Aim
To understand how functional traits and evolutionary history shape the geographic distribution of plant life on Earth, we need to integrate high‐quality and global‐scale distribution data with ...functional and phylogenetic information. Large‐scale distribution data for plants are, however, often restricted to either certain taxonomic groups or geographic regions. Range maps only exist for a small subset of all plant species and digitally available point‐occurrence information is biased both geographically and taxonomically. Floras and checklists represent an alternative, yet rarely used potential source of information. They contain highly curated information about the species composition of a clearly defined area, and together virtually cover the entire global land surface. Here, we report on our recent efforts to mobilize this information for macroecological and biogeographical analyses in the GIFT database, the Global Inventory of Floras and Traits.
Location
Global.
Taxon
Land plants (Embryophyta).
Methods
GIFT integrates plant distributions from regional Floras and checklists with functional traits, phylogenetic information, and region‐level geographic, environmental and socio‐economic data. It contains information about the floristic status (native, endemic, alien and naturalized) and takes advantage of the wealth of trait information in the regional Floras, complemented by data from global trait databases.
Results
GIFT 1.0 holds species lists for 2,893 regions across the whole globe including ~315,000 taxonomically standardized species names (i.e. c. 80% of all known land plant species) and ~3 million species‐by‐region occurrences. Based on a hierarchical and taxonomical derivation scheme, GIFT contains information for 83 functional traits and more than 2.3 million trait‐by‐species combinations and achieves unprecedented coverage in categorical traits such as woodiness (~233,000 spp.) or growth form (~213,000 spp.).
Main conclusions
Here, we present the structure, content and automated workflows of GIFT and a corresponding web‐interface (http://gift.uni-goettingen.de) as proof of concept for the feasibility and potential of mobilizing aggregated biodiversity data for global macroecological and biogeographical research.
The Earth’s islands harbor a distinct, yet highly threatened, biological and cultural diversity that has been shaped by geographic isolation and unique environments. Island systems are key natural ...laboratories for testing theory in ecology and evolution. However, despite their potential usefulness for research, a quantitative description of island environments and an environmental classification are still lacking. Here, we prepare a standardized dataset and perform a comprehensive global environmental characterization for 17,883 of the world’s marine islands >1 km ² (∼98% of total island area). We consider area, temperature, precipitation, seasonality in temperature and precipitation, past climate change velocity, elevation, isolation, and past connectivity—key island characteristics and drivers of ecosystem processes. We find that islands are significantly cooler, wetter, and less seasonal than mainlands. Constrained by their limited area, they show less elevational heterogeneity. Wet temperate climates are more prevalent on islands, whereas desert climates are comparatively rare. We use ordination and clustering to characterize islands in multidimensional environmental space and to delimit island ecoregions, which provides unique insights into the environmental configuration and diversity of the world’s islands. Combining ordination and classification together with global environmental data in a common framework opens up avenues for a more integrative use of islands in biogeography, macroecology, and conservation. To showcase possible applications of the presented data, we predict vascular plant species richness for all 17,883 islands based on statistically derived environment–richness relationships.
Island biogeographical models consider islands either as geologically static with biodiversity resulting from ecologically neutral immigration-extinction dynamics, or as geologically dynamic with ...biodiversity resulting from immigration-speciation-extinction dynamics influenced by changes in island characteristics over millions of years. Present climate and spatial arrangement of islands, however, are rather exceptional compared to most of the Late Quaternary, which is characterized by recurrent cooler and drier glacial periods. These climatic oscillations over short geological timescales strongly affected sea levels and caused massive changes in island area, isolation and connectivity, orders of magnitude faster than the geological processes of island formation, subsidence and erosion considered in island theory. Consequences of these oscillations for present biodiversity remain unassessed. Here we analyse the effects of present and Last Glacial Maximum (LGM) island area, isolation, elevation and climate on key components of angiosperm diversity on islands worldwide. We find that post-LGM changes in island characteristics, especially in area, have left a strong imprint on present diversity of endemic species. Specifically, the number and proportion of endemic species today is significantly higher on islands that were larger during the LGM. Native species richness, in turn, is mostly determined by present island characteristics. We conclude that an appreciation of Late Quaternary environmental change is essential to understand patterns of island endemism and its underlying evolutionary dynamics.
