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Clonal growth forms in Arctic plants and their habitat
preferences: a study from Petuniabukta, Spitsbergen
Jitka KLIMEŠOVÁ1, Jiří DOLEŽAL1, 2, Karel PRACH1, 2 and Jiří KOŠNAR2
1Institute of Botany, Academy of Sciences of the Czech Republic,
Dukelská 135, CZ−379 82 Třeboň, Czech Republic
2Faculty of Science, University of South Bohemia,
Branišovská 31, CZ−37005 České Budějovice, Czech Republic
Corresponding author <klimesova@butbn.cas.cz>
Abstract: The ability to grow clonally is generally considered important for plants in Arctic
regions but analyses of clonal characteristics are lacking for entire plant communities. To
fill this gap, we assessed the clonal growth of 78 plant species in the Petuniabukta region,
central Spitsbergen (Svalbard), and analyzed the clonal and other life−history traits in the re−
gional flora and plant communities with respect to environmental gradients. We distin−
guished five categories of clonal growth organs: perennial main roots produced by non−
clonal plants, epigeogenous rhizomes, hypogeogenous rhizomes, bulbils, and stolons.
Clonal growth differed among communities of the Petuniabukta region: non−clonal plants
prevailed in open, early−successional communities, but clonal plants prevailed in wetlands.
While the occurrence of plants with epigeogenous rhizomes was unrelated to stoniness or
slope, the occurrence of plants with hypogeogenous rhizomes diminished with increasing
stoniness of the substratum. Although the overall proportion of clonal plants in the flora of
the Petuniabukta region was comparable to that of central Europe, the flora of the Petunia−
bukta region had fewer types of clonal growth organs, a slower rate of lateral spread, and a
different proportion of the two types of rhizomes.
Key words: Arctic, Svalbard, vascular plants, clonal growth, substrate.
Introduction
For plants in cold regions, like the Arctic and alpine zones, clonal growth (i.e.,
vegetative growth resulting in the production of genetically identical and poten−
tially physically independent offspring) is traditionally considered to be important
because it helps to ensure the reproductive success in a stressful environment, and
it enables the foraging for nutrients over a large area by means of an interconnected
network of rooting units (Callaghan and Emanuelson 1985; Jónsdóttir et al. 1996;
Callaghan et al. 1997). However, the paradigm of a high proportion of clonally
Pol. Polar Res. 33 (4): 421–442, 2012
vol. 33, no. 4, pp. 421–442, 2012 doi: 10.2478/v10183−012−0019−y
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growing species in cold regions was recently questioned (Jónsdóttir 2011; Klime−
šová and Doležal 2012). In these two studies, comparisons of available data indi−
cated that the proportion of clonal plants in regional floras of cold environments
(above alpine and Arctic timberline) is not higher than in reference regions from
lower latitudes or altitudes. Moreover, the authors postulated that some kinds of
clonal growth organs, namely belowground rhizomes, might be damaged by soil
cryoturbation (and therefore maladapted to cold environments) and that some hab−
itats traditionally inhabited by clonal plants in temperate zones, e.g., open water,
might be less vegetated or devoid of vascular plants in cold environments (Klime−
šová and Doležal 2011).
The first step in understanding the function of clonal growth in the Arctic is the
assessment of the distribution and habitat preferences of clonal and non−clonal
Arctic plants. Despite a long tradition in growth−form characterization and analy−
ses over the last 200 years (von Humboldt 1806; Grisebach 1872; Drude 1887;
Raunkiaer 1907; Warming 1923; Du Rietz 1931; Gimingham 1951; Hejný 1960;
Łukasiewicz 1962; Den Hartog and Segal 1964; Serebrjakov 1964; Parsons 1976;
Hallé et al. 1978; Barkman 1988; Halloy 1990; Kästner and Karrer 1995; von
Lampe 1999; Krumbiegel 1998, 1999), data concerning the local flora of Arctic
ecosystems are rare (Polozova 1981; Komárková and McKendrick 1988) and are
not focused on clonal growth. On the other hand, we do have information on the
clonal growth of a few of Arctic species (Warming 1908, 1909; Bell and Bliss
1980; Bauert 1996; Kjølner et al. 2006), and some clonal species that occur in the
Arctic also occur in alpine regions (Hartmann 1957). For these species and accord−
ing to a survey of the literature, clonal growth organs do not differ between species
growing in the Arctic and in central Europe, where a detailed classification is
available (Klimešová and Klimeš 2006, 2008). The classification developed for
central Europe could be therefore used for Arctic regions (Klimešová and de Bello
2009).
Classification of clonal growth organs, which is based on simple morphologi−
cal characters and especially on belowground organs, has two steps. First, one de−
termines whether adventitious roots or adventitious shoots are formed. Second,
one determines which organs bear buds for shoot iteration (sensu Hallé et al.
1978), which organ provides connections between ramets, and where these organs
are located (aboveground or belowground). These steps or principles have already
been successfully used for the classification of clonal growth organs in Ladakh,
West Himalaya (Klimešová et al. 2011a).
The current study was conducted in a high Arctic site in central Spitsbergen of
the Svalbard archipelago. We searched the local flora around Petuniabukta, an
area that contains about 80 species of vascular plants (about half of the flora of the
Svalbard archipelago; cf. Rønning 1996) and six plant communities could be dis−
tinguished there (Prach et al. 2012 this volume). We had the following aims: (i) to
assess the diversity of clonal growth organs and other clonal traits of the flora in
422 Jitka Klimešová et al.
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the studied area, and (ii) to evaluate the distribution of clonal growth organs and
other clonal traits in the plant communities of the area and along environmental
gradients, with particular emphasis on the slope and stoniness of the substrate. We
also analyzed other plant traits (e.g., growth forms, Raunkiaer’s life−forms) to en−
able comparison with data from the literature. To correlate clonality and environ−
mental conditions, we used two different approaches: cross−species analysis and
relative species abundance in a community; this enabled us to distinguish between
rare and common plants (Grime 2006).
Materials and methods
Plant characteristics. — The field data were collected during three expedi−
tions in 2008, 2009, and 2010 around Petuniabukta. This area is the northernmost
part of Billjefjorden, and it represents a branch of the main Svalbard fjord
Isfjorden. The time of sampling corresponded with the peak of the vegetation sea−
son, which in this area lasts from mid−June to mid−September. Plants for morpho−
logical description (several individuals of each species, if possible) were exca−
vated with their belowground organs. Plants were cleaned of soil, and their mor−
phology was examined and drawn. The plants were then dried between paper
sheets for future comparison and determinations. The plant material is stored in the
PRA herbarium (Institute of Botany, Academy of Sciences of the Czech Repub−
lic). In total 78 vascular plant species were collected and evaluated for vegetative
morphology.
For the studied species, we recorded information on several life−history traits
including growth form (dwarf shrubs, forbs, grasses, etc.), Raunkiaer’s life form
(hemicryptophytes, therophytes, etc. based on the position of renewing meristems,
Raunkiaer 1907), leaf arrangement along the stem (erosulate, semirosette, rosette),
type of root system (perennial main root or adventitious roots), and clonality. The
clonal traits included type of clonal growth organ, lateral spread, and shoot
cyclicity (life−span of a shoot) (Klimešová and Klimeš 2006, 2008). The traits re−
corded and their definition and functions are listed in Table 1.
