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Vegetationsdynamik verlandeter Biberteiche auf der Insel Navarino (Feuerland-Archipel, Chile)
(2009)
Die vorliegende Fallstudie veranschaulicht die Auswirkungen des invasiven Nordamerikanischen Bibers (Castor canadensis) auf den autochthonen Nothofagus-Wald der ca. 2500 km2 großen Insel Navarino im Feuerland-Archipel (Archipiélago de Tierra del Fuego), Chile. Dazu wurden auf den Sukzessionsflächen verlandeter Biberteiche (1) Diversität (absolute Artenzahl, mittlere Artenzahl, Artendichte, Shannon-Wert und Evenness), (2) Artenzusammensetzung, (3) Anteil gebietsfremder Pflanzenarten. (4) Baumartenzusammensetzung, (5) Dichte, (6) Stammdurchmesser und (7) die Wuchshöhe der Gehölzverjüngung untersucht. Die Ergebnisse zeigen auf den Sukzessionsflächen eine deutliche Zunahme der Diversität mit Ausnahme der mittleren Artenzahl. Die ehemaligen Biberteiche zeichnen sich durch eine charakteristische Artenzusammensetzung aus, die insbesondere durch Weide- und Überschwemmungszeiger bestimmt wird und sich erheblich von biberfreien Waldflächen unterscheidet. Der Anteil gebietsfremder Pflanzenarten variiert stark, wofür noch keine Determinanten festgestellt werden konnten. Im Unterschied zu von Bibern unbeeinflussten Nothofagus-Wäldern wird die Verjüngung auf den Sukzessionflächen von Nothofagus antarctica dominiert. Es wurden folgende fünf Faktoren identifiziert, die als wesentliche Steuergrößen für die Etablierung von Nothofagus in Betracht gezogen werden können: (1) relative Lage des Spenderbiotops, (2) Vorkommen von Totholz, (3) Beweidung, (4) Konkurrenz und (5) Überschwemmung.
Two species of the genus Ophelina Örsted, 1843 (Annelida, Opheliidae) are reported from the coast of Kuwait (Arabian Gulf) after specimens collected in the intertidal and shallow subtidal, namely Ophelina arabica sp. nov. and Ophelina grandis (Pillai, 1961). The new species is mainly characterised by features of the anal tube, which is provided with about 25 annulations at each side; the ventral margins are fully fused while dorsal margins are fused at most of their length but are free at the distal end in the shape of a conspicuous incision; the posterior end is opened with free margins; the anal tube also lacks marginal papillae but bears a pair of basal papillae and an unpaired anal cirrus attached to ventral margin at mid-length. Ophelina grandis is reported for the first time in the Arabian Gulf; specimens are fully described and compared with similar species. A key for species of Ophelina in the Indo-Pacific, Southern Asia, Indo-Malay Archipelago and Australia, is also provided.
Two new species of subgenus Heterophyllidiae subsection Cyanoxanthinae, Russula fusiformata Y.Song sp. nov. and R. purpureorosea Y.Song sp. nov., collected from the Dinghushan Biosphere Reserve (DHSBR), are described based on both morphology and a phylogenetic analysis of the internal transcribed spacer (ITS), further increasing Heterophyllidiae species diversity in the area. Differences between the two new species and related taxa are analyzed. The other 17 reported species of Russula subgenus Heterophyllidiae that have been collected from DHSBR during mushroom explorations since 2014 are also summarized. The dominant species and the ecological distribution of all 19 species are briefly discussed, and most species are presented in macrofungal plates.
The current forest policy in Germany is to change forest monocultures into mixed forests. This is based on the assumption that monocultures are less robust against climatic influences (e.g. storm, drought), more susceptible to pest organisms (JACTEL et al. 2002, WOODS 2003, BURTON et al. 1992) and are for several insect taxa known to show a lower species richness in comparison to mixed forests (YOUNG 1986, BARKMAN 1992, BURKHART & THAM 1992, DENNIS 1997, BRAGANCA et al. 1998). This investigation wanted to verify this thesis in forests consisting of European beech (Fagus sylvatica), Norway spruce (Picea abies) and of both tree species. The area of investigation was in the Solling region, a large woodland in Lower Saxony (Germany).
