Browsing by Subject "sienitiede"

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  • Spirin, Viacheslav; Volobuev, Sergey; Malysheva, Vera; Miettinen, Otto; Kotiranta, Heikki; Larsson, Karl-Henrik (Nationale Plantentuin van België, 2021)
    Plant Ecology and Evolution 154: 2, 231-244
    Background and aims – To date, Megalocystidium leucoxanthum, a corticioid fungus originally described from the Italian Alps, was considered as a widely distributed species inhabiting numerous angiosperm hosts in the northern hemisphere. Its specimens collected in different geographic areas and from various host species revealed a high morphological variability and thus obfuscated differences from the closely related M. luridum. The objective of this study was to re-establish M. leucoxanthum based on newly collected and sequenced specimens and clarify the identity of morphologically deviating collections previously ascribed to this species. Material and methods – In total, 87 specimens of Megalocystidium spp. (including two historical types) were studied by morphological methods. Their phylogenetic relations were investigated based on DNA sequences (nrITS, nrLSU, and tef1) of 29 specimens. Key results – Based on morphological, ecological and DNA data, we showed M. leucoxanthum sensu typi is a rare species restricted to Alnus alnobetula in subalpine and subarctic zones. Consequently, records from other hosts (mostly representatives of Salicaceae) belong to three other species, M. olens, M. perticatum, and M. salicis, described as new to science. The fourth newly introduced species, M. pellitum, occurs on the same host tree as M. leucoxanthum but it can be separated from the latter due to distinctive morphological traits and DNA sequences. Additionally, Aleurodiscus diffissus is combined in Megalocystidium and the identity of M. luridum is clarified.
  • Nirhamo, Aleksi; Pykälä, Juha; Halme, Panu; Komonen, Atte (Wiley, 2021)
    Applied Vegetation Science 24: 2
    Questions: Aspen (Populus tremula) is declining in the old-growth forests of boreal Fennoscandia. This threatens the numerous taxa that are dependent on old aspens, including many epiphytic lichens. Potential methods to aid epiphytic lichens on aspen are centered around treatments which affect the density of Norway spruce (Picea abies). In this study, we investigated how epiphytic lichen communities on aspen are affected by the variation of spruce density in the immediate vicinity of the focal aspen. Location: Southern boreal forests in Finland. Methods: We recorded the occurrence of lichens from 120 aspens in 12 semi-natural forest sites. We used spruce basal area as the measure for spruce density. The selected aspens represented a gradient in spruce basal area in the vicinity of the aspen from 0 to 36 m2/ha. We also measured other tree- and stand-level variables that are known to influence lichen occurrence. Results: Lichen communities on aspen were affected by spruce density, stand age and bark pH. Both lichen species richness and the richness of red-listed species were highest at an intermediate spruce density, and both increased with stand age. Lichen species richness was higher when bark pH was lower. Additionally, community composition was influenced the most by spruce density, followed by bark pH. Conclusions: Our study highlights the detrimental effects of high spruce density on lichen diversity on aspens. This is caused by high spruce density resulting in low light availability. Lichen diversity on aspens was highest when spruce density was intermediate. Spruce thinning in aspen-rich old-growth forests can be helpful in ensuring the long-term persistence of old-growth lichens on aspen in protected forests.
  • Karsten, P. A. (Finska Vetenskaps-Societeten, 1882)
    Bidrag till kännedom af Finlands natur och folk; 37
  • Timonen, Sari; Valkonen, Jari (Gaudeamus, 2018)
    Sienten biologia on ensimmäinen suomenkielinen yleisteos sienistä. Siitä selviävät perusasiat sienten monimuotoisuudesta, aineenvaihdunnasta, genetiikasta, toimintatavoista, ympäristövaikutuksista ja käytöstä ihmisen hyödyksi. Kirjan lukemista ja sienimaailman ymmärtämistä helpottaa kattava suomenkielinen sienitieteellinen sanasto. Kirja sopii luettavaksi niin opiskelijoille, tutkijoille, biologian opettajille kuin sieniharrastajillekin. Kirjoittajina ovat alansa parhaat suomalaiset asiantuntijat.
  • Tuovila, Hanna (Helsingin yliopisto, 2013)
    Species of Mycocaliciales are a group of small ascomycetes with pin-like ascocarps. Among Fungi, many mycocalicioid species are rather unique in having specialized to live on the resinous exudates of vascular plants. Terpenoid and phenolic resins essentially are repellents for fungi, but some of these species even appear to use resins for their nutrition. This peculiar ecology has a long evolutionary history, judging from 20 to 40 Ma old amber fossils, in which the ascocarps growing on ancient resin bear remarkable resemblance to those of extant resinicolous species. In addition to resinicolous species, mycocalicioid fungi also include species that are saprotrophic on lignum or associated with lichens or non-symbiotic algal colonies. The aim of this theses was to study the diversity, ecology and evolutionary relationships of mycocalicioid fungi, especially the resinicolous species. The study is based on specimens collected from different parts of the world, and analyzed using both molecular and morphological methods. In this study seven new resinicolous Chaenothecopsis species are described from boreal North America and Europe, tropical Africa, and temperate China, four from angiosperm exudates and three from conifer resins. Two newly found fossils of Chaenothecopsis from Eocene and Oligocene ambers are described and their relations to extant species are elucidated. The phylogenetic relationships of several species and lineages, and the evolution of the resinicolous ecology are discussed in considerable detail. In addition, new morphological and chemical characters that can be used in future taxonomic studies are described.
