Non-native populations of an invasive tree outperform their native conspecifics.

Heidi Hirsch,Henrik Von Wehrden,Isabell Hensen,Daniel Renison,Karsten Wesche,Matthias Hartmann,Catherina Wypior

doi:10.1093/aobpla/plw071

Abstract

Introduced plants often face new environmental conditions in their non-native ranges. To become invasive, they need to overcome several biotic and abiotic filters that may trigger adaptive changes in life-history traits, like post-germination processes. Such early life cycle traits may play a crucial role in the colonization and establishment success of invasive plants. As a previous study revealed that seeds of non-native populations of the woody Siberian elm, Ulmus pumila, germinated faster than those of native populations, we expected growth performance of seedlings to mirror this finding. Here, we conducted a common garden greenhouse experiment using different temperature and watering treatments to compare the biomass production of U. pumila seedlings derived from 7 native and 13 populations from two non-native ranges. Our results showed that under all treatments, non-native populations were characterized by higher biomass production and enhanced resource allocation to aboveground biomass compared to the native populations. The observed enhanced growth performance of non-native populations might be one of the contributing factors for the invasion success of U. pumila due to competitive advantages during the colonization of new sites.

Highlights

Organisms that become successful invaders after being introduced into non-native ranges must pass several selective biotic or abiotic filters that may trigger rapid evolutionary change (Novak 2007; Prentis et al 2008)
Our results showed that under all treatments, non-native populations were characterized by higher biomass production and enhanced resource allocation to aboveground biomass compared to the native populations
The post-hoc analysis of this interaction revealed that the warmer temperature treatment had a stronger positive effect for the aboveground biomass production under the wet water treatment than under the medium and dry water treatments (v2 1⁄4 5.59, df 1⁄4 1, adjusted P 1⁄4 0.036) and to the dry water treatment

Summary

Introduction

Organisms that become successful invaders after being introduced into non-native ranges must pass several selective biotic or abiotic filters that may trigger rapid evolutionary change (Novak 2007; Prentis et al 2008). Such change can contribute to their invasion success, for VC The Authors 2016. A shift in growth strategies in non-native populations often indicates enhanced efficiency of resource allocation (Zou et al 2007)

Methods

Results

Discussion

Conclusion