| 1. |
- Thulin, Mats, 1948-
(author)
-
Acacia fumosa sp. nov. (Fabaceae) from eastern Ethiopia
- 2008
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In: Nordic Journal of Botany. - 0107-055X .- 1756-1051. ; 25:5-6, s. 272-274
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Journal article (peer-reviewed)abstract
- The new species Acacia fumosa is described and illustrated. It is confined to the Somali National Regional State (Ogaden) in eastern Ethiopia, where it is dominant and widespread on limestone hills in an area of at least 8 000 km2. Acacia fumosa is closely related to A. ochracea in south-western Somalia, but differs, for example, in its ash grey, smooth and non-flaking bark, densely pubescent leaves, and pink flowers.
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| 2. |
- Lidén, Magnus, 1951-
(author)
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New species, combinations, and records of Hypecoum, Dactylicapnos and Corydalis (Fumariaceae) in China
- 2008
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In: Nordic Journal of Botany. - 0107-055X .- 1756-1051. ; 25:1-2, s. 1-5
-
Journal article (peer-reviewed)abstract
- Five new species of Fumariaceae from the Flora of China area, viz. Hypecoum zhukanum (sect. Leptocarpae), Dactylicapnos gaoligongshanensis (sect. Dactylicapnos), D. leiosperma (sect. Minicalcara), Corydalis laxiflora and C. tianshanica (subgenus Cremnocapnos sect. Stricute), are described. Dactylicapnos burmanica comb. nov., D. grandifoliolata and D. macrocapnos are reported from China for the first time, and the new combinations Dactylicapnos ventii (basion.: Dicentra ventii T. C. Khanh), D. schneideri (basion.: Dicentra schneideri Fedde) and D. burmanica (basion.: Dicentra burmanica K. R. Stern) are validated. Novelties in Corydalis subgenus Corydalis will be published separately.
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| 3. |
- Tyler, Torbjörn
(author)
-
On Hieracium incurrens (Asteraceae) and similar species in central Sweden.
- 2007
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In: Nordic Journal of Botany. - 0107-055X. ; 25:3-4, s. 152-160
-
Journal article (peer-reviewed)abstract
- Hieracium incurrens Saelan ex Norrl., originally described from Finland, has been reported from Sweden several times and independently by different authors. Still, however, its presence in Sweden has remained dubious and it has become obvious that the different reports are referable to different taxa and the name has thus been, at least partially, misapplied. In the present study, all Swedish material and putative taxa that have been suggested to belong to H. incurrens, as well as some additional closely similar taxa, is critically compared with authentic material of the latter from Finland. It is concluded that H. incurrens do indeed occur in central Sweden, namely in the eastern coastal provinces closest to Finland. However, the relevant material has mostly been referred to H. longilingua Johanss., which is here considered to be a later synonym of H. incurrens. Material previously referred to H. incurrens from other parts of Sweden does, however, represent other taxa. Five accepted species of this affinity are described and discussed in some detail and one species, viz. H. oestmanii T. Tyler is described anew. In addition, the unrelated species H. arnoldii T. Tyler is described anew based on material from the provinces of Hälsingland and Medelpad.
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| 4. |
- Kärnefelt, Ingvar
(author)
-
Editorial
- 2009
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In: Nordic Journal of Botany. - 0107-055X. ; 25:1, s. 4-4
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Journal article (peer-reviewed)abstract
- Abstract is not available
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| 5. |
- Lind, Henrik, et al.
(author)
-
Metapopulation pollination in the deceptive orchid Anacamptis pyramidalis
- 2007
-
In: Nordic Journal of Botany. - 0107-055X .- 1756-1051. ; 25:3-4, s. 176-182
-
Journal article (peer-reviewed)abstract
- Pollen dispersal between local plant populations within a range of 6 kin in a geographically defined metapopulation of the lepidopteran-pollinated deceptive orchid Anacamptis pyramidalis was studied on the island Oland in the Baltic Sea. Local A. pyramidalis populations were examined for pollinators, flowering individuals, and fruit set. Population sizes of pollen vector species were estimated using a mark-release-recapture technique. As pollen vectors, the burner moth Zygaena minos and the butterfly Aporia crataegi dominated. 205 out of 745 marked lepidopterans were pollinarium carriers. The proportion carriers of the total was considerably higher in Z. minos (50.3%), than in A. crataegi (21.5%) and nymphalidae (8.2%). Furthermore, Z minos moved much shorter distances than A. crataegi did, while no difference in potential pollen dispersal distances were found between males and females. The number of individual vectors recaptured in another local population of A. pyramidalis was low: A. crataegi (8) and Z minos (1). The ratio of pollinaria transferred to another local A. pyramidolis population compared to pollinaria remaining within the same local population was 1:41. This study highlights that pollen dispersal distances vary between pollen vector species.
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| 6. |
- Tyler, Torbjörn
(author)
-
Editorial
- 2007
-
In: Nordic Journal of Botany. - 0107-055X. ; 25:1, s. 3-3
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Journal article (peer-reviewed)abstract
- Abstract is not available
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| 7. |
- Tyler, Torbjörn
(author)
-
How complete and correct was Linnaeus’ knowledge and classification of the Swedish flora?
- 2007
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In: Nordic Journal of Botany. - 0107-055X. ; 25:1-2, s. 7-8
-
Journal article (peer-reviewed)abstract
- The degree to which Carolus Linnaeus managed to describe the vascular plant species diversity of his native country, and the proportion of his taxonomic decisions concerning the rank and generic classification of these same species that are considered correct by present-day taxonomists, is analyzed by comparing the most recent checklist of the Swedish flora, excluding later immigrants, with the works of Linnaeus. It is concluded that 79% of the species occurring in Sweden by the year 1700 were recognized and accepted by Linnaeus. Of these, ca 74% are still today accepted with the same rank, and are referred to the same genus. Thus, one answer to the current popular question of to what extent 'Linnaeus was right' is: approximately three quarters!
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| 8. |
- Alatalo, Juha, 1966-, et al.
(author)
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Effect of Altitude on the Sex-Ratio in Populations of Silene Acaulis (Caryophyllaceae) : Effect of Altitude on the Sex-Ratio in Populations of Silene Acaulis (Caryophyllaceae)
- 1995
-
In: Nordic Journal of Botany. - 0107-055X .- 1756-1051. ; 15:3, s. 251-256
-
Journal article (peer-reviewed)abstract
- Predicted increase of female frequencies in gynodioecious Silene acaulis was tested along an altitude gradient in northern Sweden. Average female frequencies for the four sites increased with altitude from 42% to 59% within a short geographical distance. This follows the outcrossing hypothesis, that female frequencies should be positively correlated with selfing rates of hermaphrodites in populations. More adverse environmental conditions should favour gynodioecy in areas where reproduction to a greater part relies on vegetative reproduction or selfing. Further, a significant difference in corolla width was found between females and the larger hermaphrodites, but not between sites. Cushion size and the number of flowers per cushion decreased with altitude.
