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Clonal growth forms in Arctic plants and their habitat preferences: A study from Petuniabukta, Spitsbergen


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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.
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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 <>
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.
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
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
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
characteristics Categories Definition / Reference Function
Growth forms
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
Erosulate Leaf distribution along shoot
/ Klimešová and Klimeš
Competitive ability (erosulate) versus
disturbance avoidance (rosette)
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
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
Lateral spread
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
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
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
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.
type Typical species Habitat description
No. of
No. of
% of area
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, Braya
purpurascens, Draba sp. div.
Sparse vegetation on
young, unstabilized
fluvial sediments,
morains, screes, or
maritime terraces
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, D. alpina,
D. caespitosa
Around streams and
eutrophic spots near
Papaver dahlianum, Silene
uralensis subsp. arctica
On fine screes at higher
altitudes, with both low
vegetation cover and
species richness
Festuca baffinensis, Cochlearia
groenlandica, Saxifraga
hieracifolia, S. nivalis, S. cespitosa,
S. cernua, Cerastium arcticum
Species−rich vegetation
developed on eutrophic
soils under bird nesting
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 (
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
hypogeogenous rhizome
epigeogenous rhizome
main root
Raunkiaer life forms
010203040506070 80
Growth forms
0 102030405060
Leaf distribution
Lateral spread [cm/yr]
0 5 10 15 20 25 30 35
spread 5–10
spread 1–5
spread > 1
Number of species
Shoot cyclicity
0 1020304050
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. 14.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
-0.6 1.0
epigeogenous rhizome
hypogeogenous rhizome
main root
both root system
bicyclic shoot
polycyclic shoot
Dryas octopetala
Saxifraga oppositifolia
Carex-moss .spp
Deschampsia borealis
Papaver dahlianum
Festuca baffinensis
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
(a) Shrub
Dr Sa Ca De Pa Fe
(c) Grass
100 (b) Forb
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).
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
100 (a) Epigeogenous rhizome
100 (b) Hypogeogenous rhizome
Dr Sa Ca De Pa Fe
(c) Root-splitter
Dr Sa Ca De Pa Fe
(d) Pseudovivipary
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.
Category Number of
Differences between
six communities
with stoniness
with slope
Pweighted Punweighted rweighted runweighted rweighted runweighted
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
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
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
rhizome 25 8.4 0.061 0.003 −0.25 0.00 −0.01 0.15
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
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
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
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
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
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.
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
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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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... Clonal growth is an important life-history trait that can provide plants with a higher probability of persistence, as well as competitive advantages related to the ability to deal with disturbances (resistance and resilience), nutrient acquisition, and reproduction (Bazzaz 1996;Stueffer et al. 1996;Klimešová et al. 2012Klimešová et al. , 2017Klimešová et al. , 2018. In consequence, clonal expansion is expected to be associated with higher competitive ability due to more flowering shoots and greater reproductive capacity; however, there is also an increased probability of geitonogamy or self-pollination between flowers of the same individual or clone (Vallejo-Marín et al. 2010) putatively reducing seed viability (e.g., Husband and Schemske 1996) and causing loss of population genetic diversity. ...
... Clonal growth is widely distributed in all biomes. It is present in 51% of angiosperms from temperate regions, and particularly common in wetland habitats (Barrett et al. 1993;Klimešová et al. 2012Klimešová et al. , 2018. Most wetland habitats can be regarded as island-like systems whose units are spatially and temporally isolated and as systems where connectivity highly depends on the size and proximity of the isolated units (MacArthur and Wilson 1967;Itescu 2018). ...
