580 Pflanzen (Botanik)
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We present a preliminary discussion about cauliflory, sexual dimorphism and biogeographic patterns in Drypetes Vahl (Putranjivaceae Endl.), focused on Africa. We also present a taxonomic treatment for two new species of cauliflorous trees of this genus from the rainforests of western Central Africa, one endemic to Gabon and known from six gatherings, D. aphanes Quintanar, D.J.Harris & Barberá sp. nov., and the other distributed in Gabon and the Republic of the Congo, D. cauta D.J.Harris, Barberá & Quintanar sp. nov., also known from another six gatherings. They are presented along with D. gabonensis Pierre ex Hutch., known from 25 gatherings made throughout western Central Africa, a species with markedly dimorphic flowers between sexes compared to the rest of the species in the genus. Specimens of these two new species have been confused with D. gabonensis due to some morphological resemblances. This treatment includes the detailed descriptions of these three species, the typification of their names, a comparative table summarizing their main morphological differences, an identification key, an illustration and information about their habitat and distribution. A provisional IUCN Red List assessment shows that D. gabonensis and D. cauta sp. nov. are ‘Vulnerable’ species, and D. aphanes sp. nov. is ‘Endangered’. After the publication of these new species, Drypetes consists of 86 species in continental Africa and the Malagasy Region and 219 species for the whole world.
The Stachytarpheta longispicata complex is a group of seven accepted infraspecific taxa endemic to the Brazilian Cerrado, defined by its pedicellate flowers with salmon or dark red corollas. Due to the great morphological variation and very brief original descriptions, these taxa have controversial circumscriptions. We evaluated the morphological variation through the morphometric analysis of 11 natural populations in addition to nomenclatural types to assess the current infraspecific circumscriptions and clarify the limits of these taxa. A set of 36 continuous vegetative and reproductive characters was measured for each of the 115 specimens sampled, encompassing the morphological variability in the group and its geographic distribution. A compiled data matrix formed the basis for the multivariate analysis (UPGMA, PCA, and DA). Our results recovered five consistent groups corresponding to the four subspecies, and all three recognised varieties treated in the same morphological group. Quantitative and qualitative characters not previously studied in detail are important to delimit the five groups. A taxonomic rearrangement is proposed for the complex, circumscribing five distinct species: Stachytarpheta brevibracteata, S. longipedicellata, S. longispicata, S. minasensis, and S. ratteri. The taxonomic treatment includes four new combinations and names at new rank, two new synonyms, and one lectotype. Descriptions, an identification key, geographical distribution map, illustrations, and provisional conservation assessments are also provided.
Acacia meiantha Tindale & Herscovitch, (Fabaceae) a low to medium shrub with root suckering, is only known to occur at three locations, Clarence, Carcalgong and Mullion Creek in Central West New South Wales. These disjunct populations each separated by >60 km, are considered as isolated subpopulations. A compilation of recent field surveys shows that of the 42,000 stem clusters/aggregates of Acacia meiantha estimated across the three geographic locations, the majority, 39,900 (96%) occur in the Mullions Range State Forest subpopulation, where 61% of clusters occur in the remnant native forest areas and 39% in the plantation forestry compartments. At Carcalgong 1,566 stem clusters were recorded along narrow roadside reserves. The Clarence subpopulation consists of < 400 stem clusters precariously situated among a confluence of road, railway and electricity power-line easements. Ecological observations of habitat are presented; information relating to genetic diversity, seed biology, reproductive biology and response to fire is found to be Data Deficient. The threatened species listing as Endangered under both State and Commonwealth legislation is warranted; the species does not occur on any conservation lands, has restricted distribution and abundance, and is vulnerable to ongoing threats. The area (AOO) and extent of occupancy (EOO) are calculated. It occurs at three locations (< 5), has an estimated EOO of 2,900 km2 (< 5,000 km2) and an AOO of 80 km2 (< 500 km2) (IUCN (2019) thresholds in brackets); there are significant threats to the extent and quality of habitats. Additional opportunities for improving the conservation of the species, particularly in the Mullions Range State Forest, over and above those outlined in the site-managed initiatives of the current Saving our Species program, are presented.
Ipomoea beninensis Akoègn., Lisowski & Sinsin (Convolvulaceae) is the only endemic plant known for Benin. To date, no data exist on its usages, distribution, abundance, and threats. An improved understanding of indigenous know- ledge and of local practices can provide insight into how the species could be sustainably conserved. We interviewed 114 local residents for collecting ethnobotanical and ethnoecological data in six sites known to host the species. Data were pro- cessed by calculation of descriptive statistics and variance and multivariate analyses. A total of twelve uses were reported. Among them, treatment of varicella (19%), malaria (18%) and fodder (17%) were the most recurrent. These mainly involve use of the species rootstock. Almost all respondents mentioned decline of the species in natural habitats. None of them was aware about the endemic status of the species. Consequently, negative practices toward the protection of I. beninensis were prevalent among local residents. Several conservation measures are proposed to ensure the longterm survival of I. beninensis.
