This study investigated the development of biological soil crusts (biocrusts) in an early successional subtropical forest plantation and their impact on soil erosion. Within a biodiversity and ...ecosystem functioning experiment in southeast China (biodiversity and ecosystem functioning (BEF) China), the effect of these biocrusts on sediment delivery and runoff was assessed within micro-scale runoff plots under natural rainfall, and biocrust cover was surveyed over a 5-year period. Results showed that biocrusts occurred widely in the experimental forest ecosystem and developed from initial light cyanobacteria- and algae-dominated crusts to later-stage bryophyte-dominated crusts within only 3 years. Biocrust cover was still increasing after 6 years of tree growth. Within later-stage crusts, 25 bryophyte species were determined. Surrounding vegetation cover and terrain attributes significantly influenced the development of biocrusts. Besides high crown cover and leaf area index, the development of biocrusts was favoured by low slope gradients, slope orientations towards the incident sunlight and the altitude of the research plots. Measurements showed that bryophyte-dominated biocrusts strongly decreased soil erosion, being more effective than abiotic soil surface cover. Hence, their significant role in mitigating sediment delivery and runoff generation in mesic forest environments and their ability to quickly colonise soil surfaces after disturbance are of particular interest for soil erosion control in early-stage forest plantations.
Mosses are often overlooked; however, they are important for soil-atmosphere interfaces with regard to water exchange. This study investigated the influence of moss structural traits on maximum water ...storage capacities (WSCmax) and evaporation rates, and species-specific effects on water absorption and evaporation patterns in moss layers, moss-soil-interfaces and soil substrates using biocrust wetness probes. Five moss species typical for Central European temperate forests were selected: field-collected
,
,
and
; and laboratory-cultivated
and
WSC
ranged from 14.10 g g
for
(Lab) to 7.31 g g
for
when immersed in water, and 11.04 g g
for
(Lab) to 7.90 g g
for
when sprayed, due to different morphologies depending on the growing location. Structural traits such as high leaf frequencies and small leaf areas increased WSC
. In terms of evaporation, leaf frequency displayed a positive correlation with evaporation, while leaf area index showed a negative correlation. Moisture alterations during watering and desiccation were largely controlled by species/substrate-specific patterns. Generally, moss cover prevented desiccation of soil surfaces and was not a barrier to infiltration. To understand water’s path from moss to soil, this study made a first contribution.
We studied the influence of regional and local variables on the liverwort diversity within natural forest vegetation of Uganda to contribute to our understanding of the mechanisms and processes ...determining species richness. To this end, we compared the species richness distribution patterns of epiphytic and non-epiphytic liverworts (Marchantiophytina) in 24 plots in the forests of four Ugandan national parks. We recorded a total of 119 species and subspecies from 18 families, including 16 new species records for the country. We used generalized linear models (GLMs) and the relative variable importance of regional and local climatic and environmental variables to assess their respective impact on the species diversity. We found that the richness patterns of total and epiphytic richness were largely driven by regional climatic factors related to temperature and water-availability. In contrast, species diversity of non-epiphytic and rare species was additionally strongly determined by local-scale microhabitat factors such as height of forest canopy and slope inclination, reflecting the availability of suitable microhabitats. We conclude that macroclimatic variables perform well in predicting epiphytic liverwort richness, whereas the adequate prediction of non-epiphytic richness requires site-specific variables. Also, we propose that richness of epiphytic liverworts will be impacted more directly by climate change than richness of non-epiphytic and rare species.
With 280 accepted species, the genus Riccardia S.F.Gray (Aneuraceae) is one of the most speciose genera of simple thalloid liverworts. The current classification of this genus is based on ...morphological and limited-sampling molecular studies. Very few molecular data are available and a comprehensive view of evolutionary relationships within the genus is still lacking. A phylogeny focusing on relationships within the large genus Riccardia has not been conducted. Here we propose the first worldwide molecular phylogeny of the genus Riccardia, based on Bayesian inference and parsimony ratchet analyses of sequences from three plastid regions (psbA-trnH, rps4, trnL-F). The results support the monophyly of Riccardia and a new monospecific genus, Afroriccardia Reeb & Gradst. gen. nov., is described based on molecular and morphological evidence. The results indicate that several currently recognized infrageneric divisions and a few species are not monophyletic, suggesting that further analyses are needed to arrive at a proper understanding of the phylogeny of the genus. Although evidence for an Andean clade was found, most of the species appear scattered in different clades without clear geographical segregation. Broader sampling and further analyses are necessary in order to improve our understanding of the phylogeny of this poorly known liverwort genus.
