Arfin Khan, MAS; Vetter, V; Reshi, Zafer A; Dar, Parvaiz A; Jentsch, A: Factors influencing seedling emergence of three global invaders in greenhouses representing major eco-regions of the world, Plant Biology, 20, 610-618 (2018) [Link]
Success of germination and seedling emergence in new environments are crucial first steps in the life history of global plant invaders and thus play a key role in processes of range expansion. We examined the germination and seedling emergence success of three global plant invaders - Lupinus polyphyllus, Senecio inaequidens, and Verbascum thapsus - in greenhouses and climate chambers under climate regimes corresponding to seven eco-regions. Seed materials were collected from one non-native population for L. polyphyllus and S. inaequidens, and from 12 populations for V. thapsus (six natives and six non-natives). Experimental climates had significant effects on species responses. No species germinated in the dry (humidity ≤ 50%) and cool (temperature ≤ 5°C) experimental climates. But, all species germinated and emerged in two moderately cool (12-19°C) and in three warm (24-27°C) experimental climates. In general, V. thapsus showed higher fitness than S. inaequidens and L. polyphyllus. The climate of the seed source region influenced responses of native and non-native populations of V. thapsus. Non-native populations of V. thapsus, originating from the warmer seed source, showed higher performance in warm experimental climates and lower performance in moderately cool experimental climates compared to native populations. Responses of V. thapsus populations were also related to precipitation of the seed source region in moderately dry experimental climates. The warm, semi-arid and humid experimental climates are suitable for the crucial first steps of invasion success by L. polyphyllus, S. inaequidens and V. thapsus. The species adaption to its source region modified the responses of our studied plants under different experimental climates representing major eco-regions of the world.

last modified 2019-03-28