Vegetation and environmental characteristics. — Of the 78 species, 60
were recorded on 53 sampling plots (phytosociological relevés) of the surface
5 × 5 m. The plots where vegetation composition was recorded (species composi−
tion and visual estimation of cover by vascular plant species, mosses, and stones,
and visual assessment of stoniness and slope) were non−randomly distributed be−
cause large areas were devoid of vascular plants (very unstable slopes, glaciers).
The relevés were placed so as to include all vegetation types and habitats in all
parts of the delimited areas. Taxonomy and nomenclature follows Elvebakk and
Prestrud (1996).
Clonal plants in Svalbard 423
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424 Jitka Klimešová et al.
Table 1
List of studied plant characteristics of vascular plants in Petuniabukta. Individual clonal
growth organs are defined as follows: main root – perennial main root providing the only
connection between aboveground and belowground plant parts and thus characterizing
non−clonal perennials; hypogeogenous rhizome – belowground stem initiated below−
ground, bearing scale leaves and usually having long internodes; epigeogenous rhizome
– belowground stem initiated aboveground and only later pulled into the soil or covered
by soil, usually bearing green leaves and having short internodes; bulbils – bulbils and
plantlets in axils of leaves and/or in inflorescence; stolons – aboveground creeping
stems.
Plant
characteristics Categories Definition / Reference Function
Growth forms
(%)
Shrub
Basic growth forms with
delimitation based on
taxonomy / Elvebakk and
Prestrud 1996
Taxonomical groups share many traits and
therefore they usually have similar
functions in the ecosystem and similar
strategies
Forb
Grass
Sedge
Horsetail
Leaf
distribution
(%)
Erosulate Leaf distribution along shoot
/ Klimešová and Klimeš
2006
Competitive ability (erosulate) versus
disturbance avoidance (rosette)
Semirosette
Rosette
Raunkiaer’s
life forms
Hemicryptophytes Vertical distribution of
overwintering parts from
which spring regrowth
occurs (renewal bud or seed)
/ Raunkiaer 1907
Response to climatic conditions: the more
severe the conditions (winter frosts,
summer draught), the lower the position of
buds in relation to the soil surface; when
permafrost is present, overwintering buds
are concentrated on the soil surface
Geophytes
Therophytes
Chamaephytes
Clonal growth
organ CGO
(%)
Main root
Organ through which
potential for clonal growth is
realized / Klimešová and
Klimeš 2006
Rhizomes anchor the plant and enable
lateral spread and storage of carbohydrates
whereas bulbils and stolons serve only for
clonal multiplication. Perennial main roots
increase plant anchorage and storage of
carbohydrates but their potential for clonal
growth by splitting is very limited
Epigeogenous
rhizome
Hypogeogenous
rhizome
Bulbils
Stolone
Lateral spread
[cm/yr]
Nonclonal
Lateral spread due to clonal
growth / Klimešová and
Klimeš 2006
Lateral spread enables the plant to colonize
a new substrate and avoid intraspecific
competition. Limited lateral spread could
be expected in situations where facilitation
is important
<1
1–5
5–10
Dispersable
Shoot cyclicity
Monocyclic Number of years (cycles)
from resprouting of bud to
flowering and fruiting of
shoot / Klimešová and
Klimeš 2006
In stressful environments, shoots tend to be
polycyclic because they need more time for
development
Bicyclic
Polycyclic
Root system
Main root Main root developes from
seminal root of embryo,
roots formed on stem parts
are adventitious roots /
Klimešová and Klimeš 2006
Only plants capable of producing
adventitious roots have the potential for
clonal growth because the main root rarely
splits; this restricts clonal multiplication
Adventitious roots
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For comparative purposes, phytosociological relevés were classified into six
community types based on dominant species. Their description and extent in the
studied area are indicated in Table 2 (for further details, see Prach et al. 2012 this
volume).
Statistical analyses. — To assess whether the communities differed in studied
plant traits, we calculated for each sampling plot (relevé) the proportion of species
with given traits. In assessing these proportions, we used two approaches: (i)
cross−species analysis based on presence or absence, i.e., the analysis did not take
into account species differences in abundance (abundance is equivalent to plant
cover in this paper); and (ii) weighted analysis taking into account species abun−
dance in a plot. Studies of trait composition may yield different results depending
on whether or not species importance includes abundance. Differences in plant
characteristics among the six community types were tested with ANOVA and post
hoc unequal N HSD tests. Because of the non−normality of the data in some of the
tested variables, significance levels of factors were determined using randomiza−
tion procedures. The observed test statistic was compared with the null distribution
Clonal plants in Svalbard 425
Table 2
The characteristics of plant communities in Petuniabukta (Prach et al. 2012 this volume).
Total area covered by vegetation was about 33 km2.
Community
type Typical species Habitat description
No. of
vascular
plants
No. of
relevés
% of area
with
vegetation
Dryas
octopetala
Dryas octopetala, Carex misandra,
C. nardina, C. rupestris, Saxifraga
oppositifolia, Casiope tetragona,
Salix polaris, Eutrema edwardsii,
Salix reticulata
Stabilized surfaces, dry
and exposed sites, from
low to high altitude
10 19 40
Saxifraga
oppositifolia
Saxifraga oppositifolia, Braya
purpurascens, Draba sp. div.
Sparse vegetation on
young, unstabilized
fluvial sediments,
morains, screes, or
maritime terraces
81345
Carex−moss
Carex subspathacea, C. paralella,
Ranunculus pygmaeus, Equisetum
sp. div., Pucciphippsia vacillans,
Eriophorum scheuchzeri
In alluvial wet habitats,
snow beds, or on seepages 13 12 6
Deschampsia
borealis
Deschampsia borealis, D. alpina,
D. caespitosa
Around streams and
eutrophic spots near
settlements
93<1
Papaver
dahlianum
Papaver dahlianum, Silene
uralensis subsp. arctica
On fine screes at higher
altitudes, with both low
vegetation cover and
species richness
53<1
Festuca
baffinensis
Festuca baffinensis, Cochlearia
groenlandica, Saxifraga
hieracifolia, S. nivalis, S. cespitosa,
S. cernua, Cerastium arcticum
Species−rich vegetation
developed on eutrophic
soils under bird nesting
sites
14 2 <1
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of the test statistic obtained via Monte−Carlo resampling with 9999 permutations.
Analyses were run using R software (R Development Core Team 2010).
Overall differences in trait composition between the six communities were
evaluated with constrained ordination and redundancy analysis (RDA, no stan−
dardization by samples was applied) using the program Canoco for Windows (Ter
Braak and Šmilauer, 1998). The six community types were used as explanatory
dummy variables, and their effects were tested using the Monte Carlo permutation
test (999 unrestricted permutations). Additionally, plot level factors – slope incli−
nation and proportion of ground covered by stones (stoniness) – were used as sup−
plementary environmental variables. The results of multivariate analysis were vi−
sualized in the form of a bi−plot ordination diagram constructed by the CanoDraw
program (http://www.canodraw.com/).
