Tree species effects on fungal richness and community structure
Kuupäev
2020-11-02
Autorid
Ajakirja pealkiri
Ajakirja ISSN
Köite pealkiri
Kirjastaja
Abstrakt
Erinevad seenerühmad on looduses olulised orgaanilise aine lagundajad, haigustekitajad või juursümbiondid, kes aitavad puudel omastada mineraalaineid. Puud mõjutavad oma ümbrust läbi varise ja juureeritiste. Puuliikide kooskasvamine loob segametsades erinevad elupaigalaigud, mis suurendab muude organismide elurikkust metsades, kus kasvab rohkem puuliike. Elurikkus suurendab ökosüsteemide tootlikkust ja stabiilsust muutuvate keskkonnatingimuste vastu. Enda doktoritöös käsitlen seente elurikkuse seost puude varise ja peremeestaimede liigirikkusega ning teiste puuliikide naabruse mõjuga. Leidsin, et mida rohkem sisaldab lagunev lehevaris erinevate puuliikide lehti, seda suurem on selles seente liigirikkus. Samas juurte liigirikkuse mõju seente mitmekesisusele on nõrk. Lehevarise koosseis määrab ka lagundajate ja taimepatogeenide liigilise koosseisu. Kuuse ektomükoriisaseente liigiline koosseis erineb kase–kuuse segametsa ning kuuse monokultuuri vahel. Kase naabrus mõjutab mulla keemilisi omadusi ja seeläbi ektomükoriissete seente kooslusi. Ektomükoriisaseente liigirikkus on globaalsel skaalal seotud peremeestaimede liigirikkusega, kuid regionaalsel tasemel on seosed mulla omaduste ja konkreetsete puuliikidega tähtsamad. Oma tööst järeldan, et metsa liigirikkus tõepoolest suurendab seente elurikkust, mõju tugevus sõltub aga konkreetsetest puuliikidest ning mulla ja muu taimkatte omadustest.
Fungi play key roles in forest ecosystems. Various groups of fungi drive organic matter decomposition and soil nutrient cycling, act as tree root symbionts or cause diseases. Trees are influential components of forest habitats that modify their surroundings via shedding litter and root exudates, but little is known about the functional importance of tree species diversity on soil organisms and soil biological processes. Mixtures of tree species can create fine-scale environmental heterogeneity that supports higher biodiversity in forest stands. Biodiversity enhances productivity and stability, buffering ecosystems against changing environmental conditions. In this thesis, I examined fungal diversity in relation to plant litter, host plant diversity and tree neighbourhood effects. Leaf litter mixtures with higher plant species richness harboured higher fungal diversity, indicating that heterogeneity of resources in litter mixtures provides more habitats and allows a larger number of fungal species to co-exist. Conversely, the root litter richness effect on fungal diversity was weak. Furthermore, leaf litter composition had a strong effect on composition of saprotrophic and plant pathogenic fungi. Richness of ectomycorrhizal fungi was positively related to host plant richness at global scale. At regional scale, fungal richness correlated with plant richness, but this effect was related to improved soil conditions in mixed forests. Communities of ectomycorrhizal fungi on spruce roots differed in spruce monocultures and mixed stands of birch and spruce, which points to the influence of birch on soil quality. To conclude, tree species richness and fungal diversity are usually positively correlated, but the direct impact of plant richness depends on the context, including the influence of particular plant species and analysis of other factors.
Fungi play key roles in forest ecosystems. Various groups of fungi drive organic matter decomposition and soil nutrient cycling, act as tree root symbionts or cause diseases. Trees are influential components of forest habitats that modify their surroundings via shedding litter and root exudates, but little is known about the functional importance of tree species diversity on soil organisms and soil biological processes. Mixtures of tree species can create fine-scale environmental heterogeneity that supports higher biodiversity in forest stands. Biodiversity enhances productivity and stability, buffering ecosystems against changing environmental conditions. In this thesis, I examined fungal diversity in relation to plant litter, host plant diversity and tree neighbourhood effects. Leaf litter mixtures with higher plant species richness harboured higher fungal diversity, indicating that heterogeneity of resources in litter mixtures provides more habitats and allows a larger number of fungal species to co-exist. Conversely, the root litter richness effect on fungal diversity was weak. Furthermore, leaf litter composition had a strong effect on composition of saprotrophic and plant pathogenic fungi. Richness of ectomycorrhizal fungi was positively related to host plant richness at global scale. At regional scale, fungal richness correlated with plant richness, but this effect was related to improved soil conditions in mixed forests. Communities of ectomycorrhizal fungi on spruce roots differed in spruce monocultures and mixed stands of birch and spruce, which points to the influence of birch on soil quality. To conclude, tree species richness and fungal diversity are usually positively correlated, but the direct impact of plant richness depends on the context, including the influence of particular plant species and analysis of other factors.
Kirjeldus
Väitekirja elektrooniline versioon ei sisalda publikatsioone
Märksõnad
trees (botany), Fungi, species diversity, species composition