Exotic invaders dominating native species

Dr Kevin Burns from Victoria University's School of Biological Sciences has spent 10 years documenting the ecosystem of an archipelago of small islands off the south coast of Wellington.

2005. Photograph of the apex of a single island in the archipelago in the first year of observations.

2015. The apex a decade later, which shows the fate of several individuals of a native shrub species (Coprosma repens) across the observation period. It also shows several individuals of an exotic shrub species (Lupinus arboreus) that colonised the island in 2010 and has since spread prolifically.

During this time the numbers of exotic plants making their home here has increased quickly, with the evidence suggesting that from being in the minority they now out number native plants.

What's more that ''exotic invasion'' is still taking place. So what's driving the immigration and extinction of certain species ?

Does this mirror what's happening in the rest of the country? And what can be done to slow the invasion?

Dr Burns talks to Kathryn Ryan.