Abstracts of volume 74, 2002
Duchoslav M. (2002): Flora and vegetation of stony
walls in East Bohemia (Czech Republic). – Preslia 74: 1–25.
This paper deals with the flora and vegetation of stony walls (wall tops,
vertical wall surfaces) in East Bohemia. In total, 207 species of vascular
plants and 60 mosses were identified in 114 recorded relevés. Flora of walls is
composed of a high number of accidental species. Only two species (Poa
compressa, Taraxacum sect. Ruderalia) were frequently
recorded on walls. Differences in species’ traits (life strategy, life
form, dispersal) and ecological requirements of plants (light, moisture) were
analysed between vertical wall surfaces and wall tops. Due to high floristic
heterogeneity, many communities can be classified only at the level of higher
syntaxa. In total, 10 communities were reported on the studied walls.
Communities on wall tops were dominated by Poa compressa, P.
palustris subsp. xerotica, P. nemoralis subsp.
rigidula, Conyza canadensis and Syringa vulgaris. Four
communities dominated by Corydalis lutea, Cymbalaria muralis,
Asplenium ruta-muraria and Cystopteris fragilis were identified
on vertical wall surfaces. Their structure, species composition, ecology and
distribution are briefly discussed.
Rotreklová O., Krahulcová A., Vaňková D., Peckert T.
& Mráz P. (2002): Chromosome numbers and breeding systems in some species
of Hieracium subgen. Pilosella from Central Europe. – Preslia,
Praha, 74: 27–44.
Chromosome numbers are given for 16 taxa (and one interspecific hybrid) of
Hieracium subgen. Pilosella originating from Central Europe:
H. apatelium Nägeli et Peter (2n = 45), H. aurantiacum L. (2n =
36), H. bauhini Besser (2n = 36, 45, 54), H. brachiatum Bertol.
ex DC. (2n = 45, 48, 63, 72), H. densiflorum Tausch (2n = 36), H.
echioides Lumn. (2n = 18, 27, 36), H. floribundum Wimm. et Grab. (2n
= 36, 45), H. glomeratum Froel. (2n = 36, 45), H. guthnickianum
Hegetschw. (2n = 54), H. lactucella Wallr. (2n = 18), H. onegense
(Norrl.) Norrl. (2n = 18), H. pilosella L. (2n = 36, 45, 54), H.
piloselliflorum Nägeli et Peter (2n = 36, 45), H. piloselloides
Vill. (2n = 36), H. rothianum Wallr. (2n = 36), H. schultesii F.
W. Schultz (2n = 45), and the hybrid H. floribundum × H.
aurantiacum (2n = 36). New chromosome numbers are reported for H.
brachiatum and H. floribundum. The octoploid cytotype (2n = 72),
recorded in H. brachiatum, is the highest ploidy level ever found in
plants from the subgen. Pilosella originating from the field.
Aneuploidy, rare in this subgenus in Europe, occurs in this hybridogenous
species as well: it was recorded in one plant (2n = 48) collected in a hybrid
swarm H. pilosella × H. bauhini. The breeding system in H.
bauhini, H. brachiatum, H. densiflorum, H. echioides,
H. pilosella, H. piloselloides, and H. rothianum was
studied. The sexual reproduction of pentaploid H. pilosella is a new
observation: it means an increase of diversity in possible reproduction modes
of those cytotypes having odd chromosome numbers.
Nováková S. (2002): Algal flora of subalpine peat bog
pools the Krkonoše Mts. – Preslia 74: 45–56.
During a two-year investigation of the Úpské rašeliniště peat bog and the
Pančavské rašeliniště peat bog in the Krkonoše Mts (Czech Republic) about 228
taxa of cyanobacteria and algae were found. The diatoms were the dominant group
in most of the investigated samples. The relationship between algal flora and
the environmental characteristics of the pools was studied. The pH, shading and
type of bed were most important factors influencing algal communities in the
pools.
Vassiliades D. & Persson K. (2002): A new winter-
flowering species of Colchicum from Greece. – Preslia, Praha 74:
57–65.
A new species, Colchicum asteranthum Vassil. et K. Perss.
(Colchicaceae), endemic to the Peloponnese in Greece, is described. It
is a small winter-flowering plant with synanthous leaves and soboliferous
corms, the latter a rare feature in the genus. The species has no obvious
relations, but it shows some affinity to the S Turkish endemic C.
minutum K. Perss.
