What is the best way to reduce threats from invasive species?

The best thing you could do is eradicate them as early as possible before they spread. For example 3 seeds of a foreign plant are brought to your country and dropped in the park down the road from your house. They grow and become small trees. You recognise them as a foreign trees or at least trees that aren't locally provenant, so you I'D. them correctly, and it turns out that they are nasty invasive species. You could do 2 things, one, let them set seed and proliferate throughout your community destroying your bushland. or, you could kill the 3 plants and save your local bushland with minimal physical effort or use of local resources. Same with animals. And the same on a larger scale. for example these plants have dropped their seed and spread all around the park. You could do nothing and let them keep spreading into other parks or you could start a plan of management and get in there and try to kill as many as you can and stop it from seeding and proliferating. The greater the number of different invasive plants or animals the more complex the removal process becomes and professional advise must be sought. Sometimes amateurs remove large amounts of for example Lantana camara but underneath the lantana is the seed of many herbacious invasive weeds which grow and seed faster than the people can remove them. The seeds of the herbacious weeds then become terribly invasive in the surrounding land or properties. In which case killing small amounts of Lantana at a time may have been a better option. Lantana can also provide habitat for small birds in areas that all their natural habitat has been removed. THINK OF THE ECOSYSTEM AS ONE WHOLE. =]