  • Miettinen, Otto (2011)
    Helsingin yliopiston kasvitieteen julkaisuja
    Tutkimus käsittelee kääpien sukulaisuussuhteita. Käävät ovat kantasienten (Basidiomycota) muotoryhmä, joiden itiöemien alapinta muodostuu yhteensulautuneista pilleistä. Muotoryhmänä kääpiä voi verrata vaikka puihin siinä mielessä, että käävät kuten puutkaan eivät ole samankaltaisuudestaan huolimatta kaikki sukua toisilleen. DNA:n käyttö sukulaisuussuhteiden selvittämisessä on aloittanut mullistuksen kääpien luokittelussa. Aiemmin käytetty, itiöemien ominaisuuksiin perustunut luokittelu on osoittautunut keinotekoiseksi sukulaisuussuhteiden kannalta. Tutkimuksessani syvennyttiin useamman kääpäsuvun polveutumishistoriaan hyödyntäen DNA:ta ja perinteisiä menetelmiä. Tutkimuksen keskeisimmät tulokset liittyvät sitkokääpien sukuun (Antrodiella). Tämä noin 70 lajia sisältävä suku osoittautui rikkonaiseksi - sitkokääpiin luetut lajit kuuluvat kahteen sienilahkoon ja oikesti vähintään 13 sukuun. Tutkimuksessa löytyi kaksi Suomelle uutta sitkokääpää, leppikääpä (A. ichnusana) ja nipukkakääpä (A. leucoxantha). Uudet suvut kuvattiin Suomessa esiintyville sirppikääville (Sidera) ja talikääville (Obba). Uusi kääpäsuku ja -laji kuvattiin myös Indonesiasta (Sebipora aquosa). Valtaosa sitkokääpiin luetuista lajeista kuuluu orakarakoiden heimoon (Steccherinaceae), joka rajattiin tässä tutkimuksessa uudelleen. Heimoon kuuluvat mm. karakäävät (Junghuhnia) ja orakasmaiset orakarakat (Steccherinum). Sen sisällä selvitettiin kääpien ja orakkaiden sukulaisuussuhteita. Perinteisesti käävät ja orakkaat on viety eri sukuihin riippumatta niiden mikroskooppisesta samankaltaisuudesta. Tulosten valossa orakarakoiden heimossa käävät ja orakkaat pysyvät pääosin erillisissä suvuissa, mutta tästä on myös poikkeuksia (Antrodiella, Metuloidea ja Steccherinum). Lähes kaikki DNA:n perusteella määriteltävissä olevat suvut ovat tunnistettavissa itiöemien ominaisuuksiensa perusteella. Tulokset antavat eväitä kääpien luokitteluun laajemminkin osoittamalla, mitkä ominaisuudet ovat luokittelun kannalta merkityksellisiä. Tarkentunut tieto lajimäärästä ja lajien sukulaisuussuhteista hyödyttää ekologista tutkimusta sekä arvioita lajien uhanalaisuudesta. Tutkimuksen aikana luotua DNA-kirjastoa käytetään lajien tunnistamiseen. Tuloksia voidaan hyödyntää myös etsittäessä bioteknologisia sovelluksia käävistä, sillä sovellusten kannalta kiinnostavat ominaisuudet seuraavat usein sienten sukupuuta.
  • Purhonen, Jenna; Nerea, Abrego; Komonen, Atte; Huhtinen, Seppo; Kotiranta, Heikki; Læssøe, Thomas; Halme, Panu (Nature Publishing Group, 2021)
    Scientific Reports 11: 1
    The general negative impact of forestry on wood-inhabiting fungal diversity is well recognized, yet the effect of forest naturalness is poorly disentangled among different fungal groups inhabiting dead wood of different tree species. We studied the relationship between forest naturalness, log characteristics and diversity of different fungal morpho-groups inhabiting large decaying logs of similar quality in spruce dominated boreal forests. We sampled all non-lichenized fruitbodies from birch, spruce, pine and aspen in 12 semi-natural forest sites of varying level of naturalness. The overall fungal community composition was mostly determined by host tree species. However, when assessing the relevance of the environmental variables separately for each tree species, the most important variable varied, naturalness being the most important explanatory variable for fungi inhabiting pine and aspen. More strikingly, the overall species richness increased as the forest naturalness increased, both at the site and log levels. At the site scale, the pattern was mostly driven by the discoid and pyrenoid morpho-groups inhabiting pine, whereas at the log scale, it was driven by pileate and resupinate morpho-groups inhabiting spruce. Although our study demonstrates that formerly managed protected forests serve as effective conservation areas for most wood-inhabiting fungal groups, it also shows that conservation planning and management should account for group- or host tree -specific responses.