Article

Molecular, morphological, and ecological differences between the terrestrial and aquatic forms of Oxyrrhynchium speciosum (Brid.) Warnst. (Brachytheciaceae)

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Abstract

Oxyrrhynchium speciosum (Brid.) Warnst. is a relatively uncommon moss that can be found in wetland habitats across Europe and New Zealand. In this paper, we address the morphological, molecular and ecological relationships between the aquatic form of O. speciosum discovered in a deep, Chara-dominated lake (Budzisławskie, NW Poland) and its terrestrial relatives. Morphological assessments revealed a considerable difference between terretrial and deep-water samples of O.speciosum. The aquatic form of O. speciosum was, on average, 12 times larger, with more branched stems (4–30 times) and longer leaves (1–2 times). Investigation of ITS1-5·8S-ITS2-26S region sequences, however, revealed no distinction between the terrestrial and aquatic forms. An analysis of the ecological data suggests that the presence of O. speciosum in deep lake habitats is not incidental (as with many land species developing in aquatic environments). On the contrary, aquatic forms have a distinct ecological niche. Our results confirm that both forms of O. speciosum are closely related to O. hians (Hedw.) Loeske (a terrestrial species). The data indicate that O. speciosum is nested within a well-supported O. hians clade and separation of these species may be connected with polyploidization that occurred during their evolution.

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... The aquatic form is on average 12 times larger with more branched stems (4-30 times) and longer leaves compared to the terrestrial form. But molecular studies show no distinction between the two forms [33]. ...
... Particularly in North Africa, it is only mentioned in Algeria [19]. Oxyrrhynchium speciosum is relatively rare in New Zealand [33] and Switzerland [23] and abundant in Turkey, Bulgaria [34,35]. In Morocco, its frequency in the study site is very rare. ...
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The extensive sampling of the bryophytic flora of the Izarène massif, region of the city of Ouezzane in Moroccan North-West, revealed the presence of two new taxafor the Moroccan bryoflora. These are Amblystegium radical and Gymnostomum aeruginosum var.aeruginous, which belong to the Amblystegiaceae and Pottiaceae families, respectively. With illustrations, the site and the two taxa are described, as well as their distribution and ecology.
... The aquatic form is on average 12 times larger with more branched stems (4-30 times) and longer leaves compared to the terrestrial form. But molecular studies show no distinction between the two forms [33]. ...
... Particularly in North Africa, it is only mentioned in Algeria [19]. Oxyrrhynchium speciosum is relatively rare in New Zealand [33] and Switzerland [23] and abundant in Turkey, Bulgaria [34,35]. In Morocco, its frequency in the study site is very rare. ...
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... In vielen Fällen ist die Artabgrenzung auch aktuell teilweise unklar: Ein erstes Beispiel ist die Gruppe um Brachythecium salebrosum mit mehreren morphologisch distinkten Taxa, die jedoch eine (nahezu) identische ITS-Sequenz aufweisen (IGNATOV et al. 2008, IGNATOV & MILYUTINA 2010. Ein zweites Beispiel sind die aquatische und die terrestrische Form von Oxyrrhynchium speciosum, die sich morphologisch und ökologisch klar unterscheiden, nicht jedoch genetisch, und die beide innerhalb der variablen Art Oxyrrhynchium hians clustern, was auf eine rezente Artbildung über Polyploidisierung aus dieser haploiden Art hindeutet (GĄBKA et al. 2014). Schwierige Abgrenzungen innerhalb der Gattung Rhynchostegiella oder in der Gruppe um Sciuro-hypnum reflexum wären weitere Beispiele (DRAPER & HEDENÄS 2009, PATIÑO et al. 2017. ...
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A list of mosses, comprising 52 species from 23 families, is provided for the Kermadec Islands, northern New Zealand. Cyclodictyon blumeanum is recorded new to New Zealand. Hypnum trachypelma is placed in synonymy with Eurhynchium speciosum, and lectotypes are designated for the names Hypnum trachypelma and Neckera kermadecensis. The moss flora of the Kermadec Islands contributes a significant subtropical element to the New Zealand mainland flora.
