Importance of invasion mechanisms varies with abiotic context and plant invader growth form

1. Many invasion hypotheses propose biotic interactions as the main mechanism to explain non-native species' success.  Despite the evidence that the strength of biotic interactions varies with abiotic context, it remains unclear whether the importance of the different mechanisms proposed to explain invasion predictably varies with abiotic context and whether this variation is consistent across different growth forms.
2. We reviewed studies at a global scale to evaluate whether evapotranspiration, latitude, precipitation, and temperature influence the importance of disturbance, enemy release, facilitation, and novel weapons mechanisms to explain non-native plant invasions.  In total, we calculated 171 effect sizes for ~300 non-native plant species covering a wide range of environmental conditions and growth forms.
3. Environmental context and plant growth form influenced the role played by each invasion mechanism.  The importance of disturbance in facilitating invasion exhibited a quadra...