Abstract:

Biological invasions are ubiquitous worldwide and have demonstrable negative impacts (e.g., rapid biodiversity losses, substantial economic losses, decreased ecosystem services, and irreversible environmental damage). Quantifying the impacts of biological invasions is among the core questions in invasion biology, and also a practical issue in ecosystem management. Existing approaches have two serious shortcomings: (1) the absence of true controls and (2) the presence of confounding non-invasion effects. These approaches, therefore, cannot precisely quantify the impacts of biological invasions in the field. Here, I explicitly highlight these long-overlooked drawbacks when quantifying invasion impacts, and propose two potential solutions: (1) creating true controls at the beginning of studies and (2) considering a “synchronous control” over the course of an experiment. These solutions might help us to precisely understand the impacts of biological invasions.

Key words: assessing approaches, biological invasions, invasion impacts, true control, synchronous control