Motivation: The BioTIME database contains raw data on species identities and abundances in ecological assemblages through time. These data enable users to calculate temporal trends in biodiversity... Show moreMotivation: The BioTIME database contains raw data on species identities and abundances in ecological assemblages through time. These data enable users to calculate temporal trends in biodiversity within and amongst assemblages using a broad range of metrics. BioTIME is being developed as a community-led open-source database of biodiversity time series. Our goal is to accelerate and facilitate quantitative analysis of temporal patterns of biodiversity in the Anthropocene.Main types of variables included: The database contains 8,777,413 species abundance records, from assemblages consistently sampled for a minimum of 2 years, which need not necessarily be consecutive. In addition, the database contains metadata relating to sampling methodology and contextual information about each record.Spatial location and grain: BioTIME is a global database of 547,161 unique sampling locations spanning the marine, freshwater and terrestrial realms. Grain size varies across datasets from 0.0000000158 km(2) (158 cm(2)) to 100 km(2) (1,000,000,000,000 cm(2)).Time period and grainBio: TIME records span from 1874 to 2016. The minimal temporal grain across all datasets in BioTIME is a year.Major taxa and level of measurement: BioTIME includes data from 44,440 species across the plant and animal kingdoms, ranging from plants, plankton and terrestrial invertebrates to small and large vertebrates. Show less
Soudzilovskaia, N.A.; Van der Heijden, M.G.A.; Cornelissen, J.H.C.; Makarov, M.I.; Onipchenko, V.G.; Maslov, M.M.; ... ; Bodegom, P.M. van 2015
A significant fraction of carbon stored in the Earth’s soil moves through arbuscular mycorrhiza(AM) and ectomycorrhiza (EM). The impacts of AM and EM on the soil carbon budgetare poorly understood... Show moreA significant fraction of carbon stored in the Earth’s soil moves through arbuscular mycorrhiza(AM) and ectomycorrhiza (EM). The impacts of AM and EM on the soil carbon budgetare poorly understood.We propose a method to quantify the mycorrhizal contribution to carbon cycling, explicitlyaccounting for the abundance of plant-associated and extraradical mycorrhizal mycelium. Wediscuss the need to acquire additional data to use our method, and present our new globaldatabase holding information on plant species-by-site intensity of root colonization by mycorrhizas.We demonstrate that the degree of mycorrhizal fungal colonization has globally consistentpatterns across plant species. This suggests that the level of plant species-specific rootcolonization can be used as a plant trait.To exemplify our method, we assessed the differential impacts of AM : EM ratio and EMshrub encroachment on carbon stocks in sub-arctic tundra. AM and EM affect tundra carbonstocks at different magnitudes, and via partly distinct dominant pathways: via extraradicalmycelium (both EM and AM) and via mycorrhizal impacts on above- and belowground biomasscarbon (mostly AM).Our method provides a powerful tool for the quantitative assessment of mycorrhizal impacton local and global carbon cycling processes, paving the way towards an improved understandingof the role of mycorrhizas in the Earth’s carbon cycle. Show less
AimMost vascular plants on Earth form mycorrhizae, a symbiotic relationship between plants and fungi. Despite the broad recognition of the importance of mycorrhizae for global carbon and nutrient... Show moreAimMost vascular plants on Earth form mycorrhizae, a symbiotic relationship between plants and fungi. Despite the broad recognition of the importance of mycorrhizae for global carbon and nutrient cycling, we do not know how soil and climate variables relate to the intensity of colonization of plant roots by mycorrhizal fungi. Here we quantify the global patterns of these relationships.LocationGlobal.MethodsData on plant root colonization intensities by the two dominant types of mycorrhizal fungi world-wide, arbuscular (4887 plant species in 233 sites) and ectomycorrhizal fungi (125 plant species in 92 sites), were compiled from published studies. Data for climatic and soil factors were extracted from global datasets. For a given mycorrhizal type, we calculated at each site the mean root colonization intensity by mycorrhizal fungi across all potentially mycorrhizal plant species found at the site, and subjected these data to generalized additive model regression analysis with environmental factors as predictor variables.ResultsWe show for the first time that at the global scale the intensity of plant root colonization by arbuscular mycorrhizal fungi strongly relates to warm-season temperature, frost periods and soil carbon-to-nitrogen ratio, and is highest at sites featuring continental climates with mild summers and a high availability of soil nitrogen. In contrast, the intensity of ectomycorrhizal infection in plant roots is related to soil acidity, soil carbon-to-nitrogen ratio and seasonality of precipitation, and is highest at sites with acidic soils and relatively constant precipitation levels.Main conclusionsWe provide the first quantitative global maps of intensity of mycorrhizal colonization based on environmental drivers, and suggest that environmental changes will affect distinct types of mycorrhizae differently. Future analyses of the potential effects of environmental change on global carbon and nutrient cycling via mycorrhizal pathways will need to take into account the relationships discovered in this study. Show less
