Saturday, April 14, 2018
Non-Native Shrubs Shade Out Spring Wildflowers
This time of year, you can tell with one glance how many non-native shrubs are growing in a local woodland. Non-natives like privet, winged euonymus, and bush honeysuckle leaf out earlier than most native shrubs, reflective of their having evolved in a different climate from our own. Many of our woodlands are now thick with these non-native shrubs, and their early leafing out has ecological consequences. The spring ephemeral wildflowers have evolved to utilize the sunlight available during that window of time in spring when the woody plants above them are still dormant. Introduce woody plants that leaf out earlier, and the wildflowers can't store up enough energy to bloom the next year.
This problem will be exacerbated as we lose the many ash trees in our woodlands, since the nonnative shrubs will likely grow all the more densely as more sunlight reaches the understory in summertime. At Herrontown Woods, we're cutting down the non-native invasive shrubs, to allow more sunlight to reach spring wildflowers, and also to allow native shrubs a chance to thrive.