Results
Characteristics of the local flora. — In the local flora of Petuniabukta, we re−
corded one annual and 77 perennial species. Among the perennial species, we dis−
tinguished five categories of clonal growth organs: non−clonal plants with a peren−
nial main root, clonal plants with epigeogenous rhizomes, hypogeogenous rhi−
zomes, bulbils, and stolons (Figs 1–3).
The most abundant growth forms among vascular plants in Petuniabukta re−
gion were forbs, followed by grasses, sedges, dwarf−shrubs, and horsetails (Fig. 1).
Most vascular plants were perennial hemicryptophytes, and most of the remainder
were either chamaephytes or geophytes; only one species (Koenigia islandica)
was classified as a therophyte. About 38% of the species were non−clonal peren−
nial plants (forbs) with perennial main root (Fig. 1). Clonal plants generally pre−
vailed over non−clonal plants, and included all grasses, sedges, and most of the
forb species. The most abundant clonal plants were those with short epigeogenous
rhizomes; clonal plants with hypogeogenous rhizomes were less abundant (Fig. 1).
Only a few species were able to form longer rhizomes with lateral spread 5–10 cm
per year (the horsetails Equisetum arvense and E. variegatum; the grasses
Dupontia psilosantha and Poa arctica; the sedge Carex subspathacea; and cot−
ton−grass Eriophorum scheuchzeri) (Fig. 2).
Plant characteristics in different plant communities. — When vegetation
around Petuniabukta was divided into six community types (Table 2 and Fig. 4) and
compared in terms of trait composition using multivariate redundancy analysis
(RDA), the differences were highly significant and explained 40.4 and 42.8% of the
total variation in abundance−weighted and cross−species (unweighted) data, respec−
tively (both P= 0.001). The results of both weighted data and data unweighted by
abundance showed similar patterns. Therefore, only results from the former ap−
proach are presented in the RDA ordination diagram (Fig. 5). The main trait
426 Jitka Klimešová et al.
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compositional changes along the first ordination axis were associated with substrate
age, i.e., the first axis separated the Dryas octopetala community (drier, exposed
places) and Carex−moss community (wet, alluvial habitats) on old, stabilized sur−
faces from the Saxifraga oppositifolia community (young, stony deposits from
streams and glaciers) and Papaver dahlianum community (fine screes on steep
slopes at higher altitudes) on young, unstabilized surfaces. The compositional
changes along the second ordination axis seemed to be associated with the topo−
graphic moisture gradient, i.e., the second axis separated drier habitats (Dryas
octopetala community) from wetter habitats (Carex−moss and Deschampsia spp. al−
luvial communities).
The first RDA axis was associated with the occurence of non−clonal forbs with
perennial main roots, which prevailed in the Papaver dahlianum and Saxifraga
oppositifolia communities on steep and stony slopes of young surfaces (Figs 4, 5).
The smallest number of non−clonal forb species was found in the most widespread
type of community (the Dryas octopetala community), where shrubby species (D.
octopetala, Cassiope tetragona, Salix polaris, and S. reticulata) with erosulate
polycyclic shoots predominated (Fig. 6) and were accompanied by clonal tussock
sedges and grasses with short lateral spread and adventitious roots (e.g.,Carex
Clonal plants in Svalbard 427
Clonal growth organs
0 5 10 15 20 25 30 35
stolones
bulbils
hypogeogenous rhizome
epigeogenous rhizome
main root
Raunkiaer life forms
010203040506070 80
chamaephytes
therophytes
geophytes
hemicryptophytes
Growth forms
0 102030405060
horsetail
sedge
grass
herb
shrub
Leaf distribution
01020304050
rosette
semirosette
erosulate
Lateral spread [cm/yr]
0 5 10 15 20 25 30 35
dispersable
spread 5–10
spread 1–5
spread > 1
nonclonal
Number of species
Shoot cyclicity
0 1020304050
monocyclic
bicyclic
polycyclic
Number of species
Fig. 1. Spectra of plant characteristics in the flora of Petuniabukta, central Spitsbergen, Svalbard.
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428 Jitka Klimešová et al.
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nardina, C. misandra,Pucciphippsia vacillans). Clonal plants were in general
more abundant on older, stabilized surfaces with better developed soils (Dryas
octopetala,Carex−moss, and Deschampsia borealis community types) than on
young, unstabilized surfaces. Clonal plants with short epigeogenous rhizomes
were common in all community types (representing >40% of the species, Fig. 7);
they were most common in the Deschampsia borealis alluvial vegetation (repre−
Clonal plants in Svalbard 429
Fig.3. Field view on representative species with selected clonal growth organs. 1.Dryas octopetala,
perennial main root and epigeogenous rhizomes. 2.Festuca baffinensis epigeogenous rhizome.
3.Koenigia islandica annual plant. 4.Salix polaris, hypogeogenous and epigeogenous rhizomes.
5.Cassiope tetragona, epigeogenous rhizome. 6.Papaver dahlianum, non−clonal perennial, peren−
nial main root. 7.Braya purpurascens, non−clonal perennial, perennial main root. 8.Silene uralensis
subsp. arctica, nonclonal perennial, perennial main root. 9.Carex misandra, epigeogenous rhizome.
10.Eryophorum scheuchzeri, hypogeogenous rhizome. 11.Ranunculus pygmaeus, epigeogenous
rhizome. 12.Saxifraga cernua, epigeogenous rhizome and bulbills in leaf axils. (Photo K. Prach)
Fig. 2.Herbarium specimens of representative species with selected clonal growth organs. 1.Carex
parallela, short hypogeogenous rhizome. 2.Festuca vivipara, epigeogenous rhizome and plantlets in
inflorescence. 3.Carex misandra, epigeogenous rhizome. 4.Cochlearia groenlandica, biennial or
monocarpic perennial. 5.Carex subspathacea, long hypogeogenous rhizome. 6.Braya purpura−
scens, non−clonal perennial, perennial main root. 7.Equisetum scirpoides, long hypogeogenous rhi−
zome. 8.Draba oxycarpa, non−clonal perennial, perennial main root. 9.Carex saxatilis, hypogeo−
genous rhizome. 10.Ranunculus sulphureus, epigeogenous rhizome. 11.Silene uralensis subsp.
arctica, nonclonal perennial, perennial main root. 12.Eutrema edwardsii, nonclonal perennial, pe−
rennial main root. 13.Saxifraga flagellaris subsp. platysepala, stolons with offspring plantlets.
14.Saxifraga hieracifolia, epigeogenous rhizome. 15.Poa alpina, epigeogenous rhizome and
plantlets in the inflorescence. 16.Saxifraga nivalis, epigeogenous rhizome. 17.Taraxacum arcticum,
nonclonal perennial, perennial main root. 18.Koenigia islandica, annual plant. 19.Saxifraga oppo−
sitifolia, epigeogenous rhizome. 20.Salix reticulata epigeogenous rhizome.(Photo M. Dvorský)
®
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senting >70% of the species) but were also very common in the Saxifraga
oppositifolia vegetation on fresh fluvial and moraine deposits and in the Festuca
baffinensis vegetation developed under bird nesting sites (Figs 4, 5, 7). The species
with epigeogenous rhizomes that most contributed to vegetation cover in individ−
ual communities were Deschampsia borealis and Bistorta vivipara in the De−
schampsia borealis community type; Trisetum spicatum,Festuca baffinensis, and
Saxifraga cernua in the Festuca baffinensis community type; and Dryas octo−
petala and Cassiope tetragona in the Dryas octopetala community type.
