Characterization of Invasiveness, Thermotolerance and Light Requirement of Nine Invasive Species in China

Abstract

Understanding responsible functional traits for promoting plant invasiveness could be important to aid in the development of adequate management strategies for invasive species. Seed traits play an important role in the plant life cycle by affecting dispersal ability, formation of the soil seed bank, type and level of dormancy, germination, survival and/or competitive ability. We assessed seed traits and germination strategies of nine invasive species under five temperature regimes and light/dark treatments. Our results showed a considerable level of interspecific variation in germination percentage among the tested species. Both cooler (5/10 °C) and warmer (35/40 °C) temperatures tended to inhibit germination. All study species were considered small-seeded, and seed size did not affect germination in the light. Yet, a slightly negative correlation was found between germination in the dark and seed dimensions. We classified the species into three categories according to their germination strategies: (i) risk-avoiders, mostly displaying dormant seeds with low G%; (ii) risk-takers, reaching a high G% in a broad range of temperatures; (iii) intermediate species, showing moderate G% values, which could be enhanced in specific temperature regimes. Variability in germination requirements could be important to explain species coexistence and invasion ability of plants to colonize different ecosystems.

Storage on Maternal Plants Affects Temperature Requirements during Germination in Rumex obtusifolius

“…In the case of R. obtusifolius, Figure 2 clearly shows its antagonistic effect. When it comes to PC2, the most important factors favoring the germination of R. obtusifolius are SYN, SH and SW. SH and SW clearly show us that slightly heavier seeds have a favored faster germination, while lighter seeds may present slower germination, a fact that was recently demonstrated in a study with nine other invasive species from China [58]. Arthrocnemum macrostachyum and Suaeda vermiculata, other invasive species from China, showed the same behavior [34] as well as 19 other species studied [59] in the same climate and natural conditions as those presented in this work.…”

“…Lara, et al [60], studying the effect of the source of nitrate used on the germination of Lycopersicon esculentum, also showed a higher MGT with lower SYN values. Eight different pasture-forming grasses also showed the same antagonistic behavior between SYN and TMG [58]. In this same PCA, we can infer that larger seeds have a lower germination with a lower synchrony.…”

“…In this same PCA, we can infer that larger seeds have a lower germination with a lower synchrony. In this item, the current bibliography does not allow us to make a direct inference, since larger or smaller seeds can present different germination strategies, with larger seeds presenting larger or smaller SYN [34,58].…”

Interannual Variation in Gas Exchange and Leaf Anatomy in Cenostigma pyramidale Is Exacerbated through El Niño and La Niña Climate Events

“…This increase in leaf temperature is inversely related to photosynthesis, often leading to reduced photosynthetic activity, as shown in this study, where these features showed a negative correlation (r = −0.692) between them. On the other hand, plants inhabiting arid and xerophytic habitats tend to exhibit characteristics that promote the formation of smaller, thicker leaves [22,36,40,86,87]. Larger leaves tend to possess reduced convection coefficients and exhibit greater resistance to heat transfer through the boundary layers of the leaves in comparison to their smaller counterparts [69].…”

Seed longevity and germination of the emerging invasive species wavyleaf basketgrass (Oplismenus undulatifolius) under varied light regimes

“…Alternatively, narrow germination requirements may promote invasion success by ensuring favorable conditions for seedling establishment, such as through microhabitat selection (Carvalho et al 2021; Gioria et al 2018; Kudoh et al 2007; Makana and Thomas 2005; Marushia et al 2010; Stromberg et al 2007; Wainwright et al 2012). As plants may encounter diverse environmental conditions following initial dispersal to new locations, broad light requirements for germination may strongly influence where invasive plants may be successful, whereas strict light requirements may optimize seedling establishment and growth (Bhatt et al 2023; Castillo et al 2013).…”