Sádlo J.& Bufková I. (2002): Vegetation of the
Vltava river alluvial plain in the Šumava Mts (Czech Republic) and the problem
of relict primary meadows. – Preslia 74: 67–83. [In Czech]
Nutrient-rich terrestric habitats form small areas in the peaty alluvial
plain of upper stream of the Vltava river. Their vegetation consists of birch
and grey alder alluvial woodland, willow and bridewort scrub and tall grassland
of sedges, grasses and forbs. A hypothesis that this vegetation is an Early
Holocene relic is presented. The relict origin is supported by recent dynamics
of habitats and vegetation, findings of palynology, palaeoecology and history
of land use, and by the analogical composition and history of relict vegetation
of northernmost Europe. The refugial effect of the habitat is suggested by
stable conditions on high temporal and spatial scales, and by permanent
reclaiming of open gaps along the stream.
Pyšek P., Sádlo J. & Mandák B. (2002): Catalogue
of alien plants of the Czech Republic. – Preslia 74: 97–186.
Alien flora of the Czech Republic is presented. In Appendix 1, 1378 alien
taxa (33.4% of the total flora) are listed with information on the taxonomic
position, origin, invasive status (casual, naturalized, invasive; a new
category post-invasive is introduced), time of immigration (archaeophytes vs.
neophytes), habitat type invaded (natural, seminatural, human-made), vegetation
invaded (expressed as occurence in phytosociological alliances), mode of
introduction into the country (accidental, deliberate), and date of the first
record. Number of phytogeographical as well as biological and ecological
attributes were compiled for each species in the database; its structure is
presented in Appendix 2 as a suggestion for similar work elsewhere. Czech alien
flora consists of 24.1% of taxa which arrived before 1500 (archaeophytes) and
75.9% neophytes. There are 891 casuals, 397 naturalized and 90 invasive
species. Of introduced neophytes, 21.9% became naturalized, and 6.6% invasive.
Hybrids contribute with 13.3% to the total number of aliens, and the
hybridization is more frequent in archaeophytes (18.7%) than in neophytes
(11.7%). If the 184 hybrids are excluded from the total number of aliens, there
are 270 archaeophytes and 924 neophytes in the Czech flora, i.e. total of 1195
taxa. Accidental arrivals account for 53.4% of all taxa and deliberate
introduction for 46.6%; the ratio is reversed for neophytes considered
separately (45.5 vs. 54.5%). Majority of aliens (62.8%) are confined to human-
made habitats, 11.0% were recorded exclusively in natural or seminatural
habitats, and 26.2% occur in both types of habitat. Archaeophytes and neophytes
occur in 66 and 83 alliances, respectively, of the phytosociological system.
Flora is further analysed with respect to origin, life histories, life forms
and strategies. Only 310 species (22.4% of the total number of all alien taxa)
are common or locally abundant; others are rare, based on a single locality or
no longer present. The following 19 taxa are reported as new for the Czech
alien flora: Agrostis scabra, Alhagi pseudalhagi, Allium
atropurpureum, Bromus hordeaceus subsp. pseudothominii,
Carduus tenuiflorus, Centaurea ×gerstlaueri,
Centaurea nigra ×phrygia, Cerastium
×maureri, Gilia capitata, Helianthus strumosus,
Hieracium pannosum, Hordeum leporinum, Oenothera
coronifera, Papaver atlanticum subsp. mesatlanticum,
Parietaria pennsylvanica, Polypogon fugax, Rodgersia
aesculifolia, Sedum pallidum var. bithynicum, Sedum
stoloniferum; these represent results of our own field research as well as
of herbaria search, and unpublished data from colleagues. Other 44 taxa are
reported as escaping from cultivation for the first time. Twenty two
archaeophytes are listed in the Red List of the Czech flora.
Kaplan Z., Plačková I. & Štěpánek J. (2002):
Potamogeton ×fluitans (P. natans × P.
lucens) in the Czech Republic. II. Isozyme analysis. – Preslia 74:
187–195.
Evidence from isozyme electrophoresis confirmed previous hypothesis on the
occurrence of interspecific hybridization between Potamogeton natans L.
and P. lucens L. formulated on the basis of morphology and stem anatomy.
Isozyme phenotypes of the morphologically intermediate plants were compared
with those obtained from the putative parents growing in the same locality.