Relative to plants with epigeogenous rhizomes, those with hypogeogenous
rhizomes were less abundant (Fig. 7) and more spatially restricted; they were
abundant in alluvial habitats and snow beds, i.e.,intheCarex−moss community
type (Figs. 4, 5). Plants with longer hypogeogenous rhizomes (lateral spread >1
cm per year) that most contributed to vegetation cover were Carex subspathacea
430 Jitka Klimešová et al.
Fig. 4. The most common vegetation types in Petuniabukta, central Spitsbergen, Svalbard. 1–4.Dryas
octopetala community: 1. wetter habitats with Carex misandra and Salix polaris;2. soil polygons;
3. fell fields; 4. dry habitats with Carex rupestris.5. Early successional stages with Saxifraga oppositi−
folia community, sparse vegetation on young, unstabilized fluvial and morainic sediments. 6.Carex−
moss community of alluvial wet habitats, snow beds, and seepages. 7.Deschampsia borealis commu−
nity around streams and eutrophicated spots near settlements. 8.Papaver dahlianum community on
scree at higher altitudes. 9.Festuca baffinensis community, species−rich vegetation of eutrophic soils
under bird nesting sites. (Photo K. Prach)
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and Equisetum variegatum (dominant in permanently wet depressions), Carex
paralella (dominant in alluvial habitats with fluctuating water table), and Salix
polaris and Equisetum arvense (dominant in old, sufficiently wet surfaces that
did not dry in summer). The only species with short hypogeogenous rhizomes
(lateral spread <1 cm per year) that attained relatively high cover (>20%) was
Carex rupestris, a co−dominant of Dryas octopetala on old and dry surfaces.
Plants with hypogeogenous rhizomes were rare in the Festuca baffinensis com−
munity type (the only representative was Salix polaris), which was the most spe−
cies−rich community in Petuniabukta and which occurred on eutrophic spots un−
der bird nesting sites. Plants attaining higher cover in the Festuca baffinensis
community type were forbs (Saxifraga cespitosa,Saxifraga cernua and Cera−
stium arcticum) and grasses (Trisetum spicatum) with semirosette leaf distribu−
tion, epigeogenous rhizomes and short lateral spread; these forbs and grasses
were accompanied by rosette forbs (Draba corymbosa,D. oxycarpa,D. sub−
capitata,Papaver dahlianum,andCochearia groenlandica) with dicyclic shoots
and perennial main root (Figs 2, 4, 5, 7).
Clonal plants in Svalbard 431
-0.8
1.0
-0.6 1.0
shrub
horsetail
forb
grass
sedge
erosulate
semirosette
rosette
hemicryptophyte
geophyte
therophyte
chamaephyte
stolones
bulbills
epigeogenous rhizome
hypogeogenous rhizome
root-splitter
nonclonal
spread>1cm
spread1-5cm
spread5-10cm
dispersable
main root
both root system
advent.root
monocyclic
bicyclic shoot
polycyclic shoot
Dryas octopetala
Saxifraga oppositifolia
Carex-moss .spp
Deschampsia borealis
Papaver dahlianum
Festuca baffinensis
slope
stones
E1
E0
RDA: unweighted (cross-species)
Fig. 5. Redundancy analysis biplot of plant life−history traits (response variables) in relation to six
vegetation types. Response variables are represented by dotted arrows, while supplementary environ−
mental variables are represented by solid gray arrows. Plant communities are represented by
centroides (triangles). The angles between arrows indicate correlations between variables.
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Individual clonal traits, growth forms, and life forms showed similar patterns
with respect to their occurrence in communities when unweighted data and data
weighted by abundance were considered (Table 3, Figs 6, 7). Exceptions were
shrubs with erosulate shoots and forbs with semirosette shoots; the former were
overrepresented when analysis was based on abundance (indicating their ability to
occupy space and dominate vegetation), and the latter were underrepresented
when analysis was based on abundance, especially in the Dryas octopetala,
Saxifraga oppositifolia, and Carex−moss community types (Figs 4, 6).
Plant characteristics along environmental gradients. — Differences in
habitat preferences for plants with different growth and life form categories were
also evident from correlations with the plot−level environmental factors of slope
inclination and stoniness (Fig. 8). Species number and cover of non−clonal forbs
with perennial main root increased with increasing stoniness and steepness of the
432 Jitka Klimešová et al.
Plant communities
0
20
40
60
80
100
abundance-weighted
cross-species
(a) Shrub
*
*
0
20
40
60
80
100
Dr Sa Ca De Pa Fe
(c) Grass
*
*
0
20
40
60
80
100 (b) Forb
*
0
20
40
60
80
100
Dr Sa Ca De Pa Fe
(d) Sedge
Fig. 6. Pair−wise comparisons of abundance−weighted proportions vs. cross−species proportions of
four abundant growth form categories among six community types in Petuniabukta. Dr: Dryas
octopetala shrubby vegetation on old, stabilized surfaces; Sa: Saxifraga oppositifolia community,
sparse vegetation on young, unstabilized fluvial and morainic sediments; Ca: Carex−moss commu−
nity on alluvial wet habitats, snow beds, and seepages; Da: Deschampsia borealis community around
streams and eutrophicated spots near settlements; Pa: Papaver dahlianum community on scree at
higher altitudes; Fa: Festuca baffinensis community, species−rich vegetation of eutrophicated soils
under bird nesting sites. * significant differences between the two means (post−hoc test – unequal N
HSD test).
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slope, while clonal species, both sedges and horsetails with hypogeogenous rhi−
zomes and long lateral spread, decreased with increasing stoniness and slope
steepness (Table 3 and Fig. 8).
Discussion
All but one plant species from Petuniabukta (central Spitsbergen) were peren−
nial, and two−thirds of the plant species were clonal. Clonality was represented by
four types of clonal growth organs. The six principal plant communities in the stud−
ied area differed with respect to composition of growth forms, Raunkiaer life forms
(except for rare therophytes), leaf distribution along the shoot (except for rosette
shoots), clonal growth organs, lateral spread, and root system. Most plant character−
istics were also correlated with the two examined gradients: slope and stoniness.
These general findings are discussed in greater detail in the following sections.