This paper contains the results of research on a large assemblage of jumping spiders collected by J.-C. Ledoux from Ivory Coast in 1974–75. In total, 105 species are included. Three new genera are erected Pulcherula gen. nov., Sphericula gen. nov. and Vicirionessa gen. nov. Two generic names are synonymized, Polemus Simon, 1902 with Baryphas Simon, 1902 and Brancus Simon, 1902 with Thyene Simon, 1885. Twenty eight new species are described: Afraflacilla albopunctata sp. nov. (♀), Ansienulina lamottei sp. nov. (♂), Asemonaea pusilla sp. nov. (♀), Detalik cavally sp. nov. (♀), Evarcha zougoussi sp. nov. (♀), Heliophanus (Heliophanus) minimus sp. nov. (♂♀), Hyllus ignotus sp. nov. (♀), Hyllus solus sp. nov. (♀), Hyllus unicolor sp. nov. (♀), Icius bandama sp. nov. (♂♀), Langona recta sp. nov. (♂), Malizna zabkai sp. nov. (♀), Menemerus niangbo sp. nov. (♀), Myrmarachne galea sp. nov. (♀), Phintella brevis sp. nov. (♂), Phintella globosa sp. nov. (♀), Phintella occidentalis sp. nov. (♂), Phintella transversa sp. nov. (♂), Pochytoides mirabilis sp. nov. (♂♀), Pochytoides tonkoui sp. nov. (♀), Pochytoides tournieri sp. nov. (♂), Pulcherula magna gen. et sp. nov. (♂), Rhene ferkensis sp. nov. (♀), Sonoita ledouxi sp. nov. (♂♀), Sphericula globulifera gen. et sp. nov. (♀), Thiratoscirtus silvestris sp. nov. (♂♀), Tusitala bandama sp. nov. (♀) and Tusitala cornuta sp. nov. (♂). Five specific names are synonymized: Polemus chrysochirus Simon, 1902 with Baryphas jullieni Simon, 1902, Viciria mondoni Berland & Millot, 1941with Malloneta guineensis Simon, 1902, Brancus lacrimosus Wesołowska & Edwards 2008 with Vicirionessa fuscimana (Simon, 1903), Viciria monodi Berland & Millot, 1941 and Viciria equestris pallida Berland & Millot, 1941 with Vicirionessa equestris (Simon, 1903). Hyllus natali peckhamorum Berland & Millot, 1941 is removed from synonymy of Hyllus brevitarsis Simon, 1902, revalidated and its rank is raised as Hyllus peckhamorum Berland & Millot, 1941 stat. nov. Also rank of Telamonia aequipes minor Lessert, 1925 is elevated as Phintella minor (Lessert, 1925) stat. nov. Menemerus dubius Berland & Millot, 1941 is removed from nomina dubia. This species is considered valid and is redescribed. A lectotype is designated for it. The male of Mexcala torquata Wesołowska, 2009 and females of Hyllus tuberculatus Wanless & Clark, 1975, Iranattus principalis (Wesołowska, 2000), Myrmarachne eidmanni Roewer, 1942 and Thiratoscirtus tentativus (Szűts & Jocqué, 2001) are described for the first time. Many new combinations are proposed. Twenty ex Brancus are recombined: Hyllus nigeriensis (Wesołowska & Edwards, 2012) comb. nov., Thyene blaisei (Simon, 1902) comb. nov., Thyene calebi (Kanesharatnam & Benjamin, 2018) comb. nov., Thyene mutica (Simon, 1902) comb. nov., Thyene verdieri (Berland & Millot, 1941) comb. nov., Vicirionessa besanconi (Berland & Millot, 1941) gen. et comb. nov., Vicirionessa fuscimana (Simon, 1903) gen. et comb. nov., Vicirionessa mustela (Simon, 1902) gen. et comb. nov., Vicirionessa niveimana (Simon, 1902) gen. et comb. nov., Vicirionessa occidentalis (Wesołowska & Russell-Smith, 2011) gen. et comb. nov., Vicirionessa peckhamorum (Lessert, 1927) gen. et comb. nov., Vicirionessa signata (Dawidowicz & Wesołowska, 2016) gen. et comb. nov. Four ex Viciria are recombined: Vicirionessa chabanaudi (Fage, 1923) gen. et comb. nov., Vicirionessa equestris (Simon, 1903) gen. et comb. nov., Vicirionessa prenanti (Berland & Millot, 1941) gen. et comb. nov., Vicirionessa tergina (Simon, 1903) gen. et comb. nov. and one species ex Hyllus: Vicirionessa albocincta (Thorell, 1899) gen. et comb. nov. Furthermore, the following two new combinations are proposed: Thiratoscirtus tentativus (Szűts & Jocqué, 2001) comb. nov. (ex Bacelarella) and Baryphas galeatus (Simon, 1902) comb. nov. (ex Polemus). For 11 species known so far from single records new data are presented: Heliophanus butemboensis Wesołowska, 1986, Hyllus lwoffi Berland & Millot, 1941, Hyllus tuberculatus Wanless & Clark, 1975, Menemerus dubius Berland & Millot, 1941, Mexcala torquata Wesołowska, 2009, Neaetha maxima Wesołowska & Russell-Smith, 2011, Pachyballus miniscutulus Wesołowska, Azarkina & Wiśniewski 2020, Phintella paludosa Wesołowska & Edwards, 2012, Thiratoscirtus gambari Wesołowska & Russell-Smith, 2011, Tusitala guineensis Berland & Millot, 1941 and Tusitala lutzi Lessert, 1927.