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In plants, long-distance dispersal is both attenuated and directed by specific movement vectors, including animals, wind, and/or water. Hence, movement vectors partly shape metapopulation genetic patterns that are, however, also influenced by other life-history traits such as clonal growth. We studied the relationship between area, isolation, plant-species richness, reproduction, and dispersal mechanisms with genetic diversity and divergence in 4 widespread wetland plant-species in a total of 20 island-like kettle-hole habitats surrounded by an intensive agricultural landscape. Our results showed that genetic parameters reflect the reproduction strategies with the highest genetic diversity being observed in the non-clonal, outcrossing Oenanthe aquatica compared to the clonal Lycopus europaeus, Typha latifolia, and Phragmites australis. Lycopus showed a positive relationship between genetic diversity and kettle-hole area, but a negative relationship with the number of neighboring kettle holes (less isolation). Genetic diversity increased with plant-species richness in the clonal species Phragmites and Lycopus; while it decreased in the non-clonal Oenanthe. Finally, genetic divergence and, therefore, connectivity differed between alternative dispersal strategies, where wind-dispersed Typha and Phragmites had a higher gene flow between the analyzed kettle holes compared with the insect-pollinated, hydrochorous Lycopus and Oenanthe. Our study provides information on genetic patterns related to reproduction and dispersal mechanisms of 4 common wetland species contributing to the understanding of the functioning of plant metacommunities occurring in kettle holes embedded in agricultural landscapes.
... Previous studies have noted belowground bud banks in environments with frequent disturbance (Fidelis et al., 2014;Pausas et al., 2018) and also in arid climates (Rundel, 1996;Parsons and Hopper, 2003;Procheş et al., 2006;Sosa and Loera, 2017). Geophytic plants are also common in temperate climates in both woodlands (Whigham, 2004) and grasslands (Herben and Klimešová, 2020), as well as in montane environments and arctic regions (Klimešová et al., 2011;Klimešová et al., 2012). ...
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The evolution of geophytes in response to different environmental stressors is poorly understood largely due to the great morphological variation in underground plant organs, which includes species with rhizomatous structures or underground storage organs (USOs). Here we compare the evolution and ecological niche patterns of different geophytic organs in Solanum L., classified based on a functional definition and using a clade-based approach with an expert-verified specimen occurrence dataset. Results from PERMANOVA and Phylogenetic ANOVAs indicate that geophytic species occupy drier areas, with rhizomatous species found in the hottest areas whereas species with USOs are restricted to cooler areas in the montane tropics. In addition, rhizomatous species appear to be adapted to fire-driven disturbance, in contrast to species with USOs that appear to be adapted to prolonged climatic disturbance such as unfavorable growing conditions due to drought and cold. We also show that the evolution of rhizome-like structures leads to changes in the relationship between range size and niche breadth. Ancestral state reconstruction shows that in Solanum rhizomatous species are evolutionarily more labile compared to species with USOs. Our results suggest that underground organs enable plants to shift their niches towards distinct extreme environmental conditions and have different evolutionary constraints.
... temperate grasslands). For example, rhizomes are rare on undeveloped stony soils in the arctic (Klimešová et al., 2012); sprouting from roots is uncommon in aquatic communities but tends to prevail among perennial weeds of agricultural land (Sosnová et al., 2010;Klimešová and Martínková, 2022). Annual and stoloniferous plants tend to prefer nutrientrich habitats, with rhizomatous plants being in the middle and non-clonal perennials at the nutrient-poor end of the gradient . ...
Background and Aims Clonality is a key life history strategy promoting on-spot persistence, space occupancy, resprouting after disturbance and resource storage, sharing and foraging. These functions provided by clonality can be advantageous under different environmental conditions, including resource paucity and fire-proneness, which define most mediterranean-type open ecosystems, such as southwest Australian shrublands. Studying clonality-environment links in underexplored mediterranean shrublands could therefore deepen our understanding of the role played by this essential strategy in open ecosystems globally. Methods We created a new dataset including 463 species, six traits related to clonal growth organs (CGOs; lignotubers, herbaceous and woody rhizomes, stolons, tubers, stem fragments), and edaphic predictors of soil water availability, nitrogen and phosphorus from 138 plots. Within two shrubland communities, we explored multivariate clonal patterns and how the diversity of CGOs, abundance weighted, and unweighted proportions of clonality in plots changed along with the edaphic gradients. Key Results We found clonality in 65% of species; the most frequent were those with lignotubers (28%) and herbaceous rhizomes (26%). In multivariate space, plots clustered into two groups; one distinguished by sandy plots and plants with CGOs, the other by clayey plots and non-clonal species. CGO diversity did not vary along the edaphic gradients (only marginally with water availability). The abundance-weighted proportion of clonal species increased with N and decreased with P and water availability, yet these results were CGO-specific. We revealed almost no relationships for unweighted clonality. Conclusions Clonality is more widespread in shrublands than previously thought, and distinct plant communities are distinguished by specific suites (or lack) of CGOs. We show that weighting belowground traits by aboveground abundance affects the results, with implications for trait-based ecologists using abundance-weighting. We suggest unweighted approaches for belowground organs in open ecosystems until belowground abundance is quantifiable.