Soil erosion continues to be one of the most serious environmental problems of our time and is exacerbated by progressive climate change. Until now, forests have been considered an ideal erosion ...control. However, even minor disturbances of the forest floor, for example, from heavy vehicles used for timber harvesting, can cause substantial sediment transport. An important countermeasure is the quick restoration of the uncovered soil surface by vegetation. To date, very little attention has been paid to the development of nonvascular plants, such as bryophytes, in disturbed areas of temperate forests and their impact on soil erosion. This study examined the natural succession of pioneer vegetation in skid trails on four soil substrates in a central European temperate forest and investigated their influence on soil erosion. For this purpose, rainfall simulations were conducted on small-scale runoff plots, and vegetation was continuously surveyed during the same period, primarily to map the development of bryophytes and the occurrence of biological soil crusts (biocrusts).
Abstract
A new epiphytic species of Diplasiolejeunea (Spruce) Schiffn. from the Amazonian region of southern Ecuador is described and illustrated. Diplasiolejeunea mayaykuensis Schäf.-Verw. & ...Heinrichs, sp. nov. is characterized by ascending to squarrose leaves, narrowly ovate(-lanceolate) underleaf lobes with acute to subobtuse apices, well developed lobule teeth and lobules with strongly involute free margins. Morphologically, D. mayaykuensis closely resembles D. brunnea Steph. and D. cavifolia Steph. The locality is situated in the western escarpment of the Cordillera del Condor.
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•Comprehensive molecular phylogeny of the epiphytic thalloid liverwort Metzgeria.•Austrometzgeria is a member of Metzgeria.•The cosmopolitan morpho-species M. furcata and M. ...leptoneura are not monophyletic.•Metzgeria originated in Gondwana during the Cretaceous.•Epiphytic thalloid liverworts evolved between the Triassic and Cretaceous.
Among liverworts, the epiphytic lifestyle is not only present in leafy forms but also in thalloid liverworts, which so far has received little attention in evolutionary and biogeographical studies. Metzgeria, with about 107 species worldwide, is the only genus of thalloid liverworts that comprises true epiphytes. In the present study, we provide the first comprehensive molecular phylogeny, including estimated divergence times and ancestral ranges of this genus. Analyses are based on a plastid marker dataset representing about half of the Metzgeria species diversity. We show for the first time with molecular data that Austrometzgeria is indeed a member of Metzgeria and that two morpho-species M. furcata and M. leptoneura are not monophyletic, but rather represent geographically well-defined clades. Our analyses indicate that Metzgeria started to diversify in the Cretaceous in an area encompassing today’s South America and Australasia. Thus, Metzgeria is one of the few known epiphytic liverwort genera whose biogeographic history was directly shaped by Gondwana vicariance. Subsequent dispersal events in the Cenozoic resulted in the colonization of Asia, Africa, North America, and Europe and led to today’s worldwide distribution of its species. We also provide the first reliable stem age estimate for Metzgeria due to the inclusion of its sister taxon Vandiemenia in our dating analyses. Additionally, this stem age estimate of about 240 million years most likely marks the starting point of a transition from a terrestrial to an epiphytic lifestyle in thalloid liverworts of the Metzgeriales. We assume that the Cretaceous Terrestrial Revolution played a key role in the evolution of epiphytic thalloid liverworts similar to that known for leafy liverworts.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
A comprehensive survey of the liverwort family Pelliaceae including molecular, morphological and biogeographical data reveals a deep split of the taxa into two main clades each corresponding to a ...morphologically clearly delimited group. Therefore, the recognition of two distinct genera within the Pelliaceae is suggested: (1) Pellia, which comprises P. appalachiana, P. columbiana, P. epiphylla, and P. neesiana, and (2) Apopellia, formerly described as a subgenus of Pellia including A. alpicola, A. endiviifolia, and A. megaspora. According to phylogenetic analyses of a concatenated sequence matrix spanning three plastid regions (trnL-F, rps4, rpl16), P. epiphylla var. borealis is nested within P. epiphylla. There is conflicting evidence for the monophyly of A. megaspora. While maximum likelihood significantly supports its monophyly, Bayesian inference resolves a grade of eastern and western North American specimens. Apopellia endiviifolia is monophyletic but forms three genetically distinct groups of different geographical distribution. Shared characters of Apopellia vs. Pellia are: apical cell wedge-shaped vs. hemidiscoid, slime hairs pluricellular vs. two-celled, thickening bands lacking vs. well developed, male tubercles aperture cells inconspicuous vs. cells papilliforme, archegonia posture erect vs. horizontal to ascending, calyptra smooth vs. two-celled hairs. Both, a description including habitat and distribution of all seven currently known species of Pelliaceae and a key to the species is provided.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NMLJ, NUK, OILJ, PNG, SAZU, SBCE, SBMB, UL, UM, UPUK
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