Isolation is a driving factor of species richness and other island community attributes. Most empirical studies have investigated the effect of isolation measured as distance to the nearest ...continent. Here we expanded this perspective by comparing the explanatory power of seventeen isolation metrics in sixty-eight variations for vascular plant species richness on 453 islands worldwide. Our objectives were to identify ecologically meaningful metrics and to quantify their relative importance for species richness in a globally representative data set. We considered the distances to the nearest mainland and to other islands, stepping stone distances, the area of surrounding landmasses, prevailing wind and ocean currents and climatic similarity between source and target areas. These factors are closely linked to colonization and maintenance of plant species richness on islands. We tested the metrics in spatial multi-predictor models accounting for area, climate, topography and island geology. Besides area, isolation was the second most important factor determining species richness on the studied islands. A model including the proportion of surrounding land area as the isolation metric had the highest predictive power, explaining 86.1% of the variation. Distances to large islands, stepping stone distances and distances to climatically similar landmasses performed slightly better than distance to the nearest mainland. The effect of isolation was weaker for large islands suggesting that speciation counteracts the negative effect of isolation on immigration on large islands. Continental islands were less affected by isolation than oceanic islands. Our results suggest that a variety of immigration mechanisms influence plant species richness on islands and we show that this can be detected at macro-scales. Although the distance to the nearest mainland is an adequate and easy-to-calculate measure of isolation, accounting for stepping stones, large islands as source landmasses, climatic similarity and the area of surrounding landmasses increases the explanatory power of isolation for species richness.
Recent years have seen an explosion in the availability of biodiversity data describing the distribution, function, and evolutionary history of life on earth. Integrating these heterogeneous data ...remains a challenge due to large variations in observational scales, collection purposes, and terminologies. Here, we conceptualize widely used biodiversity data types according to their domain (what aspect of biodiversity is described?) and informational resolution (how specific is the description?). Applying this framework to major data providers in biodiversity research reveals a strong focus on the disaggregated end of the data spectrum, whereas aggregated data types remain largely underutilized. We discuss the implications of this imbalance for the scope and representativeness of current macroecological research and highlight the synergies arising from a tighter integration of biodiversity data across domains and resolutions. We lay out effective strategies for data collection, mobilization, imputation, and sharing and summarize existing frameworks for scalable and integrative biodiversity research. Finally, we use two case studies to demonstrate how the explicit consideration of data domain and resolution helps to identify biases and gaps in global data sets and achieve unprecedented taxonomic and geographical data coverage in macroecological analyses.
One of the best-known general patterns in island biogeography is the species–isolation relationship (SIR), a decrease in the number of native species with increasing island isolation that is linked ...to lower rates of natural dispersal and colonization on remote oceanic islands. However, during recent centuries, the anthropogenic introduction of alien species has increasingly gained importance and altered the composition and richness of island species pools. We analyzed a large dataset for alien and native plants, ants, reptiles, mammals, and birds on 257 (sub) tropical islands, and showed that, except for birds, the number of naturalized alien species increases with isolation for all taxa, a pattern that is opposite to the negative SIR of native species. We argue that the reversal of the SIR for alien species is driven by an increase in island invasibility due to reduced diversity and increased ecological naiveté of native biota on the more remote islands.
Dissecting global turnover in vascular plants König, Christian; Weigelt, Patrick; Kreft, Holger
Global ecology and biogeography,
February 2017, Volume:
26, Issue:
1/2
Journal Article
Peer reviewed
Aim: To provide a global assessment of turnover in vascular plants across geographical settings and taxonomic and functional groups. We tested whether turnover and its spatial and environmental ...drivers are affected by the geographical setting and whether taxonomic and functional groups exhibit specific turnover patterns that are associated with their ecological characteristics. Location: Global. Methods: We collated a global dataset of vascular plant checklists comprising 258 island and 346 mainland units. We created subsets based on the geographical setting of study units (mainland, islands, different island types) as well as taxonomic and functional properties of species (angiosperms, gymnosperms, pteridophytes, trees, shrubs, herbs). For the entire dataset, and each subset, the distance decay of similarity was assessed using generalized linear models. To disentangle the relative importance of spatial and environmental drivers of turnover, we employed generalized dissimilarity models. Finally, the model results were used to predict compositional similarity of vascular plants across a global grid. Results: The distance decay of similarity was stronger for mainland units than for islands. Among taxonomic and functional groups, the rate of decay was lowest for pteridophytes and highest for shrubs. Partitioning of turnover into distance-and environment-related effects revealed fundamental differences between mainland and island systems, with geographical distance being more important on the mainland than on islands. This trend was consistent across taxonomic and functional groups. Main conclusions: Our results reveal an important role of geographical context in shaping beta-diversity patterns. We argue that geographical settings are characterized by specific configurations of ecological filters that have a strong impact on the magnitude and structure of turnover. Moreover, taxonomic and functional groups are differentially successful in passing these filters, resulting in group-and setting-specific turnover patterns. Exploring these interdependences for different taxa and geographical settings at different scales will help to improve our understanding of beta diversity.
