Why does Native Biodiversity Matter?
Like many plants that European settlers brought with them to North America, intentionally or by accident, Norway maple has become something of an unruly and unwelcome guest. Thousands of Norway maples have been planted as street trees throughout eastern North American, and these trees have released millions upon millions of seeds into the environment. The seeds that land on a nearby lawn may germinate, but they are soon mowed before they become very tall. However, seeds that land in vacant lots or get washed down the storm sewers to the banks of the streams and rivers that flow through our towns have the chance to germinate, grow, and flourish. Now, these Norway maples are more than just occasional upstarts - in many areas they outnumber and are out-competing the native trees of our riverside (riparian) forests. This story is echoed hundreds of times by other Eurasian plants that were brought for our gardens or came as weeds in our crop seeds. Garlic mustard, purple loosestrife, European buckthorn, giant reed grass (Phragmites australis), Scots pine, black locust, tree of heaven, ... the list is huge, and growing. Not only do these non-native plants out-compete our native plants (and thus make some of our native plants more and more rare), they frequently perform poorly as food, shelter, or habitat for the native fungi and animals that formerly depended on native plants for these functions. Invasive species are second only to habitat destruction as a cause of the loss of biodiversity worldwide. Growing only native plants in our yards and gardens is something we can all do to help reverse these trends.