Characteristics of the local flora. — The current study documented annual
plants, non−clonal plants with perennial main roots, and clonal plants with other
types of clonal growth organs (epigeogenous rhizome, hypogeogenous rhizome,
Clonal plants in Svalbard 433
Plant communities
0
20
40
60
80
100 (a) Epigeogenous rhizome
*
0
20
40
60
80
100 (b) Hypogeogenous rhizome
a
a
0
20
40
60
80
100
Dr Sa Ca De Pa Fe
(c) Root-splitter
*
0
20
40
60
80
100
Dr Sa Ca De Pa Fe
(d) Pseudovivipary
abundance-weighted
cross-species
Fig. 7. Pair−wise comparisons of abundance−weighted vs. cross−species proportions of four clonal
growth organs among six community types in Petuniabukta. Abbreviations for community types on
the horizontal axis as in Fig. 6. * significant differences between the two means (post−hoc test – un−
equal N HSD test)
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bulbills and stolons) in Petuniabukta. These general categories of plant traits also
occur in central Europe, where the clonal classification was elaborated (Klimešová
and Klimeš 2008). Another 12 categories of clonal growth organs that were identi−
fied in central Europe were not found in Petuniabukta (e.g., turions, plant frag−
ments, budding plants, bulbs, and tubers). While the most common types of clonal
growth organs in Petuniabukta is perennial main root of non−clonal plants and
epigeogenous rhizomes, the most common in central Europe are epigeogenous and
hypogeogenous rhizomes (Klimešová and Klimeš 2008). The lack of certain
clonal growth organs in Petuniabukta is largely due to the lack of aquatic plants,
which possess specialized clonal growth organs that are not found in nonaquatic
communities (Sosnová et al. 2010, 2011).
The clonal growth spectrum in Petuniabukta is characterized by a high propor−
tion of plants multiplying by bulbils produced either in inflorescences or in leaf
axils. The most abundant species dispersing only by bulbils is Bistorta vivipara.
434 Jitka Klimešová et al.
Fig. 8. Relationships between selected growth forms, clonal growth organs, and environmental vari−
ables (stoniness and slope inclination). Abundance unweighted data are represented by filled circles,
and abundance weighted data are represented by open circles. The significant relationships are fitted
by regression lines (see Table 1).
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Bulbils are a very efficient alternative to regeneration by seed; they are larger than
seeds but smaller than offspring produced by other clonal growth organs, and for
some plants bulbils are the predominant or only way of multiplication (e.g.,
Saxifraga cernua,Kjølner et al. 2006; Bistorta vivipara, Bauert 1996). The num−
ber of plant species that depend on bulbils and plantlets in the studied area is
Clonal plants in Svalbard 435
Table 3
List of studied life−history traits of vascular plants in plant communities of Petuniabukta,
number of species in individual categories, differences between abundance weighted and
cross−species proportions (% difference), Pvalues (for Type I error estimate) from ANOVA
analyses comparing six community types for each trait category (weighted or not by species
cover), and correlation coefficients with environmental variables.
Plant
charac−
teristics
Category Number of
species
%
difference
Differences between
six communities
Correlation
with stoniness
Correlation
with slope
Pweighted Punweighted rweighted runweighted rweighted runweighted
Growth
forms
(%)
Shrub 4 18.9 0.000 0.000 −0.31 −0.28 −0.25 −0.22
Forb 35 −14.8 0.001 0.000 0.55 0.56 0.33 0.51
Grass 11 −2.7 0.032 0.008 0.03 0.11 0.29 −0.03
Sedge 8 −1.1 0.000 0.120 −0.43 −0.50 −0.35 −0.36
Horsetail 2 −0.4 0.000 0.010 −0.29 −0.45 −0.21 −0.32
Leaf
distri−
bution
(%)
Erosulate 10 24.6 0.008 0.001 −0.35 −0.07 −0.25 0.11
Semirosette 30 −18.4 0.024 0.001 0.19 0.05 0.22 −0.04
Rosette 20 −6.2 0.706 0.368 0.07 0.00 0.05 −0.09
Raun−
kiaer
life
forms
Hemicrypto−
phytes 52 −15.4 0.000 0.000 0.34 0.26 0.31 0.33
Geophytes 2 −1.6 0.000 0.208 −0.23 −0.25 −0.17 −0.30
Therophytes 1 −0.1 0.389 0.372 −0.12 −0.05 −0.12 −0.05
Chamaephytes 5 17.1 0.000 0.000 −0.36 −0.23 −0.25 −0.21
Clonal
growth
organ
CGO
(%)
Epigeogenous
rhizome 25 8.4 0.061 0.003 −0.25 0.00 −0.01 0.15
Hypogeogenous
rhizome 10 4.4 0.000 0.000 −0.41 −0.53 −0.39 −0.44
Main root 27 −11.3 0.000 0.073 0.45 0.42 0.36 0.41
Bulbils 5 −1.4 0.137 0.172 −0.17 −0.26 0.21 0.09
Stolones 1 −0.2 0.387 0.308 0.05 −0.06 0.15 −0.12
Lateral
spread
[cm/yr]
Nonclonal 26 −12.9 0.000 0.216 0.44 0.39 0.39 0.46
<1 26 2.3 0.000 0.000 −0.38 −0.51 −0.25 −0.52
1–5 5 9.0 0.183 0.000 0.00 0.53 0.09 0.45
5–10 6 2.0 0.000 0.000 −0.33 −0.50 −0.31 −0.37
Dispersable 5 2.9 0.532 0.348 0.21 −0.17 0.09 −0.26
Shoot
cyclicity
Monocyclic 6 6.9 0.050 0.008 −0.16 −0.40 −0.21 −0.39
Dicyclic 31 −15.7 0.006 0.019 0.12 0.04 0.32 0.29
Polycyclic 23 8.9 0.098 0.003 −0.01 0.27 −0.03 0.15
Root
system
Main 27 −9.0 0.003 0.010 0.42 0.27 0.15 0.12
Adventitious 33 9 0.005 0.002 −0.42 −0.27 −0.15 −0.12
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phylogenetically constrained in that the taxonomic diversity of bulbil− or plantlet−
producing plants is not high (they are produced only by Bistorta vivipara and sev−
eral species in the Saxifraga genus and Poaceae family), and it is therefore difficult
to decide whether it is the production of bulbils or the other shared characteristics
that is responsible for the success of the species in the high Arctic.
There is little comparative information on clonal growth in cold climates, and
the principles of clonal−trait description used in the CLO−PLA 3 database for central
Europe could serve as a basis for comparison (Klimešová and de Bello 2009). Be−
fore the current study, however, the approach was only applied to the flora of central
Europe and East Ladakh (Klimešová et al. 2011a). Relative to the flora of the Czech
Republic, the Ladakh flora has a lower proportion of clonal species, a higher diver−
sity of non−clonal growth forms, and fewer plants with hypogeogenous rhizomes,
especially outside of wetlands (see below). East Ladakh and Svalbard are similar in
that they both have a cold climate, but they differ in other environmental factors:
Ladakh is arid, and the plant communities occur along a large altitudinal gradient,
and Svalbard is mesic, with plants occurring preferentially at a very low altitude.
Although we lack comparative data on clonal growth traits from the Arctic, the
current study provides useful information on the proportions of growth forms
(shrubs, graminoids, forbs and horsetails) (Table 4). The data indicate that the
composition of vegetation in Svalbard, and presumably in other Arctic regions is
quite variable, especially in the proportion of shrubs. While shrubs play an impor−
tant role in Petuniabukta, no species was recorded from Edgeøya, Svalbard.