P. natans and P. lucens differed consistently in at least 12 loci
and possessed different alleles at 7 loci. The hybrid had no unique alleles and
exhibited an additive “hybrid” isozyme pattern for all 7 loci that
could be reliably analysed and where the parents displayed different enzyme
patterns. Both true parental genotypes were detected among samples of plants of
P. lucens and P. natans from the same locality. The hybrid plants
represent a recent F1 hybrid generation resulting from a single hybridization
event. Consistent differences in enzyme activity between submerged and floating
leaves of P. natans and P. ×fluitans were observed
in all interpretable enzyme systems.
Váňa J. & Kučera J. (2002): Cephalozia
macrostachya confirmed in the Czech Republic. – Preslia 74:
197–200.
Cephalozia macrostachya Kaal. has been recently found in the
‘Swamp’ mire near Doksy (Northern Bohemia). The following revision
of herbarium specimens of Cephalozia loitlesbergeri Schiffn. revealed
one more specimen of C. macrostachya, collected already in 1965 in the
Krušné hory Mts. The habitat preferences for both species in Central Europe are
discussed and it is assumed that while C. loitlesbergeri is a clearly
upland species of open, acidic raised bogs, C. macrostachya seems to
prefer lowland poor fens or lagg parts of bogs in middle altitudes.
Komárek J. & Komárková-Legnerová J. (2002):
Contribution to the knowledge of planktic cyanoprokaryotes from central Mexico.
– Preslia 74: 207–233.
The diversity of freshwater and inland saline planktic cyanoprokaryote
microflora (cyanobacteria, cyanophytes) in Mexico depends on the wide variation
of the biotopes in this country. There are no detailed studies, describing the
planktic cyanoprokaryotic species from this region. This paper lists 51
planktic morphospecies, which were found in various water bodies in central
Mexico during May 1992 and March-September 1993. Four new species
(Cyanobacterium lineatum, Cyanotetras aerotopa, Anabaena
fallax, Cylindrospermopsis taverae) are described, and important
species commented. Various species characteristic for various types of
reservoirs (volcanic lakes, lakes and artificial reservoirs with diverse
trophic levels, hypertrophic pools, saline coastal lakes) were found. Taxonomic
and ecological elaborations of the planktic cyanobacteria of Mexico (from an
ecological, geographical as well as sanitary point of view – eutrofication,
biomass production, toxicity) are urgently needed.
Pokorný P. (2002): Palaeogeography of forest trees in
the Czech Republic around 2 000 BP: Methodical approach and selected results. –
Preslia 74: 235–246.
Spatial variations in regional forest composition are analyzed for the
period around 2 000 years before present in the territory of the Czech
Republic. The results of pollen analyses at 16 different sites (original data
and those published by other authors) form the basis of this study. The results
are preliminary because of the small number of sites sampled. This article
demonstrates the possibilities of the approach and is the first step to a wider
application in the future. The conclusions indicate that pollen analysis is
accurate enough in most cases for the reconstruction of past forest composition
on a regional scale, and different deposits reflect spatial heterogeneity.
Altitude, intensity of human impact, and soil type were the major factors
affecting past distribution of forest trees. Oak and hornbeam woodlands,
although widely affected by human activity, dominated the lowlands. Beech and
silver fir were an important admixture in these communities. Although oak was
present at higher altitudes, the occurrence of upland oak woodlands was limited
more than indicated by recent geobotanical reconstructions. Instead, mixed
forests existed at middle altitudes, often dominated by silver fir and beech.
In less favourable habitats, spruce was common. Such upland forests extended
high into the mountains, where because of the more severe climatic conditions
beech and spruce started to dominate over silver fir.
Snogerup S., Zika F. P. & Kirschner J. (2002):
Taxonomic and nomenclatural notes on Juncus. – Preslia 74:
247–266.
New combinations and other nomenclatural notes on the Juncaceae
(Juncus sections Iridifolii, Steirochloa and
Juncotypus) are proposed within the framework of the preparation of the
“Flora of the World” monograph of the family. New combinations are
proposed in Juncus prismatocarpus, J. arcticus, J.
balticus and J. effusus. On the basis of the new evaluation of
Pacific North American plants examined by H. L. Lint in an unpublished thesis,
two names are elevated to the species rank (J. hesperius and J.
exiguus), and a new species is described (J. laccatus), all related
to J. effusus.
