DOI: 10.5061/dryad.tmpg4f4xd
title: Data from: Different functional characteristics can explain different dimensions of plant invasion success

description: The success of invasive plant species can be evaluated using different
 dimensions, such as, range size, abundance, and impact. These different
 dimensions do not always covary but are rarely separated, suggesting an
 urgency to disentangle the functional mechanisms behind them. A dataset of
 leaf traits and four dimensions of invasion success (i.e., range size,
 local abundance, impact on native plant abundance, and impact on native
 plant diversity) were compiled for 395 non-native plant species in the US
 and Europe. Associations among dimensions of invasion success and between
 leaf traits and dimensions were analyzed with general linear models (LMs)
 and supplemented by phylogenetic generalized least square (PGLS) models,
 which control for the phylogenetic relatedness across species. The
 pair-wise associations between most pairs of invasion dimensions were weak
 or neutral. The only exception was the association between impact on
 native plant abundance and impact on native plant diversity, which was
 strongly positive. Traits of species that have large range sizes were
 associated with a high metabolic rate; whereas, traits of species that
 were abundant or had a strong impact at the local scale were associated
 with low metabolic rate. In addition, traits of species with a large range
 size or having strong impacts on native plant abundance were associated
 with acquisitive strategies; whereas, traits of species with a high local
 abundance or strong impacts on native plant diversity were associated with
 conservative strategies. Synthesis: Different dimensions of invasion
 success were associated with different functional traits. Invasion success
 at the regional scale was related to traits that promote rapid
 colonization; whereas, invasion success at the local scale was related to
 traits that are potentially less preferred by herbivores. Some locally
 successful invaders even possessed traits that facilitate a high-stress
 tolerance and conservative strategy, which were similar to locally
 abundant native species. Therefore, an ambiguous definition of “invasion
 success” in mechanism-related studies may produce inconsistent or even
 controversial conclusions, highlighting the importance of separately
 studying different dimensions of invasion success.
description: Four dimensions of invasion success were calculated: two
 occupancy and abundance dimensions (range size and local abundance) and
 two impact dimensions (impact on native plant abundance and impact on
 native plant diversity). The range size of each non-native species was
 quantified as the relative occurrence frequency of the focal species which
 was based on the number of equal-sized grid cells occupied by each species
 in its non-native range, and was projected from the geographic records in
 the Global Biodiversity Information Facility (GBIF) (https://www.gbif.org/). The local abundance of each non-native species was calculated as the median percent cover of the focal species across all sites that it occurred. The impact of each non-native species on native plant abundance (or diversity) was quantified as the cover (or diversity) loss of native species due to a 1% increase in the cover of the focal species [i.e., the opposite of the estimated coefficient of the log-linear regression between the cover of the focal non-native species and the total cover (or Shannon-Wiener index) of the native plants at those sites containing the focal species]. After removing the coefficients of the models with insignificant R<sup>2</sup> values, we obtained a total of 63 and 83 available estimates for each species’ impact on the abundance and diversity of native plants, respectively. As to leaf trait data, we downloaded the values of 8 frequently measured leaf traits [leaf carbon content (LCC), leaf nitrogen content (LNC), leaf carbon/nitrogen ratio (C:N), leaf dry weight (LDW), leaf fresh weight (LFW), leaf dry matter content per dry weight (LDMC), leaf area (LA), and specific leaf area (SLA)] from the TRY trait database (https://www.try-db.org/) (request ID 5836). For the 96 species that were exclusively non-native to the US, we extracted their trait values as measured in North America and obtained data for 51 species with at least one available trait value. Similarly, for the 28 species that were exclusively non-native to Europe, we extracted their trait values as measured in Europe and obtained available data for 19 species. For the 512 species that were non-native to both ranges, we extracted their trait values from both ranges and calculated the averaged value across the two ranges. If the value of a trait was only available for one range, we used that available value to represent the trait value across ranges.