DOI: 10.5061/dryad.8sf7m0cvh
title: Alien plant fitness is limited by functional trade-offs rather than a long-term increase in competitive effects of native communities

description: Alien plants experience novel abiotic conditions and interactions with
 native communities in the introduced area. Intra- and interspecific
 selection on functional traits in the new environment may lead to
 increased population growth with time since introduction (residence time).
 However, selection regimes might differ depending on the invaded habitat.
 Additionally, in high-competition habitats, a build-up of biotic
 resistance of native species due to accumulation of eco-evolutionary
 experience to aliens over time may limit invasion success. We tested if
 the effect of functional traits and the population dynamics of aliens
 depends on interspecific competition with native plant communities. We
 conducted a multi-species experiment with 40 annual Asteraceae that differ
 in residence time in Germany. We followed their population growth in
 monocultures and in interspecific competition with an experienced native
 community (varying co-existence times between focals and community). To
 more robustly test our findings, we used a naïve community that never
 co-existed with the focals. We found that high seed mass decreased
 population growth in monocultures but tended to increase population growth
 under high interspecific competition. We found no evidence for a build-up
 of competition-mediated biotic resistance by the experienced community
 over time. Instead, population growth of the focal species was similarly
 inhibited by the experienced and naïve community. By comparing the effect
 of experienced and naïve communities on population dynamics over two years
 across a large set of species with a high variation in functional traits
 and residence time, this study advances the understanding of the long-term
 dynamics of plant invasions. In our study system, population growth of
 alien species was not limited by an increase of competitive effects by
 native communities (one aspect of biotic resistance) over time. Instead,
 invasion success of alien plants may be limited because initial spread in
 low-competition habitats requires different traits than establishment in
 high-competition habitats.
description: Applications used: R-software for statistical computing.
description: README of “Data from: Alien plant fitness is limited by functional
 trade-offs rather than a long-term increase in competitive effects of
 native communities” **General description of the data files:** General
 information: The data file
 “Brendel\_Schurr\_Sheppard\_2023\_lambda0.e0.f0.lambda1.csv” contains data
 which was collected from a common garden experiment at a field station of
 the University of Hohenheim (48°42’45.2”N, 9°11’23.6”E) in Stuttgart,
 Germany, during the growing seasons 2016 and 2017. The data file
 “Brendel\_Schurr\_Sheppard\_2023\_AsteraceaePhylogeny” contains the
 phylogenetic information of the Asteraceae study species extracted from
 the Daphne Phylogeny (Durka & Michalski 2012, Ecology 93). One
 line represents: One experimental mesocosm for the data file
 “Brendel\_Schurr\_Sheppard\_2023\_lambda0.e0.f0.lambda1.csv”. NA-values in
 the dataset refer to mesocosms, species, or populations, for which no data
 is available. **Variables:**
 “Brendel\_Schurr\_Sheppard\_2023\_lambda0.e0.f0.lambda1.csv” | **Name** |
 **Unit** | **Description** | | :--- | :--- | :---------- | | aster.id | NA
 | Asteraceae study species identity following the nomenclature of The
 Plant List | | aster.pop | NA | Asteraceae study species population (e.g.,
 24\_A = capital letter indicates seed material from a wild population;
 53\_Hohenheim = city name indicates seed material from the respective
 botanical garden) | | daphne.id | NA | Asteraceae study species name as in
 Daphne database (Durka & Michalski 2012 Ecology) | | pot.id | NA |
 number of the pot/mesocosm | | block | NA | experimental block, where the
 mesocosm was located | | mrt | years | minimum residence time of the
 Asteraceae study species measured as the difference between the first
 record in the wild and the starting year of the experiment (2016) | |
 community | NA | indication of the treatment: monoculture (1.MONO),
 experienced **C**entral **E**uropean community (2.CE), and naïve **N**orth
 **Am**erican community (3.NAm) | | lambda0 | NA | Growth rate of the seed
 population measured as the number of seeds produced per mesocosm by the
 end of 2016 divided by the number of seeds initially added to the mesocosm
 (i.e. 20 seeds) | | e0 | NA | establishment rate measured as the number of
 individuals per mesocosm by the end of 2016 divided by the number of seeds
 initially added to the mesocosm (20) | | n1 | NA | number of individuals
 per mesocosm by the end of 2016 | | s0 | NA | number of seeds initially
 added to the mesocosm (20) | | f0 | NA | fecundity measured as the number
 of seeds per mesocosm by the end of 2016 divided by the number of
 individuals per mesocosm by the end of 2016 | | lambda1 | | Growth rate of
 the seed population measured as the number of seeds produced per mesocosm
 by the end of 2017 divided by the number of seeds produced per mesocosm by
 the end of 2016 | | seed.mass | mg | mass of an individual seed measured
 at population level before the start of the experiment (see section
 “Functional trait measurement”) | | height.max | cm | maximum
 height/height at maturity measured at population level on transplanted
 individuals (see section “Functional trait measurement”) | | sla |
 mm<sup>2</sup>/mg | specific leaf area measured at population
 level on transplanted individuals (see section “Functional trait
 measurement”) |