... The study area is located in the Arctic tundra zone, covered mostly with moss, lichens and discontinuous dwarf shrubs vegetation. There are six main plant community types in the Petunia Bay region: Dryas octopetala, Saxifraga oppositifolia, Carex − moss, Deschampsia borealis, Papaver dahlianum, Festuca baffinensis (Klimešová et al., 2012). The highest vegetation can be found in the western section of the Ebba Valley, i.e., close to the mouth of the Ebba River. ...
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Quantitative measurements of aeolian activity at high latitudes are not currently carried out on a large scale, even though these processes are important elements of the geomorphic system of polar regions, which are particularly affected by climate change. This study presents the results of aeolian deposition rates measured and calculated for one of the central Spitsbergen postglacial valleys (Ebba Valley). The results are based on seven summer season field campaigns (2012-2018), as well as on AMS 14 C and OSL dating of niveo-aeolian and aeolian sediments. Contemporary mean aeolian deposition rates ranged from 0.1 to 22.9 g⋅m − 2 ⋅day − 1 over selected parts of the valley and averaged from 2.1 to 12.3 g⋅m − 2 ⋅day − 1 over the studied summer seasons. Interestingly strong relationships (r 2 = 0.71, p = 0.017) between mean air temperature and mean aeolian deposition were observed, possibly indicating the importance of the source material delivered to the valley by fluvioglacial processes. Moreover, aeolian deposition dependence on the source material reflected in the local nature of the process was observed. Niveo-aeolian deposition rates were estimated for the period since the 11th century, through the Little Ice Age, till the second half of the 20th century and revealed a rather constant value of 0.05 cm per year. Since then, the niveo-aeolian deposition rate has significantly increased and equalled 0.3 cm per year, which may be related to rising air temperatures and associated pan-Arctic environmental changes.
... Rhizomes mobilized for rapid growth during the brief summer can follow the front of the melting snow. The vegetative and floral buds of rhizomes as well as their stores of carbohydrates allow rhizomes to be instrumental in colonization (Klimešová et al. 2012). The rhizomatous Epilobium anagalidifolium and Oxyria digyna were found near the snowfield edges, which have low percent cover and are ostensibly open to colonization. ...
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The snowfields and glaciers of Glacier National Park, Montana, USA, are retreating due to climate change. This presents alpine plants with changes in habitat and hydrology as the extent of snowfield plant habitat diminishes. We established georeferenced transects at the formerly permanent snowfields of Siyeh Pass, Piegan Pass, and at the Clements Mountain Moraine in the Lewis Mountain Range of Glacier National Park for long-term monitoring of plant functional traits and species distribution. Field observations, taxonomic literature, and measurements of collected leaves provided data to calculate community weighted trait means (CWTM) of quantitative functional traits and the relative percent cover (RPC) of qualitative functional traits. The total percent cover of plants increased significantly with distance from the snow. Raunkiaer plant growth forms differed significantly as there was a greater abundance of cryptophytes with subterranean overwintering buds near the snow but a greater abundance of woody chamaephytes and phanerophytes away from the snow. The significantly lower CWTM of specific leaf area (SLA, mm²/mg dry weight) away from the water-rich snowfield edge suggests xeromorphy as a response to water limitation. Rhizomes may be an important colonizing mechanism for habitat exposed by retreating snow and ice, as the RPC of rhizomatous species was significantly greater near the snow and since rhizomes are clonal and carry vegetative and reproductive buds. The distribution of plant functional traits and species can be used to predict responses of alpine plants to the disappearance of snowfields and glaciers.