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| 9. |
- Alatalo, Juha, 1966-
(author)
-
Gender lability in trioecious Silene acaulis (Caryophyllaceae)
- 1997
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In: Nordic Journal of Botany. - : Wiley. - 0107-055X .- 1756-1051. ; 17:2, s. 181-183
-
Journal article (peer-reviewed)abstract
- Gender expression of individual cushions of Silene acaulis was shown to vary between years. Fifteen of thirty-nine (= 38%) cushions monitored changed gender expression between 1993 and 1995. Cushions dominated by female flowers were shown to be more stable in gender expression than cushions dominated by male or hermaphrodite flowers.
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| 10. |
- Alatalo, Juha, 1966-, et al.
(author)
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Pollen viability and limitation of seed production in a population of the circumpolar cushion plant, Silene acaulis (Caryophyllaceae)
- 2001
-
In: Nordic Journal of Botany. - : Wiley. - 0107-055X .- 1756-1051. ; 21:4, s. 365-372
-
Journal article (peer-reviewed)abstract
- Pollen viability among genders and limitation of female seed production in a natural trioecious population of the circumpolar cushion plant Silene acaulis was examined. Pollen viability was estimated by an in vitro pollen germination experiment. Both male and hermaphrodite flowers displayed large variation in pollen viability (0-53% in hermaphrodite and 0-54% in male flowers). There was a significant difference between genders in pollen viability: male plants had on average higher pollen viability than hermaphrodite plants. Resource and pollen limitation of seed production was studied by an experiment consisting of three treatments; (I) hand-pollination and removal of all other flowers on the cushion, (II) harid-pollination without removal of other flowers, and (III) open pollination without removal of flowers, Hand-pollination increased seed production, whereas removal of flowers had no effect on seed production. Abortion of pollinated ovules during seed development and seed mass did not differ among treatments. To control for effect of fruit number on seed production, data from naturally pollinated individuals was used. There was a positive correlation between both total number of seeds and fruit number, mean seed number per fruit and fruit number, respectively. These results indicate that seed production of S. acaulis is mainly limited by pollen availability whereas resource competition between fruits is not important as a limiting factor. The possible role of male quality differences between genders and pollen limitation of seed production for maintenance of trioecious reproductive systems is discussed.
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| 11. |
- Altola, Juha, 1966-, et al.
(author)
-
EFFECT OF ALTITUDE ON THE SEX-RATIO IN POPULATIONS OF SILENE ACAULIS (CARYOPHYLLACEAE)
- 1995
-
In: Nordic Journal of Botany. - : Wiley. - 0107-055X .- 1756-1051. ; 15:3, s. 251-256
-
Journal article (peer-reviewed)abstract
- Predicted increase of female frequencies in gynodioecious Silene acaulis was tested along an altitude gradient in northern Sweden. Average female frequencies for the four sites increased with altitude from 42% to 59% within a short geographical distance. This follows the outcrossing hypothesis, that female frequencies should be positively correlated with selfing rates of hermaphrodites in populations. More adverse environmental conditions should favour gynodioecy in areas where reproduction to a greater part relies on vegetative reproduction or selfing. Further, a significant difference in corolla width was found between females and the larger hermaphrodites, but not between sites. Cushion size and the number of flowers per cushion decreased with altitude.
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| 12. |
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| 13. |
- Andersson, Stefan
(author)
-
Ecotypic divergence in Crepis tectorum (Asteraceae): inferring trait lability and correlational constraints from hormonally manipulated phenotypes
- 2019
-
In: Nordic Journal of Botany. - : Wiley. - 1756-1051 .- 0107-055X. ; 37:3
-
Journal article (peer-reviewed)abstract
- Despite long‐standing interest in the evolutionary role of plant hormones, relatively few studies have used hormonally manipulated phenotypes to address questions about phenotypic evolution in plants. In the present investigation, I subjected plants of Crepis tectorum subsp. pumila to simple gibberellin (GA) treatments under both field and greenhouse conditions to assess developmental lability and correlational constraints of phenotypic traits that distinguish this dwarf ecotype from conspecific populations of the much taller weed ecotype (subsp. tectorum). The hormonally manipulated plants largely phenocopied the weed ecotype in leaf shape, plant stature and branching habit, indicative of both high lability and tight integration of traits reflecting gross morphology. Floral size traits sometimes declined after GA application, especially under field conditions. The latter result conflicts with the positive correlations between floral and vegetative size traits seen in previous comparative analyses and point to a tradeoff that could act as a constraint on ecotype divergence. The response to GA was consistent in direction for most traits, as opposed to the magnitude of response, which varied depending on the trait, the population, the growing environment and the timing and level of hormone application. Taken together, the results highlight the potential for simple hormonal changes to cause large, plastic shifts in phenotype, but also illustrate the constrained nature of such influences.
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| 14. |
- Antonelli, Alexandre, 1978, et al.
(author)
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Pollination of the Lady's slipper orchid (Cypripedium calceolus) in Scandinavia - taxonomic and conservational aspects
- 2009
-
In: Nordic Journal of Botany. - : Wiley. - 0107-055X .- 1756-1051. ; 27:4, s. 266-273
-
Journal article (peer-reviewed)abstract
- The Lady's slipper orchid Cypripedium calceolus L. is considered one of the most beautiful orchids of Europe. Consequently, the species has suffered from over-collecting and is now critically endangered in many countries. Although pollination success is suspected to influence the long-term survival of Cypripedium calceolus, relatively little is known about the identity of its pollinators in mainland Sweden - a region that comprises the largest European populations. In order to identify which species pollinate eight representative populations in mainland Sweden, we observed and sampled visitors to flowers using a standardized protocol. Specimens were identified and any pollen smear found on their body was examined for the presence of Cypripedium pollen. Nine species were recognized as effective pollen vectors (Andrena cineraria, A. carantonica, A. haemorrohoa, A. helvola, A. nigroaenea, A. praecox, Colletes cunicularius, Lasioglossum fratellum and L. fulvicorne), four of them for the first time in Scandinavia. This is the first time that a species of Colletes is reported to carry pollen of Cypripedium in this region. All but one specimens were females. Our results suggest a taxonomically heterogeneous pollinator fauna for Cypripedium calceolus and are discussed in light of the management of this species.
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| 15. |
- Arnell, Matilda, 1987-, et al.
(author)
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Reproductive success, fruit removal and local distribution patterns in the early-flowering shrub Daphne mezereum
- 2023
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In: Nordic Journal of Botany. - 0107-055X .- 1756-1051. ; :10
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Journal article (peer-reviewed)abstract
- In insect-pollinated, bird-dispersed plants, both investment in reproduction and reproductive success involve interactions between plants and their pollinators and dispersers. The outcome of these plant–animal interactions may be affected by the number of flowers and fruits, as well as by the plants' local environment and by spatial associations among plants. In this study we mapped the spatial distribution of individuals in a population of the early flowering, fleshy-fruited shrub Daphne mezereum, in a forest in boreo-nemoral Sweden. For all mapped individuals we collected data on numbers of flowers and fruits and fruit removal, for three consecutive years. We analysed spatial associations among individuals, and the effects on reproductive performance and fruit removal of plant height, numbers of flowers and fruits, distance to forest edge, and neighbouring flower and fruit density. Our results show that the density of D. mezereum increases with increasing proximity to forest edge. The number of flowers produced, as well as fruit set and fruit removal, show the same positive relationship with increasing proximity to forest edges. We further show that individuals are aggregated up to distances of about 10 m. The flower production of neighbouring conspecific individuals within 10 m is negatively related to fruit set whereas the fruit production of neighbours is positively related to fruit removal. Our main conclusion is that the spatial distribution of D. mezereum affects reproductive success and fruit removal, which in turn has the potential to feed back to the spatial distribution pattern. Combining studies of reproduction with spatial analyses is important to advance our understanding of the dynamics of plant populations.
