- August 22, 2016
Flowering plants are foundational in the understory of a structurally diverse habitat. Their role is multifaceted–as sources of food for pollinators, caterpillars, birds, and other herbivores, to create aesthetic appeal, and as homes for ecologically important fauna like predatory insects. Without flowering plants these crucial ecological relationships would collapse, changing the nature of the site, and its potential ecosystem services dramatically. This is true especially for native flowers.
Native flowers, like native trees and native shrubs, evolved in concert with the insects that are native to North America. In many examples, the relationship is so mutually dependent that to lose one could be detrimental to the specie(s) that it co-evolved with. In North America the Monarch’s dependant relationship with milkweed is a common example. Another famous example is Darwin’s Orchid (Angraecum sesquipedale), whose sole pollinator is the Morgan’s Sphinx moth (Xanthopan morganii praedicta), which was discovered over twenty years after Darwin theorized there must be a pollinator specifically designed to pollinate the unusually long nectary of this orchid native to Madagascar.
Which came first, the flower or the pollinators?
Like the chicken or the egg question, scientists are still analyzing fossil evidence to understand the co-evolution of mutualistic partnerships such as flowering plants and pollinators. The first insects evolved approximately 400 million years ago, well before the age of flowering plants, also known as angiosperms, which emerged at least 120 million years ago, possibly earlier. Bees are given credit for being our most prolific flowering-plant pollinators, and for good reason. It turns out that their emergence and diversification, occurred between 140-110 million years ago, which aligns closely with the proliferation of angiosperms.open_in_new
You may also have heard of the plant-insect co-evolutionary arms race, where plants continuously evolve to produce chemicals that deter herbivory by insect predators; and, in turn, those insect predators evolve to overcome those chemical obstacles. This is the driving force behind a lot of the close relationships between certain plants and insects, and the source of many chemically-complex secondary metabolites at the center of critical ecological interactions.
Relationships between plants and insects are so strong, that the absence or presence of a particular plant will determine the absence or presence of particular insects. Doug Tallamy studied yards with abundant native plants and those with predominantly nonnative vegetation. Results showed that native plant yards, like this Habitat Network Featured Site, pictured above, support the largest diversity of native herbivores (primarily insects).open_in_new Additionally, more eggs were laid on native plants than nonnative plants. These results might be explained because non-native plants don’t have relationships with local insects. They didn’t evolve in concert with them, so these plants attract less of a diversity of insects than the natives. Providing access to native flowerbeds may help a diversity of native insects flourish.
Tallamy’s findings are extremely relevant given the pressures that pollinators are experiencing in North America and worldwide. Insect pollinators like bees, butterflies, and moths likely need more access to flowering host plants in order to thrive.
Research in the United Kingdom found that farmers who create wildlife-friendly hedgerows of flower-rich native plants documented an increase in native macro moths, which are important pollinators.open_in_new This land management technique is becoming more common among those interested in protecting pollinators and creating habitat, like the farmer pictured above in Mississippi who is allowing a row of native flowers to grow alongside his crops. This feature has the potential to be a game changer for pollinators living around wildlife-friendly farms.open_in_new The farmers may benefit with better pollination services in their cultivated fields.open_in_new
The benefits of native flowerbeds aren’t limited to increasing habitat for insects and pollinators. Birds need an abundance of insects to thrive. Insectivorous birds use insects as their primary food resource; and, around 96% of native terrestrial birds in North America raise their young on insects. Chickadees, a common backyard favorite, require between 5,000-8,000 caterpillars per brood, and they often have two brood attempts each spring/summer. The ecological significance of native flowering plants cannot be overstated. To have diverse, functional habitat, we need native flowersbeds. Shrubby plants (those with woody stems) support the greatest diversity of caterpillars (a bird favorite), but natives, in general, support more lepidoptera diversity than nonnatives.
Planting native flowerbeds is a fun, creative activity that can cater to your garden size, sense of landscape aesthetic, and soil composition. Ideally, you will create native flowerbeds that provide blooms throughout the growing season. This helps to ensure pollinators have a ready nectar and pollen supply at all times. Pictured is a group of students planting a pollinator garden in Philadelphia, Pennsylvania.
Each ecoregion will have a slightly different list of recommended native flowering plants (check-out your personal ecoregion list here). This list provides ideas by state and this list is compiled by an avid plant nativist, Benjamin Vogt. Vogt’s list focuses on attracting butterflies but the list is extensive and covers a wide variety of growing ranges. For very wet soils, wetland areas, and rain gardens, this list of native flowering plants may fit the bill. Arid Southwest desert regions, might benefit from considering these ten plants in their landscape. Like with many aspects of healthy ecosystems, diversity matters. A diverse collection of native flowering plants will likely provide the most ecological benefit.
Note on Pesticides
At Habitat Network we encourage gardeners to avoid using pesticides. Literally meaning, “pest killer.” Broad applications of pesticides can have unforeseen negative consequences, such as killing beneficial insects,open_in_new potentially contaminating soil and water,open_in_new and exposing people,open_in_new children,open_in_new and petsopen_in_new to chemicals that may have deleterious effects. See our article on herbicides for more information and helpful ideas to fight pests without using chemicals.
Finding native flowering plants can be big challenge. Use our local resources tool to help with this process. Simply enter your zip code and then scroll down to find nurseries located in your region. Most large box stores do not carry many native plants, or they may carry native cultivars, which are native plants that have been crossed with similar non-natives for beneficial characteristics such as larger blooms, brighter colors, or disease resistance. Be cautious, there is some evidence that native cultivars may not provide the same ecosystem benefits as true native varieties. Smaller, local nurseries, like the one pictured above in southern California, often carrying native plants, several even specialize specifically in natives. Your best chance to locate those resources is by using our local resources tool which will link you directly to a list of nurseries in your region.
The influence of native flowerbeds cannot be overstated. As we face increasing pressures to preserve habitat for declining populations of pollinators who we rely on for the pollination of ¾ of our food supply,open_in_new we must continue to create native flowerbeds around our homes and communities. In return, flower’s brighten our landscapes, make us smile as they bloom, and add ecological complexity that you, the bees, the birds, moths, and butterflies will be grateful for.
MAP Your Native Flowerbeds
Under Toolshed, choose Second for mapping a habigon. Select Non-woody Plants as the habitat choice.
We catagorize this habitat as Annuals, Perennials, Ground-cover, Flowers, Herbs and Ferns. Most native flower beds are non-woody. Map the section on your map that correlates with this habitat. Then, use the characteristics to tell us more details.
Open up the Info box by clicking on the green tab. See the image above. Open the Basic Information and label the habitat Native Flowerbed.
Click on the Characteristics and tell us how you manage this habitat.