Kaplan Z. (2002): Linear-leaved species of
Potamogeton in the Czech Republic III. P. obtusifolius and P.
friesii. – Preslia 74: 267–280. [In Czech]
The third part of a revision of linear-leaved species of the genus
Potamogeton in the Czech Republic is given. Two species, P.
obtusifolius and P. friesii, are dealt with in this contribution.
Species descriptions, relevant synonyms, illustrations, a list of specimens
examined and distribution maps are provided. P. obtusifolius grows
almost exclusively in the Bohemian part, particularly in S and E Bohemia,
whereas in Moravia it is confined to a few localities mainly in its NE part
(Silesia). It is classified as a threatened species of the Czech flora. P.
friesii has been collected only in a few localities in C and NE Bohemia.
Last time it was seen in 1989 but has not been confirmed in the site since
then; thus the species belongs among missing (and probably extinct) taxa in the
Czech Republic.
Dančák M. (2002): Glyceria striata – a
new alien grass species in the flora of the Czech Republic. – Preslia
74: 281–289.
Glyceria striata (Lam.) Hitchc., a species native to North America,
was found as an alien species on several localities in the Hostýnské vrchy Mts
(eastern Moravia). It grows there on disturbed sites in artificial, usually
spruce and alder woods at an altitude of 340–550 m a.s.l. The way of
introduction of G. striata to this area is uncertain. However, it is
present as an alien in many European countries. A detailed synonymy and
description of species is given. Taxonomy and systematics are shortly discussed
and determination key within the Czech species of the genus Glyceria is
also given. Notes on the distribution and the history of naturalization of the
species in Europe as well as notes on its ecology are included.
Rejmánek M. & Rejmánková E. (2002): Biogeography
of artificial islands: effects of age, area, elevation, and isolation on plant
species richness. – Preslia 74: 307–314.
Vascular flora of 71 artificial islands of varying agewas analyzed in 22
fishponds, Třeboň Basin, the Czech Republic. Data on species richness were
interpreted in terms of Wilson’s (1969) hypothesis on the development of
biotic communities. An increase in species richness during the non-interactive
stage (one to two years) and a decrease in the interactive stage (three to six
years) were both statistically significant. As predicted, by Wilson’s
hypothesis, there was also an increase in species richness in the assortative
stage (seven to >50 years), however, this trend was not significant. This
successional pattern was confirmed by the vegetation development recorded on 34
re-sampled islands. For these islands the positive change in species richness
during the assortative stage was significant based on both paired t- and
binomial tests. Contributions of island area, elevation, and isolation during
individual successional stages were evaluated. As a whole, this is probably the
first clear confirmation of Wilson’s hypothesis for vascular plant
communities on islands.
Raspopov I. M., Adamec L. & Husák Š. (2002):
Influence of aquatic macrophytes on the littoral zone habitats of the Lake
Ladoga, NW Russia. – Preslia 74: 315–321.
Hydrobotanical and hydrobiological field work was carried out at Lake
Ladoga in NW Russia, mostly at Impilahti Bay in the northern part of the lake.
In a shallow medium dense stand of Elodea canadensis (1452 plants.m-2; mean 192 g.m-2 of
dry weight) in Impilahti Bay, between 12:00 to 18:00 hours in August 1996, the
water was by 1.0–1.4 °C warmer and its pH 1.05–1.2 higher than open
water. In the stand, pH increased almost to 9.0. In the same stand, water
become supersaturated with O2 to 134% at midday
on a sunny August day, and to only 105% on a cloudy day. The daily pH and
[O2] fluctuations within the medium dense E.
canadensis stand in Impilahti Bay were much less than those measured in
dense stands of this species, e.g., in shallow eutrophic Czech fishponds.
Communities of littoral phytophilous zooplankton, living pelagically or
slightly attached on the plants, formed in the macrophyte stands. The littoral
phytophilous zooplankton complex was on average 4 times more abundant and had a
38 times greater biomass per water volume (0.26–164.2 g dry weight.m-3) than that in the open water near the macrophyte
communities (0.05–4.91 g dry weight.m-3)
or was 3 times more abundant and had on average a 10 times greater biomass,
respectively, than that in the open water in the middle of the bay. This does
not accord with theory, which predicts that ecotones have the highest
biodiversity and productivity.
Oťaheľová H. & Valachovič M. (2002):
Effects of the Gabčíkovo hydroelectric-station on aquatic vegetation of the
Danube river (Slovakia). – Preslia 74: 323–331.
