Partnering with Pollinators
By Robin Eng, PPC Ecological Projects Manager
It’s pollinator week! Here at the PPC, we make a lot of land-care decisions with the intent of supporting native pollinator species. This comes into account when we plant new trees and flowers, but also in the way we care for the garden beds throughout the year.
When many of us think of pollinators, we first think of the honeybee. But did you know that there are over 4000 species of native bees that also act as pollinators? In addition, wasps, flies, moths, and beetles are important insect pollinators, but even vertebrates such as birds, bats, and small mammals can act as pollinator species. Pollinators truly come in all shapes and sizes, so the habitat that supports them needs to be equally diverse.
So, what makes for a good pollinator habitat? Let’s dig into a few details.
Pollinators need more than just pollen. To support pollinators, we need to think about more than just the flowers that they feed on. Pollinators have unique habitat needs that must be met for their day-to-day survival and continued reproduction. A place to rest between bouts of feeding and safe spaces to lay eggs and overwinter are just as important for pollinators' survival as the nectar and pollen they eat. For many species, fallen leaves from our deciduous trees provide important over-wintering cover for pupae, eggs, or dormant larvae. The dried flower stalks of the past season’s blooms can also act as important pollinator habitat. Suspended above the forest floor, the hollow stems of spent flowers provide a dry and protected space where insect larvae can ride out the harsh and wet winter weather.
The importance of diversity. We all love a beautiful bloom, and part of what makes flowers so special is their transience – the thrill of seeing your favorite flower just wouldn’t be the same if they were blooming all year long. In fact, most flowering plants only bloom for a couple of weeks to a couple of months each year. For this reason, it's important to plant a variety of pollinator species that collectively have bloom times that span the whole growing season, from early spring through late fall. While this paves the way for dynamic and beautiful spaces, it also ensures that there is a variety of food and nutritional value. Just like a blueberry doesn’t have the same nutritional value as a watermelon, blooms from different species provide pollen and nectar of varying qualities as well. Having a diverse combination of pollinator plants ensures that native pollinator species receive a varied diet and adequate food resources throughout the season.
Not all plants are equal in the eyes of a pollinator. Did you know that a majority of our native plant-feeding insects are actually specialists, meaning they feed on only a few specific plant species? While we have thousands of native pollinator species and thousands of pollen-producing native plants, thousands of generations of adaptation between these species have resulted in non-negotiable preferences between the two. And these specialized relationships go both ways. Some pollinators are dependent on the pollen and nectar of specific plants, while certain flowers can only be pollinated by certain pollinator insects or animals. Having a diverse suite of plants is incredibly important to supporting a diverse suite of insect and animal pollinators. The more flowering diversity you plant, the more pollinator diversity you are likely to support.
But why do we care about pollinators? Despite our insulated homes and technological advances, humans are still inextricably dependent on the healthy functioning of our natural spaces. Ecosystem services such as erosion control, storm mitigation, temperature mitigation and air and water purification are all dependent on persistence of biodiverse plant and animal communities, of which pollinators are an integral part. In fact, a great majority of flowering plants (including many of our majestic trees) rely on pollinator species to ensure successful reproduction. In addition to the ecosystem services provided by pollinator-supported ecosystems, approximately 1/3 of all the food we eat is dependent on pollinators for successful crop production. Finally, pollinators are a delight to observe! Butterflies, hummingbirds, bees, bugs, and a suite of other species are readily visible visiting flowers, feeding on nectar, and collecting pollen for their broods. Having pollinator plants in your yard and parks is a simple way to highlight and observe the beauty and complexity of life in this world we all share.
The Parks Conservancy's efforts to enhance pollinator habitats are generously supported by Giant Eagle?