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| 16. |
- Arup, Ulf, et al.
(author)
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A new taxonomy of the family Teloschistaceae
- 2013
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In: Nordic Journal of Botany. - : Wiley. - 0107-055X. ; 31:1, s. 16-83
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Research review (peer-reviewed)abstract
- The lichen family Teloschistaceae is one of the larger families of lichenized fungi. Currently it includes one very large heterogenous genus, Caloplaca, with some 1000 or more species with a vast variation in morphology, anatomy and chemistry. The rest of the family is split into 1015 smaller genera, each with 20 or fewer species. There is no modern classification of the family based on molecular data. Here we attempt a first phylogenetic evaluation of a large part of the family, including a total of 337 species. Of these, 162 were used in a combined phylogenetic analysis of the ribosomal RNA sequence markers nrITS, nrLSU and mrSSU, using Bayesian inference. We also analysed all species using nrITS data, split into four different analyses. As a result we propose a new classification of the family, where a total of 39 genera are recognized, of which 31 are newly described or resurrected. The new genera are: Athallia, Austroplaca, Bryoplaca, Calogaya, Cerothallia, Flavoplaca, Gondwania, Haloplaca, Orientophila, Pachypeltis, Parvoplaca, Rufoplaca, Shackletonia, Scutaria, Sirenophila, Solitaria, Squamulea, Stellarangia, Teloschistopsis, Usnochroma, Variospora, Villophora and Wetmoreana. Resurrected genera are Blastenia, Dufourea, Follmannia, Gyalolechia, Leproplaca, Polycauliona, Pyrenodesmia and Xanthocarpia. The species Orientophila subscopularis is described as new. A third subfamily, Teloschistoideae, is proposed to accommodate the genus Teloschistes and related genera, parallel to the two previously recognized subfamilies Xanthorioideae and Caloplacoideae. We also show the large plasticity in both morphological and anatomical characters between closely related species within genera, indicating the low value of these as evolutionary markers. The secondary chemistry is a better marker in some parts of the family. We recognize a large number of geographically delimited clades with clear centres of evolution, but often showing large variation in morphology and anatomy.
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| 17. |
- Athanasiadis, Athanasios, et al.
(author)
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The genera Melyvonnea gen.nov. and Mesophyllum s.s. (Melobesioideae, Corallinales, Rhodophyta) particularly from the central Atlantic Ocean
- 2014
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In: Nordic Journal of Botany. - : Wiley. - 0107-055X. ; 32:4, s. 385-436
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Journal article (peer-reviewed)abstract
- We propose the new genus Melyvonnea to accommodate species previously included in Mesophyllum having: a) perithallial protuberances that may branch and dominate over the encrusting base, b) monoecious gametophytes with gametangial conceptacles occasionally developed in superimposition, c) spheroid carposporangial chambers (lacking a central pedestal), and d) filaments lining canals of multiporate roofs composed of 3 to 5 cells with distinctively elongate basal cells. The new genus shares with Mesophyllum the development of a predominantly coaxial hypothallium. Melyvonnea presently accommodates three species in the Central Atlantic, viz. the generitype Melyvonnea canariensis (Foslie) comb. nov. from the Canary Islands, Melyvonnea erubescens (Foslie) comb. nov. (= Mesophyllum incertum; type locality: Bermuda) from the western Atlantic, Melyvonnea aemulans (Foslie & Howe) comb. nov. from Puerto Rico, and one Indo-Pacific species, Melyvonnea madagascariensis (Foslie) comb. nov. We also emend Mesophyllum Lemoine to encompass Northern Hemisphere species that lack the above apomorphies of Melyvonnea and in addition develop a central pedestal in carposporangial conceptacles (via dissolution of the surrounding cells) with gonimoblasts bending down to fill the empty space. Mesophyllum sensu stricto currently includes six species in the NE Pacific (M. aleuticum, M. conchatum, M. crassiusculum, M. lamellatum, M. megagastri, M. vancouveriense), two species in the western Atlantic (M. mesomorphum and M. syntrophicum), and three species in the NE Atlantic and the Mediterranean Sea (M. expansum, M. lichenoides, M. philippii). Gametophytic species of each genus show a mainly disjunct distribution being restricted to the tropics-subtropics (Melyvonnea) and the temperate waters of the Northern Hemisphere (Mesophyllum s.s.). This classification is supported by a consensus of studies of all well-known species of Mesophyllum sensu Adey (1970), and is based on a phylogenetic analysis of morphological and anatomical characters in addition to molecular evidence.
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| 18. |
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| 19. |
- Backlund, Anders, 1965-, et al.
(author)
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A revision of Cycniopsis (Scrophulariaceae)
- 1993
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In: Nordic Journal of Botany. - Copenhagen, Denmark : NORDIC JOURNAL OF BOTANY. - 0107-055X .- 1756-1051. ; 13, s. 185-194
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Journal article (peer-reviewed)
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| 20. |
- Bakker, Jan P., et al.
(author)
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Shading results in depletion of the soil seed bank
- 2014
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In: Nordic Journal of Botany. - : Wiley. - 0107-055X .- 1756-1051. ; 32:5, s. 674-679
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Journal article (peer-reviewed)abstract
- To what extent is the decline of characteristic dry alvar species related to the decline in the soil seed bank during scrub encroachment? We recorded the number of flower stems in the vegetation in relation to light attenuation along an encroachment series progressing from open alvar through small gaps inside dense scrub of Juniperus communis (cover of 60%) to intact dense scrub (cover of 100%) on the island of oland, Sweden. This measurement of potential reproduction (number of flower stems) was then compared to the number of species in the soil seed bank at each site along the alvar encroachment series. Scrub encroachment results in light attenuation between and under the shrubs. The total number of flower stems averaged over all species was similar between gaps and open alvar, but that of alvar species was significantly lower in the gaps, indicating that light attenuation could reduce their seed set. Shading in gaps is related to depletion of the soil seed bank and loss of alvar species, particularly those that do not form a persistent soil seed bank.
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| 21. |
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| 22. |
- Bergström, Gunnar, 1934, et al.