Naree and Yantabulla stations (31,990 ha) are found 60 km south-east of Hungerford and 112 km north-west of Bourke, New South Wales (lat. 29° 55'S; long. 150°37'N). The properties occur on the Cuttaburra Creek within the Mulga Lands Bioregion. We describe the vegetation assemblages found on these properties within three hierarchical levels (Group, Alliance & Association). Vegetation levels are defined based on flexible UPGMA analysis of coverabundance scores of all vascular plant taxa. These vegetation units are mapped based on extensive ground truthing, SPOT5 imagery interpretation and substrate. Three ‘Group’ level vegetation types are described: Mulga Complex, Shrublands Complex and Floodplain Wetlands Complex. Within these Groups nine ‘Alliances’ are described: Rat’s tail Couch – Lovegrass Grasslands, Canegrass Grasslands, Lignum – Glinus Shrublands, Coolibah – Black Box Woodlands, Turpentine – Button Grass – Windmill Grass Shrublands, Turpentine – Hop Bush – Kerosene Grass shrublands and Mulga Shrublands. Sixteen ‘Associations’ are described 1) Mulga – Poplar Box Shrubland, 2) Mulga – Poplar Box – Bastard Mulga Shrubland, 3) Turpentine – Hop Bush – Senna Shrubland, 4) Turpentine – Elegant Wattle – Boobialla Shrubland, 5) Turpentine – Hop Bush – Daisy Bush Shrubland, 5) Belah – Rosewood – Turpentine Bush Shrubland, 6) Belah – Rosewood – Turpentine Bush Shrubland, 7) Ironwood – Leopardwood – Supplejack Shrubland, 8) Yapunyah – Black Box – River Cooba Woodland, 9) Coolibah – River Cooba – Yapunyah Woodland, 10) Rat’s tail Couch – Lovegrass – Fairy Grass Grassland and Herbfield, 11) Rat’s tail Couch – Lovegrass – Purslane Grassland and Herbfield, 12) Darling Pratia – Rat’s tail Couch – Spike Rush Herbfield, 13) Canegrass Grassland, 14) Glinus – Groundsel – Lignum Herbfield, 15) Poplar Box – Mulga – Coolibah Woodland and 16) Black Box Woodland. In total 355 vascular plant taxa were found of which 6% were considered exotic in origin. A population of Dentella minutissima; a species listed as threatened (endangered) under the New South Wales Threatened Species Conservation Act 1995 was found. A summary of select structural and habitat attributes within Alliances is also presented.
A new species of Rhaphiostylis, R. minima sp. nov. from Liberia and Ivory Coast, is described and illustrated here. It is characterised by its comparatively small size, an ovate to lanceolate leaf blade with long drip tip and a partly glabrous ovary that is in shape in between those of R. elegans Engl. and R. preussii Engl. Rhaphiostylis elegans is lectotypified and illustrated here.
Status and restoration potential of heathlands and sand grasslands in the southwest of Luxembourg
(2017)
In Europe, semi-natural nutrient-poor ecosystems such as sand grasslands and heathlands have shown extreme declines in surface area and species richness within the last century. The remaining sites are hence of high conservation value. This study analysed the vascular plant species inventory of established and recently restored heathlands and sand grasslands in the southwest of Luxembourg. Analyses to explain differences in vegetation composition between “old” (remnant sites or sites restored a long time ago) and “new” (recently restored) sites in relation to environmental variables were carried out with DCAs and ANOVA/Mann-Whitney-U tests, respectively. The vegetation of old heathlands had few character species of typical heathland communities (Calluno-Ulicetea, Nardetalia), whereas new heathland sites were preponderantly marked by taxa of meso- or eutrophic grasslands and ruderal communities. New heathland sites mainly differed from old sites by higher soil phosphorus contents. Sand grassland vegetation was species-rich and composed by species of the Sedo-Scleranthetea and Festuco-Brometea. With increasing age of the sites, vegetation composition shifted to grass dominance with species of the Molinio-Arrhenateretea. New sand grasslands differed from old sand grasslands by higher soil pH, higher soil potassium content and lower graminoid cover. The differences between new and old sites of both habitat types could mainly be explained by successional processes or were a result of topsoil removal. In some cases, former anthropogenic impact at or in close proximity of restored sites resulted in unsuitable conditions, such as alkaline soil on former landfill sites or highly eutrophic soil due to intensive agriculture. Future management options for the study sites are discussed.
