| 1. |
- Ekholm, Adam, et al.
(författare)
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Herbivory in a changing climate-Effects of plant genotype and experimentally induced variation in plant phenology on two summer-active lepidopteran herbivores and one fungal pathogen
- 2022
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Ingår i: Ecology and Evolution. - : Wiley. - 2045-7758. ; 12:1
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Tidskriftsartikel (refereegranskat)abstract
- With climate change, spring warming tends to advance plant leaf-out. While the timing of leaf-out has been shown to affect the quality of leaves for herbivores in spring, it is unclear whether such effects extend to herbivores active in summer. In this study, we first examined how spring and autumn phenology of seven Quercus robur genotypes responded to elevated temperatures in spring. We then tested whether the performance of two summer-active insect herbivores (Orthosia gothica and Polia nebulosa) and infection by a pathogen (Erysiphe alphitoides) were influenced by plant phenology, traits associated with genotype or the interaction between these two. Warm spring temperatures advanced both bud development and leaf senescence in Q. robur. Plants of different genotype differed in terms of both spring and autumn phenology. Plant phenology did not influence the performance of two insect herbivores and a pathogen, while traits associated with oak genotype had an effect on herbivore performance. Weight gain for O. gothica and ingestion for P. nebulosa differed by a factor of 4.38 and 2.23 among genotypes, respectively. Herbivore species active in summer were influenced by traits associated with plant genotype but not by phenology. This suggest that plant attackers active in summer may prove tolerant to shifts in host plant phenology-a pattern contrasting with previously documented effects on plant attackers active in spring and autumn.
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| 2. |
- Faticov, Maria, 1991-, et al.
(författare)
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Different spatial structure of plant-associated fungal communities above- and belowground
- 2023
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Ingår i: Ecology and Evolution. - 2045-7758. ; 13:5
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Tidskriftsartikel (refereegranskat)abstract
- The distribution and community assembly of above- and belowground microbial communities associated with individual plants remain poorly understood, despite its consequences for plant–microbe interactions and plant health. Depending on how microbial communities are structured, we can expect different effects of the microbial community on the health of individual plants and on ecosystem processes. Importantly, the relative role of different factors will likely differ with the scale examined. Here, we address the driving factors at a landscape level, where each individual unit (oak trees) is accessible to a joint species pool. This allowed to quantify the relative effect of environmental factors and dispersal on the distribution of two types of fungal communities: those associated with the leaves and those associated with the soil of Quercus robur trees in a landscape in southwestern Finland. Within each community type, we compared the role of microclimatic, phenological, and spatial variables, and across community types, we examined the degree of association between the respective communities. Most of the variation in the foliar fungal community was found within trees, whereas soil fungal community composition showed positive spatial autocorrelation up to 50 m. Microclimate, tree phenology, and tree spatial connectivity explained little variation in the foliar and soil fungal communities. Foliar and soil fungal communities differed strongly in community structure, with no significant concordance detected between them. We provide evidence that foliar and soil fungal communities assemble independent of each other and are structured by different ecological processes.
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| 3. |
- Faticov, Maria, 1991-
(författare)
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Spatial and temporal ecology of oak-associated fungal communities
- 2021
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Plants host a large diversity of microorganisms, which includes fungi, bacteria and archaea. Among these, fungi are highly diverse, and known to play a vital role in plant health and in regulation of the essential ecosystem functions. Nevertheless, we still lack a comprehensive understanding of the forces structuring plant-associated fungal communities in space and time. The main aim of this thesis was to decipher the drivers of the spatial patterns and temporal dynamics of fungal communities on plants. To this aim, I focused on Quercus robur and its associated fungi. Using a combination of observational and experimental studies, I assessed i) the distribution and drivers of the above- and belowground fungal communities at the landscape scale; ii) the role of climatic and trophic factors in defining the niches of cryptic species within a pathogen complex on oak and iii) the relative importance of warming, plant genotype and their interaction in shaping oak phenology and the seasonal dynamics of the associated fungal and insect communities.I found that aboveground fungal communities were highly variable among leaves within a single tree, and that belowground fungal communities had a stronger spatial structure than aboveground fungi at the landscape scale. Yet, climate, tree phenology or the distribution of the host tree did not explain spatial patterns in the above- and belowground communities. When focusing on three cryptic powdery mildew species within a pathogen complex on oak, I demonstrated that the climatic dimension is more important than the species interaction dimension for niche differentiation of these cryptic pathogens. A field heating experiment showed strong seasonal change in the structure of the foliar fungal community, with experimental warming playing an important role in driving this change. This experiment also revealed that warming and plant genotype jointly shape plant phenology, disease levels and insect abundance across the growing season.In conclusion, my findings suggest that abiotic forces can override biotic forces in structuring spatial patterns and temporal dynamics of fungal communities associated with plants. The particularly strong impact of warmer temperatures on foliar fungi in some of my studies indicates that climate warming has the potential to structure foliar fungal communities, with important implications for plant health, interactions between plants and other organisms and ecosystem functions.
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