(author)
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Floral scent chemistry within the genus Linnaea (Caprifoliaceae)
- 2018
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In: Nordic Journal of Botany. - : Wiley. - 0107-055X .- 1756-1051. ; 36:3
-
Journal article (peer-reviewed)abstract
- ‘Beauty bush’ and ‘twin flower’ are common names attributed to two well-recognizable species belonging to the genus Linnaea (16 spp.) – L. amabilis and L. borealis – long admired by botanists and gardeners for their perfumed paired bell-shaped flowers. In the present study, we investigated their floral scent compositions through gas chromatography – mass spectrometry (GC-MS) analysis of dynamic headspace samples. Because the flowers of L. borealis in wild populations are fragrant both during the day and in the evening, circadian variation of scent emission was also assessed for this species. In total, 26 chemical compounds comprise the floral scent bouquets of L. amabilis and L. borealis, identified as monoterpenes (14), benzenoids and phenylpropanoids (5), aliphatics (3), sesquiterpenes (3) and irregular terpenes (1). Whereas monoterpenes, notably (-)-α- and β-pinene, dominated the scent of L. amabilis (over 82% relative abundance), benzene derivates: 1,4 dimethoxybenzene, anisaldehyde, 2-phenylethanol, benzaldehyde and nicotinaldehyde were exclusive to analysed headspace samples of L. borealis, accounting for 52% to 100% of their relative compositions, in three Swedish populations. A southwestern Finnish population was characterized by the four first mentioned benzenoid compounds and large amounts of (-)-α- and β-pinenes plus two aliphatic substances. The scent compounds identified for both species are ubiquitous and may serve as generalist attractants/stimulants for a broad assortment of anthophilous insects. The basic work on the flower scent of L. amabilis and L. borealis should inspire studies of their pollination biology, primarily the behaviour-guiding roles of the characteristic emitted volatiles. © 2017 The Authors
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| 23. |
- Birgander, Johanna, et al.
(author)
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Activity of temperate grassland plants and symbiotic fungi during the winter - implications for community structure and carbon cycling in a changing climate
- 2012
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In: Nordic Journal of Botany. - : Wiley. - 0107-055X. ; 30:5, s. 513-521
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Journal article (peer-reviewed)abstract
- Several investigations have revealed surprisingly high activities during the winter in vegetation and soil in temperate and subarctic areas. Plants have been found to photosynthesize even under snow cover and at temperatures below freezing, and decomposer microorganisms can function, at low rates, all year around. In temperate grasslands, the vegetation includes winter annual herbs as well as bryophytes, which have the potential to be active and are thus susceptible to changing temperatures during winter. If temperatures stay below freezing and there is a snow cover, an increase in temperatures could in fact decrease the soil temperature due to reduced insulation by snow cover. On the other hand, if winter temperatures initially fluctuate around the freezing point, an increase by a few degrees might produce frost-free conditions. Based on available data, the composition of plant communities are strongly influenced by temperature conditions in the preceding winter. We conclude that the winter season in grasslands needs more research attention, to start to resolve which species are active and how they respond to a changing climate.
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| 24. |
- Boberg, Pelle, et al.
(author)
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The effect of high temperatures on seed germination of one native and two introduced conifers in Patagonia
- 2010
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In: Nordic Journal of Botany. - Chichester : Wiley-Blackwell. - 0107-055X .- 1756-1051. ; 28:2, s. 231-239
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Journal article (peer-reviewed)abstract
- We examined the effect of thermal shock on the germination of seeds of three conifers, two introduced (Pseudotsuga menziesii and Pinus ponderosa), and one native to Patagonia (Araucaria araucana). Previous research has suggested increased susceptibility to invasions in burnt areas, and therefore, the effect of simulated fire (heat) on seed germination in these native and introduced species was compared. Seeds were heated to two different heat intensities (50°C and 100°C) for 1 or 5 min, which is within the temperature range reached in the upper soil layers during forest fires. Germination tests were then carried out in a growth chamber. The heat treatments had a negative effect on the germination of P. menziesii at temperatures of 100°C, and a negative effect on the germination of P. ponderosa at the temperature of 100°C and the exposure of 5 min. The heat treatments had no affect at all on A. araucana. The species with larger seeds (A. araucana) had higher survival rates after the thermal shocks. Also intraspecific differences in seed sizes possibly point at larger seeds surviving thermal shocks better than smaller seeds. In addition, thermal shock caused a delay in the onset of germination in the two introduced species, while it did not change the time for germination in A. araucana. © The Authors. Journal compilation © Nordic Journal of Botany 2010.
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| 25. |
- Brunet, Jörg, et al.
(author)
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Disturbance of the herbaceous layer after invasion of an eutrophic temperate forest by wild boar
- 2016
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In: Nordic Journal of Botany. - : Wiley. - 0107-055X. ; 34, s. 120-128
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Journal article (peer-reviewed)abstract
- Disturbances of the soil and the tree canopy are crucial factors determining the diversity, composition and biomass of the herbaceous layer in forests. This study presents a detailed account of ground vegetation in permanent plots surveyed before and after invasion of wild boar (Sus scrofa) to a temperate deciduous broadleaf forest. Specifically, we aimed to quantify the effect of wild boar rooting on cover, richness and composition of spring ephemerals, summer green herbs and saplings of woody species in relation to tree canopy cover. Rooting frequency in sample plots increased from 0% in 2010 to 61% in 2013. In heavily rooted plots, the mean cover of spring ephemeral geophytes (mainly Anemone nemorosa, A. ranunculoides and Ranunculus ficaria) decreased from 75% to 39% between 2010 and 2013. Species richness of summer green herbs generally increased between 2010 and 2013 and was additionally positively affected by heavy rooting and low canopy cover. Rooting also caused heterogenization of the herbaceous layer and amplified ongoing compositional changes induced by changing light conditions. Frequency and richness of spring ephemeral and woody species remained unchanged. We conclude that overall species richness of the herbaceous layer may increase in the short-term as a result of increased plant recruitment and seed dispersal. However, wild boar rooting can greatly reduce the ground cover of spring ephemerals in eutrophic broadleaf forests, thereby threatening their important ecological function. To avoid long-term losses of characteristic spring flora elements, local population control of wild boar is necessary to reduce abundance and frequency of soil rooting.
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| 26. |
- Cousins, Sara A. O., et al.
(author)
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Land use history and site location are more important for grassland species richness than local soil properties
- 2009
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In: Nordic Journal of Botany. - : Wiley. - 0107-055X .- 1756-1051. ; 27, s. 483-489
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Journal article (peer-reviewed)abstract
- Lately there has been a shift in Sweden from grazing species-rich semi-natural grasslands towards grazing ex-arable fields in the modern agricultural landscape. Grazing ex-arable fields contain a fraction of the plant species richness confined to semi-natural grasslands. Still, they have been suggested as potential target sites for re-creation of semi-natural grasslands. We asked to what extent does fine-scale variation in soil conditions, management history and site location effect local plant diversity in grazed ex-arable fields. We examined local soil conditions such as texture, pH, organic carbon, nitrogen (N) and extractable phosphate (P) and effects on plant richness in ten pairs of grazed ex-fields and neighbouring semi-natural grasslands in different rural landscapes. Each grassland pair where in the same paddock. A multivariate test showed that site location and land use history explained more of differences in species richness than local soil property variables. Plant species richness was positively associated to grazed ex-fields with low pH, low N and P levels. Sites with high plant richness in semi-natural grasslands also had more species in the adjacent grazed ex-fields, compared to sites neighbouring less species-rich semi-natural grasslands. Although both soil properties and species richness were different in grazed ex-fields compared to semi-natural grassland, the site location within a landscape, and vicinity to species-rich grasslands, can override effects of soil properties. In conclusion, if properly located, ex-arable fields may be an important habitat to maintain plant diversity at larger spatio-temporal scales and should considered as potential sites for grassland restoration.
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| 27. |
- Danilov, Roman, et al.
