Invasive grasses do not always exhibit superior and faster plant life-history traits in the introduced range than in the native range

By

Vilà, Montserrat
Trillo, Alejandro
Morón-López, Raúl
D'Antonio, Carla
Funk, Jennifer L.
Parker, Ingrid M.
Rodríguez-Parra, Alba
Castro-Díez, Pilar

Type

Article

Date of Publication

2025-11-27

Original Publication

NeoBiota : advancing research on alien species and biological invasions

Volume

104

Pages

203--223

Subjects

Clinal variation , common garden , Invasive plants , lifespan , Mediterranean grasslands , Phenology , polyploidy , range comparison

Contributed by

Pensoft Publishers

Language

English

Published by

Sophia, Bulgaria Pensoft Publishers

Identifiers

DOI: https://doi.org/10.3897/neobiota.104.162821

 

Abstract

<br> Many invasive plants are larger, and produce more seeds in populations from the introduced range compared to those from their native range. Annual invasive plants might also benefit in their introduced range from fast germination, early seed production and shorter life cycles. Using three species of annual grass native to Spain and invasive in California (<br> Avena barbata<br> ,<br> Bromus hordeaceus<br> and<br> Brachypodium distachyon<br> spp. complex), we tested the hypothesis that plants from the introduced range are not only larger and more fecund, but they also have faster life cycles than plants from the native range. Additionally, these plant traits are expected to vary along climate gradients, both in the introduced and in the native populations. Hence, we collected seeds from introduced and native populations across different climate conditions and then grew them all under a common outdoor condition. In support of our hypothesis, we found that<br> Avena<br> plants from the introduced range were larger, more fecund and had a shorter lifespan than from the native range. By contrast,<br> Bromus<br> plants invested less biomass in reproduction in the introduced range. In<br> Brachypodium<br> , seeds from the introduced range germinated later and flowering was delayed compared to the native range. These plants also produced fewer seeds and had a shorter lifespan in the introduced range. Genome size analysis indicated that<br> Brachypodium<br> plants from the introduced range are tetraploid while, in the native range, diploid and tetraploid individuals co-occur. We found some trait variation could be explained by climate differences amongst populations, but this was mostly within the native range, suggesting that our study taxa are not yet locally adapted to climatic conditions of their introduced range. Overall, our common garden experiment indicated that the invasion success of these annual grasses is not clearly associated with superior biomass, reproduction or fast plant life-history traits. For<br> Brachypodium<br> , polyploidy may play a role in its invasion success.<br>