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Records made in the late 1970s in 57 small (0.5–200 ha) lakes in southern Finland (about 61°30′N) were used to examine ecological gradients, species assemblages, and two a priori classifications of lakes. The a priori groupings were: (1) general limnological types (hypertrophic, eutrophic, clear-water meso-eutrophic, mesotrophic, clear-water oligotrophic and brown-water oligotrophic lakes); (2) the traditional Finnish botanical lake type classification. The material was classified with TWIN-SPAN and ordinated with detrended correspondence analysis (DCA) and canonical correspondence analysis (CCA).The species richness and the occurrence of various growth forms vary greatly, being highest in the clear-water meso-eutrophic and eutrophic lakes, and lowest in brown-water oligotrophic waters. For helophytes, however, species richness was highest in eutrophic and hypertrophic lakes. The trophic state (indicated by the specific conductivity and the summer water pH) determines the occurrence of many helophyte species; for hydrophytes the principal determinants are trophic state and water transparency.There was a relatively good correspondence between the results of multivariate analyses and a priori classifications of lakes, especially in most nutrient-poor and nutrient-rich, as well as in some clear-water lakes. The mesotrophic and eutrophic lake categories, do, however, overlap widely. The ordination diagrams indicate an ecological continuum, and only relative importance of lake classifications.Ninety-four macrophyte species separate into a few main groups along the oligotrophy-eutrophy gradient.
Article
Phylogenetic relationships of the aquatic moss genus Platyhypnidium and terrestrial species of Rhynchostegium were explored using a phylogeny based on three DNA sequence regions, the nuclear ITS1-5.8S-ITS2, and the plastid trnL-F and trnD-T. This is the first study using trnD-T in the phyogeny of mosses. Platyhypnidium appeared polyphyletic and most of its species were found within a Rhynchostegium clade including species from four different genera: Rhynchostegium, Eriodon, Eurhynchiella and Platyhypnidium. Use of the name Rhynchostegium requires conservation against Eriodon. Within Rhynchostegium s.l., aquatic Rhynchostegium species (i.e., Platyhypnidium) were resolved in four geographically delimited groups: an Afro-European group, an American-East Asiatic group, a Malesian-Australian group and a group comprising the South American P. fuegianum together with Eriodon and Eurhynchiella. Topologies from independent analyses of plastid and nuclear data did not show conflict, and the occurrence of hybridzation events in the clade was therefore not supported. The phylogeny indicates numerous habitat shifts between terrestrial and aquatic habitats, as well as between different terrestrial (epiphytic and epigeic) habitats, which may have affected taxonomic complexity in Rhynchostegium. New morphological characters, such as a striate leaf lamina, axillary hairs composed of relatively short cells, and clearly differentiated cells of the costa, separate Platyhypnidium species within Eurhynchioideae from those in the Oxyrrhynchium-Donrichardsia clade (Helicodontioideae). Two morphologically unique specimens, Platyhypnidium muellerii from Hawaii and Platyhypnidium sp. from Northern Australia, are described as Donrichardsia bartramii and Rhynchostegium brevinerve. The new genus Hedenaesia (Helicodontioideae) is established to accommodate Platyhypnidium austrinum.