(author)
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Autumn phytoplankton assemblages in temperate lakes of different eutrophication level in the middle part of Sweden
- 2000
-
In: Nordic Journal of Botany. - : Wiley. - 0107-055X .- 1756-1051. ; 20:2, s. 225-232
-
Journal article (peer-reviewed)abstract
- Phytoplankton assemblages were studied during autumn 1998 in oligo-, meso- and eutrophic lakes in central Sweden (62°54'N). Differences in phytoplankton assemblages have been detected both in space and time. In eutrophic lakes coccoid Chlorophyceae dominated quantitatively during September and October. Diatoms were the most diverse group in all types of lakes in September and in meso- and oligotrophic lakes in October. In November Cryptophyceae became the most abundant group in all lakes. The total richness of species decreased in the meso- and oligotrophic environments in November compared to September and October, whilst in the eutrophic environment it remained almost unchanged. Cluster analyses, using both presence-absence and presence-absence in combination with abundance matrices, showed similar results and a good resolution between the lakes of different eutrophication conditions. We conclude that the phytoplankton assemblages of the lakes studied depended on the trophic conditions and thus they can be used for resolution between different eutrophication levels.
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| 28. |
- Ekman, Stefan
(author)
-
Fellhaneropsis almquistiorum sp nov from Europe (Pilocarpaceae, lichenized Ascomycota)
- 2015
-
In: Nordic Journal of Botany. - : Wiley. - 0107-055X .- 1756-1051. ; 33:6, s. 641-645
-
Journal article (peer-reviewed)abstract
- Fellhaneropsis almquistiorum S. Ekman, a lichenized ascomycete in the family Pilocarpaceae (Lecanorales, Lecanoromycetes) is described as new to science. It is characterized by the thin and filmy crustose thallus, small photobiont, apothecia with a yellowish to black disk and well developed black margin that becomes excluded with age, dark green and brown pigmentation in the proper exciple and hypothecium, a hymenium without pigment or with some green and brown pigment, more or less fusiform and 3-septate ascospores, abundant black pycnidia, and long and filiform conidia. The species is currently known from central Sweden and central Germany, where it inhabits shaded and acid to neutral rocks with few competing lichens. Historical records were all misidentified as Bacidia coprodes or any of its synonyms or misapplied names. Some specimens of F. almquistiorum contain a previously unrecorded pigment, tentatively named here Almquistiorum-yellow. This pigment is intensely golden yellow in water, does not react with KOH and fades with the addition of HCl or HNO3. A key to all known, pycnidiate members of Fellhaneropsis is provided.
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| 29. |
- Ekman, Stefan, 1965-
(author)
-
Four new and two resurrected species of Bacidina from Sweden, with notes and a preliminary key to the known Scandinavian species
- 2023
-
In: Nordic Journal of Botany. - : John Wiley & Sons. - 0107-055X .- 1756-1051. ; 2023:5
-
Journal article (peer-reviewed)abstract
- Four species of Bacidina (Ramalinaceae, Lecanorales, Ascomycota) are described as new to science from northern Europe (mainly Swedish material): Bacidina ferax S.Ekman, Bacidina lignicola S.Ekman, Bacidina maculans S.Ekman and Bacidina populnea S.Ekman. Another two species are resurrected from synonymy: Bacidina caerulea (Körb.) S.Ekman (based on Bacidia caerulea Körb.) and Bacidina circumpallens (Nyl.) S.Ekman (based on Lecidea circumpallens Nyl.). An additional four combinations are made: Bacidina friesiana (Hepp) S.Ekman (based on Biatora friesiana Hepp), Bacidina subfuscula (Nyl.) S.Ekman (based on Lecidea subfuscula Nyl.), Bacidina tarandina (Nyl.) S.Ekman (based on Lecidea tarandina Nyl.) and Bacidina tenella (Kullh.) S.Ekman (based on Bacidia tenella Kullh.). The morphology, distribution and nomenclature of all 28 species of Bacidina currently known from Scandinavia (Sweden, Norway, Denmark) are treated and an identification key is provided. In addition, Bacidina friesiana is discussed (for comparison with B. caerulea) even if it is not currently known from Scandinavia. Two of the treated species (B. epithallina ined., B. parasitica ined.) are parasites on cyanolichens but are not formally introduced here because of the scarcity of available material. Bilimbia arceutinoides Anzi is reduced to synonymy with Bilimbia sabuletorum (Schreb.) Arnold and Lecidea luteola var. chlorotica Ach. is reduced to synonymy with Bacidia rubella (Hoffm.) A.Massal. It is concluded that despite the present work, the diversity of the genus Bacidina remains insufficiently understood, at least in Scandinavia.
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| 30. |
- Ekman, Stefan, 1965-, et al.
(author)
-
Three overlooked species of Bacidia from insular Laurimacaronesia
- 2021
-
In: Nordic Journal of Botany. - : John Wiley & Sons. - 0107-055X .- 1756-1051. ; 39:3
-
Journal article (peer-reviewed)abstract
- We discuss the taxonomy of three species of Bacidia occurring in insular Laurimacaronesia. Two of them, B. amylothelia (Vain.) Vain. and B. endoleucoides (Nyl.) Zahlbr., which were previously described from Angola and Madeira, respectively, are found here to belong in Bacidia s. str. (Ramalinaceae). Modern descriptions and illustrations are provided for the first time. Bacidia amylothelia is similar to B. areolata Gerasimova & A. Beck, B. campalea (Tuck.) S. Ekman & Kalb, B. fusconigrescens (Nyl.) Zahlbr., B. heteroloma (Vain.) Zahlbr., B. millegrana (Taylor) Zahlbr. and B. suffusa (Fr.) A. Schneid. and is reported here from the Canary Islands. Bacidia endoleucoides is most likely to be confused with B. absistens (Nyl.) Arnold, B. friesiana (Hepp) Korb., B. salazarensis B. de Lesd. and B. caesiovirens S. Ekman & Holien and was found to be widely distributed in the Canary Islands and Azores in addition to Madeira. The third species, Bacidia deludens S. Ekman, Tonsberg & van den Boom, is described here as new to science. Bacidia deludens is characterised by a greyish, crustose thallus with whitish soralia, pale apothecia with crystals in the hymenium and proper exciple, acicular ascospores with 3-19 septa, and the production of fumarprotocetraric acid as the consistently present major substance. It is described here from the Canary Islands and Madeira. Although conservatively treated here in Bacidia, we argue that it is likely to belong in the Malmideaceae. An identification key to all known species of Bacidia s. str. in insular Macaronesia is provided.
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| 31. |
- Eneström, Johanna, et al.
(author)
-
Partitioning of genetic variation in the weedy clonal herb Aegopodium podagraria (Apiaceae) in Sweden
- 2009
-
In: Nordic Journal of Botany. - Chichester : Wiley-Blackwell. - 0107-055X .- 1756-1051. ; 27:5, s. 437-443
-
Journal article (peer-reviewed)abstract
- Although sexual reproduction appears to be rare in many clonal plant species, the majority of clonal species show similar levels of genetic variation to non-clonal plant species. Aegopodium podagraria is a noxious garden weed and has become a successful invader in many natural habitats. Earlier studies have demonstrated population differentiation in life-history traits between different A. podagraria populations in Sweden. In this study, we used three methods to assess genetic variation in this species. Using analyses of molecular markers (chloroplast DNA PCR-RFLP and allozyme electrophoresis) we did not detect any variation between different A. podagraria clones. However, a multivariate analysis of leaflet shape in five populations from central Sweden revealed considerable variation both within and between populations. The variation found in leaflet shape is suggested to be genetically based because the leaves were collected from plants grown from seed under similar conditions in a common garden environment. These relatively high levels of variation within and between populations indicate that there is likely to be repeated seedling recruitment within established populations. © The Authors. Journal compilation.
