Climate Warming May Facilitate Invasion of the Exotic Shrub Lantana camara

Abstract

Plant species show different responses to the elevated temperatures that are resulting from global climate change, depending on their ecological and physiological characteristics. The highly invasive shrub Lantana camara occurs between the latitudes of 35°N and 35°S. According to current and future climate scenarios predicted by the CLIMEX model, climatically suitable areas for L. camara are projected to contract globally, despite expansions in some areas. The objective of this study was to test those predictions, using a pot experiment in which branch cuttings were grown at three different temperatures (22°C, 26°C and 30°C). We hypothesized that warming would facilitate the invasiveness of L. camara. In response to rising temperatures, the total biomass of L. camara did increase. Plants allocated more biomass to stems and enlarged their leaves more at 26°C and 30°C, which promoted light capture and assimilation. They did not appear to be stressed by higher temperatures, in fact photosynthesis and assimilation were enhanced. Using lettuce (Lactuca sativa) as a receptor plant in a bioassay experiment, we also tested the phytotoxicity of L. camara leachate at different temperatures. All aqueous extracts from fresh leaves significantly inhibited the germination and seedling growth of lettuce, and the allelopathic effects became stronger with increasing temperature. Our results provide key evidence that elevated temperature led to significant increases in growth along with physiological and allelopathic effects, which together indicate that global warming facilitates the invasion of L. camara.

Allelopathic effects of dominant ground vegetation species on initial growth of Pinus sylvestris L. seedlings in response to different temperature scenarios

“…The extracts prepared from tested species inhibited the radicle growth of pine seedlings more than hypocotyl growth at all temperatures. These findings agree to the results of previous studies indicating that seedling roots are more sensitive to allelochemicals than shoots (Zhang et al 2014).…”

“…. These results match with those observed in previous studies showing that increased temperature stimulates the production of higher allelochemical concentrations, which could have stronger effects on acceptor species (Wang et al 2011, Zhang et al 2014. However, our results indicated a different response of the root and shoot extracts of dominant species to seed germination at all temperatures compared with the data obtained in previous studies (Mahmoodzadeh et al 2015, Gulzar & Siddiqui 2014.…”

Predicting the potential distribution of Lantana camara L. under RCP scenarios using ISI-MIP models

“…Therefore, the distribution of L. camara in the coming decades may not occur uniformly but rather more patchily reflecting the availability of favorable microhabitats (Taylor et al 2012b). In a recent pot experiment, Zhang et al (2014) reported that elevated temperatures led to significant increases in growth of L. camara along with physiological and allelopathic effects. These findings further suggest that global warming resulting from climate change is likely to facilitate invasion of L. camara into new regions of the world.…”

Dynamics of Understory Shrub Biomass in Six Young Plantations of Southern Subtropical China

“…The number of shrub species was obviously higher in AC than that in other plantations, which was the highest in AC, and the lowest in NS. This can be ascribed to the understory abiotic and biotic conditions and the characteristics of species [33,34]. Shrub germination may be affected by herbs through competition for nutrients and light; higher herb biomass hinders shrub species germination [35,36].…”