Globally, rising temperatures are increasingly favoring warm-affiliated species. Although changes in community composition are typically measured by the mean temperature affinity of species (the Community Temperature Index, CTI), they may be driven by different processes and accompanied by shifts in the diversity of temperature affinities and breadth of species thermal niches. To resolve the pathways to community warming in Finnish flora and fauna, we examined multidecadal changes in the dominance and diversity of temperature affinities among understory forest plant, freshwater phytoplankton, butterfly, moth, and bird communities. CTI increased for all animal communities, with no change observed for plants or phytoplankton. In addition, the diversity of temperature affinities declined for all groups except butterflies, and this loss was more pronounced for the fastest warming communities. These changes were driven in animals mainly by a decrease in cold-affiliated species and an increase in warm-affiliated species. In plants and phytoplankton the decline of thermal diversity was driven by declines of both cold- and warm-affiliated species. Plant and moth communities were increasingly dominated by thermal specialist species, and birds by thermal generalists. In general, climate warming outpaced changes in both the mean and diversity of temperature affinities of communities. Our results highlight the complex dynamics underpinning the thermal reorganization of communities across a large spatio-temporal gradient, revealing that extinctions of cold-affiliated species and colonization by warm-affiliated species lag behind changes in ambient temperature, while communities become less thermally diverse. Such changes can have important implications for community structure and ecosystem functioning under accelerating rates of climate change.

Dataset of the experimental data obtained for the study “The interaction between microplastics and microalgae affects community assembling and nutrient availability” (published on Communications Earth and Environment, DOI: 10.1038/s43247-024-01706-y). This include 5 different tabular files, which are listed below:Algae growth Values of chlorophyll fluorescence (as a proxy of algal biomass growth, in arbitrary units) in all treatments between days 1 and 17 of the experiment in the 4 different replicates (shown as different columns).Biofilm growth on plastic Measures of biofilm coverage (in % of plastic fragment's surface) via image analysis after optical microscopy and chlorophyll fluorescence via spectroscopy (after the analysis of 3 replicates per batch, relative standard deviation below 20%). Data at day 0 indicate the fragments before the incubation with the pelagic community. Data are shown for each treatment containing plastic (i.e., plastic, biofilm and dispersal).Nutrient concentrations Nutrient concentration in every replicate at different days from the beginning of the experiment. Data are average values after three measure replicates (relative standard deviation below 5%). Data below LODs are shown as LOD/2.Pelagic community composition Counting values of the different algal species from optical microscopy measurement of all treatments after 5, 8 and 15 days (average values after 3 replicates of measures (relative standard deviation below 25%). The inoculum of the pelagic community before the beginning of the experiment is also included. Species not present in the community or not detected are shown as ND.Photosynthetic efficiency Values of photosynthetic efficiency (measured with pulse-amplitude-modulated fluorescence) in all treatments at day 5, 8 and 15 of the experiment in the 4 different replicates (shown as different columns).

Dataset of the experimental data obtained for the study “The interaction between microplastics and microalgae affects community assembling and nutrient availability” (published on Communications Earth and Environment, DOI: 10.1038/s43247-024-01706-y). This include 5 different tabular files, which are listed below:Algae growth Values of chlorophyll fluorescence (as a proxy of algal biomass growth, in arbitrary units) in all treatments between days 1 and 17 of the experiment in the 4 different replicates (shown as different columns).Biofilm growth on plastic Measures of biofilm coverage (in % of plastic fragment's surface) via image analysis after optical microscopy and chlorophyll fluorescence via spectroscopy (after the analysis of 3 replicates per batch, relative standard deviation below 20%). Data at day 0 indicate the fragments before the incubation with the pelagic community. Data are shown for each treatment containing plastic (i.e., plastic, biofilm and dispersal).Nutrient concentrations Nutrient concentration in every replicate at different days from the beginning of the experiment. Data are average values after three measure replicates (relative standard deviation below 5%). Data below LODs are shown as LOD/2.Pelagic community composition Counting values of the different algal species from optical microscopy measurement of all treatments after 5, 8 and 15 days (average values after 3 replicates of measures (relative standard deviation below 25%). The inoculum of the pelagic community before the beginning of the experiment is also included. Species not present in the community or not detected are shown as ND.Photosynthetic efficiency Values of photosynthetic efficiency (measured with pulse-amplitude-modulated fluorescence) in all treatments at day 5, 8 and 15 of the experiment in the 4 different replicates (shown as different columns).

Covariation in species richness and community structure across taxonomical groups (cross-taxon congruence) has practical consequences for the identification of biodiversity surrogates and proxies, as well as theoretical ramifications for understanding the mechanisms maintaining and sustaining biodiversity.  We found there to exist a high cross-taxon congruence between phytoplankton, zooplankton and fish in 73 large Scandinavian lakes across a 750 km longitudinal transect. The fraction of the total diversity variation explained by local environment alone was small for all trophic levels while a substantial fraction could be explained by spatial gradient variables. Almost half of the explained variation could not be resolved between local and spatial factors, possibly due to confounding issues between longitude and landscape productivity. There is strong consensus that the longitudinal gradient found in the regional fish community results from post-glacial dispersal limitations, while there is much less evidence for the species richness and community structure gradients at lower trophic levels being directly affected by dispersal limitation over the same time scale. We found strong support for bi-directional interactions between fish and zooplankton species richness, while corresponding interactions between phytoplankton and zooplankton richness were much weaker. Both the weakening of the linkage at lower trophic levels and the bi-directional nature of the interaction indicates that the underlying mechanism must be qualitatively different from a trophic cascade.