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| 32. |
- Eriksson, Ove, et al.
(author)
-
Legacies of historic charcoal production affect the forest flora in a Swedish mining district
- 2021
-
In: Nordic Journal of Botany. - : Wiley. - 0107-055X .- 1756-1051. ; 39:11
-
Journal article (peer-reviewed)abstract
- Iron production was historically associated with major impacts on forests worldwide, as vast amounts of wood were harvested to produce the charcoal needed for heating the furnaces and reducing iron oxides in the ore to iron. This impact has left abundant legacies which potentially may remain in the present-day vegetation. We investigated how remains of historic charcoal production, mainly from the 18th to the early 20th century, at still remaining charcoal kiln platforms (CKPs), affect the current species richness, species occurrences and cover of vascular plants in the ground vegetation in a Swedish mining district located in the boreo-nemoral forest zone. CKPs have a significantly higher species richness than the surrounding forest, and they also affect cover (negatively) for ericaceous species typically dominating the forest ground vegetation. Several forest species are more frequent at CKPs, and these also harbor significantly more uncommon species, of which many are typical for traditionally managed grasslands. These latter species are likely to represent remnants in present-day forests reflecting former land-use such as livestock grazing. The soil chemistry at CKPs is strongly deviating from the surrounding forest, and this, together with a lower cover of ericaceous shrubs, are the most likely mechanisms behind the higher species richness. CKPs represent conspicuous and abundant historic anthropogenic habitats in the forest vegetation. As far as we are aware, the flora at CKPs in boreal and boreo-nemoral forests has not previously been investigated in detail, and they deserve more attention, both from a biological and a cultural–historical perspective.
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| 33. |
- Eriksson, Ove, 1956-
(author)
-
The power of observation : Eugen Warming (1918) Om Jordudløbere (‘Underground runners') and the ecology and evolution of clonal plants
- 2023
-
In: Nordic Journal of Botany. - 0107-055X .- 1756-1051. ; 2023:7
-
Research review (peer-reviewed)abstract
- Although often overlooked, the Danish botanist Eugen Warming was one the founders of ecology as a science. He also wrote extensively on plant life forms, including an essay from 1918, Om Jordudløbere (‘Underground runners'), which specifically focused on clonal plants. As was common among naturalists during the 19th century, Warming was exceptionally skillful in drawing conclusions from plain observation. The present paper examines how Warming understood and interpreted the ecology and evolution of clonal plants, and compares his insights with those emanating during the revival of research on clonal plants from the late 1970s onward. Several of the key topics in this revival were treated already by Warming, particularly clonal plants' ability of mobility by horizontal growth, the features affecting the ‘splitting' of genets into independent ramets, and how clonal life forms evolve. Despite these thematic similarities, Warming's direct impact on later research was limited, with the possible exception of the concept of plant functional types. This does not preclude that Warming's insights have bearing on the current research agenda on the ecology and evolution of clonal plants. The paper ends with a brief discussion of horizontal growth as a means to extend genet lifespan, thereby providing a basis for evolution of clonal plant life form through processes acting within genets.
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| 34. |
- Franzén, Markus, et al.
(author)
-
Seed set differs in relation to pollen and nectar foraging flower visitors in an insect-pollinated herb
- 2009
-
In: Nordic Journal of Botany. - : Wiley. - 0107-055X .- 1756-1051. ; 27:4, s. 274-283
-
Journal article (peer-reviewed)abstract
- Assessing the relative contributions to seed sets of each of a plant species' floral visitors provides an indication of the relative influence of these visitors on the plants' reproductive success. In this study we compared the seed set of the gynodioecious Knautia arvensis (Dipsacaceae) in 49 local plant populations in two regions of southern Sweden. We measured the seed set for hermaphroditic and female plant individuals. In both plant sexes and both regions, the seed set was positively related to the abundance of Apidae. The seed set was negatively related to the abundance of pollen-foraging solitary bees (Halictidae, Megachilidae) and beetles (Oedemeridae, Malachidae). The seed set was not related to plant population size, plant density or female frequency. Our results confirm that pollination success in generalised plant-pollinator systems varies between pollinator groups. Flower-visitors foraging for pollen might not contribute to increased pollination success in generalised pollination systems.
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| 35. |
- Frisch, Andreas, et al.
(author)
-
Arthonia incarnata (Arthoniaceae), a rare and poorly known old-growth forest lichen new to Asia
- 2017
-
In: Nordic Journal of Botany. - : Wiley. - 0107-055X. ; 35, s. 587-594
-
Journal article (peer-reviewed)abstract
- The rare and poorly known Northern Hemisphere old-growth forest lichen Arthonia incarnata is reported for the first time for Asia from Japan and Korea. A detailed description and illustration is provided for the species based on the collections from Japan and South Korea. Bayesian and RAxML analyses of mtSSU, nLSU and RPB2 sequence data show A. incarnata to be only distantly related to the other Arthonia species hitherto sequenced and in particular to superficially similar species occurring in the same type of habitat such as A. didyma, A. spadicea and A. vinosa. For the analysis we generated new sequence data of A. incarnata for the mtSSU (5 specimens) and RPB2 (5) gene loci. Slight variation was observed in sequence data of the RPB2 gene between collections from eastern Asia and Sweden, but this is not substantiated by differences in morphology or ecological behaviour. Arthonia incarnata is confined to humid forests and only grows on parts of tree trunks shaded from precipitation and running water such as the lower side of leaning trunks or cavities at the base of trees. The species is found on trees with acidic bark, in eastern Asia mainly on Betula but also on coniferous trees and on dead wood. It was not found on bark of Salix (caprea), a common substrate for the species in Europe.
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| 36. |
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| 37. |
- Garcia, Yedra, et al.
(author)
-
Spatial variation in scent emission within flowers
- 2021
-
In: Nordic Journal of Botany. - : John Wiley & Sons. - 0107-055X .- 1756-1051. ; 39:7
-
Journal article (peer-reviewed)abstract
- Floral scent is considered an important long-distance signal that attracts pollinators, but also has been suggested to function at shorter distances such as within-flower nectar guides or as a defense against antagonists. Indeed, in some species floral scent production and emission show spatial patterns of variation within flowers, as certain compounds are exclusively emitted from specific floral tissues. In other species, the different volatile organic compounds that constitute the floral bouquet are emitted evenly from the entire flower. Here, we summarize the current evidence on floral scent variation within flowers by combining a literature review of published data on tissue-level floral scent variation (41 species) with floral scent dissections (17 species). For each species, we recorded the total number of volatile compounds separately and grouped in major chemical classes. To facilitate comparisons across diverse species, we compared volatiles emitted by 1) the whole flower, 2) the visual floral tissues (i.e. petals and colored structures), 3) non-visual floral tissues (i.e. green parts and reproductive structures), as well as 4) the compounds emitted by both visual and non-visual tissues. Results show that floral scent variation is frequent, but by no means ubiquitous, occurring in species from distantly related groups. We discuss the two main functional hypotheses promoting floral scent variation within flowers, i.e. as a pollinator attractant at short-distances or a defensive function against antagonists, together with non-functional hypotheses (e.g. pleiotropic effects, ecological costs). We point out further directions on this topic and suggest experimental approaches testing the attractiveness of compounds emitted by different floral parts alone and in combination with other floral signals. Our synthesis provides a foundation for future studies on the functional ecology of floral scent and reinforces the idea of high complexity in floral chemical signals.
