Spatially-Explicit Estimation of Geographical Representation in Large-Scale Species Distribution Datasets

Abstract

Much ecological research relies on existing multispecies distribution datasets. Such datasets, however, can vary considerably in quality, extent, resolution or taxonomic coverage. We provide a framework for a spatially-explicit evaluation of geographical representation within large-scale species distribution datasets, using the comparison of an occurrence atlas with a range atlas dataset as a working example. Specifically, we compared occurrence maps for 3773 taxa from the widely-used Atlas Florae Europaeae (AFE) with digitised range maps for 2049 taxa of the lesser-known Atlas of North European Vascular Plants. We calculated the level of agreement at a 50-km spatial resolution using average latitudinal and longitudinal species range, and area of occupancy. Agreement in species distribution was calculated and mapped using Jaccard similarity index and a reduced major axis (RMA) regression analysis of species richness between the entire atlases (5221 taxa in total) and between co-occurring species (601 taxa). We found no difference in distribution ranges or in the area of occupancy frequency distribution, indicating that atlases were sufficiently overlapping for a valid comparison. The similarity index map showed high levels of agreement for central, western, and northern Europe. The RMA regression confirmed that geographical representation of AFE was low in areas with a sparse data recording history (e.g., Russia, Belarus and the Ukraine). For co-occurring species in south-eastern Europe, however, the Atlas of North European Vascular Plants showed remarkably higher richness estimations. Geographical representation of atlas data can be much more heterogeneous than often assumed. Level of agreement between datasets can be used to evaluate geographical representation within datasets. Merging atlases into a single dataset is worthwhile in spite of methodological differences, and helps to fill gaps in our knowledge of species distribution ranges. Species distribution dataset mergers, such as the one exemplified here, can serve as a baseline towards comprehensive species distribution datasets.

Similar responses of native and alien floras in European cities to climate

“…The level of plant species invasion, which was defined as the proportion of alien species averaged across the seven sampled habitats within each city, therefore did not show any significant change along the Mediterranean‐to‐temperate climatic gradient. Our result is in accordance with those from the studies of Kalwij, Robertson, Ronk, Zobel, and Pärtel () and Ronk et al. (), which were based on grid atlas data on the whole (not only urban) flora, and they found the same decreasing trend in both native and alien species richness from Central to Southern Europe.…”

Patterns of modern pollen and plant richness across northern Europe

“…To characterise plant richness, we merged the two largest plant atlases available in Europe, Atlas Florae Europaeae (Jalas & Suominen, ; Jalas, Suominen, & Lampinen, ; Jalas, Suominen, Lampinen, & Kurtto, ; Kurtto, Lampinen, & Junikka, ) and Atlas of North European Vascular Plants (Hultén & Fries, ) as described in Kalwij, Robertson, Ronk, Zobel, and Pärtel (). The resulting dataset is the most comprehensive broad‐scale plant distribution data to date, with distribution information for 5,221 European plant taxa (species and subspecies), i.e.…”

Annual monitoring reveals rapid upward movement of exotic plants in a montane ecosystem

“…Such historical data, however, are often confounded by observer bias and sampling intensity (Wolmarans et al 2010;Kalwij et al 2014a) (Wilson et al 2007), even when considered at the spatial scale of an entire region or country. Consequently, the temporal precision and accuracy of minimum residence time of exotic species in southern Africa does not match that of our study design.…”

“…An inevitable downside of such datasets is that their accuracy is biased towards areas and time periods with a high collection intensity (Kalwij et al 2014a). As a result, these datasets do not have a sufficiently high spatio-temporal resolution to relate trends in species distribution to certain environmental drivers (Pyšek et al 2011).…”

“…Species distribution data therefore need to be sufficiently detailed to detect spatio-temporal trends (Pauchard et al 2009;Walther et al 2009). However, data that are typically being used, such as atlas data or herbarium records lack the temporal precision and coverage to meet this need (Pyšek et al 2011;Kalwij et al 2014a), especially for inconspicuous exotics in montane ecosystems (Walther et al 2009). Instead, repeated observations on exotics across an elevational gradient could be used to detect trends in distributional range and to gain better insights into the underlying mechanisms of range expansion.…”