Why are native plants so important?
Native plants are the necessary heart of healthy ecosystems. Plants power the food web for the rest of life on earth. Within this web, it is the balance of co-evolutionary relationships that allows millions of different species to all live closely together within a shared place. In a local ecosystem, only the plants that have evolved over an extended period of time with the other flora and fauna present can successfully feed the entire web and keep it stable.
Native Plants Host the Insects We Need
Native plants host a vastly greater number and variety of insect species than non-natives. And although we humans have been programmed to think otherwise, insects are critical to our ecosystems and therefore to us. For example, insects and other arthropods provide about 60% of the avian diet overall, and they are virtually the sole food source for nesting terrestrial birds. Without insects, our beautiful songbirds couldn’t survive or raise their young. Without ponds and vernal pools teeming with insect life, there would be no spring peepers or amphibians. Insects are a vital hub in our web of life, critical intermediaries between plants and the animal world. We need them and they need native plants.
Pollination Systems— Made Possible by Natives
The vast majority of plants on earth are flowering plants (angiosperms) and most of those are pollinated by animals— primarily insects, but also a few birds, bats, and others. While some pollinators are generalists that can effectively pollinate a small number of plant species, others are specialists that may be able to pollinate only a single plant species! In either case, the shape and structure of a every plant’s flower is quite unique, and the physiology and behavior of its pollination partner(s) create a mutualistic relationship that deeply intertwines the lives of each. Our native pollinators depend upon our native plants, and vice versa.
Host-specific Lepidoptera (Butterflies and Moths)
Many butterflies and moths are host-specific and can only reproduce if they lay their eggs on a single plant genus or species that is edible to their larvae. Our current poster child for this issue is the Monarch butterfly, now widely understood to be able to survive and reproduce only on milkweeds (Asclepias spp.). But such host specificity is relatively common in the Lepidopteran world, showing us why our native plants are so essential to the future of our beautiful butterflies and moths. Only if we re-establish healthy native plant landscapes can we prevent the continued loss of species. In Massachusetts more than 25% of all butterfly species are in serious decline and are considered of conservation concern.
The Bottom Line: Plants provide the foundation for life by capturing the energy of the sun and converting it into biomass for the rest of us to eat, and native plants promote the biodiversity necessary for balanced ecosystems. Increasing the health and diversity of these organic systems is critical to counteracting climate change. If we humans want to survive and have a sustainable future, it is time to pay attention to the importance of growing natives everywhere.