Warming delays the phenological sequences of an autumn‐flowering invader

Abstract

Phenology can play an important role in driving plant invasions; however, little is known about how climate warming, nitrogen (N) deposition, and invasion stages influence the phenological sequences of autumn‐flowering invaders in a subtropical climate. Accordingly, we conducted an experiment to address the effects of experimental warming, N‐addition, and community types on the first inflorescence buds, flowering, seed‐setting, and dieback of invasive Solidago canadensis. Warming delayed the onset of first inflorescence buds, flowering, seed‐setting, and dieback; N‐addition did not influence these four phenophases; community types influenced the onset of first seed‐setting but not the other phenological phases. Seed‐setting was more sensitive to experimental manipulations than the other phenophases. The onset of first inflorescence buds, flowering, and seed‐setting was marginally or significantly correlated with ramet height but not ramet numbers. Our results suggest that future climate warming might delay the phenological sequences of autumn‐flowering invaders and some phenophases can shift with invasion stages.

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

“…In its native range (i.e., North America), the inflorescence of S. canadensis is evident in late July or early August (Werner et al, 1980). However, in its invaded range (i.e., China), it does not start flowering until September (Peng et al, 2018(Peng et al, , 2019. Solidago canadensis is a perennial forb with large clonal colonies, can grow up to 4 m, and its flowers are self-sterile and seeds are wind-dispersed (Abhilasha et al, 2008;Dong et al, 2015).…”

“…At the beginning of the experiment, we set up 256 mesocosms including dozens of plant assemblages from seed (i.e., monocultures of S. canadensis and mixtures consisting of S. canadensis and four native plant species from North America or China). The conditions of mesocosms and their photographs have been described previously (Peng et al, 2018). As described above, each mesocosm was either a monoculture or a mixture.…”

“…Accordingly, there were about 20 S. canadensis populations per manipulation initially. The long-term experiment has been described previously (Peng et al, 2018(Peng et al, , 2019. Briefly, our longterm experiment was a factorial design and included five factors (see above), each with two levels.…”

“…Since climate warming can influence plant invasions (Bradley et al, 2010), this has particular relevance to seed quality and seed germination (Aragn-Gastlum et al, 2018). For example, recent studies have shown that climate warming may strongly influence seed quality and seed germination (Aragn-Gastlum et al, 2018;Li et al, 2018) and plant mortality and phenology during the invasion process (Peng et al, 2018;He and He, 2020). Plant populations from native and non-native ranges perform differentially, including reproductive output, seedling recruitment, individual density, and competitive ability (Lockwood et al, 2013).…”

“…Here, we concentrated on one scientific question: how climate warming influences the seed quality and subsequent germination of native and invasive Solidago canadensis populations. Solidago canadensis was selected as a focal species, because it is among seriously noxious invaders in China (Dong et al, 2015) and sensitive to climate warming (Peng et al, 2018(Peng et al, , 2019. The central hypothesis was that climate warming may influence the seed quality and subsequent germination of native S. canadensis populations stronger than those of invasive counterparts, because native populations of Centaurea maculosa and S. canadensis are more sensitive to climate warming than invasive populations (He et al, 2012;Peng et al, 2019).…”