Lost before found? : On systematics and conservation of lichen genus Micarea Fr. (Pilocarpaceae, Ascomycota)

The lichenized genus Micarea Fr. (Ascomycota) comprises ca. 100 species. All species in the genus are crustose and mostly inconspicuous. The species are known from wide range of habitats, where they can cover large surface areas. Many of them are epiphytes on bark or wood, but several are also frequently encountered on rocks or soil. Some of the species are specialized living in old-growth forests or in strict microhabitats, and these species may be sensitive to forest management practices. Micarea includes one of the largest groups of congeneric obligate lignicoles depended entirely on dead wood. In addition, many species are regarded as facultative lignicoles. Micarea prasina group is a monophyletic subgroup within the genus, including the type species of the genus Micarea prasina Fr. At the moment, the group includes 28 species. Challenges in species delimitation within this group are often noted. For example, the type species M. prasina is known for its phenotypic variability and taxonomic difficulties. The aim of this thesis was to investigate the deficiently known lichen genus Micarea focusing especially on the M. prasina group. Moreover, the aim was to gather new information on the distribution, taxonomy, systematics, and evolution of wood-dependency within this group. We also studied the conservation biology of wood dependent communities of Micarea and decomposer fungi, and underline the importance of cooperation between taxonomists and ecologists. The specimens for the thesis were collected from several European countries and from the USA. In addition, herbaria collections were examined. The main results are: 1.) We present a three-loci phylogeny of the Micarea prasina group and circumscribe nine new species based on phenotypic characters and phylogenetic analysis. Crystalline granules are studied as a novel character for the species. They are shown highly relevant in linking the old type specimen of M. prasina to fresh material. Also, a new species for North America is discovered. 2.) We bring new insights to the evolution of wood-inhabiting Micarea species and their reproduction. We suggest that lignicolous substratum requirement has evolved multiple times independently, and that obligate lignicoles are usually anamorphic. 3.) We show that local forest continuity is important for species rich Micarea communities. These communities seem to depend on dead standing pine trees that have been available continuously for long periods. However, local continuity did not explain diversity of decomposer fungi. Our results indicate that species diversity is still rather poorly known even in the relatively well-studied areas of Europe. Understanding species boundaries is a necessity for reliable conclusions in habitat requirements and threat status of the species. Two of the new species described in this study are likely obligate lignicoles occupying strict microhabitats. Intense forest management can pose a real threat to these species.Tyynyjäkäliin (Micarea Fr.) kuuluu maailmanlaajuisesti noin 100 lajia. Kaikki suvun lajit ovat pieniä ja varsin huomaamattomia rupijäkäliä, joiden ekologinen rooli on kuitenkin merkittävä. Lajit muodostavat usein laajoja kasvustoja kaarnalle, lahopuulle ja kiville. Osaa lajeista tavataan ainoastaan vanhoissa metsissä tai ne ovat erikoistuneet kapeisiin mikrohabitaatteihin. Lahopuulla tyynyjäkälät ovat yksi yleisimmistä jäkäläsuvuista. Tämän väitöskirjan tarkoituksena oli lisätä tietämystä puutteellisesti tunnetusta tyynyjäkälien suvusta, keskittyen erityisesti ns. Micarea prasina -ryhmään. Työssä kerättiin tietoa lajien levinneisyydestä, sukulaisuussuhteista, lahopuulla elävien lajien evoluutiosta sekä luonnonsuojelubiologiasta. Materiaalina käytettiin keruita Suomesta ja useista muista Euroopan maista sekä USA:sta. Lisäksi käytiin läpi useiden kansainvälisten herbaarioiden näytteitä. Tulokset osoittavat: 1.) Lajiston monimuotoisuus on luultua suurempaa. Perustuen kolmeen DNA-alueeseen ja fenotyyppisiin tuntomerkkeihin työssä kuvataan kahdeksan tieteelle uutta lajia ja lisäksi nostetaan yksi taksoni synonyymitasolta lajitasolle. Ilmoitamme myös yhden Pohjois-Amerikalle uuden lajin. 2.) Lahopuulle sopeutuminen vaikuttaa lajien lisääntymisbiologiaan. Lahopuulle sopeutuminen on tapahtunut useissa kehityslinjoissa itsenäisesti ja kyseiset lajit lisääntyvät ensisijaisesti suvuttomasti. 3.) Metsän paikallinen jatkuvuus vaikuttaa positiivisesti tyynyjäkäläyhteisöjen monimuotoisuuteen. Kyseiset yhteisöt hyötyvät vanhojen pystyyn kuolleiden mäntyjen jatkumosta. Tulokset viittaavat myös siihen, että lajisto on yhä puutteellisesti tunnettua jopa varsin hyvin tutkituissa Euroopan maissa. Lajirajojen luotettava hahmottaminen on keskeistä lajien elinympäristövaatimusten ja uhanalaisuuden arvioinnissa. Kaksi väitöskirjassa tieteelle uutena kuvattua lajia ovat todennäköisesti harvinaisia ja täysin riippuvaisia lahopuusta. Tällaiset lajit ovat herkkiä metsätalouden aiheuttamille muutoksille, etenkin lahopuun määrän vähenemiselle. Onkin syytä pohtia, menetämmekö lajeja jo ennen kuin löydämme niitä

Additions to the diversity of lichens and lichenicolous fungi living on decaying wood in Finland.