... In the autumn and spring, soil is prone to cryoturbation (mixing of soils from different layers within permafrost because of freeze-thaw cycles) and to solifluction (the movement of soil down a slope during freeze-thaw cycles (Ping et al., 2015;Van Vliet-Lanoë, 1988)); consequently, physical damage to perennating organs can be extensive. Geophytes are generally absent from such places, while hemicryptophytes and chamaephytes (plants with buds on persistent aboveground shoots, near the soil surface) dominate (Dahl, 1975;Klimešová et al., 2012). Low temperature and biomass production also slow soil development, thus there is less soil available for the protection and growth of belowground structures (Dere et al., 2016). ...
The physical avoidance of overwinter damage is important for determining the success of herbaceous perennial plants in climates with cold winters. Exposure to damaging frost can be affected by contemporary climatic change, which can include an increase in winter air temperatures, changes in precipitation and changes in the timing and severity of warm and cold events. In this review, we consider the specific adaptations of herbaceous plants to avoid harsh winter conditions via perennating organs, what is known about their responses to warming winters, and what future directions the research of overwintering in herbs should explore. Herbaceous plants have adapted to harsh winter conditions in part by investing carbohydrates into belowground organs of perennation instead of aboveground biomass. The location of renewal buds and stored carbohydrates belowground increases their protection against freezing temperatures, and they can be further protected via insulation from plant litter or snow cover. Climate change can affect overwintering organs by altering snow cover depth and duration, thus increasing or decreasing the exposure of plants to frost, and may initiate an earlier or a later onset of growth in the spring. Winter warming can increase productivity in some species, but directly or indirectly decrease it in others and may lead to a loss of specialized plants, for example, in snowbed communities. Plants with shallow structures and taproots may be particularly vulnerable to increased soil frost penetration resulting from reduced snow cover. Measures of organ biomass and storage carbohydrate content can be used to assess how winter conditions affect allocation, storage, and the potential for growth in the spring. When destructive measures cannot be taken, the use of trait measures, such as perennating organ type, or its traits, such as depth and size of bud bank, can add further strength to the assessment of responses across multiple species. To fully understand the effects of changing winter conditions on perennial herbaceous plants, researchers must better account for plant overwintering strategies, their drivers, costs, and benefits. A free Plain Language Summary can be found within the Supporting Information of this article.
... Donor ramets generally show integration-mediated 'specialization for abundance' in terms of morphology and biomass allocation, but not in terms of physiology (Alpert & Stuefer, 1997). The general benefits of physiological integration on clonal plant performance may have contributed to the wide distribution of clonal plants in nature and their dominance in ecosystems such as grasslands, wetlands and tundra (Grace, 1993;Klimešová et al., 2011Klimešová et al., , 2012Tomáš et al., 2014). ...
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Clonal plants play key roles in maintaining community productivity and stability in many ecosystems. Connected individuals (ramets) of clonal plants can translocate and share, for example, photosynthates, water and nutrients, and such physiological integration may affect performance of clonal plants both in heterogeneous and homogeneous environments. However, we still lack a general understanding of whether or how physiological integration in clonal plants differs across homogeneous versus heterogeneous environments. We compiled data from 198 peer‐reviewed scientific studies conducted in 19 countries with 108 clonal plant species from 35 families, and carried out a meta‐analysis of effects of physiological integration on 16 traits related to plant growth, morphology, physiology or allocation. Our analyses evaluated these relationships in (A) heterogeneous environments where at least one resource essential for plant growth (e.g. light, soil water and mineral nutrients) or non‐resource factor (e.g. grazing, trampling and burial) is spatially non‐uniformly distributed and (B) homogeneous environments where all these factors are spatially uniformly distributed. Physiological integration increased growth of whole clones in both homogeneous and heterogeneous environments due to its highly significant contribution to growth of recipient ramets. Integration did not affect growth of donor ramets in heterogeneous environments, but decreased it in homogeneous environments. Integration affected physiological traits of donor ramets in neither homogeneous nor heterogeneous environments. It did not affect any physiological traits of recipient ramets in homogeneous environments, but increased most of them in heterogeneous environments. For donor ramets, integration increased height by 53% and internode length by 37% in heterogeneous environments, but had no effect in homogeneous environments. For recipient ramets, integration increased height by 73% in homogeneous environments and by 115% in heterogeneous environments, and increased internode length by 35% only under heterogeneous environments. In heterogeneous environments, integration increased biomass allocation to roots of donor ramets under high water/nutrient conditions and decreased it under high light. Physiological integration plays a strong role in clonal plant physiology, morphology and growth, especially for recipient ramets in heterogeneous environments. Therefore, physiological integration may have contributed to the widespread of clonal plants in nature and their dominance in many ecosystems. It may also play important roles in invasion success of alien clonal plants and in maintaining functions and stability of ecosystems where clonal plants are abundant. A free Plain Language Summary can be found within the Supporting Information of this article.