Vegetation in the river Danube was studied in 1972–2001 to document the
changes associated with the construction of a water reservoir. Before 1993,
only a single species of aquatic plant, Potamogeton pectinatus, was
known to occur in the main channel of the river Danube, which forms the
frontier between Slovakia and Hungary. In the 1980s the building of the
Gabčíkovo hydroelectric power station started and was finished in 1993. At
present, five different aquatic habitats occur in the study area. (i) In the
upper part of the Čunovo reservoir, there are stands of reed; Zannichellia
palustris and Elodea nuttallii were the first other macrophytes to
colonize this area where there are now 11 species. (ii) The Old Danube consists
of shallows and margins of the original riverbed, which since 1992 (1851–1811
river km) were occupied predominantly by Zannichellia palustris. The
adjacent pools were colonized by Elodea nuttallii, Potamogeton
species, Batrachium trichophyllum, Ceratophyllum demersum and
Lemnaceae species, and Phalaris arundinacea dominates the
littoral areas. (ii) The bypass canal harbours only the moss Cinclidotus
riparius growing on the boulders. (iv) Two seepage canals were rapidly
overgrown by macrophytes, many species of which were threatened species in
Slovakia (Apium repens, Groenlandia densa, Hippuris
vulgaris, Chara species). (v) Succession occurred in river arms on
the left bank after the damming of the river which resulted in changes in
spatial distribution and species composition of macrophytes; a North- American
alien species Elodea nuttallii spread rapidly there.
Moravcová L., Zákravský P. & Hroudová Z. (2002):
Germination response to temperature and flooding of four Central European
species of Bolboschoenus. – Preslia 74: 333–343.
Germination of four Central European Bolboschoenus species (B.
yagara, B. koshewnikowii, B. maritimus and B.
laticarpus) was studied. The need for stratification and the influence of
temperature and water regime on seed germination were tested in the laboratory.
Cold wet stratification in the laboratory as well aswater stratification in the
field enhanced the germination of all species. Germination was facilitated by
increasing stratification length, but differed between species. Field
stratification in water improved the germination of all species compared to
stratification in soil. Germination requirements of the four
Bolboschoenus species, despite the broader ecological amplitude of B.
laticarpus, were similar. The best germination occurred after four months
of field stratification in cold water. All species germinated best in aerobic
conditions when the day/night temperature fluctuations were high (30/10 °C).
These conditions correspond to those occurring where the seedlings tend to
establish themselves in the field: exposed pond bottoms or wet soil in field
depressions.
Kaplan Z. (2002): Linear-leaved species of
Potamogeton in the Czech Republic IV. P. pusillus s.l. and P.
trichoides. – Preslia 74: 345–371. [In Czech]
The fourth part of a revision of linear-leaved species of the genus
Potamogeton in the Czech Republic is given, dealing with P.
pusillus s.l. and P. trichoides. The appropriate taxonomic concept
and species delimitation within P. pusillus s.l. are discussed. Because
of still unresolved taxonomic difficulties and high percentage of specimens
that cannot be assigned to one of the two traditionally distinguished species,
P. pusillus s. str. (syn. P. panormitanus) and P.
berchtoldii, the broader concept of P. pusillus s.l. has tentatively
been adopted in this revision. This species complex is widespread in the Czech
Republic, absent only in relatively small areas of the highest elevations and
the driest areas without suitable biotopes. P. pusillus s.l. is the
commonest taxon of Potamogeton in standing waters. P. trichoides,
a well defined species distinguished by several morphological characters,
occurs scattered mainly in S, C and E Bohemia and S and C Moravia, with most
localities concentrated in S Bohemia. It is considered as strongly threatened
species of the Czech flora. Species descriptions, relevant synonyms,
illustrations, a list of specimens examined and distribution maps are provided
for both species. P. rutilus was once reported from the Czech Republic
in error. No specimen from this country has been found in herbaria.
Sukopp H. (2002): On the early history of urban
ecology in Europe. – Preslia 74: 373–393.
Early investigations on the ecology of cities were in the tradition of
natural history and focused on single biotopes. Of special interest were the
plants and animals introduced into newareas directly or indirectly by man. In
Central Europe, studies of anthropogenic plant migrations and cultural history
were combined in a specific way, the so called Thellungian paradigm. The
succession of vegetation on ruins after the bombing during the Second World War
was studied in many cities. Ecological studies on whole cities started in the
1970s with investigations on energy flow and nutrient cycling. Today the term
urban ecology is used in two different ways: in developing programs for
sustainable cities, and in investigation of living organisms in relation to
their environment in towns and cities.
