Plants, Insects, & Birds
Pause to imagine the sounds of summer. For many, there are few things as lovely as sitting outside in the warm sunshine listening to the rustle of the wind as it moves through your landscape, the hum of grasshoppers rubbing their legs together, or the chatter of a flock of young birds exploring their new world. Summer is here and our yards should be teeming with life. How much life depends, in part, on the types of plants you have in your landscape.
In the United States there are 75 to 100 million acres of exotic plants in managed landscapes.1 This area is almost equivalent to the size of Wisconsin. Non-native plants, introduced from all over the world, can create modified ecosystems that research suggests do not support the same level of biodiversity as native-plant ecosystems. A study in a Philadelphia suburban neighborhood compared sites landscaped with exotic plants to those with native plants. They found that exotic-plant yards had reduced bird abundance and fewer lepidopterans (moths and butterflies).1
Why might this be? The simple answer is that many components of ecosystems are interdependent. A plant originally from Japan may not provide the correct chemical signals to announce to a butterfly native to North America that it is a suitable place to lay its eggs. Missed breeding opportunities send a ripple through the food web to native birds, a large percentage of which feed their nestlings caterpillars during breeding season. Less habitat for butterflies to lay their eggs means fewer caterpillars, and less food to feed nestlings.
Homeowners and communities can improve their local environments by:
selecting native plants. From private gardens to city parks and medians, every patch of native landscape is important;
creating demand at local nurseries and stores for native plants. Ask what plants are native. Ask if they can order native plants. Only 13% of all nursery sales are native plants.1 Lack of access to native plants may be driving the use of non-native plants;
educating neighbors, nurseries, community landscapers, and urban planners on the intricacies of ecosystems. Encourage them to consider planting natives instead of exotic or non-native plants;
engaging in citizen science. The data citizen scientists provide will help us understand more about the relationship between native plants and biodiversity. Without the science, we cannot appropriately shift practices or policy.
1 Wilde, H. D., Gandhi, K. J., & Colson, G. (2015). State of the science and challenges of breeding landscape plants with ecological function. Horticulture Research, 2.