... Root and rhizome apices Klimešová et al., 2012 Facilitates movement of roots and rhizomes into new areas. ...
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The effects of plants on the biosphere, atmosphere, and geosphere are key determinants of terrestrial ecosystem functioning. However, despite substantial progress made regarding plant belowground components, we are still only beginning to explore the complex relationships between root traits and functions. Drawing on literature in plant physiology, ecophysiology, ecology, agronomy and soil science, we review 24 aspects of plant and ecosystem functioning and their relationships with a number of traits of root systems, including aspects of architecture, physiology, morphology, anatomy, chemistry, biomechanics and biotic interactions. Based on this assessment, we critically evaluate the current strengths and gaps in our knowledge, and identify future research challenges in the field of root ecology. Most importantly, we found that below-ground traits with widest importance in plant and ecosystem functioning are not those most commonly measured. Also, the fair estimation of trait relative importance for functioning requires us to consider a more comprehensive range of functionally-relevant traits from a diverse range of species, across environments and over time series. We also advocate that establishing causal hierarchical links among root traits will provide a hypothesis-based framework to identify the most parsimonious sets of traits with strongest influence on the functions, and to link genotypes to plant and ecosystem functioning.
Global climate change has great effects on ecosystems via changes in air and soil temperature. While the effects of temperature have been extensively studied, relatively few studies have truly separated the impact of soil temperature from that of air temperature. Furthermore, little is known about how removal of older ramets may affect the performance of their interconnected younger ramets of bamboos. By maintaining air temperature constantly (at 17 °C) in growth chambers and manipulating soil temperature (2, 7, 12, 17 and 22 °C) using thermostatic water bath systems, we tested the effects of soil temperature and removal of the older ramets on survival, growth and physiology of its interconnected young ramet of a bamboo Indocalamus decorus. Soil temperature significantly affected the survival of the young ramet of I. decorus and also the growth and photosynthetic rate of the surviving young ramet when the shoots of its connected older ramets were not removed. Removing shoots of the older ramets greatly enhanced the survival of the young ramet at the two highest soil temperatures (17 and 22 °C) and the growth of the surviving ramet at 7 and 12 °C. We conclude that shoot removal of older ramets can interact with soil temperature to affect survival and growth of young ramets of the bamboo, and that resource sharing (translocation of photosynthates) from older ramets to young ramets of the bamboo is rather limited. Instead, newly emerged, interconnected ramets of bamboos may compete fiercely for resources stored in rhizomes. These results suggest that bamboo forest management should consider the balance between resource sharing and competition for resources stored in rhizomes under ongoing global climate change.
The recent deglaciation of large polar areas has exposed stretches of land, allowing spontaneous primary succession. The exposed substrate is colonized by soil biota participating in soil formation – a process in which soil characteristics and the biotic community affect each other mutually. Soil fauna was studied along three transects in glacier valleys around Petunia Bay on Svalbard in the High Arctic, representing chronosequences of soil development on plots deglaciated for ten to approximately ten thousand years. Community development was characterised by progressive addition of species, with many pioneer species remaining present throughout soil development. Generally, the abundance and species richness of soil animals increased from the initial to the well-developed sites. Altogether 93 taxa of soil fauna were identified, including 21 species of rotifers, 38 genera of nematodes, 8 species of tardigrades, 21 species of springtails and 4 species of enchytraeids. Rotifers were the earliest colonizers, found already in the initial stage, followed by nematodes in plots several tens of years old. They were followed by tardigrades, which – although in low abundances – established populations in the third stage of the chronosequences, 10³-year-old. Collembolans formed stable populations at the end of the chronosequence in the third and fourth stages, 10³ to 10⁴ years old. Enchytraeids only appeared at the end of the chronosequence. Assemblages were significantly driven mostly by the age of the plot, association with a given transect and nutrient availability.
