Let’s break down this phrase to help us better understand “Invasive Alien Species”:

Alien species refers to plants, animals and microorganisms that are exotic, non-native, introduced or non-indigenous, with respect to a particular ecosystem.

Not all alien species are invasive. They become invasive only when they cause change and threaten native biological diversity.

Generally, the spread of an Invasive Alien Species involves four stages:
Introduction, Establishment, Invasion and Spread.

In this blog, we will be using these four stages as a guideline, discussing how IAS is introduced to Singapore, why they become established, how they are invasive and cause change to the biodiversity, and attempts in Singapore to contain their spread, drawing links to Conservation Psychology along the way.