Article
Platyhypnidium pringlei [≡ Eurhynchium pringlei] is an uncommon, montane species of aquatic Brachytheciaceae occurring across central Mexico and in Guatemala. A morphologically distinct form of this moss is found disjunctively in some sheltered coves of the Blue Ridge Mountains in the southeastern United States. Both of these forms are sterile. A similar but more robust female plant is known from Arizona and California. In Himalayan India fertile forms of P. pringlei exist. These are apparently dioicous and have sporophytes with rostrate opercula and weakly roughened setae. Here we describe the sporophytes of P. pringlei for the first time and we discuss the variation, distribution and ecology of the species. Morphologically the several forms of P. pringlei intergrade, but in North America they appear to be geographically isolated. We tested the monophyly of Platyhypnidium using nuclear ribosomal internal transcribed spacer (ITS) data from 47 collections of Brachytheciaceae. Although most of Platyhypnidium is an artificial segregate of the terrestrial genus Rhynchostegium, P. pringlei has its affinities with Oxyrrhynchium hians [≡ Eurhynchium hians]. Two other closely related aquatic species are E. selaginellifolium from Hawaii and Donrichardsia macroneuron from Texas, and at least one more aquatic relative is known from China. Based on morphological and molecular congruence between these aquatic mosses and terrestrial species of Oxyrrhynchium like O. hians, O. speciosum and O. savatieri, the new combinations O. pringlei, O. selaginellifolium and O. macroneuron are made. Morphologically these aquatic species are characterized by a dark green color, infrequent branching, a loose foliation, a homomallous leaf arrangement, short laminal cells and long costae.
Article
Numbered in hundreds of thousands, and ranging from <1 ha in area to Europe’s largest lake (Lake Ladoga), North European softwater lakes (lime-deficient waterbodies, ranging from low-nutrient, low pH to meso-eutrophic, circumneutral pH) support an important plant component of the biodiversity resources of Europe. Within this region (comprising the British Isles, Scandinavia, and the North European Plain from Brittany to the Baltic States), some 24 softwater lake euhydrophyte community types occur, including stress-tolerant isoetid communities which particularly characterise softwater lake vegetation. A number of rare species are supported, including plants, such as Eriocaulon aquaticum, which are found nowhere else in Europe. In line with the predictions of the hump-back model of diversity–productivity relationships in lakes, the individual plant diversity found in softwater lakes in this region is low (six or fewer euhydrophyte species present, e.g. in acidic, ultraoligotrophic lakes) to moderately high (>20 euhydrophyte species in lakes with, for example, mesotrophic conditions with pH <7.0). Overall, however, a large set of plant species (>100) occurs, forming assemblages which play a vital role in the functioning of softwater lake ecosystems. Lake area, altitude, trophic state and water quality have been found to be good predictors of macrophyte species richness for lakes within this area. Major threats to the survival of softwater lake vegetation include acidification, eutrophication, increased recreational use of lakes, and the effects of lake regulation for hydro-electric schemes. All such pressures tend to reduce the diversity of typical softwater species present in affected lakes. In addition, there is increasing concern about the possible impacts of global CO2 increase for the continued survival of (especially) isoetid vegetation which is strongly adapted to ambient conditions of limited dissolved inorganic carbon availability in softwater lakes. The implications of such global change for the maintenance of softwater lake plant diversity in northern Europe are potentially severe.
Article
Softwater lakes possess a highly characteristic vegetation adapted to limited carbon availability. Based on hydrology, vegetation and geographic distribution, a boreal and an atlantic lake type can be distinguished. In general, boreal softwater lakes occur in remote areas where eutrophication is a local phenomenon and acidifying input is low. A number of these lakes are, however, very susceptible to eutrophication and acidification. Reducing the input of nutrients and/or liming the stream or catchment is generally sufficient to restore typical softwater vegetation. The vegetation of atlantic softwater lakes are subject to many anthropogenic degradation processes. Removal of nutrient-rich, anoxic, organic sediments is a prerequisite for restoration of these lakes. In acidified or acid-sensitive lakes, subsequent controlled inlet of calcareous, nutrient-poor water is more adequate than direct liming. The effects of these restoration measures strongly depend on interaction with processes, such as atmospheric deposition, drainage, catchment acidification, eutrophication and reduced colonisation rates.
