Do invasive species matter?
By Teri MacArthur | The Woodlands Township Environmental Services Dept.
If “greening” our surroundings is a good idea, why are residents of The Woodlands removing hundreds of pounds of plants and vines from open spaces every week? Well, not all vegetation is created equal.
Soil organisms, insects and wildlife have co-evolved with native plants for eons, and in so doing have formed beneficial relationships. Exotic plants, transplants from afar, don’t have those same relationships and can’t offer the benefits of food and shelter that native plants do.
Making matters worse, when those exotics are invasive, like the all-too-common air potato vine, Japanese climbing fern and nandina, they overwhelm and displace the natives. Soil organisms, insects and wildlife suffer the consequences.
Consider Doug Tallamy’s note from his article in Bird Watcher Digest:
“Some plants are far better at producing insect bird food than others. For example, oaks support 557 species of caterpillars (bird food) in the mid-Atlantic states alone, whereas nonnative Zelkova trees from Asia support none at all. Ninety percent of insects that eat plants can only eat specific plants; if those plants are absent from landscapes, so will be bird food they produce.
“Unfortunately, this is the case in our yards and managed landscapes when we remove native plant communities that are good at making insect bird food and replace them with vast lawns and ornamental plants from other parts of the world that produce few insects in North America. This oversight must end if we want birds in our future.”
Air Potato Vine: Can reach 65” covering shrubs/ trees. Difficult to remove. Biological controls (eg. insects that feed on plant) showing success. Potato bulbils toxic.
Japanese Climbing: FERN Survives in shade or sun, can grow year round, shading entire trees. Pull young plants by hand. Cut larger infestations or mow new growth.
Nandina: Heavenly bamboo, an evergreen shrub up to 7’ tall with extensive root system. Hand pulling may be the most effective control. Berries and leaves toxic.
Chinese Tallow: Aggressive root system saps water from nearby plants. Transforms diverse habitat into tallow forests. Pull seedlings by hand. Cut down large trees. Toxins in leaves, fruits and sap.
Asian Privets: Japanese, Chinese, glossy and waxyleaf all invasive. Grows 25”/year. Dominates forest understory. Uproot small plants. Cut back/mow shrubs to reduce spread. Toxic fruit, leaves
Elephant Ears: Fast grower in warm, wet conditions. Remove entire plant, leave no fragments. Needle-like crystals in all parts cause irritation if ingested raw. Sap can also irritate sensitive skin.