Bornkamm R. (2002): On the phytosociological
affiliations of an invasive species Senecio inaequidens in Berlin. –
Preslia 74: 395-407.
During the years 1996–2001 phytosociological relevés were made of
stands containing Senecio inaequidens in the city of Berlin and its
surrounding. Data on the structure of the stands were recorded, life form
spectra and ecological indicator values were calculated. This species,
previously not known in the region before 1993, was found in 9 different
phytosociological units (allliances). Growth parameters of S.
inaequidens differed widely between these units and were positively
correlated with cover and height of the surrounding vegetation. The conclusion
drawn was that this species is one of the driving forces in the development
from annual to perennial vegetation and has a role similar to that of other
dominant species. From the indicator values of the stands surrounding S.
inaequidens the following Ellenberg indicator values for the species were
derived: Light L 8, temperature T 6, continentality K 4, moisture F 4, soil
reaction R 7, nitrogen N 0 (= vague), and hemeroby values H α- and β-
euhemerobic. Comparisons with data in literature from W and NW Germany show a
broader sociological and ecological amplitude of S. inaequidens in this
area, which was colonized by this species in the 1970s. The geographical
expansion of this species is not yet finished, and further colonization within
its area of distribution is likely to occur in plant communities with low
degrees of hemeroby and growing in moister habitats.
Kim Y.-M., Zerbe S. & Kowarik I. (2002): Human
impact on flora and habitats in Korean rural settlements. – Preslia 74:
407–419.
Land use has direct and indirect effects on the environmental conditions,
which play a major role in the dynamics and changes in landscape. In Central
Europe, the hemeroby approach is broadly used to quantify human impact on
habitats and their vegetation. In this paper, the hemeroby approach was adopted
for studying the rural settlements in the East Asian Republic of Korea. Flora
and habitats of eight villages were analysed. The habitats were classified
according to the five degrees on the hemeroby scale (oligo-, β-meso-,
α-meso-, eu-, and polyhemerobic). Hemeroby indicator values were derived
for species that were typical of a specific level of hemeroby. Habitats with
the same level of hemeroby were grouped. The highest species number was found
in habitats that were only moderately influenced by man. This corresponds to
the intermediate disturbance hypothesis. The flora of habitats that were
subject to the highest level of human impact (polyhemerobic)was characterized
by a high proportion of annual species, but unexpectedly not by the highest
proportion of non-native species.
Sýkora K. V., Kalwij J. M. & Keizer P.-J. (2002):
Phytosociological and floristic evaluation of a 15-year ecological management
of roadside verges in the Netherlands. – Preslia 74: 421–436.
This paper investigates and evaluates the effects of ecological management
on the vegetation of roadside verges in the Netherlands, conducted by the
Ministry of Transport (PublicWorks Department). A total of 545 relevés, made
between 1986 and 1988, were re-examined in 2001. Data were analysed for changes
in number of species, rarity of species, red list (endangered) species and
syntaxonomical species groups. The total number of species almost did not
change. Common species increased while rare species decreased. The red list
species declined by 40%. Species from shrub and woodland, from fertile, wet
soils and from nitrophilous fringes increased, while species characteristic of
relatively open and nutrient-poor habitats and some pioneer communities
decreased. Plant communities were valued, and phytosociological changes were
evaluated, using the deductive method of Kopecký and Hejný and knowledge about
vulnerability, rarity and replaceability. In 44.5% of the 465 evaluated
relevés, the vegetation value remained unchanged, in 23.0% it decreased and in
32.5% it increased. The different trends tended to counterbalance one another,
resulting in an unchanged mean vegetation value. The increase in vegetation
value is mainly due to the increase in relevés containing species rich
Arrhenatheretum-subassociations. The decrease is mainly due to a
decrease in moist heath, dry sandy pioneer communities and grasslands on
relatively poor soils, and the increase of species-poor nitrophilous tall herb
communities and woody vegetation. In some of the verges studied, the vegetation
value decreased as a result of inappropriate management and construction.
Suggestions for improvement are given. Local successes indicate that
appropriate management can considerably improve the botanical value of roadside
verges, and consequently their value for other life forms.
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