The Future of Alien Invasions: the impact of rates of introduction, and introduction bias, on the richness and composition of alien assemblages

Project Description:

A defining feature of the Anthropocene is the human-mediated translocation of species to areas beyond their natural biogeographic boundaries. Numbering in the tens of thousands, these species, termed aliens, can cause substantial environmental and economic impacts. Despite well-known negative impacts, the rate and magnitude of alien species introductions is increasing worldwide; currently, almost 600 new alien species are known to establish each year. As well as increased rates of introduction, different types of species are being introduced as a result of expanding trade routes and changing demands for different types of pets, ornamental plants and agricultural products.

The rate and magnitude of alien species introductions is a problem because it influences the number of alien species that establish and become invasive at a location. The arrival of new types of species poses a particular problem for biosecurity; biosecurity largely relies on knowledge of which species have been introduced in the past, and on research that has “profiled” alien species that have already become invasive. When the types of species introduced in the first place are biased, the arrival of new types of species – with different sets of traits to past invaders – may prevent accurate identification of high risk invasive species.

This PhD will use theory and empirical data to quantify introduction rates and the extent of introduction bias using case studies from vertebrates and plants. The knowledge and understanding gained will be used to forecast the types of species that will become introduced and invasive in the future.

Policy Impact of Research:

Given the environmental and economic impacts of alien species, it is essential to understand how increasing globalization and accelerating rates of biotic exchange may alter which places are vulnerable to invasion, and which species are likely to become invasive. Findings from this PhD will inform biosecurity and invasive species management.

Research Relating to this Project:

1. No saturation in the accumulation of alien species worldwide
2. Dissecting the null model for biological invasions: A meta-analysis of the propagule pressure effect
3. Introduced species that overcome life history tradeoffs can cause native extinctions