The intensification of agricultural practices has led to a severe decrease in grassland biodiversity. Although there is strong evidence that organic farming can reduce the negative impacts of land use, knowledge regarding the most beneficial management system for species richness on organic grasslands is still scarce. This study examines differences in the biodiversity of plants and butterflies on rotationally and continuously grazed pastures as well as on meadows cut twice per year on two large organic suckler cow farms in NE Germany. Vegetation and flower abundance, as factors likely to influence butterfly abundance and diversity, were compared and used to explain the differences. The data attained by vegetation assessments and monthly transect inspections from May to August were analyzed using descriptive statistics and nonparametric methods. The abiotic site conditions of the studied plots had more influence on plant species numbers than the management method. Dry and nutrient-poor areas (mainly poor types of Cynosurion) and undrained wet fens (Calthion) were important for phytodiversity, measured by the absolute number of species, indicator species for ecologically valuable grasslands and the Shannon Index. Meadows tended to have more indicator species than pastures, where small-scale special sites such as wet depressions were crucial for plant diversity. Butterfly diversity was very low, and 90% of the recorded butterflies were individuals of the generalist species Pieris napi. Butterfly abundance depended mainly on occurrence of specific habitat types and specific larval host plants. Supply of flowers was crucial only in certain time periods. Differences in butterfly abundance between the management systems could be explained by the site conditions of the studied grasslands. We conclude that meadows are more favorable to support ecologically valuable plant species; however, their extension is contradictory to the organic farming method of suckler cows maintained outside of stables. Rotationally grazed pastures could be a compromise that would enhance the temporal heterogeneity of flower abundance and vegetation structure. The plant diversity on pastures should be improved by less intensive grazing on special sites and plant species enrichment by means of hay transfer. For enhancing butterfly diversity we suggest to reduce land use intensity especially on poor soils. Considering the economic perspective of the farms, small parts of the agricultural area could be sufficient if connectivity to other suitable habitats is assured. Flower abundance and diversity of larval host plants could be promoted by high diversity of farming practices as well as pre-serving small uncut strips of meadows.
High grazing pressure from over-abundant macropods (kangaroos) is perceived to have a detrimental impact on biodiversity. Studies have shown potential changes in state and retardation of degraded vegetation recovery while other investigations have shown correlations with increased floristic diversity. The responses of grasslands to high impact macropod grazing may not be universal. Endangered Themeda triandra-dominated grasslands, on coastal headlands of New South Wales (NSW) and the associated threatened flora are thought to be negatively affected by high macropod grazing. We assess these assumptions via a comparative investigation across 46 headlands (467 plots) on the North Coast of NSW, and a BACI (Before and After Control Incident) design grazing exclusion experiment at a particularly significant site. We compare floristic richness, species density, evenness, Shannon H, Whittaker Beta Diversity, occurrence of listed threatened flora, average sward height and macropod density. Look At Me Now Headland (LAMN), between Coffs Harbour and Woolgoolga has one of the highest recorded population densities of macropods. Here 16 permanent plots were placed with grazing exclusion cages erected around half. Sampling occurred annually (October-November) for four consecutive years (2015-2018). Under high macropod grazing pressure LAMN Headland was found to have the highest scores for total richness, species density, species diversity and moderate to high values for species evenness and beta diversity. Within grazing exclusion plots the sward height increased significantly and was associated with a significant decrease in species density, beta and alpha diversity. Our results indicate that macropod grazing, even at the highest intensities, may be beneficial to floristic species diversity within the endangered Themeda-grasslands of coastal headlands and seacliffs within the North Coast Bioregion of NSW; our broader comparative study would suggest that this may also be the case on other headlands.