Graminoids attain their highest cover in Devon, Canada, whereas graminoids were
the least abundant growth forms on two of the Petuniabukta sites. Forbs, on the
other hand, represented the highest proportion of growth forms at Petuniabukta
(Table 4). Because graminoids are often rhizomatous, it seems likely that the spec−
tra of clonal growth forms will differ among different parts of the Arctic.
A preponderance of hemicryptophytes among Raunkiaer’s life forms is typical
of high Arctic and alpine subnival communities (Nakhutsrishvili and Gamtsem−
lidze 1984; Pokarzhevskaya 1995; Klimeš 2004). In those habitats where low
snow cover hinders the occurrence of shrubs and the stoniness of the substratum
and/or permafrost prohibit deep placement of bud−bearing organs, the hemicrypto−
436 Jitka Klimešová et al.
Table 4
Average cover (%) of the most abundant growth forms in the plant communities. Data
(except of Petuniabukta) from Komárková and McKendrick (1988).
Growth form
Petuniabukta
Svalbard
78°38’
Edgeøya
Svalbard
78°05’
Devon
Canada
75°33'
Barrow
Alaska
71°18’
Atkasook
Alaska
70°29’
Shrubs 18 0 12 8 38
Graminoids 30 30 60 54 38
Forbs 52 70 28 38 24
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phytes, which produce their renewal buds close to the soil surface, are the most
successful life form. However, dominance by chamaephytes has been reported
from Arctic locations, as well (e.g., Matveyeva 1994).
The prevailing shoot architecture for Petuniabukta in the current study was
semirosette, which was typical of half of the examined plants in the area, and
which also was typical of plants in the subnival zone of the Caucasus (Nakhutsri−
shvili and Gamtsemlidze 1984). In the alpine zone of the Caucasus, however,
Pokarzhevskaya (1995) reported that about 80% of the plants had semirosette
shoots. We could speculate that shoot architecture is less important in harsh envi−
ronments (high Arctic and subnival zone) than in less extreme environments be−
cause the plants in harsh environments are very small. On the other hand, the spa−
tial distribution of shoots could be important in harsh environments, as is indicated
by the increasing number of cushion plants at high altitudes in mountains (Nakhut−
srishvili and Gamtsemlidze 1984; De Bello et al. 2011). Only one typical cushion
plant (Silene acaulis) was, however, detected in the current study.
The plants in Petuniabukta have much less mobility (lateral spread) than the
plants in central Europe (Klimešová and Klimeš 2008; Klimešová et al. 2011b).
This result is in accord with other observations in cold climates (Nakhutsrishvili
and Gamtsemlidze 1984; Pokarzhevskaya 1995; Klimeš 2003), although we still
lack data for another Arctic locality.
A root system consisting exclusively of a main root that lacks the ability to
form adventitious roots, and consequently that lacks the ability to grow clonally,
was characteristic of one−third of the plants from the Petuniabukta area (and nearly
half of plants recorded in plant communities). This value is similar in that reported
for other cold areas (Polozova 1981; Nakhutsrishvili and Gamtsemlidze 1984;
Pokarzhevskaya 1995; Rusch et al. 2011) with the exception of dry regions of the
Western Himalayas (Klimeš 2003).
Plants from Petuniabukta have biennial (dicyclic) or perennial (polycyclic)
shoots whereas those in the more temperate central European region have mainly
annual (monocyclic) shoots (Klimešová and Klimeš 2008). These results suggest
that plants require more time for inflorescence development in the stressful envi−
ronment of the high Arctic than in temperate regions (Alexandrova 1983).
Plant characteristics in different plant communities. — The plant charac−
teristics differed substantially among the plant communities in Petuniabukta.
Characteristics were similar only for the Papaver dahlianum and the Saxifraga
oppositifolia communities (both typically occur on slopes and host non−clonal forb
species with perennial main roots) and for the Carex−moss and Deschampsia bore−
alis communities (both occur in wet and flat habitats and host clonal plants with
long, hypogeogenous rhizomes). Other communities had unique characteristics.
The largest differences in clonal growth organs among the plant communities
in Petuniabukta were found in the proportion of hypogeogenous rhizomes. Plant
species possessing this clonal growth organ represented 20% of the species or
Clonal plants in Svalbard 437
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plant cover in the wet plant community dominated by mosses along brooks, snow
beds, and seepages while their representation on young substrates, stony slopes,
and under bird cliffs was negligible. The opposite tendency was recorded for
plants with perennial main roots, which were dominant on young substrates but
less represented in wet habitats. This replacement of rhizomatous plants by
non−clonal plants with perennial main roots in communities along a gradient of re−
duced water availability is in accord with observations from temperate areas that
wetland habitats host higher number of rhizomatous species than mesic or dry sites
(van Groenendael et al. 1996; Klimeš et al. 1997; Sosnová et al. 2011).
Plants that grow clonally using plantlets or bulbils (pseudovivipary) were the
most represented in Petuniabukta communities growing on fine soil in alluvial de−
posits or in snow beds under bird cliffs, whereas they were missing in the Papaver
dahlianum community that spread over stony substrates. In a glacier foreland in
the Alps, in contrast, regeneration of Poa alpina by plantlets was found in areas
with stony substrate in early successional stages with poor vegetation cover but not
later, when plant cover was high (Winkler et al. 2010).
Several plant characteristics differed or did not differ between the studied
communities depending on whether plant cover was or was not taken into account
(i.e., depending on whether abundance weighting was or was not used). These
characteristics were the proportion of plants that were sedges, were non−clonal,
had a lateral spread of 1–5 cm, had a main root, or had polycyclic shoots. In these
cases, taking or not taking plant cover into account greatly affected the statistical
analysis because of the dominance or the rarity of the species with these characters
in the communities. The determination of whether characteristics differed among
communities was unaffected by abundance weighting for only a few characteris−
tics, which were the proportion of plants with rosette shoots and with dispersible
vegetative diaspores; this further indicates the large differences among the com−
munities in the area.
Plant characteristics along environmental gradients. — The sensitivity of
hypogeogenous rhizomes to unstable and stony substrates was confirmed by a sig−
nificant negative correlation with stoniness and slope and the occurrence of plants
with hypogeogenous rhizomes. This relationship indicates that a negative correla−
tion between spacer length (length of rhizomes between shoots) of hypogeogenous
rhizomes and temperature (Klimešová et al. 2011b) is probably mediated by soil
properties.