Article
This report summarizes a study of the chemical and biological characteristics of three oligotrophic lakes located in a region that receives a moderately acidic precipitation (mean annual pH 4.5–4.6), and a sulfate deposition of about 20 kg/ha/yr. The two brownwater lakes are relatively acidic (pH 4.5 and 4.8), and much of their acidity is attributable to organic anions. The brownwater lakes also have a large concentration of aluminum and iron, but these are bound to dissolved organic matter and are relatively non-toxic to biota. Average phytoplankton production was largest in the clearwater lake. This was due to its relatively deep euphotic zone, since the average unit-volume productivity did not differ much among the lakes. In fact, productivity at light optimum was largest in the most acidic brownwater lake, probably because of its larger phosphorus concentration. The clearwater lake had extensive macrophyte vegetation, which covered its bottom to a depth of 6.5 m. In the brownwater lakes, macrophytes were confined to shallow nearshore water because of the limited water transparency. Zooplankton density and biomass were largest in the most acidic brownwater lake, probably because of allochthonous organic particulates and little fish predation. Benthic invertebrates were abundant in all three lakes, and were dominated by insects, especially Chironomids. Lakes in the study area appear to be sustaining fish populations at more acidic pHs than elsewhere. This may be due to the large concentration of dissolved organic matter in many lakes, which complexes and partially detoxifies metals such as aluminum.
Article
Nuclear ribosomal DNA (internal transcribed spacer region) and chloroplast DNA (trnL-trnF region) were sequenced from 40 samples representing all three genera (Brachelyma, Dichelyma, and Fontinalis) and 18 species of the aquatic moss family, Fontinalaceae. Phylogenetic reconstructions recovered from separate and combined analyses were used to test the hypotheses that Fontinalis and Dichelyma are monophyletic (Brachelyma is monotypic), that groups of species within Fontinalis based on leaf morphology (keeled, concave, plane) form monophyletic groups, and that species delineation based on morphological characters within Fontinalis are congruent with nr- and cpDNA gene trees. Using Brachelyma subulata to root the tree, both Dichelyma and Fontinalis are monophyletic and patristically divergent (each united by >15 synapomorphic mutations). Groups of species within Fontinalis defined by leaf morphology are polyphyletic and it is clear that leaf morphology is labile in the genus. As defined morphologically, species of Fontinalis are nonmonophyletic for both nr- and cpDNA sequences and populations of some morphological taxa are separated in widely divergent clades. Molecular evidence suggests that at least some morphospecies are artificial, defined by convergent leaf forms. The weight of the evidence indicates that F. antipyretica is positively paraphyletic, with European populations more closely related to (i.e., share a more recent common ancestor with) European endemic species than to North American populations that are morphologically conspecific. North American populations are more closely related to North American endemic species.
Article
We describe MUSCLE, a new computer program for creating multiple alignments of protein sequences. Elements of the algorithm include fast distance estimation using kmer counting, progressive alignment using a new profile function we call the log‐expectation score, and refinement using tree‐dependent restricted partitioning. The speed and accuracy of MUSCLE are compared with T‐Coffee, MAFFT and CLUSTALW on four test sets of reference alignments: BAliBASE, SABmark, SMART and a new benchmark, PREFAB. MUSCLE achieves the highest, or joint highest, rank in accuracy on each of these sets. Without refinement, MUSCLE achieves average accuracy statistically indistinguishable from T‐Coffee and MAFFT, and is the fastest of the tested methods for large numbers of sequences, aligning 5000 sequences of average length 350 in 7 min on a current desktop computer. The MUSCLE program, source code and PREFAB test data are freely available at http://www.drive5. com/muscle.
Musci Europaei Exsiccati. Die laubmoose Europas unter mitwirkung namhafter bryologen und floristen Abbreviation
  • E Bauer
The identity of a gathering of Eurhynchium speciosum (Brid.) Jur. from Turkey
  • S V Mcadam
Mosses (Diplolepideae)
  • M O Hill
  • C D Preston
A review of deep water bryophytes with new records from USSR. Hikobia
  • M S Ignatov
  • N B Kurbatova
Lund: Swedish Natural Science Research Council
  • E Nyholm
Allgemeine botanische Zeitschrift für Systematik
  • C Warnstorf