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Sharpening species boundaries in the Micarea prasina group, with a new circumscription of the type species M. prasina

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Four new epiphytic species in the Micarea prasina group from Europe

In this study we clarify the phylogeny and reassess the current taxonomy of the Micarea prasina group, focusing especially on the M. byssacea and M. micrococca complexes. The phylogeny was investigated using ITS, mtSSU and Mcm7 regions from 25 taxa belonging to the M. prasina group. A total of 107 new sequences were generated. Data were analyzed using maximum parsimony and maximum likelihood methods. The results reveal five undescribed well-supported lineages. Four of the lineages represent new species described as Micarea pseudomicrococca Launis & Myllys sp. nov., M. czarnotae Launis, van den Boom, Serusiaux & Myllys sp. nov., M. microareolata Launis, Pykala & Myllys sp. nov. and M. laeta Launis & Myllys sp. nov. In addition, a fifth lineage was revealed that requires further study. Micarea pseudomicrococca is characterized by an olive green granular thallus, small cream-white or brownish apothecia lacking the Sedifolia-grey pigment and two types of paraphyses up to 2 mu m wide. Micarea czarnotae forms a granular, densely granular or continuous olive green thallus, convex to hemispherical apothecia often with the Sedifolia-grey pigment and no crystalline granules in the thallus. Micarea microareolata is characterized by a +/- pale green areolate thallus (composed of goniocysts), cream-white apothecia lacking the Sedifolia-grey pigment and narrow spores. Micarea laeta has a vivid to olive green granular thallus, pale apothecia lacking the Sedifolia-grey pigment and wider spores compared to M. microareolata. Descriptions, images and a key are provided for the new species. Crystalline granules are introduced as a novel species-level character for Micarea.peerReviewe

Effects of local forest continuity on the diversity of fungi on standing dead pines

Human-induced fragmentation affects forest continuity, i.e. availability of a suitable habitat for the target species over a time period. The dependence of wood-inhabiting fungi on landscape level continuity has been well demonstrated, but the importance of local continuity has remained controversial. In this study, we explored the effects of local forest continuity (microhabitat and stand level) on the diversity of wood-inhabiting fungi on standing dead trunks of Scots pine (Paws sylvestris L.). We studied species richness and community composition of decomposers and Micarea lichens on 70 trunks in 14 forests in central Finland that differed in their state of continuity. We used dendrochronological methods to assess the detailed history of each study trunk, i.e. the microhabitat continuity. The stand continuity was estimated as dead wood diversity and past management intensity (number of stumps). We recorded 107 species (91 decomposers, 16 Micarea lichens), with a total of 510 occurrences. Using generalized linear mixed models, we found that none of the variables explained decomposer species richness, but that Micarea species richness was positively dependent on the time since tree death. Dead wood diversity was the most important variable determining the composition of decomposer communities. For Micarea lichens, the community composition was best explained by the combined effect of years from death, site and dead wood diversity. However, these effects were rather tentative. The results are in line with those of previous studies suggesting the restricted significance of local forest continuity for wood-inhabiting fungi. However, standing dead pines that have been available continuously over long periods seem to be important for species-rich communities of Micarea lichens. Rare specialists (e.g. on veteran trees) may be more sensitive to local continuity, and should be at the center of future research.Peer reviewe

Understanding the evolution of phenotypical characters in the Micarea prasina group (Pilocarpaceae) and descriptions of six new species within the group

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Lichens from the Vadstena Monastery churchyard – the burial place of Eric Acharius

A list of 120 taxa observed at the Vadstena Monastery churchyard includes some rare species and a few lichenicolous fungi. Lecanora semipallida is reported from the province Östergötland [Ostrogothia] for the first time

Ekologien ja systemaatikkojen yhteistyö tuottaa uutta tietoa kotelosienilajistosta

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Local forest continuity – important for species-rich Micarea lichen communities, but less so for decomposers

Fragmentation has a negative effect on forest continuity, i.e. availability of a suitable habitat for the target species over a time period (1). The dependence of wood-inhabiting fungi on landscape level continuity is well acknowledged, but the role of local continuity has remained unclear. We explored the effects of local forest continuity (microhabitat and stand level) on the diversity of fungi inhabiting standing dead trunks of Scots pine (Pinus sylvestris L.). Specifically, we studied the species richness and community composition of decomposers and Micarea lichens. The study included 70 trunks in 14 forests in central Finland with varying state of continuity. We assessed the detailed history of each study trunk with dendrochronological methods to estimate microhabitat continuity. Dead wood diversity and past management intensity (number of cut stumps) were used as estimates for stand continuity. Altogether, we recorded 107 species (91 decomposers and 16 Micarea lichens) with 510 occurrences. To study the effects of environmental variables, we used generalized linear mixed models for species richness, and Bioenv-analysis and Nonmetric Multidimensional Scaling for community composition. None of the variables explained species richness of decomposers, but there was a positive correlation between Micarea species richness and the time since tree death. The results for community composition analyses were rather tentative. Nevertheless, the community composition of decomposers was best explained by dead wood diversity, and for Micarea lichens, the community composition was mostly determined by the combined effect of years from tree death, site, and dead wood diversity. Our results are in line with those of previous studies suggesting the restricted significance of local forest continuity for wood-inhabiting fungi. However, species-rich Micarea lichens communities seemed to depend on standing pines that have been available over long periods after their death. Local forest continuity might be more important for rare specialists (e.g. on veteran trees), and therefore, future research should focus on such species. 1. Nordén, B., Dahlberg, A., Brandrud, T.E., Fritz, Ö., Ejrnaes, R., Ovaskainen, O., 2014. Effects of ecological continuity on species richness and composition in forests and woodlands: a review. Ecoscience 21, 34–45. doi:10.2980/21-1-3667peerReviewe