Diversity- and density-mediated allelopathic effects of resident plant communities on invasion by an exotic plant

Abstract

Aims Resident plants can exert allelopathic effects on introduced exotic plants, and resistance to exotic plant invasions usually increases with diversity and density of the resident plant communities. We hypothesize that allelopathic effects increase with increasing diversity and density of the community, and thereby contribute to the community's resistance against invaders. Methods To test these hypotheses, we conducted two greenhouse experiments in which we grew five individuals of the exotic invasive plant Solidago canadensis in pots without residents and in artificially assembled resident plant communities either with two levels of diversity (4 or 8 resident plant species) or two levels of density (8 or 32 individuals, representing 8 species). We used activated carbon as the allelopathy-neutralizer treatment in both the diversity and the density experiment.

The effect of nitrogen and temperature changes on Solidago canadensis phenotypic plasticity and fitness

“…S. canadensis is a perennial herb and was first introduced into Shanghai, China, in 1935 for ornamental purposes (Xu, Peng, Feng, & Abdulsalih, 2014). S. canadensis is widely distributed over more than 20,000 acres along the southeast coast and the Yangtze River basin in China (Li et al, 2016; Ren et al, 2019), due to its rapid and prolific vegetative and generative growth (Hartnett & Bazzaz, 1983), strong allelopathic effects (Adomako et al, 2019), and high resource‐use efficiency (Wan et al, 2018). All the sampled plants of S. canadensis in China were hexaploid (Li et al, 2016).…”

Effects of <i>Solidago canadensis</i> Invasion and Climate Warming on Soil Net N Mineralization

“…2. Although invasive S. canadensis had positive allelopathic effects on its own growth [65], in our short-term cultured experiment, invasive species might not have had long enough residence time to exhibit its allelopathic effects into full play, especially for the rhizomes that did not form completely [53,66,67]. 3.…”

Effects of cutting and sowing seeds of native species on giant ragweed invasion and plant diversity in a field experiment

“…For example, sowing seeds of native wet meadow species can successfully control the invasion of Phalaris arundinacea and lead to a transition to a new native plant community (Reinhardt Adams and Galatowitsch 2008). Seed density is a significant factor for the control of Solidago canadensis (Adomako et al 2019). Increasing seed density clearly has a significant inhibitory effect against the establishment of seedlings of Phragmites australis (Byun et al 2015) and Sicyos angulatus (Byun et al 2020).…”

“…Accumulating evidence indicates that seed density regulates biotic resistance to invasion (Reinhardt Adams and Galatowitsch 2008;Nemec et al 2013;Byun et al 2015;Adomako et al 2019). Sowing a high number of seeds of native species can create a dense and complex canopy that blocks sunlight and efficiently uptakes soil resources (Lindig-Cisneros and Zedler 2002b;Lindig-Cisneros and Zedler 2002a).…”