54 research outputs found

    New and interesting Campylopus records from South Africa

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    New records are presented based on a collection of Campylopus specimens made by the second author in the Western Cape Province of South Africa. The austral species Campylopus clavatus (R. Brown) Wils. in Hook. and Campylopus vesticaulis Mitt. are reported for the first time for Africa, and Campylopus acuminatus Mitt. var. kirkii (Mitt.) J.-P. Frahm is recorded for the second time for Africa. Campylopus arctocarpus (Hornsch.) Mitt. ssp. madegassus (Besch.) J.-P. Frahm is reported for the first time for the Republic of South Africa, and this is the southernmost record of this species. Campylopus simii Schelpe is not synonymous with C. julaceus Jaeg. ssp. arbogastii (Ren. & Card.) J.-P. Frahm but combined here as new as a variety of C. pilifer Brid

    The mosses of Terra Nova National Park, Eastern Newfoundland, a bryofloristic analysis and interpretation

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    The known moss flora of Terra Nova National Park, eastern Newfoundland, comp~ises 210 species. Eighty-two percent of the moss species occurring in Terra Nova are widespread or widespread-sporadic in Newfoundland. Other Newfoundland distributional elements present in the Terra Nova moss flora are the northwestern, southern, southeastern, and disjunct elements, but four of the mosses occurring in Terra Nova appear to belong to a previously unrecognized northeastern element of the Newfoundland flora. The majority (70.9%) of Terra Nova's mosses are of boreal affinity and are widely distributed in the North American coniferous forest belt. An additional 10.5 percent of the Terra Nova mosses are cosmopolitan while 9.5 percent are temperate and 4.8 percent are arctic-montane species. The remaining 4.3 percent of the mosses are of montane affinity, and disjunct between eastern and western North America. In Terra Nova, temperate species at their northern limit are concentrated in balsam fir stands, while arctic-montane species are restricted to exposed cliffs, scree slopes, and coastal exposures. Montane species are largely confined to exposed or freshwater habitats. Inability to tolerate high summer temperatures limits the distributions of both arctic-montane and montane species. In Terra Nova, species of differing phytogeographic affinities co-occur on cliffs and scree slopes. The microhabitat relationships of five selected species from such habitats were evaluated by Discriminant Functions Analysis and Multiple Regression Analysis. The five mosses have distinct and different microhabitats on cliffs and scree slopes in Terra Nova, and abundance of all but one is associated with variation in at least one microhabitat variable. Micro-distribution of Grimmia torquata, an arctic-montane species at its southern limit, appears to be deterJ]lined by sensitivity to high summer temperatures. Both southern mosses at their northern limit (Aulacomnium androgynum, Isothecium myosuroides) appear to be limited by water availability and, possibly, by low winter temperatures. The two species whose distributions extend both north and south or the study area (Encalypta procera, Eurhynchium pulchellum) show no clear relationship with microclimate. Dispersal factors have played a significant role in the development of the Terra Nova moss flora. Compared to the most likely colonizing source (i .e. the rest of the island of Newfoundland), species with small diaspores have colonized the study area to a proportionately much greater extent than have species with large diaspores. Hierarchical log-linear analysis indicates that this is so for all affinity groups present in Terra Nova. The apparent dispersal effects emphasize the comparatively recent glaciation of the area, and may also have been enhanced by anthropogenic influences. The restriction of some species to specific habitats, or to narrowly defined microhabitats, appears to strengthen selection for easily dispersed taxa

    Pleistocene range dynamics in the eastern Greater Cape Floristic Region: A case study of the Little Karoo endemic Berkheya cuneata (Asteraceae)

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    AbstractThe glacial–interglacial climate cycles of the Pleistocene played a significant role in dramatically altering species distributions across the globe. However, the climate of the Greater Cape Floristic Region is thought to have been decoupled from global fluctuations and the current Mediterranean climate remained relatively buffered during this period. Here we explore the roles of climate stability and the topographic complexity of the region on the range history of an endemic Little Karoo plant, Berkheya cuneata, using ensemble species distribution modelling and multi-locus phylogeography. The species distribution models projected onto downscaled climate simulation of the Last Glacial Maximum demonstrated a considerable range contraction and fragmentation into the western and eastern Little Karoo, separated by the Rooiberg inselberg. This population fragmentation is mirrored in the phylogeographic structuring of both chloroplast and nuclear DNA. These results suggest that sufficient climatic buffering coupled with regionally complex topography ensured the localised population persistence during Pleistocene climate cycles but these features have also promoted population vicariance in this, and likely other, Little Karoo lowland species

