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Bryophytes (mosses, liverworts and hornworts) are the most basal lineages among extant land plants. However, there is controversy regarding their monophyletic or paraphyletic origin. Moreover, the most basal group of bryophytes also remains questionable. Due to this it is a matter of debate which lineage of bryophytes acts as transition link between bryophytes and pteridophytes. In order to resolve these issues we conducted a bioinformatics analysis on available chloroplast genomes of 1 green alga, 5 bryophytes, 4 pteridophytes, and 6 gymnosperms. Our study is based on multiple genome analysis through whole proteome comparison. The higher number of orthologous identified in Anthoceros (a hornwort), in comparison to other bryophytes considered, against all pteridophytes strongly support hornworts as transition link between bryophytes and pteridophytes.
The present phylogenetic analysis was conducted using mitochondrial genome sequences of plants to infer evolutionary relationship of bryophytes. Paraphyly of bryophytes was shown by reconstructed trees. Liverworts are the first to diverge therefore appeared as sister to land plants in nucleotide based trees. However protein sequences based tree show mosses and liverworts to form a joint clade. Hornworts formed sister relationship with vascular plants.
Mosses of Venezuela
(2010)
926 taxa of mosses are listed for Venezuela completed by bibliographical references. Many significant additions have been added or changed from the original document completed in 2007, particularly a complete review of all the bryophytes on the original Venezuela list. This was caused because the TROPICOS group had revised all the existing bryophytes, to bring them up to the most recent views. This may not be popular, but otherwise there is no TROPICOS. This document was originally written 3 years ago, and we now have to familiarise ourselves with the new TROPICOS situation, which will now become the new standard - but with so many changed names, we might have problems in mapping our familiar system to the new one.
A botanical survey of the vegetation of Strzelecki National Park, on south-western Flinders Island, Tasmania
(lat. 40° 13' S; long. 148° 06' E) resulted in 313 vascular plant taxa, being recorded. Of these, 16 are introduced. Of the native flora, 9 are currently considered threatened according to the Tasmanian Threatened Species Protection Act 1995. Some of these occur on the calcareous rocks and soils on the western coastal fringe of the Park.
There is low species diversity in large areas, for reasons that include extensive ground disturbance by pigs, very high fire frequency in some areas and the depauperate nature of island floras.
There were also 137 species of liverworts and mosses recorded for the Park. Most plant habitats on Flinders Island are represented in the Park. The flora retains an interesting rainforest and wet forest element which shares floristic similarities with rainforest gullies in mainland south-eastern Australia, with the Tasmanian north-eastern highlands, and even with western Tasmania. There are also some affinities with the dry Bass Strait and southern Australian floras. The pattern and composition of the vegetation is strongly shaped by several factors. Extensive fires have been promoted by fuel accumulation and deliberate burning on the Park perimeter. Topography strongly influences the vegetation (Mt Strzelecki is 756 m high) due to the degree of exposure to strong winds and protection from fire. Cloud capping of the mountain increases the potential moisture available. Wind is a large local factor in vegetation structure. Controls on vegetation at any given site are also responsive to aspect, bedrock depth and other factors.
Eleven vegetation mapping communities are defined, the Park being important for the reservation of several of these. The Park is characterised by the presence of rainfall and evapotranspiration extremes and the vegetation varies accordingly, with rainforest patches in fire protected niches of the mountains and dry heathland on the coastal areas. Strong westerly winds combined with the abruptly rugged mountainous topography have caused some violent localised destruction of forest and scrub canopies by wind.
A small collection of bryophytes made during holidays on Réunion in September 2009 revealed 6 species new to the island (Brachymenium acuminatum, B. dicranoides, Bryum lanatum, Campylopus clavatus, Mielichhoferia bryoides and Oxyrhynchium hians). Campylopus crateris has been found for the first time with sporophytes. These new records are incorporated in a new alphabetic list of the mosses of Réunion. Keys for the species for several genera are given.
