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- Beimforde, Christina, et al.
(författare)
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Estimating the Phanerozoic history of the Ascomycota lineages: Combining fossil and molecular data
- 2014
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Ingår i: Molecular Phylogenetics and Evolution. - : Elsevier BV. - 1055-7903 .- 1095-9513. ; :78, s. 386-398
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Tidskriftsartikel (refereegranskat)abstract
- The phylum Ascomycota is by far the largest group in the fungal kingdom. Ecologically important mutualisticassociations such as mycorrhizae and lichens have evolved in this group, which are regarded as keyinnovations that supported the evolution of land plants. Only a few attempts have been made to date theorigin of Ascomycota lineages by using molecular clock methods, which is primarily due to the lack ofsatisfactory fossil calibration data. For this reason we have evaluated all of the oldest available ascomycetefossils from amber (Albian to Miocene) and chert (Devonian and Maastrichtian). The fossils representfive major ascomycete classes (Coniocybomycetes, Dothideomycetes, Eurotiomycetes, Laboulbeniomycetes,and Lecanoromycetes). We have assembled a multi-gene data set (18SrDNA, 28SrDNA, RPB1 andRPB2) from a total of 145 taxa representing most groups of the Ascomycota and utilized fossil calibrationpoints solely from within the ascomycetes to estimate divergence times of Ascomycota lineages with aBayesian approach. Our results suggest an initial diversification of the Pezizomycotina in the Ordovician,followed by repeated splits of lineages throughout the Phanerozoic, and indicate that this continuousdiversification was unaffected by mass extinctions. We suggest that the ecological diversity within eachlineage ensured that at least some taxa of each group were able to survive global crises and rapidlyrecovered.
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| 5. |
- Kaasalainen, Ulla, et al.
(författare)
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Complex interaction networks among cyanolichens of a tropical biodiversity hotspot
- 2021
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Ingår i: Frontiers in Microbiology. - : Frontiers Media S.A.. - 1664-302X. ; 12
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Tidskriftsartikel (refereegranskat)abstract
- Interactions within lichen communities include, in addition to close mutualistic associations between the main partners of specific lichen symbioses, also more elusive relationships between members of a wider symbiotic community. Here, we analyze association patterns of cyanolichen symbionts in the tropical montane forests of Taita Hills, southern Kenya, which is part of the Eastern Afromontane biodiversity hotspot. The cyanolichen specimens analyzed represent 74 mycobiont taxa within the order Peltigerales (Ascomycota), associating with 115 different variants of the photobionts genus Nostoc (Cyanobacteria). Our analysis demonstrates wide sharing of photobionts and reveals the presence of several photobiont-mediated lichen guilds. Over half of all mycobionts share photobionts with other fungal species, often from different genera or even families, while some others are strict specialists and exclusively associate with a single photobiont variant. The most extensive symbiont network involves 24 different fungal species from five genera associating with 38 Nostoc photobionts. The Nostoc photobionts belong to two main groups, the Nephroma-type Nostoc and the Collema/Peltigera-type Nostoc, and nearly all mycobionts associate only with variants of one group. Among the mycobionts, species that produce cephalodia and those without symbiotic propagules tend to be most promiscuous in photobiont choice. The extent of photobiont sharing and the structure of interaction networks differ dramatically between the two major photobiont-mediated guilds, being both more prevalent and nested among Nephroma guild fungi and more compartmentalized among Peltigera guild fungi. This presumably reflects differences in the ecological characteristics and/or requirements of the two main groups of photobionts. The same two groups of Nostoc have previously been identified from many lichens in various lichen-rich ecosystems in different parts of the world, indicating that photobiont sharing between fungal species is an integral part of lichen ecology globally. In many cases, symbiotically dispersing lichens can facilitate the dispersal of sexually reproducing species, promoting establishment and adaptation into new and marginal habitats and thus driving evolutionary diversification.
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| 6. |
- Kaasalainen, Ulla, et al.
(författare)
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Diversity of Leptogium (Collemataceae, Ascomycota) in East African Montane Ecosystems
- 2021
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Ingår i: Microorganisms. - : MDPI. - 2076-2607. ; 9:2
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Tidskriftsartikel (refereegranskat)abstract
- Tropical mountains and especially their forests are hot spots of biodiversity threatened by human population pressure and climate change. The diversity of lichens in tropical Africa is especially poorly known. Here we use the mtSSU and nuITS molecular markers together with morphology and ecology to assess Leptogium (Peltigerales, Ascomycota) diversity in the tropical mountains of Taita Hills and Mt. Kasigau in Kenya and Mt. Kilimanjaro in Tanzania. The sampled habitats cover a wide range of ecosystems from savanna to alpine heath vegetation and from relatively natural forests to agricultural environments and plantation forests. We demonstrate that Leptogium diversity in Africa is much higher than previously known and provide preliminary data on over 70 putative species, including nine established species previously known from the area and over 60 phylogenetically, morphologically, and/or ecologically defined Operational Taxonomic Units (OTUs). Many traditional species concepts are shown to represent morphotypes comprised of several taxa. Many of the species were only found from specific ecosystems and/or restricted habitats and are thus threatened by ongoing habitat fragmentation and degradation of the natural environment. Our results emphasize the importance of molecular markers in species inventories of highly diverse organism groups and geographical areas.