    Cloud water interception and resilience of tropical montane bryophytes to climate change in cloud forests of La Reunion

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    Tropical montane cloud forests (TMCFs) are characterized by frequent cloud immersion, host a high diversity of global biodiversity and provide vital ecosystem services to insular populations. Climate change on islands, is expected to both raise the cloud height base as a result of temperature increase and to increase the frequency of extreme events like drought. Bryophytes contribute a signiïŹcant biomass in these systems yet the role of cloud water and the resilience of bryophytes to drought in island TMCFs is still poorly known. In La Reunion, we implemented a novel method to follow cloud water interception by bryophytes in the TMCF using in situlysimeters. We showed that two abundant TMCF liverworts possess an excellent ability to intercept and store cloud water, and that stored water ïŹ‚uctuated according to climatic conditions. In order to better understand the ecophysiology of TMCF bryophytes, we examined chlorophyll ïŹ‚uorescence, under laboratory conditions, for 16 bryophyte species in response to dehydration and rehydration. This was accompanied by measurements of water retention capacity and relative water content of each species. Highest Water Retention Capacity and Relative Water Content were recorded for Sphagnumsp ( 2174 %: 91,37 %) and Anthocerossp ( 1540 %; 7815 %). Dry down curves showed that species with high water storage capacity are favored by maintaining longer optimal photosynthetic activity. After one week of desiccation, half of the species could recover 50 % of their optimal photosynthetic activity within 24 h of rehydration. Most species, after 7 weeks of desiccation, could not recover their original photosynthetic activity after rehydration. These experiments highlight the presence of various strategies for managing desiccation by TMCF bryophytes at the microhabitat level. Bryophytes inhabiting the TMCF, exhibit a strong strategy in either tolerance or drought avoidance or a combination of both strategies, indicating a better adaptation to drought than expected. However, impact of repetitive drought on the physiology of the TMCF species remains unknown. The multiplicity of responses recorded for TMCF bryophytes regarding their physiology and life forms indicate that climate change will have distinct impacts on species

    <i>Sematophyllum rheophyticum</i> (Bryopsida, Sematophyllaceae), a new rheophytic species from Rwanda

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    Background: Sematophyllum is a pantropical genus of approximately 170 species. The genus has never been revised on a global scale and is poorly known in many areas of the world. This is perhaps especially true in Africa where 60 accepted species are recorded, many seemingly endemic to the eastern and central tropical areas. Further taxonomic work will enable better understanding of the genus, its biogeography and regional patterns of plant diversity; help guide conservation efforts; and facilitate a broader understanding of the evolution of the Afrotropical flora. Objectives: The objective of this study is to describe a new species of Sematophyllum from Rwanda, part of the mega-diverse Albertine Rift system. Methods: Light microscopy was used to compare anatomical and morphological details of the putative new species with specimens of other members of the genus with which it could potentially be conspecific. Results: Sematophyllum rheophyticum W.R. Buck & Hedd. was described as new and is currently known only from the type locality at Gisakura, Nyungwe National Park, Rwanda. It is distinguishable from all congeners by a unique combination of characters including the concave, abruptly acuminate leaves, the alar areolation and the rheophytic habitat. Conclusion: Sematophyllum rdicum is a new species, defined by a combination of several anatomical characters, known currently only from the type locality. Furthermore, it is one of only a few species in the genus that occurs in rheophytic habitats. Its phylogenetic relationships are obscure and will probably need to be evaluated with molecular evidence

    Picobryum, a new genus of Pottiaceae (Bryophyta) from South Africa, and an erratum for Acaulonopsis.

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    A new genus, Picobryum (Pottiaceae, Bryophyta), including one new species, Picobryum atomicum, is described from the western Cape Province of South Africa. The new taxon is somewhat similar to Syntrichia gametophytically but differs in the trait combination: stem very short, central strand absent; leaves strongly reflexed to squarrose when moist, usually folded longitudinally on one side, bases sheathing, margins plane throughout, irregularly and weakly bordered in 1(–2) rows with somewhat thick-walled, less papillose cells; papillae large, simple to bifid, 1–2 per lumen; paroicous; seta essentially absent; capsule cleistocarpic, globose, and short-apiculate; calyptra mitrate. Locality data for the type of Acaulonopsis fynbosensis R.H.Zander & Hedd. are corrected in an erratum
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