Das Nahe-Tal zeichnet sich durch sonnexponierte Steilhänge mit mineralreichen Silikatgesteinen aus, deren naturnahe xerotherme Vegetationskomplexe eine sehr hohe Arten- und Gesellschaftsdiversität aufweisen. Gegenstand dieser Arbeit sind die im Übergang von Trockenrasen zu Gebüschen/Wäldern wachsenden Staudensaum-Gesellschaften, die größtenteils zu den Trifolio-Geranietea sanguinei gehören. Der kleinräumige floristische Wechsel in diesem Übergangsbereich wird am Beispiel eines Transektes durch einen xerothermen Vegetationskomplex dargestellt. Die Pflanzengesellschaften werden in einer syntaxonomischen Übersicht und einzeln mit ihren (meist gebietsspezifischen) Varianten beschrieben (Tab. 1-6; 148 Aufnahmen). Die häufigste Assoziation ist das Geranio-Dictamnetum auf besonders warm-trockenen Standorten, während das im UG seltenere Geranio-Peucedanetum cervariae basenreichere, aber weniger extreme Bereiche besiedelt, außerdem eine floristisch weniger gut gekennzeichnete Geranium sanguineum-Gesellschaft. Weit verbreitet ist auch die Trifolium alpestre-GeSeilschaft etwas basenärmerer Böden. Auf noch saureren Substraten kommt das Teucrietum scorodoniae aus der Klasse Melampyro-Holcetea mollis vor. Vergleichend werden einige Angaben zu pH-Werten der vorwiegend flachgründigen Böden, zu Artenzahlen und zur Verbreitung der Gesellschaften gemacht. Abschließend zeigt das Phänospektrum eines Diptam-Saumes beispielhaft die hohe phänologische Diversität und Vielfarbigkeit dieser Säume.
Anhand von Vergleichen vegetationskundlicher Aufnahmen aus den Jahren 1966-1968 und 1999-2000 werden die zeitlichen Veränderungen der Vegetation in bodensauren Buchenwäldern und Fichtenbeständen des Solling (Niedersachsen) untersucht. Besonders für die Fichtenbestände lässt sich dabei ein Rückgang im Deckungsgrad der Bodenvegetation bei gleichzeitiger Zunahme der Artenzahlen pro Fläche belegen. Arten der Waldschläge und -verlichtungen sind neu zu der ursprünglichen Artenkombination der Bestände hinzugekommen. Steigende Tendenzen bei den mittleren Stickstoffzahlen belegen eine Zunahme von Stickstoffzeigern in der Bodenvegetation von Buchen- und Fichtenbeständen, während mit den Säurezeigern die Trennarten des Luzulo-Fagetum abgenommen haben. In Zusammenhang mit diesen anthropogenen Veränderungen der Bodenvegetation durch Eutrophierung und Kalkung wird die zukünftige Entwicklung mitteleuropäischer bodensaurer Buchenwaldgesellschaften diskutiert.
A floristic description is presented of the study sites of the Research Training Group “The role of biodi-versity for biogeochemical cycles and biotic interactions in temperate deciduous forests”. To investi-gate different aspects of plant biodiversity in Hainich National Park (Thuringia), deciduous forest stands with low, medium and high canopy tree species diversity were compared. The results of species richness and forest communities show that the research sites are characterised by a typical central European forest flora. Greater vascular plant species richness occurs with higher diversity of tree species. Six of altogether twelve research sites are assigned to the beech forest alliance (Galioodorati-Fagion), the second half belongs to the oak-hornbeam forest alliance (Carpinionbetuli). Suballiances within the Galioodorati-Fagion in the study area include the Galio-Fagetum and the Hordelymo-Fagetum. All Carpinionbetuli relevées are assigned to the suballiance Stellario-Carpinetum.