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- Ovaskainen, Otso, et al.
(författare)
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Global Spore Sampling Project: A global, standardized dataset of airborne fungal DNA
- 2024
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Ingår i: Scientific Data. - 2052-4463. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- Novel methods for sampling and characterizing biodiversity hold great promise for re-evaluating patterns of life across the planet. The sampling of airborne spores with a cyclone sampler, and the sequencing of their DNA, have been suggested as an efficient and well-calibrated tool for surveying fungal diversity across various environments. Here we present data originating from the Global Spore Sampling Project, comprising 2,768 samples collected during two years at 47 outdoor locations across the world. Each sample represents fungal DNA extracted from 24 m3 of air. We applied a conservative bioinformatics pipeline that filtered out sequences that did not show strong evidence of representing a fungal species. The pipeline yielded 27,954 species-level operational taxonomic units (OTUs). Each OTU is accompanied by a probabilistic taxonomic classification, validated through comparison with expert evaluations. To examine the potential of the data for ecological analyses, we partitioned the variation in species distributions into spatial and seasonal components, showing a strong effect of the annual mean temperature on community composition.
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- Räsänen, Matti, et al.
(författare)
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Carbon dioxide and methane fluxes from mounds of African fungus-growing termites
- 2023
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Ingår i: Biogeosciences. - 1726-4170. ; 20:19, s. 4029-4042
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Tidskriftsartikel (refereegranskat)abstract
- Termites play an essential role in decomposing dead plant material in tropical ecosystems and are thus major sources of gaseous C emissions in many environments. In African savannas, fungus-growing termites are among the ecologically most influential termite species. We studied the gas exchange from mounds of two closely related fungus-growing species (Macrotermes subhyalinus and M. michaelseni, respectively) in two habitats representing different vegetation types (grassland, bushland) together with soil fluxes around the mounds. The fluxes from active termite mounds varied from 120 to 2100 mg CO2-C m-2h-1 for carbon dioxide (CO2) and from 0.06 to 3.7 mg CH4-C m-2 h-1 for methane (CH4) fluxes. Mound CO2 fluxes varied seasonally with a 64 % decrease and 41 % increase in the fluxes from the dry to wet season at the grassland and bushland sites, respectively. During the wet season, the CO2 fluxes were significantly correlated with termite mound volume. The diurnal measurements from two M. michaelseni mounds suggest that the gas fluxes peak during the daytime, possibly reflecting changes in mound internal air circulation. Soil fluxes of both CO2 and CH4 were enhanced at up to 2 m distance from the mounds compared to the local soil respiration, indicating that, in addition to mound ventilation structures, a small proportion of the metabolic gases produced also leave the nest via surrounding soils.
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| 9. |
- Schmidt, Alexander R., et al.
(författare)
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Selaginella in Cretaceous amber from Myanmar
- 2022
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Ingår i: Willdenowia. - : BioOne. - 0511-9618 .- 1868-6397. ; 52:2, s. 179-245
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Tidskriftsartikel (refereegranskat)abstract
- Selaginella (Selaginellales, Selaginellaceae) is the most speciose genus of lycophytes and, with approximately 750 recognized present-day species, also one of the largest genera of vascular plants. However, the evolutionary history of this species richness remains largely unresolved. Recent research suggests that Selaginella was diverse already in the mid-Cretaceous and shows that S. subg. Stachygynandrum dates back at least to the incipient Angiosperm Terrestrial Revolution some 100 million years ago. Here, we describe 20 new fossil-species of Selaginella based on fertile shoots and spores preserved in mid-Cretaceous Kachin amber from Myanmar and emend the previously described S. cretacea. Ten of the species (S. ciliifera, S. cretacea, S. grimaldii, S. heterosporangiata, S. longifimbriata, S. minutissima, S. ohlhoffiorum, S. patrickmuelleri, S. villosa, S. wangxinii) represent S. subg. Stachygynandrum because they possess anisophyllous strobili. The other eleven species have isophyllous strobili. Two of them (S. isophylla, S. wunderlichiana) are tentatively assigned to S. subg. Ericetorum, whereas the others (S. amplexicaulis, S. aurita, S. heinrichsii, S. konijnenburgiae, S. obscura, S. ovoidea, S. pellucida, S. tomescui, S. wangboi) cannot be placed into any fossil or extant subgenus. The fossils described in this study nearly duplicate the documented record of free-sporing plants from Kachin amber. The abundance and diversity of cryptogams, along with the absence of xerophytes among the taxa, is suggestive of constantly high humidity in the understory of the source forests of this amber.
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