca, G.A.B., Kent, J., 2000.Biodiversity hotspots for conservation priorities. Nature 403, 853–858.

Niklfeld, H., 1973. Über Grundzüge der Pflanzenverbreitung in Österreich undeinigen Nachbargebieten. Verhandlungen der zoologisch-botanischenGesellschaft Österreich 113, 53–69.

Niklfeld, H., 1998. Mapping the flora of Austria and the eastern Alps. Valdôtained’Histoire Naturelle 51, 53–62.

Niklfeld, H., Schratt-Ehrendorfer, L., 1999. Rote Liste gefährdeter Farn- undBlütenpflanzen (Pteridophyta und Spermatophyta) Österreichs. 2. Fassung. In:H. Niklfeld (Ed.), Rote Listen gefährdeter Pflanzen Österreichs, 2 Auflage. GrüneReihe, vol. 10, pp. 33–151.

Niklfeld, H., Schratt-Ehrendorfer, L., Englisch, T., 2008. Muster der Artenvielfalt derFarn- und Blütenpflanzen in Österreich. In: Sauberer, N., Moser, D., Grabherr, G.(Eds.), Biodiversität in Österreich. Haupt Verlag, Bern, pp. 87–102.

Ohlemüller, R., Anderson, B.J., Araujo, M.B., Butchart, S.H.M., Kudrna, O., Ridgely,R.S., Thomas, C.D., 2008. The coincidence of climatic and species rarity: high riskto small-range species from climate change. Biology Letters. doi:10.1098/rsbl.2008.0097.

Ozenda, P., 1995. L’endémisme au niveau de l’ensemble du système alpin. ActaBotanica Gallica 142, 753–762.

Ozenda, P., 1988. Die Vegetation der Alpen im europäischen Gebirgsraum. Fischer,Stuttgart.

Pauli, H., Gottfried, M., Dirnböck, T., Dullinger, S., Grabherr, G., 2003. Assessing thelong-term dynamics of endemic plants at summit habitats. In: Nagy, L.,Grabherr, G., Körner, C., Thompson, D.B.A. (Eds.), Alpine Biodiversity inEurope. Ecological Studies, vol. 167, pp. 195–207.

Pawłowski, B., 1970. Remarques sur l’endémisme dans la flore des Alpes et desCarpates. Vegetatio 21, 181–243.

Pils, G., 1995. Die Bedeutung des Konkurrenzfaktors bei der Stablisierunghistorischer Arealgrenzen. Linzer biol. Beitr. 27, 119–149.

Rabitsch, W., Essl, F. (Eds.), 2009. Endemiten – Kostbarkeiten Österreichs.Naturwissenschaftlicher Verein Kärntens, Klagenfurt.

R Development Core Team (2006). R: A Language and Environment for StatisticalComputing. R Foundation for Statistical Computing, Vienna, Austria. ISBN 3-900051-07-0 <http://www.R-project.org>.

Rosenzweig, M., 1995. Species Diversity in Space and Time. Cambridge UniversityPress, Cambridge.

Sauberer,N., Grabherr, G., 1995. Fachliche Grundlagen zur Umsetzung der FFH-Richtlinie, Schwerpunkt Lebensräume. Umweltbundesamt Report R-115,Vienna.

Schönswetter, P., Tribsch, A., Barfuss, M., Niklfeld, H., 2002. Several Pleistocenerefugia detected in the high alpine plant Phyteuma globulariifolium Sternb. &Hoppe (Campanulaceae) in the European Alps. Molecular Ecology 11, 2637–2647.

Schönswetter, P., Stehlik, I., Holderegger, R., Tribsch, A., 2005. Molecular evidencefor glacial refugia of mountain plants in the European Alps. Molecular Ecology14, 3547–3555.

Schwartz, M.W., Iverson, L.R., Prasad, A.M., Matthews, S.N., OConnor, R.J., 2006.Predicting ectinctions as a result of climate change. Ecology 87, 1611–1615.

Taberlet, P., Fumagalli, L., Wust-Saucy, A.G., Cosson, J.F., 1998. Comparativephylogeography and postglacial colonization routes in Europe. MolecularEcology 7, 453–464.

Thomas, C.D., Cameron, A., et al., 2004. Extinction risk from climate change. Nature427, 145–148.

size and niche breadth of Austrian endemic plants. Biol. Conserv. (2009),

12 F. Essl et al. / Biological Conservation xxx (2009) xxx–xxx

ARTICLE IN PRESS

Thuiller, W., Lavorel, S., Araujo, M.B., Sykes, M.T., Prentice, I.C., 2005. Climate changethreats to plant diversity in Europe. Proceedings of the National Academy ofScience 102, 8245–8250.

Tribsch, A., 2004. Areas of endemism of vascular plants in the Eastern Alps inrelation to Pleistocene glaciation. Journal of Biogeography 31, 747–760.

Tribsch, A., Schönswetter, P., 2003. Patterns of endemism and comparativephylogeography confirm palaeo-environmental evidence for Pleistocenerefugia in the Eastern Alps. Taxon 52, 477–497.

UK BAP, 2008. UK Biodiversity Action Plan Website. <http://www.ukbap.org.uk/>(cited 16.05.2008).

Please cite this article in press as: Essl, F., et al. Distribution patterns, rangedoi:10.1016/j.biocon.2009.05.027

Umweltbundesamt, 2008. Naturschutzfachliches Informationssystem Austria(NISA). <http://gis.umweltbundesamt.at/austria/natur/nisa/Default.faces>(cited 16.05. 2008).

Van Husen, D., 1987. Die Ostalpen in den Eiszeiten. Geologische Bundesanstalt,Vienna.

Wohlgemuth, T., 1998. Modelling floristic species richness on a regional scale: acase study in Switzerland. Biodiversity and Conservation 7, 159–177.

Wohlgemuth, T., Nobis, M., Kienast, F., Plattner, M., 2008. Modelling vascular plantdiversity at the landscape scale using systematic samples. Journal ofBiogeography 35, 1226–1240.

size and niche breadth of Austrian endemic plants. Biol. Conserv. (2009),