Natives-Introduced-Invasives

What is the difference between native plants, introduced plants, and invasive plants?

Let’s start with the difference between a native plant and an introduced plant. 

Short answer: a native plant is one that has evolved with the native insect population present in our ecosystems today, therefore it can support complex food webs at the base of the food chain.  An introduced plant is one that has been introduced from an ecosystem outside of it evolutionary homeland. 

Why does it matter?  Introduced plants do a poor job at supporting native insects and bird populations (birds rely on caterpillars to feed their young... 6,000-9,000 caterpillars to raise one nest of baby songbirds!).

When we talk about native plants versus introduced plants, the intent of this conversation is not to “villainize” certain plants, but to understand their service (or disservice) to a particular ecosystem.  Most plants have the capacity to be either a villain in a foreign land, or to be a hero in their native land.  For example, the Common Reed, in its homeland in Europe, supports 170 insect species; but in North America is supports only 5 inspect species, and it has been in North America for 100’s of years

Okay, then are all introduced plants harmful?  No. 

While introduced plants aren’t doing much to assist our native ecosystems, some do more damage than others; we call the damaging plants invasive species.   What is an invasive species?  Non-native invasive species are easily spread and increase their populations rapidly, and they do it at the detriment of native plant populations that support the local food web.  With no natural enemies from their homelands to keep them in check, non-native invasives gain a distinct advantage over natives, choking them out of ecosystems that depend on them.

What are a few examples of particularly aggressive non-native invasives?  Bradford Pear, Mimosa, and Privet are common examples that we see spreading all throughout Alabama.  And of course, we’re all too familiar with Kudzu. 

What’s the city doing to reduce non-native invasives in Mountain Brook?  The department of Planning/Sustainability and Parks/Rec are partnering to identify and map invasives in city parks and traffic medians.  A GIS program has been developed to specifically assist in the gathering of this data.  This project will be developed over time, and when sufficient data has been collected and mapped the information will be presented to the MB Parks Board to review and determine which invasives may be targeted for removal, and what the schedule for removal might look like.  So if you see us out there identifying plants, up close, you will know what we’re up to!

A list of 13 egregious invasives that disrupt Alabama ecosystems:

1. Mimosa
2. English Ivy
3. Kudzu
4. Wisteria
5. Chinese Privet
6. Chinese Parasol
7. Bamboo
8. Bradford Pear
9. Japanese Honeysuckle
10. Nandina
11. Japanese Barberry
12. Orange Daylily
13. Lesser Celandine