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| 38. |
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| 39. |
- Glav Lundin, Linnea, et al.
(author)
-
The decline of Gentianella campestris : three decades of population development of an endangered grassland plant in Sweden
- 2021
-
In: Nordic Journal of Botany. - : Wiley. - 0107-055X .- 1756-1051. ; 39:3
-
Journal article (peer-reviewed)abstract
- Species-rich semi-natural grasslands are declining all over northern Europe, and many plant species confined to such grasslands are currently under threat. We studied the development of populations of one such species, the field gentian Gentianella campestris, during three decades in the County of Södermanland, south of Stockholm, Sweden. Gentianella campestris is Red Listed as Endangered in Sweden. It is a strict biennial, and as far as known with only a transient seed bank. Large population fluctuations are a characteristic of this species, and its life history makes the species inherently sensitive to factors causing population reductions. We found that the number of sites with G. campestris has declined with over 60% in the last three decades. The total number of flowering individuals also show a strong decreasing trend, although there was an increase the last year (2020) at a few remaining sites. Cessation of grazing management is a major cause of the decline, but populations also disappeared from managed sites. It is possible that the management has been inappropriate, and circumstantial evidence suggests that summer drought might be an additional cause of population decline. Data from 2018, a year with an exceptional summer drought, supports this explanation. A sowing experiment indicated that recruitment of new populations is unlikely in the present-day landscape where most vegetation is unsuitable for G. campestris. Due to the poor prospects for long-term maintenance of grazing management in still remaining semi-natural grasslands, and the decline even at sites with current management, G. campestris faces a risk of becoming regionally extinct within the coming decades.
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| 40. |
- Grandin, Ulf, et al.
(author)
-
Allozyme variation at a PGI locus in differently aged populations of Moehringia trinervia (Caryophyllaceae) in a successional area
- 2002
-
In: Nordic Journal of Botany. - : Wiley. - 0107-055X .- 1756-1051. ; 22:3, s. 303-311
-
Journal article (peer-reviewed)abstract
- We studied genetic effects of the colonisation process during primary succession by analysing allozyme variation at a PGI locus in differently aged populations of Moehringia trinervia, which is a selfing annual with low dispersal ability. The populations studied come from islands and shores created in the 1880s by a drop in the water table of a Swedish lake and from old parts of a large island and of the mainland. The population age is known from five vegetation analyses over a century. We have also analysed the genetic composition of M. trinervia derived from seeds in the soil. Mainland populations had a higher genetic diversity than island populations that were little differentiated and differed genetically from the mainland populations. There was no temporal trend in the distribution of genetic variation on the new islands. The presence of alleles in the extant populations was associated with the proportion of that allele in the seed bank, indicating a main recruitment from the seed bank and not by repeated immigrations. We suggest that some of the new islands were colonised by a few early founders from the mainland. Later colonisation has occurred between adjacent islands, which preserves the founder effect and could explain the uniform, low genetic variation in the island populations
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| 41. |
- Gustafsson, Susanne
(author)
-
Flowering frequency in a small population of Gymnadenia conopsea : a five year study
- 2004
-
In: Nordic Journal of Botany. - : Wiley. - 0107-055X .- 1756-1051. ; 24:5, s. 599-605
-
Journal article (peer-reviewed)abstract
- This investigation evaluates the usage of genetic markers, microsatellites, to distinguish and re-identify individual plants in a population of the orchid Gymnadenia conopsea. The study also illustrates the problem in estimating the size of a population from single year sampling as individuals can rest underground or occur in vegetative states; information extremely important for the understanding of population dynamics as well as providing information for conservation management. The total population size was, based on information from microsatellite loci, estimated to 84 individuals and vastly larger than the annual number of flowering plants (mean 31.4 individual s/year). Flowering frequency varied from 24-49%, 53 individuals flowered once, five individuals were flowering four years and a single individual was flowering five years. A common pattern was one or two flowering periods followed by a non-flowering period. The observed number of alleles and the observed and expected heterozygosity varied among loci, although allele frequencies and genotype frequencies did not vary significantly among years.
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| 42. |
- Göransson, Pernilla, et al.
(author)
-
Deschampsia cespitosa and soil acidification: general and trait-specific responses to acid and aluminium stress in a solution experiment
- 2011
-
In: Nordic Journal of Botany. - : Wiley. - 0107-055X. ; 29:1, s. 97-104
-
Journal article (peer-reviewed)abstract
- Genetically based adaptation and phenotypic plasticity represent important means of coping with natural or human-induced increases in soil acidity. In the present study, we examined the role of phenotypic plasticity in the grass Deschampsia cespitosa by testing for general and trait-specific responses to acid and aluminium (Al) stress. We sampled tussocks (genets) from sites in southern Sweden differing in their exposure to acid deposition, and quantified the performance of each genet under low pH and high Al levels in a solution experiment using the length and biomass of both shoots and roots as response variables. In agreement with results from a previous solution experiment, the overall performance (expressed as total biomass) declined under acid and Al stress, and there was no evidence for local genetic adaptation with respect to acidity. Three Oland populations showed signs of being stimulated by high Al levels, despite originating from relatively basic soils. We observed a significant increase in root length under high Al levels and hypothesize that this response may be adaptive in the natural soil environment, allowing growing roots to "escape" patches of soil with toxic concentrations of this element. Our results for D. cespitosa indicate that phenotypic plasticity has the potential to mitigate the negative effects of soil acidity in this species.
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| 43. |
- Hedberg, O
(author)
-
Studies in the genus Polycarpaea (Caryophyllaceae) in Ethiopia
- 1995
-
In: NORDIC JOURNAL OF BOTANY. - : NORDIC JOURNAL OF BOTANY. - 0107-055X. ; 15:5, s. 513-517
-
Journal article (other academic/artistic)abstract
- A case study is presented of a small critical group of Polycarpaea species in Ethiopia, comprising P. eriantha, P. corymbosa and P. linearifolia. Absence of clear discontinuities in individual features between the three species concerned invited the lumpi
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| 44. |
- HEDBERG, O, et al.
(author)
-
THE GENUS COLPODIUM (GRAMINEAE) IN AFRICA
- 1994
-
In: NORDIC JOURNAL OF BOTANY. - : NORDIC JOURNAL OF BOTANY. - 0107-055X. ; 14:6, s. 601-607
-
Journal article (other academic/artistic)abstract
- Recent collections of the genus Colpodium from Ethiopia and South Africa made a renewed revision of the African material of this genus desirable. Apart from the two earlier recognized African species (C. chionogeiton and C. hedbergii) a third one is descr
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| 45. |
- Hedren, M
(author)
-
Electrophoretic evidence for allotetraploid origin of Dactylorhiza purpurella (Orchidaceae)
- 1996
-
In: NORDIC JOURNAL OF BOTANY. - : NORDIC JOURNAL OF BOTANY. - 0107-055X. ; 16:2, s. 127-134
-
Journal article (other academic/artistic)abstract
- Evidence from allozyme markers suggests that the NW European Dactylorhiza purpurella (Orchidaceae) is an allotetraploid which originated from taxa closely related to the present-day D, incarnata s. 1. and D, fuchsii/D. maculata. However, Dactylorhiza purp
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| 46. |
- Hedrén, Mikael, et al.