Trockenrasen (v. a. Klassen Koelerio-Corynephoretea und Festuco-Brometea) gehören zu den auf kleinen Flächen artenreichsten Pflanzengesellschaften überhaupt und stellen ideale Modellsysteme für die Analyse von Phytodiversitätsmustern und deren Ursachen dar. Ich gebe einen Überblick der in verschiedenen Trockenrasentypen Europas auftretenden Durchschnitts- und Maximalwerte der Artenzahlen von Gefäßpflanzen, Moosen und Flechten auf unterschiedlichen Flächengrößen zwischen 1 mm2 und 100 m2. Gesellschaften der Festuco-Brometea sind generell artenreicher als jene der Koelerio-Corynephoretea. Die bislang höchsten publizierten Artendichten stammen jedoch aus dem Gypsophilo fastigiatae-Globularietum vulgaris, einer basiphilen Felsgrusflur der schwedischen Insel Öland (Ordnung Alysso alyssoidis-Sedetalia, Koelerio-Corynephoretea). Sie betragen auf 4 m2 durchschnittlich 53,6 und maximal 80 Arten. Die geringsten Artendichten unter den Trockenrasen weisen das Caricetum arenariae und das Corniculario-Corynephoretum (beide Ordnung Corynephoretalia canescentis, Koelerio-Corynephoretea) mit durchschnittlich weniger als 10 Arten auf 4 m2 auf. Die Artenzahl-Areal-Beziehung von Trockenrasen lässt sich über den ganzen betrachteten Dimensionsbereich exzellent durch eine Potenzfunktion S = c • A z beschreiben. Dabei unterscheiden sich die z-Werte verschiedener Trockenrasentypen nur geringfügig und betragen im Mittel 0,21. Das führt dazu, dass die Reihung verschiedener Trockenrasengesellschaften hinsichtlich ihrer Artenzahl auf unterschiedlichen Skalenebenen nahezu unverändert bleibt, und eröffnet die Möglichkeit, Artenzahlen auf andere Flächengrößen zu extrapolieren.
Es folgt eine Erörterung der wichtigsten Faktoren, welche die Verteilung der Phytodiversität in Trockenrasen beeinflussen. Die größte Bedeutung hat hier die Bodenreaktion. Im Allgemeinen wurden stark steigende Artendichten mit zunehmendem pH-Wert, teilweise auch ein erneuter leichter Abfall oberhalb des Neutralpunktes gefunden. Eine Abnahme der Artendichte mit zunehmender Höhenlage im Gebirge konnte zumindest in zwei Fällen auch für Probeflächen gleicher Größe nachgewiesen werden. Abschließend diskutiere ich die Gründe für den überdurchschnittlichen Artenreichtum von Trockenrasen, weise auf Forschungsdefizite hin und unterbreite Empfehlungen für die Konzeption und Durchführung künftiger Studien der Biodiversitätsforschung wie auch der pflanzensoziologischen Datenerhebung allgemein. Als vordringliche Qualitätskriterien erachte ich die Arbeit mit standardisierten Probeflächengrößen und die sorgfältige Berücksichtigung von Moosen und Flechten.
The checklist reports 712 taxa of bryophytes from Tamil Nadu, India, comprising 211 taxa in 56 genera and 32 families of liverworts, 8 taxa in 4 genera and 2 families of hornworts, and 493 taxa in 189 genera and 44 families of mosses. Literature sources for Tamil Nadu records are included for each taxon, and an extensive synonymy is provided. For currently accepted taxa, the details of types from Tamil Nadu are indicated. A map of Tamil Nadu, a synopsis of families and genera, and a bibliography are provided.
Reproduction in bryophytes is by asexual as well as sexual means. Asexual reproduction is a significant adaptation to special environments and occurs by a large variety of methods. During the last few decades, many of the bryophytes, particularly the dioecious ones are reported to have registered a decline in their fertile populations. There is, therefore, a need to understand the reasons for their disappearance.