This paper presents the results of a study on psammophilous grasslands, conducted during the years 1994-1997 and in 2008 in the Masurian Lake District (NE Poland). The study aimed at the determination of floristic composition, phytosociological diversity and habitat characteristics. Field work resulted in 511 phytosociological releves. Soil samples were taken to determine pH, hydrolytic acidity, sum of basic cations, cation exchange capacity, content of CaC03 and total carbon. In 2008, the presence of communities dominated by grey-hair grass (Corynephorus canescens) in the previously established sites was checked. TWINSPAN was used for hierarchic classification of the association Comiculario aculeatae-Corynephoretum canescentis (syn. Spergulo morisonii-Corynephoretum canescentis). Accordingly, the association is divided into four subtypes (typical subtype, subtype with Cladonia mitis, subtype with Thymus serpyllum and subtype with Festuca ovina) with nine variants. Field observations showed that the communities analyzed have been under strong anthropogenic pressure, causing their degeneration and decrease in area. The most common human uses of psammophilous grassland communities are housing development, road construction, afforestation, sand extraction, wood storage and unauthorized dumping. In contrast to the above types of land use, seasonal use of grasslands for recreation purposes (as sunbathing spots or as sports fields) does not lead to their degeneration and may have a beneficial influence on their maintenance as a component of the local landscape.
We first report from the 5th Dry Grassland Meeting held from 28th to 30st of August 2008 in Kiel, Germany. Then we take stock of the achievements of the German Arbeitsgruppe Trockenrasen and the international Working Group on Dry Grasslands in the Nordic and Baltic Region towards establishment of vegetation databases of dry grasslands in these study regions. At the conference, the European Dry Grassland Group (EDGG) was founded as an international platform of dry grassland researchers and conservationists. As networking tools it provides a homepage on the internet, publishes a quarterly electronical bulletin, and will organise the future European Dry Grassland Meetings. In the last part of this contribution, we give a short introduction to the five articles of this Special Feature. Four of them make a major contribution to supra-national classification of Koelerio-Corynephoretea and Festuco- Brometea communities, respectively, by providing syntaxonomic overviews based on comprehensive data from eastern European countries for which only few data have been available until now. The other major focus of the Feature papers is on degradation and restoration of various types of dry grasslands.
Buchenwälder sind heute die potenzielle und teilweise auch (wieder) die aktuelle zonale Vegetation in größeren Bereichen Europas. Ihr Verbreitungszentrum liegt in Mitteleuropa, mit Außengrenzen im östlichen Polen, südlichen Skandinavien und in Süd-England. In humiden Berglagen reicht das Buchenareal weit nach Süd-Europa, so bis nach Sizilien und Mittel-Griechenland. Auf frischen Standorten wachsen artenreiche, eutraphente Buchenwälder mit auffälliger phänologischer Rhythmik der Blütenpflanzen. Trotz vieler gemeinsamer, weit verbreiteter Arten gibt es floristische Gradienten mit Diversitätszentren in der Nähe der glazialen Refugien in Süd-Europa. Dies ermöglicht die Unterscheidung verschiedener Syntaxa innerhalb der Fagetalia sylvaticae. Vorgeschlagen wird eine Gliederung in 9 regionale Verbände, die durch Kombination und stufenweise Zu- bzw. Abnahme bestimmter Artengruppen charakterisiert sind. Die Dynamik der Buchenwälder wird durch natürlichen Tod der Bäume oder durch natürliche und anthropogene Störungen bedingt und zeigt eine zyklische Sukzession mit verschiedenen Stadien und Phasen, die eine große Strukturdiversität in Zeit und Raum zur Folge haben. Buchenwälder sind wichtige Holzproduzenten; besonders hohen ökonomischen Wert haben die eingestreuten Edellaubhölzer (Acer, Fraxinus, Ulmus). Uber lange Zeit war die Buche allerdings durch Nieder- und Mittelwaldwirtschaft stark zurückgedrängt. Sie konnte sich erst wieder im Zuge einer modernen, planmäßigen Forstwirtschaft ausbreiten. Heute versucht man, anstelle der Kahlschlagwirtschaft durch Femel- und Plenterschlag die natürliche zyklische Sukzession nachzuahmen. Für den Erhalt und die Wiederherstellung einer natürlichen Dynamik sind Naturwaldreservate und Nationalparke am besten geeignet.