title: 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.
authors.affiliation: Department of Botany, Institute of Ecology and Earth Sciences, University of Tartu, Tartu, Estonia; Department of Environmental Science and Engineering, Qilu University of Technology, Jinan, Shandong, China.
authors.forename: Qiaoying
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Department of Environmental Science and Engineering, Qilu University of Technology, Jinan, Shandong, China.
authors.forename: Yunchun
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, Guangdong, China.
authors.forename: Shaolin
authors.initials: S
authors.lastname: Peng
authors.affiliation: Department of Botany, Institute of Ecology and Earth Sciences, University of Tartu, Tartu, Estonia.
authors.forename: Kristjan
authors.initials: K
authors.lastname: Zobel
mesh_terms: D018533:Biomass; D002734:Chlorophyll / Q000096:biosynthesis; D004734:Energy Metabolism / Q000502:physiology; D018525:Germination / Q000187:drug effects; D057232:Global Warming; D058865:Introduced Species; D032410:Lantana / Q000254:growth & development* / Q000378:metabolism; D018545:Lactuca / Q000187:drug effects / Q000254:growth & development; D008954:Models, Biological; D010788:Photosynthesis / Q000502:physiology; D063148:Plant Dispersal; D010936:Plant Extracts / Q000633:toxicity*; D018515:Plant Leaves / Q000737:chemistry / Q000254:growth & development / Q000378:metabolism; D018547:Plant Stems / Q000254:growth & development* / Q000378:metabolism; D036226:Seedlings / Q000187:drug effects / Q000254:growth & development; D013696:Temperature
chemical_list: D010936:Plant Extracts; D002734:Chlorophyll