(author)
-
Evolution and systematics of polyploid Nigritella (Orchidaceae)
- 2018
-
In: Nordic Journal of Botany. - : Wiley. - 0107-055X. ; 36:3
-
Journal article (peer-reviewed)abstract
- Members of the orchid genus Nigritella are widespread in European mountains, but species circumscriptions and evolutionary patterns in the genus are subjects to conflicting opinions. We analyzed a representative material of Nigritella for differentiation at nuclear and plastid marker loci. In agreement with predictions from embryological studies, diploid members of Nigritella are sexual and mostly out-crossing, whereas triploid, tetraploid and pentaploid members are apomicts. The diploid taxa were poorly differentiated in the investigated molecular markers, except for the western N. gabasiana, which was separated in plastid haplotypes. Polyploid Nigritella aggregate into three groups and within each of these groups apomictic polyploids have given rise to new species. Within the N. nigra group, the tetraploid N. nigra subsp. austriaca is somewhat differentiated from the triploid subsp. nigra at nuclear as well as plastid loci. Fusion of an unreduced egg cell from subsp. nigra with a haploid microgamete from Gymnadenia conopsea gave rise to Gymnigritella runei. Within the N. widderi group, N. archiducis-joannis is poorly separated from N. widderi in molecular markers, and the pentaploid N. buschmanniae has evolved by fusion of an unreduced egg cell from N. widderi with a haploid microgamete from a diploid Nigritella. Within the N. miniata group, N. stiriaca is somewhat differentiated from N. miniata at nuclear loci, but no other segregates of N. miniata are supported at species level. Polyploid Nigritella species accumulate genetic diversity by somatic mutations. In the widespread N. nigra subsp. austriaca and N. miniata this diversity is correlated to geography. Although some polyploids may be of recent origins, each polyploid contain genetic markers no longer encountered in diploid members of the genus. According to plastid marker data, Nigritella and Gymnadenia may constitute monophyletic sister genera.
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| 47. |
- Hedrén, Mikael, et al.
(author)
-
High levels of genetic diversity in marginal populations of the marsh orchid Dactylorhiza majalis subsp. majalis
- 2018
-
In: Nordic Journal of Botany. - : Wiley. - 0107-055X. ; 36:4
-
Journal article (peer-reviewed)abstract
- Because of harsh conditions, suboptimal habitat quality and poor connectivity to other populations, plant populations at the margin of a distribution are expected to be less genetically diverse, but to be more divergent from each other than populations in the centre of a distribution. In northern Europe, northern marginal populations may also be younger than populations further to the south, and may have had less time to accumulate genetic diversity by mutation and gene flow. However, orchids have very small seeds, which are easily dispersed long distances by wind, and orchids are therefore expected to show less differentiation between marginal and central populations than other groups of seed plants. Here, we analysed whether Scandinavian populations of the tetraploid marsh orchid Dactylorhiza majalis subsp. majalis differ from central European populations in genetic diversity patterns. A total of 220 plants from eight central European and ten Scandinavian populations was examined for variation at five nuclear microsatellite loci, nuclear ITS and 13 polymorphic sites in noncoding regions of the plastid genome. The total genetic diversity was slightly lower in Scandinavia than in central Europe, both in plastid and nuclear markers, but the differences were small. Also, the Scandinavian populations were less diverse and somewhat more strongly differentiated from each other than the central European ones. Dactylorhiza majalis subsp. majalis has apparently colonized Scandinavia on multiple independent occasions and from different source areas in the south. Seed flow between Scandinavian populations has still not fully erased the patterns imprinted by early colonization. Our results suggest that marginal populations of orchids may be as important as central ones in preserving genetic diversity through Pleistocene glacial cycles. We also predict that orchids with their light seeds are better adapted than many other plants to respond to future climate changes by dispersing into new suitable areas.
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| 48. |
- Hedren, M, et al.
(author)
-
Ichthyostoma - A new genus in the Acanthaceae from NE tropical Africa
- 1996
-
In: NORDIC JOURNAL OF BOTANY. - : NORDIC JOURNAL OF BOTANY. - 0107-055X. ; 16:4, s. 441-444
-
Journal article (other academic/artistic)abstract
- Ichthyostoma thulinii, a new genus and species from Central Somalia and SE Ethiopia is described. Ichthyostoma is best placed in Acanthoideae - Odontoneminae, but is not closely related to any extant genus in that group.
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| 49. |
- Hedren, M
(author)
-
Notes on the esterase variation in Swedish Dactylorhiza incarnata s l (Orchidaceae)
- 1996
-
In: NORDIC JOURNAL OF BOTANY. - : NORDIC JOURNAL OF BOTANY. - 0107-055X. ; 16:3, s. 253-256
-
Journal article (other academic/artistic)abstract
- Swedish material of Dactylorhiza incarnata s. 1. shows little variation at commonly investigated allozyme loci. However, interpretable variation was found at one esterase locus. All plants investigated of D. incarnata var. cruenta from southern Sweden (wi
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| 50. |
- Hedrén, Mikael
(author)
-
Patterns of allozyme and morphological differentiation in the Carex flava complex (Cyperaceae) in Fennoscandia
- 2002
-
In: Nordic Journal of Botany. - 0107-055X. ; 22:3, s. 257-301
-
Journal article (peer-reviewed)abstract
- Allozyme and morphological differentiation patterns within the Carex flava complex in Fennoscandia were described by means of multivariate analyses. As a result of these studies, and considering also data on ecology, distribution and hybridization, the following taxa were recognized: C. flava with no infraspecific taxa, C. lepidocarpa with two subspecies, ssp. lepidocarpa and ssp. jemtlandica, C. demissa with no infraspecific taxa, and C oederi with three varieties, var. oederi, var. bergrothii, and var. pulchella. Carex lepidocarpa ssp. jemtlandica was allozymically divergent from ssp. lepidocarpa, indicating a long period of isolation-of the two subspecies. A poor morphological separation in some localities is apparently due to secondary contacts in connection with recolonization of Fennoscandia after the last ice age, resulting in the formation of fertile hybrids and back-crosses. The subdivision of C. oederi into three varieties is supported by ecological data and it is suggested that they have originated by parallel ecotype formation under similar selective regimes in different areas. However, the varietal limits are not-supported by differentiation in neutral (allozyme) characters. A phylogenetic hypothesis was constructed by means of neighbour-joining based allozyme data and it was indicated that C demissa may be more closely related to C lepidocarpa than to C oederi. Previous treatments that have reduced the C. flava complex to one or two species may have been based on inappropriate species concepts, too coarse methods of analysis of morphological data, ignorance of patterns of co-occurrence and hybridization, or a combination of these factors.
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