Abstract
Advancing knowledge of biodiversity requires global open‐access databases. Having large‐scale information on plant distributions, functional traits and evolutionary history will enable the ...scientific community to improve its understanding of the patterns and drivers of plant diversity on a global scale.
The Global Inventory of Floras and Traits (GIFT) is a global database of regional plant checklists that has proven successful in documenting biogeographical patterns of plants. Since the release of the first version of GIFT, the database kept on expanding. We introduce GIFT version 3.0, which contains 5169 plant checklists referring to 3400 regions worldwide. These checklists include a total of 371,148 land plant species, mostly vascular plants, of which 354,848 have accepted species names, and species‐level data for 109 functional traits. This new version of GIFT relies on new resources for taxonomic name standardization, is matched to a new plant phylogeny, comes with a new trait aggregation workflow and includes additional environmental variables.
We also present the
GIFT
R
‐package, which contains all necessary functions to retrieve distributional, functional, phylogenetic, and environmental data from the GIFT database. The package comes with a dedicated website,
https://biogeomacro.github.io/GIFT/
, which includes three vignettes to guide users in retrieving data from GIFT.
The recent development of GIFT and its associated
R
‐package provide ecologists with access to one of the largest plant databases. This will foster research into regional to global patterns of plant diversity and their underlying mechanisms. The ability to retrieve and cite data from any previous and current instance of the GIFT database will ensure the reproducibility of studies that utilise it.
Abstract
Humans cultivate thousands of economic plants (i.e. plants with economic value) outside their native ranges. To analyze how this contributes to naturalization success, we combine global ...databases on economic uses and naturalization success of the world’s seed plants. Here we show that naturalization likelihood is 18 times higher for economic than non-economic plants. Naturalization success is highest for plants grown as animal food or for environmental uses (e.g. ornamentals), and increases with number of uses. Taxa from the Northern Hemisphere are disproportionately over-represented among economic plants, and economic plants from Asia have the greatest naturalization success. In regional naturalized floras, the percentage of economic plants exceeds the global percentage and increases towards the equator. Phylogenetic patterns in the naturalized flora partly result from phylogenetic patterns in the plants we cultivate. Our study illustrates that accounting for the intentional introduction of economic plants is key to unravelling drivers of plant naturalization.
The evolution of insular woodiness Zizka, Alexander; Onstein, Renske E; Rozzi, Roberto ...
Proceedings of the National Academy of Sciences - PNAS,
09/2022, Volume:
119, Issue:
37
Journal Article
Peer reviewed
Open access
Insular woodiness (IW)-the evolutionary transition from herbaceousness toward woodiness on islands-is one of the most iconic features of island floras. Since pioneering work by Darwin and Wallace, a ...number of drivers of IW have been proposed, such as 1) competition for sunlight requiring plants with taller and stronger woody stems and 2) drought favoring woodiness to safeguard root-to-shoot water transport. Alternatively, IW may be the indirect result of increased lifespan related to 3) a favorable aseasonal climate and/or 4) a lack of large native herbivores. However, information on the occurrence of IW is fragmented, hampering tests of these potential drivers. Here, we identify 1,097 insular woody species on 375 islands and infer at least 175 evolutionary transitions on 31 archipelagos, concentrated in six angiosperm families. Structural equation models reveal that the insular woody species richness on oceanic islands correlates with a favorable aseasonal climate, followed by increased drought and island isolation (approximating competition). When continental islands are also included, reduced herbivory pressure by large native mammals, increased drought, and island isolation are most relevant. Our results illustrate different trajectories leading to rampant convergent evolution toward IW and further emphasize archipelagos as natural laboratories of evolution, where similar abiotic or biotic conditions replicated evolution of similar traits.
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