The idea that substrate instability negatively affects belowground rhizomes
dates back to Hess (1909), who found that the most successful growth forms on
screes in the Alps had perennial main roots, which enabled the plant to explore
deeper, more stable, and wetter scree strata. Similar results were obtained in the
current study, in that non−clonal plants with perennial main roots were concen−
trated in a similar kind of habitat. Furthermore, Jonasson (1986) found that rhizo−
matous species were more abundant on stable parts of soil polygons rather than in
438 Jitka Klimešová et al.
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their active centers. Klimeš (2003, 2008) considered that the small proportion of
clonal plants in the flora of Ladakh was a consequence of substrate instability,
which makes horizontal growth in stony soils difficult. This inference was con−
firmed (Klimešová et al. 2011a) when the occurrence of individual clonal growth
organs in relation to environmental gradients was evaluated, and the ratio of
hypogeogenous to epigeogenous rhizomes was also found to be smaller in Ladakh
than in Central Europe. It is, however, questionable whether this is the general pat−
tern for the Arctic because not all Arctic environments are characterized by stony
substrates, and steep slopes are also not a general characteristic of the Arctic land−
scape. Perhaps flatter Arctic landscapes that are covered by a fine−grain substrate
(e.g., north slopes in Alaska, see Raynolds et al. 2008) will host more rhizomatous
species than reported for Petuniabukta in the current study. In contrast to below−
ground rhizomes, aboveground clonal growth organs are not subject to breakage
(creeping branches of dwarf shrubs). It is also possible that plants with above−
ground clonal growth organs are adapted to disturbance and easily re−root after
disturbance (Hagen 2002). This is especially true for Saxifraga oppositifolia,
which dominates highly disturbed habitats near periodic streams.
Conclusion
Our results indicate that the spectrum of clonal growth organs is narrower in
the high Arctic than in central Europe. In particular, the high Arctic lacks plants
with clonal growth organs typical of aquatic species. In agreement with our expec−
tations, the proportion of hypogeogenous rhizomes was low, especially in habitats
with steep slopes and substrate stoniness where non−clonals with perennial main
roots prevailed. Broader generalizations on the function of clonal growth in the
Arctic will require the collection of additional data by the same methodology.
Acknowledgements. — We are indebted to Milan Štech for species determinations, to
Mirek Dvorský for help with the figures, and to Bruce Jafee for language revision. Our study
was supported by a grant from the Czech Ministry of Education (LA341, LM2010009). The
contribution by Jiří Doležal was supported by the Grant Agency of the Academy of Sciences of
the Czech Republic. (IAA600050802).
References
ALEXANDROVA V.D. 1983. Vegetation of polar deserts of USSR. Nauka, Leningrad: 141 pp.
BARKMAN J.J. 1988. New systems of plant growth forms and phenological plant types. In: M.J.A.
Werger, P.J.M. van der Aart, H.J. During and J.T.A. Verhoeven (eds) Plant form and vegetation
structure. SPB Academic Publishing, The Hague: 9–44.
BAUERT M.R. 1996. Genetic diversity and ecotypic differentiation in Arctic and alpine populations
of Polygonum viviparum.Arctic and Alpine Research 28: 190–195.
Clonal plants in Svalbard 439
Brought to you by | Smithsonian Instn Libraries
Authenticated | 160.111.254.17
Download Date | 1/13/13 2:06 PM
CALLAGHAN T.V. and EMANUALSON U. 1985. Population structure and processes of tundra plants
and vegetation. In: J. White (ed.) The population structure of vegetation. Junk Publishing,
Dordrecht: 399–439.
CALLAGHAN T.V., JONASSON S. and BROOKER R.W. 1997. Arctic clonal plants and global change.
In: H. de Kroon and J.M. van Groenendael (eds) The ecology and evolution of clonal plants.
Backhuys Publishers, Leiden: 381–403.
DE BELLO F., DOLEŽAL J., DVORSKÝ M., CHLUMSKÁ Z., ŘEHÁKOVÁ K., KLIMEŠOVÁ J. and
KLIMEŠ L. 2011. Cushion plants do not facilitate other plants under extreme altitude and dry
conditions: evidence from NW Himalaya. Annals of Botany 108: 567–573.
DEN HARTOG C. and SEGAL S. 1964. A new classification of water−plant communities. Acta Bota−
nica Neerlandica 13:367–393.
DRUDE O. 1887. Deutschlands Pflanzengeographie. Handbuch Deutsch Landes−Volksk 4: 1–502.
DURIETZ G.E. 1931. Life−forms of terrestrial flowering plants. Acta Phytogeographica Suecica 3:
1–95.
ELVEBAKK A. and PRESTRUD P. (eds) 1996. A catalogue of Svalbard plants, fungi, algae and cyano−
bacteria. Norwegian Polar Institute, Oslo: 395 pp.
GIMINGHAM C.H. 1951. The use of life form and growth form in the analysis of community structure,
as illustrated by a comparison of two dune communities. Journal of Ecology 39: 396–406.
GRIME J.P. 2006. Trait convergence and trait divergence in herbaceous plant communities: mecha−
nisms and consequences. Journal of Vegetation Sciences 17: 255–260.
GRISEBACH A. 1872. Die Vegetation der Erde nach ihrer klimatischen Anordnung I, II. W. Engel−
mann, Leipzig: 603 pp. and 635 pp.
HAGEN D. 2002. Propagation of native Arctic and alpine species with a restoration potential. Polar
Research 21: 37–47.
HALLÉ F., OLDEMAN R.A.A. and TOMLINSON P.B. 1978. Tropical trees and forests. An architec−
tural analysis. Springer Verlag, New York: 441 pp.
HALLOY S. 1990. A morphological classification of plants, with special reference to the New Zealand
alpine flora. Journal of Vegetation Science 1: 291–304.
HARTMANN H. 1957. Studien über die vegetative Fortpflanzung in den Hochalpen. Bischofberger &
Co., Buchdruckerei Untertor, Chur: 169 pp.
HEJNÝ S. 1960. Ökologische Charakteristik der Wasser− und Sumpfpflanzen in der slowakischen
Tiefebenen (Donau und Theissgebiet). SAV, Bratislava: 487 pp.
HESS E. 1909. Über die Wuchsformen der alpinen Geröllpflanzen. Arbeit aus dem Botanischen Mu−
seum des eidg. Polytechnikum Zürich, Druck von C. Heinrich, Dresden: 170 pp.
JONASSON S. and CALLAGHAN T.V. 1992. Root mechanical properties related to disturbed and
stressed habitats in the Arctic. New Phytologist 122: 179–186.
JÓNSDÓTTIR I.S. 2011. Diversity of plant life histories in the Arctic. Preslia 83: 281–300.
JÓNSDÓTTIR I.S., CALLAGHAN T.V. and HEADLEY A.D. 1996. Resource dynamics within Arctic
clonal plants. Ecological Bulletin 45: 53–64.
KÄSTNER A. and KARRER G. 1995. Übersicht der Wuchsformtypen als Grundlage für deren
Erfassung in der “Flora von Österreich”. Florae Austriacae Novitales 3: 1–51.
KJØLNER S., SASTAD S.M. and BROCHMANN C. 2006. Clonality and recombination in the Arctic
plant Saxifraga cernua.Botanical Journal of the Linnean Society 152: 209–217.
KLIMEŠ L. 2003. Life−forms and clonality of vascular plants along an altitudinal gradient in E Ladakh
(NW Himalayas). Basic and Applied Ecology 4: 317–328.
KLIMEŠ L. 2008. Clonal splitters and integrators in harsh environments of the Trans−Himalaya. Evo−
lutionary Ecology 22: 351–367.
KLIMEŠ L., KLIMEŠOVÁ J., HENDRIKS R. and van GROENENDAEL J. 1997. Clonal plant architecture:
a comparative analysis of form and function. In: H. de Kroon and J. van Groenendael (eds) The
ecology and evolution of clonal plants. Backhuys Publishers, Leiden: 1–29.
