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Selle kollektsiooni püsiv URIhttp://hdl.handle.net/10492/6178

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Sirvi Artiklid Autor "Alahuhta, Janne" järgi

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  • Pisipilt
    Kirje
    Global patterns and determinants of lake macrophyte taxonomic, functional and phylogenetic beta diversity
    (Elsevier, 2020) García-Girón, Jorge; Heino, Jani; Baastrup-Spohr, Lars; Bove, Claudia P.; Clayton, John; de Winton, Mary; Feldmann, Tõnu; Fernández-Aláez, Margarita; Ecke, Frauke; Grillas, Patrick; Hoyer, Mark V.; Kolada, Agnieszka; Kosten, Sarian; Lukács, Balázs A.; Mjelde, Marit; Mormul, Roger P.; Rhazi, Laila; Rhazi, Mouhssine; Sass, Laura; Xu, Jun; Alahuhta, Janne; Centre for Limnology, Institute of Agricultural and Environmental Sciences
    Documenting the patterns of biological diversity on Earth has always been a central challenge in macroecology and biogeography. However, for the diverse group of freshwater plants, such research program is still in its in- fancy. Here, we examined global variation in taxonomic, functional and phylogenetic beta diversity patterns of lake macrophytes using regional data from six continents. A data set of ca. 480 lake macrophyte community ob- servations, together with climatic, geographical and environmental variables, was compiled across 16 regions worldwide. We (a) built the very first phylogeny comprising most freshwater plant lineages; (b) exploited a wide array of functional traits that are important to macrophyte autoecology or that relate to lake ecosystem functioning; (c) assessed if different large-scale beta diversity patterns show a clear latitudinal gradient from the equator to the poles using null models; and (d) employed evolutionary and regression models to first identify the degree to which the studied functional traits show a phylogenetic signal, and then to estimate community- environment relationships at multiple spatial scales. Our results supported the notion that ecological niches evolved independently of phylogeny in macrophyte lineages worldwide. We also showed that taxonomic and phylogenetic beta diversity followed the typical global trend with higher diversity in the tropics. In addition, we were able to confirm that species, multi-trait and lineage compositions were first and foremost structured by climatic conditions at relatively broad spatial scales. Perhaps more importantly, we showed that large-scale processes along latitudinal and elevational gradients have left a strong footprint in the current diversity patterns and community-environment relationships in lake macrophytes. Overall, our results stress the need for an inte- grative approach to macroecology, biogeography and conservation biology, combining multiple diversity facets at different spatial scales.
  • Pisipilt
    Kirje
    Global patterns in the metacommunity structuring of lake macrophytes: regional variations and driving factors
    (Springer, 2018) Alahuhta, Janne; Lindholm, Marja; Bove, Claudia P.; Chappuis, Eglantine; Clayton, John; De Winton, Mary; Feldmann, Tõnu; Ecke, Frauke; Gacia, Esperança; Grillas, Patrick; Hoyer, Mark V.; Johnson, Lucinda B.; Kolada, Agnieszka; Kosten, Sarian; Lauridsen, Torben; Lukács, Balázs A.; Mjelde, Marit; Mormul, Roger P.; Rhazi, Laila; Rhazi, Mouhssine; Sass, Laura; Søndergaard, Martin; Xu, Jun; Heino, Jani; Centre for Limnology. Institute of Agricultural and Environmental Sciences. Estonian University of Life Sciences
    We studied community–environment relationships of lake macrophytes at two metacommunity scales using data from 16 regions across the world. More specifically, we examined (a) whether the lake macrophyte communities respond similar to key local environmental factors, major climate variables and lake spatial locations in each of the regions (i.e., within-region approach) and (b) how well can explained variability in the community–environment relationships across multiple lake macrophyte metacommunities be accounted for by elevation range, spatial extent, latitude, longitude, and age of the oldest lake within each metacommunity (i.e., across-region approach). In the within-region approach, we employed partial redundancy analyses together with variation partitioning to investigate the relative importance of local variables, climate variables, and spatial location on lake macrophytes among the study regions. In the across-region approach, we used adjusted R2 values of the variation partitioning to model the community–environment relationships across multiple metacommunities using linear regression and commonality analysis. We found that niche filtering related to local lake-level environmental conditions was the dominant force structuring macrophytes within metacommunities. However, our results also revealed that elevation range associated with climate (increasing temperature amplitude affecting macrophytes) and spatial location (likely due to dispersal limitation) was important for macrophytes based on the findings of the across-metacommunities analysis. These findings suggest that different determinants influence macrophyte metacommunities within different regions, thus showing context dependency. Moreover, our study emphasized that the use of a single metacommunity scale gives incomplete information on the environmental features explaining variation in macrophyte communities.