Arctic and alpine plant communities today are subject to an increasing frequency and intensity of anthropogenic disturbances. Good understanding of reproductive behaviour and regenerative capacity of native species is important in a restoration situation following human disturbance in Arctic and alpine vegetation. Seeds, bulbils or cuttings from 12 native Arctic and alpine species were collected from Longyearbyen in Svalbard and Dovre Mountain on the Norwegian mainland. Propagation ability was tested in greenhouse conditions. Seeds of Papaver dahlianum, Oxyria digyna, Luzula arcuata ssp. confusa, and bulbils of Bistorta vivipara all had more than 50% germination. Dryas octopetala had less than 10% germination. Both quick and slow germinators were identified among the tested species. Seed storage temperature (+4 °C, ?1 °C and ?20 °C) showed no overall effect on germination. The rooting capacity of cuttings from evergreen and deciduous species was tested. Arctostaphylos uvaursi, Empetrum nigrum ssp. hermaphroditum, Vaccinium vitis-idaea, Salix herbacea and S. polaris had more than 70% rooting ability, while Dryas octopetala and Cassiope tetragona had less than 10%. Saxifraga oppositifolia showed large variation in rooting ability, ranging from 20-90%. The species with high germination and rooting ability are used in an extended restoration experiment in the study areas.
It is argued in this paper that the diversity of plant life histories in the Arctic is much greater than indicated by general descriptions in the literature. Three basic types of life cycle are suggested as a fundamental trait-based framework for exploring the diversity of plant life histories in the Arctic: (i) annual, (ii) non-clonal perennial and (iii) clonal perennial. An overview of current understanding of traits of arctic plant life histories is provided within this framework. Based on the overview it is concluded that (i) there is a substantial diversity of plant life histories in the Arctic, and (ii) there is no single life-history trait that is specific for arctic plants. Furthermore, it is proposed that because arctic environments differ in many respects from other environments, unique combinations of life-history traits are selected among arctic plants. Consequently, arctic plants should express a unique spectrum of life histories. It is also recognized that there are large gaps in the knowledge on arctic plant life-history traits and that fine-tuned trait habitat relationships may be offset by historical, biogeographical or ecological factors, which may hamper analyses of life history habitat relationships. On the other hand, it may be rewarding in terms of an improved understanding of functional and evolutionary responses of arctic plants to climate and other environmental changes to identify potential life history syndromes (strategies) among them.
The clonal growth habit is widespread amongst nearly all plant life forms of the Arctic and Subarctic which includes the Abisko area where clonal plant species dominate all major vegetation types. They do not depend on sexual reproduction and seedling establishment for proliferation in these harsh environments, they can search for nutrients in nutrient-limited and highly heterogeneous habitats, can take up water and nutrients from many sites simultaneously and thus buffer against spatial and temporal fluctuations in availability. They efficiently utilise the once acquired resources through recycling both within individual ramets and between ramets. As a consequence, their populations are stable and this has a stabilising effect on the vegetation as a whole. However, as they conserve nutrients within the living biomass, harmful effects of pollutants can be magnified.
Selective forces of the physical environment are particularly strong in the tundra: positive plant interactions tend to replace the competition or self-thinning typical in warmer latitudes. Tundra areas are young and evolution is slow because of long life spans, low reproductive rates and a predominance of vegetative proliferation. However, recruitment from seed is important in open habitats such as fell-fields, but early mortality rates are high and recruitment is intermittent. Age class distributions resulting from vegetative reproduction show low recruitment levels but high survival rates due to the physiological interdependence of modules. The dynamic equilibrium of forest tundra plant populations is regulated by interactions between fluctuating populations of animals and plants.