As humans we have a tendency to invent problems for ourselves, and issues related to the environment are no exception. Through the desire for ornamental plants coupled with a lack of understanding of how non-native species can become problematic, we have unleashed a plague upon ourselves and our ecosystem.
All life on our planet is interconnected. Plants are the basis of our food web, and all life on earth. Plants produce the oxygen we breathe and the food we eat, they regulate the water cycle, are a source of medicine, and they store carbon helping to regulate climate. Our everyday life depends on plants.
Native Plants Support Native Insects
Native flora and fauna have evolved together over millions of years. The introduction of new species can displace natives disrupting the established and essential ecosystem services these life forms provide.
Many insects have evolved to be ‘specialists’ meaning that they breed on very specific types of plants. These plants are called host plants. A familiar example of this is found with monarch butterflies. They lay their eggs on plants in the Asclepias spp. family, commonly know as milkweed. While adults can feed on the nectar of a variety of flowers, their caterpillar offspring must have the leaves of milkweed to eat. There are thousands of other such examples of butterflies and other insects who have evolved to breed on specific host plants.
Native plants protect and restore biodiversity by supporting the insect species they co-evolved with. Here in the Northeast, that means oaks, hickory, beech, goldenrod, asters, milkweed, violets and many many other plants are what our valuable insects and the animals that feed on them need to survive. These native species of trees, shrubs and flowers support hundreds of types of insects – oak trees alone support over 500 types of moth and butterfly species. Goldenrod supports 115 species. Nesting birds need thousands of caterpillars to feed their young. Only native plants can fill that need.
Non Native Plants Harm Biodiversity
According to Doug Tallamy, University of Delaware professor and author of Bringing Nature Home, “Over 3400 species of alien plants have invaded 100 million acres of the U.S, and that area is expected to double in the next 5 years.”
Biodiversity is essential to our survival as a species because without the plants and insects that evolved together in our area birds and other wildlife can’t survive. Non-native plant species support 29 times less biodiversity than native ornamentals.
In addition to impacting natural resources and the environment, invasive plants also impact the economy and human health.
Suburban Sprawl Has Decimated Vital Habitat
To date in the United States, we have at least 40 million acres of lawn. This does not include agricultural areas, roads and other impermeable surfaces or structures. We are taking what was once biodiverse landscapes buzzing with life and transforming them into sterile landscapes. Altogether we have converted an astonishing 95% of nature to inhospitable territory, and still counting.
Combining this with the open spaces that have been over taken by invasive plants like Oriental bittersweet, Japanese barberry, glossy buckthorn, burning bush and Norway maple we have a critical situation. In regards to the issues facing our planet, including those of loss of soil productivity, deforestation, and species loss, thousands of scientists recently warned that “Soon it will be too late to shift course away from our failing trajectory.”
You Can Be Part of the Solution
Rather than feel overwhelmed by the issue, we should feel encouraged by the fact that each one of us can take action to reverse this trend, and restore biodiversity right in our own backyards.
Our suburban landscapes have the potential to be a haven for wildlife. According to Professor Doug Tallamy, professor and chair of the department of entomology and wildlife ecology at the University of Delaware, “Even modest increases in the native plant cover on suburban properties significantly increases the number and species of breeding birds, including birds of conservation concern.” City dwellers can contribute to conservation too. Urban gardens and green spaces have been shown to help support vital insect species.
We can see real, tangible results in our own environments if we put in a little effort. By removing and monitoring for invasive plants, and planting native ones, we can increase the numbers of local wildlife that depend on them for breeding, food, and forage, while at the same time beautifying our surroundings.
Check out the helpful links below to get started on making a difference in your backyard and beyond.