440 Jitka Klimešová et al.
Brought to you by | Smithsonian Instn Libraries
Authenticated | 160.111.254.17
Download Date | 1/13/13 2:06 PM
KLIMEŠOVÁ J. and DE BELLO F. 2009. CLO−PLA: the database of clonal and bud bank traits of Cen−
tral European flora. Journal of Vegetation Sciences 20: 511–516.
KLIMEŠOVÁ J. and DOLEŽAL J. 2011. Are clonal plants more frequent in cold environments than
elsewhere? Plant Ecology and Diversity 4: 373–378.
KLIMEŠOVÁ J. and KLIMEŠ L. 2006. CLO−PLA3: a database of clonal growth architecture of Cen−
tral−European plants. http://clopla.butbn.cas.cz 3rd March 2011.
KLIMEŠOVÁ J. and KLIMEŠ L. 2008. Clonal growth diversity and bud banks in the Czech flora: an
evaluation using the CLO−PLA3 database. Preslia 80: 255–275.
KLIMEŠOVÁ J., DOLEŽAL J., DVORSKÝ M., DE BELLO F. and KLIMEŠ L. 2011a. Clonal growth forms
in eastern Ladakh, Western Himalayas: classification and habitat preferences. Folia Geo−
botanica 46: 191–217.
KLIMEŠOVÁ J., DOLEŽAL J. and SAMMUL M. 2011b. Evolutionary and organismic constraints on the
relationship between spacer length and environmental conditions in clonal plants. Oikos 120:
1110–1120.
KOMÁRKOVÁ V. and MCKENDRICK J.D. 1988. Patterns in vascular plant growth forms in Arctic
communities and environment at Atkasook, Alaska. In: M.J.A.Werger, P.J.M. van der Aart, H.J.
During and J.T.A. Verhoeven (eds) Plant form and vegetation structure: adaptation, plasticity
and relation to herbivory. SPB Academic Publishing, The Hague: 45–70.
KRUMBIEGEL A. 1998. Growth forms of annual vascular plants in central Europe. Nordic Journal of
Botany 18: 563–575.
KRUMBIEGEL A. 1999. Growth forms of biennial and pluriennial vascular plants in central Europe.
Nordic Journal of Botany 19: 217–226.
ŁUKASIEWICZ A. 1962. Morfologiczno−rozwojowe typy bylin. Poznańskie Towarzystwo Przyjaciół
Nauk, Prace Komisji Biologicznej 27: 1–398.
MATVEYEVA N.V. 1994. Floristic classification and ecology of tundra vegetation of the Taymyr
paninsula, Northern Siberia. Journal of Vegetation Science 5: 813–828.
NAKHUTSRISHVILI G.S. and GAMTSEMLIDZE Z.G. 1984. Plant life in extreme high mountain condi−
tions: with the example from the Central Caucasus. Nauka, Leningrad: 123 pp.
PARSONS D.J. 1976. Vegetation structure in the Mediterranean scrub community of California and
Chile. Journal of Ecology 64: 435–447.
POKARZHEVSKAYA G.A. 1995. Morphological analyses of alpine communities of the north−western
Caucasus. Folia Geobotanica & Phytotaxonomica 30: 197–210.
POLOZOVA T.G. 1981. Life forms of vascular plants in different subzones of the Taimyr Tundra. Bul−
letin of the Academy of Sciences of the U.S.S.R, Biological series 56: 265–281.
PRACH K., KLIMEŠOVÁ J., KOŠNAR J., REDCHEKO O. and HAIS M. 2012. Variability of contemporary
vegetation around Petuniabukta, central Spitsbergen. Polish Polar Research 33 (4): 383–394
RAUNKIAER C. 1907. Planterigets Livsformer og deres Betydning for Geografien. Munskgaard, Co−
penhagen: 132 pp.
RAYNOLDS M.K., WALKER D.A., MUNGER C.A., VONLANTHEN C.M. and KADE A.N. 2008. A map
analysis of patterned−ground along a north American Arctic Transect. Journal of Geophysical
Research−Biogeosciences 113 G3: G03S03.
RD
EVELOPMENT CORE TEAM 2009. R: A language and environment for statistical computing.
ISBN 3−900051−07−0: http://www.R−project.org
RØNNING O.I. 1996. The flora of Svalbard. Norsk Polarinstitut, Oslo: 184 pp.
RUSCH G.M., WILMANN B., KLIMEŠOVÁ J. and EVJU M. 2011. Do clonal and bud bank traits vary in
correspondence with soil properties and resource acquisition strategies? Patterns in alpine com−
munities in the Scandian mountains. Folia Geobotanica 46: 237–254.
SEREBRJAKOV I.G. 1964. Zhiznennyje formy vysshikh rastenij i ich izuchenije. In: E.M. Lavrenko
and A.A. Korchagin (eds) Field geobotany. Nauka, Moskva: 146–205.
Clonal plants in Svalbard 441
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SOSNOVÁ M., VAN DIGGELEN R. and KLIMEŠOVÁ J. 2010. Distribution of clonal growth forms in
wetlands. Aquatic Botany 92: 33–39.
SOSNOVÁ M., VAN DIGGELEN R., MACEK P. and KLIMEŠOVÁ J. 2011. Distribution of clonal growth
traits among wetland habitats. Aquatic Botany 95: 88–93.
TER BRAAK C.J.F. and ŠMILAUER P. 1998. CANOCO reference manual and user’s guide to Canoco
for Windows. Microcomputer Power, Ithaca: 352 pp.
VAN GROENENDAEL J.M., KLIMEŠ L., KLIMEŠOVÁ J. and HENDRIKS R.J.J. 1996. Comparative ecol−
ogy of clonal plants. Philosophical Transactions of Royal Society, London 351: 1331–1339.
VON HUMBOLDT A. 1806. Ideen zu einer Phisiognomik der Gewächse. Cotta, Stuttgart: 28 pp.
VON LAMPE M. 1999. Vorschlag zur Bezeichnung der Innovations− und Überdauerungsorgane bei
den terrestrischen Stauden Zentraleuropas. Beiträge zur Biologie der Pflanzen 71: 335–367.
WARMING E. 1908. The structure and biology of Arctic flowering plants I. Ericineae (Ericaceae,
Pirolaceae). Meddelelser om Grönland 36: 2–71.
WARMING E. 1909. The structure and biology of Arctic flowering plants IV. Saxifragaceae. Meddelelser
om Grönland 36: 172–236.
WARMING E. 1923. Ökologiens Grundformer. Kongelike Danske Vedenskabernes Selskabs Skrifter,
Naturvidenskabelig og Mathematisk Avdelning 8: 120–187.
WINKLER E., MARCANTE S. and ERSCHBAMER B. 2010. Demographic Consequences of the Two
Reproductive Modes in Poa alpina L. along a Primary Succession Gradient in the Central Alps.
Arctic, Antarctic, and Alpine Research 42: 227–235.
Received: 26 June 2011
Accepted: 20 April 2012
442 Jitka Klimešová et al.
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