Climate Warming Facilitates Seed Germination in Native but Not Invasive Solidago canadensis Populations

Xiao-Hui Zhou,Wei-Ming He

doi:10.3389/fevo.2020.595214

Abstract

Plant performance is commonly temperature-dependent so that this performance could vary with climate warming. Seeds are among the most important propagules of plants, and seed traits strongly influence plant invasion success. Therefore, understanding seed traits under climate warming is useful for predicting invasion risks. To this end, we conducted a warming experiment with an infrared radiator and examined the effects of 5 years warming (approximately 2°C above ambient) on the seed quality and subsequent germination of Solidago canadensis from North America, where it is native (24 native populations), and from China, where it is invasive (29 invasive populations). Temperature regimes (i.e., ambient vs. warming) interacted with population sources (i.e., native vs. invasive) to significantly influence seed germination, but not thousand-seed mass. Warming significantly advanced the seed germination timing of native S. canadensis populations and increased their seed germination rate; warming did not influence the germination timing but decreased the germination rate of invasive S. canadensis populations. Across two temperature regimes combined, 24 native S. canadensis populations had smaller seeds, later germination timing, and lower germination rate than 29 invasive S. canadensis populations. These findings suggest that climate warming could facilitate the seed germination of native but not invasive populations. Our data also highlight that invasive populations might be more successful than native populations due to better seed quality and faster and higher seed germination.

Highlights

Plant invasions are complex processes (Theoharides and Dukes, 2007; Catford et al, 2009; Lockwood et al, 2013) so that dozens of hypotheses have been put forth to explain invasion success (Catford et al, 2009; Jeschke, 2014)
The first key finding of our study was that 5-year continued warming, as an environmental cue, yielded more positive effects on the seed germination of S. canadensis from its native but not introduced range
Peng et al (2019) found that native S. canadensis populations were more sensitive to climate warming and nitrogen deposition than invasive populations in terms of leaf traits, ramet growth, and phenological sequences

Summary

Introduction

Plant invasions are complex processes (Theoharides and Dukes, 2007; Catford et al, 2009; Lockwood et al, 2013) so that dozens of hypotheses (e.g., ideal weed and novel weapons) have been put forth to explain invasion success (Catford et al, 2009; Jeschke, 2014). Stolons, and rhizomes are the most important propagules of plants (Harper, 2010) and play an extremely crucial role in the invasion processes (Lockwood et al, 2005). The relative importance of seeds, stolons, and Climate Warming and Seed Traits rhizomes varies among different plant invaders (Wang et al, 2016) and/or with invasion stages within the same plant invader (Theoharides and Dukes, 2007). The relative role of different propagules depends on manners through which a given taxon is introduced from its native range into new ranges

Methods

Results

Conclusion