Why We Need to Protect Native Pollinator Habitat
Preserving Native Pollinator Plants
Doug Ottinger – Regardless of whether we live a rural lifestyle, an urban one, or something in between, our existence and continuance of the world as we know it is dependent on an ecosystem of small insect pollinators and native pollinator habitat that most people rarely notice. Approximately 30 to 35 percent of the food crops in this world depend on pollination by insects. It is estimated that almost 90 percent of all wild plants in the world are dependent on some sort of insect pollination. When many of us think of pollinators, we automatically think of the common European honey bee, Apis mellifera. While honey bees have become one of the main pollinators of domesticated food crops, they make up only a small portion of the bee species and other insect pollinators in the world. Worldwide there are some 20,000 species of wild bees. The North American continent is home to almost 4,000 of these species. Multiple species of pollinating insects are actually necessary for our ecosystem to flourish. When any of these species become extinct, we have lost an entire linking piece in our earth’s ecology.
Why are Multiple Species of Pollinators so Important?
Not all plants can be effectively pollinated by the same types of insects. We often think of honey bees buzzing around apple blossoms in the spring, as our one and only source of insect pollination. Nothing could be further from fact. Prior to the European honey bee being introduced to the Western world, native bees and other insects were prevalent and effective in pollinating the wild plants and crops grown by the indigenous people. Many native bees can fly in colder or damper conditions than common honey bees, making pollination of fruit blossoms and other plants possible under inclement conditions. Other species are better adapted to very hot and dry regions. For hundreds of years, squash and pumpkins, grown by native inhabitants of the Americas, were pollinated by species of small, solitary, ground-dwelling bees, commonly known as squash bees.
Tomatoes, peppers, and eggplants are pollinated more effectively by bumble bees, which perform “vibration pollination.” Some flowers are too small for honey bees to enter, or the pistil and stamen configurations are difficult for the honey bees to access. These types of flowers are better serviced by other insect species that have evolved with the plants. In some cases, there are symbiotic relationships between insects that make pollination possible. In certain species of Lupine, where bumble bees visit the flowers first, the bumble bee’s large size is too great for the blossom, springing it permanently open. After this, smaller species of wild bees gain access and pollinate the plant.
Many Pollinators are in Trouble
Many species of pollinators, both wild and domestic, are critically endangered today. One-fourth of North American bumble bees are currently facing extinction. Even the world of domestic beekeeping is not exempt from these problems. Commercial beekeepers are losing entire colonies of bees to a disease malady broadly termed Colony Collapse Disorder, to which there are still very few concrete answers. In some areas of the world, pears and other fruit are being pollinated by hand, because of the loss of native pollinators. If native and domestic pollinating insects are allowed to keep declining, life, as we know it, will gradually change, and not for the better.
What are Some of the Main Causes of These Declines?
One significant factor is the loss of native pollinator habitat. Urbanization and paving-over of native pollinator habitat is only one part of this. Large-scale agricultural practices are another. Native flowering plants, which provide food for the insects are being destroyed. Ditches are mowed and sprayed. Burrows made by ground-dwelling native bees are plowed under. Even so-called urban “green zones,” which often consist of large swaths of beautiful lawns and trees are nothing more than food deserts. Very few native pollinator plants remain, and any domestic flowers planted are not enough to support any sizeable insect populations or allow them to reproduce.
Widespread pesticide use has also taken a toll. One little-known issue in honey bee deaths is the use of certain systemic pesticides in treated agricultural seed, even in crops which the bees never visit or feed on. The insecticides used are absorbed by the plants as they grow. The pesticides are released into the air, in microscopic particles during transpiration. Honey bees tend to fly low, and they can easily absorb enough neurotoxin, just flying over these fields once, to prove fatal. It is believed that these same neurotoxins are taking a toll on native bees and other pollinators. Disease is also one more factor that researchers are looking at, as they try to find answers to these dilemmas.
What Can I do to Build Native Pollinator Habitat on my Property?
According to Sarah Foltz Jordan, Senior Pollinator and Habitat Restoration Specialist, Great Lakes Chapter of the Xerces Society, wildflowers are essential for pollinator food. Providing nesting and overwintering shelter for these insects is crucially important. Leaving wildflower stems and seed heads intact over the winter is imperative to this. Dead wildflower stems are important nesting habitat for about 30 percent of our native bees. Pruning stems back six to 18 inches in the spring will result in stubble which will provide homes for the bees. It may look unsightly, but the area will soon be covered by green vegetation. Leaving an old log or two is another one of the greatest advantages you can give beneficial insects such as ground beetles, fireflies, and certain native pollinators. Decaying logs are home to many of these creatures. Leaving soil undisturbed as much as possible, also gives native pollinators an advantage. Bare patches in lawns are excellent nest sites for ground-nesting bees. Mulching, which is often touted as eco-friendly, is not so friendly to many beneficial insects. Many native bees are solitary ground nesters. Mulching, especially with plastic, landscaping fabric, or very heavy wood chips, covers their burrow entrances and limits their ability to find nest sites. Leave as many native flowers as possible. When planting for bees, try to utilize wildflowers and native pollinator plants. Use species that are native to the region in which you live. Native pollinators are more adapted to the plant species they have evolved with. Lastly, try to plant a series of plants which will provide blooms and food for these insects throughout the entire season.
Some people have started making a bee hotel as an added feature to help native pollinators. These are small, simple structures that give shelter to native bees as they become re-established on your land. They can consist of untreated blocks of wood with holes drilled into them for solitary bees. Small-diameter tubes of bamboo or cardboard, banded together can serve the same purpose. If you leave an old log or two, you can also drill a few small, horizontal holes a few inches deep into the log as starter homes for these insects.
What are the Best Plants for Bees?
With thousands of flowering plants growing throughout North America, it is almost impossible to do justice to this question. However, here are 10 wild flowering plants that seem to do well across a broad spectrum of regions and are often broadly found.
- Common Goldenrod (Asteraceae sp.)
- Yarrow (Achillea millefolium)
- Native Sunflowers ( Helianthus sp.)
- Beebalm (Monarda didyma and M. fistulosa sp.)
- Columbine (Aquilegia canadensis)
- California Poppy (Eschscholzia californica)
- Wild Lupines (Lupinus perrenis)
- Wild Chokecherry blossoms (Prunus virginianus)
- Wild Blackberries or other brambles (Rubus species)
- Wild Roses (multiple species native to many areas across North America)
What native pollinators and wild flowering plants can be found in the area where you live?