What is the difference between an invasive species and a native one?The predominant definition of invasive species is an aggressive, non-native (exotic) species. Aggressive refers to the attribute of quickly colonizing, spreading, and dominating an area. In the US, "non-native" generally refers to species that were not present prior to European settlement. Not all non-native species are invasive, in fact the majority of them are not.
It's important to keep in mind that native species can also be aggressively dominant, for example in the US, Silphium perfoliatum (cup plant) or Ambrosia artemisiifolia (common ragweed). In my experience, practitioners may lump weedy native species with weedy non-native species and call them all "invasive."
Here are some definitions from the USDA: http://www.invasivespeciesinfo.g...
Native can be invasive.
Non-native can be non-invasive.
This issue is quite complex.
Where plants are changes over time as the climate changes, and they evolve during the process.
If you think you are against planting non natives, consider that almost all the food you eat is non-native and altered via selection from it's original form.
Brian Fey's answer to Lanaʻi: How did invasive deer get onto Lana'i?
Brian Fey's answer to Is bamboo invasive?
Brian Fey's answer to Invasive Species: Should we become invasivores?
What are some of the most disastrous introduced species?
A native species is one that naturally lives in an area, whether because it evolved there (as in kangaroos in Australia) or because it naturally migrated there thousands or millions of years ago (as in jaguars in a South America).
Invasive species are ones brought to an area by unnatural means (like Australian rabbits and Columbian hippos). Species naturally expanding their territories are also sometimes called invasive, but these are difficult to identify without the benefit of hindsight. South American sabertoothed cats are an example of this, as are Old World camels, New World mammoths, and African rhinos.
An invasive species is generally exotic - that is, introduced to an area from another place. An invasive species outcompetes native organisms, and might even replace them entirely. As an example, Cheatgrass (Bromus tectorum) introduced to the US from Eurasia by European settlers has displaced many native grasses in the western USA.