Tuesday Talk: How Climate Change is Killing Our Local Bees, Trees, and Plants

17 Jun 2022 10 min read

Climate change is altering the natural environment of the Washington, D.C. area, threatening the survivability of many native trees and plants as well as bees and other pollinators which are essential to growing many plants and crops.

That was one of many important messages emanating from a Tuesday Talk Webinar on Feb. 15 that featured Erin Gleeson, a hobby beekeeper and master naturalist and Tamara Belt, Ph.D., an award winning landscape designer and environmentalist. They both spoke about the harmful impact of climate change on the local environment and what local residents can do to mitigate its damaging effects.

Gleeson, co-owner of Bee Curious LLC, pointed out that honey bees alone increase our nation’s crop value by more than $15 billion each year. They are also essential to the production of many key crops, including almonds, avocados, apples, peaches, blueberries, strawberries, and many other foods.

“All of it is not going to happen without honey bees,” said Gleeson, who keeps an apiary of more than 20 beehives at the Swiss Embassy in Woodley Park with Sean Kennedy, a long-time resident of Washington, D.C.

Gleeson pointed out that honey bees are not native to the United States – they were introduced in North America in 1622. There are, however, more than 4,000 species of native bees in the U.S., which produce at least $9 billion in crop benefits nationally, according to Gleeson, a former resident of Woodley Park who holds degrees in geosciences and climate sciences.

Threatened Populations

Bee populations are declining in the Washington, D.C. area and elsewhere because of climate change and other factors, including the use of pesticides, overdevelopment, and innumerable pests that have gained a foothold in the region as a result of warmer weather.

Climate change, for example, affects the seasonality of when trees bloom, ultimately depriving bees of pollen and nectar, which they need to survive.

The area also has lost native plants because of climate change, and uninformed landscaping choices. According to Gleeson, most nurseries sell showy, non-native plants that lack sufficient amounts of pollen and nectar. And these plants don’t bloom based on schedules that native birds, bees, and other creatures are used to.

Gleeson also mentioned colony collapse disorder, CCD, which occurs when the majority of bees in a colony inexplicably disappear. The cause of CCD is unknown, but it is likely the result of various factors that include climate change, pesticide overuse, and land change.

“We have so many pests,” Gleeson lamented. “We have small hive-beetles, which can completely ruin a honey crop. We have Varroa mites, which are the equivalent of dinner-plate-sized ticks for us humans.”

Varroa mites transmit as many as 30 known viruses and probably many more that have not been detected, said Gleeson.

Insect Invasion

Tamara Belt also blamed the growing pestilence on climate change, saying, “Because we have summers that start earlier and last longer, there is a lot more time for insects to reproduce and nest.”

Belt is the founder of Hawthorne Garden Design, LLC, and serves as the Landscape Chair and Vice-Chair of the Board of the Tregaron Conservancy where she has worked for the past 15 years, designing gardens. She uses her considerable landscaping skills to make the area more hospitable to plants, trees and certain kinds of wildlife.

She sees firsthand the destruction caused by climate change. The D.C. area, she said, is losing many mature broadleaf trees such as oaks because of climate change. Dogwoods also are endangered from fungal-borne pests. As she pointed out, “there are significant shifts in plant survivability.”

“A lot of plants that used to do great in DC, no longer do well,” said Belt, who earned a Ph.D. in economics from the London School of Economics. “You see them wilting and suffering under the heat of summer.”

There are other plants, she said, cannot withstand the heavy rain falls.

If anything, the problem of climate change will grow worse, plaguing our local ecology for decades to come. Belt, citing data from a 2015 Washington, D.C. government study on Climate Change Projections, said the D.C. region will experience warmer average temperatures during the next several decades combined with longer, hotter and more intense heat waves.

At the same time, the region will endure more frequent and violent rain storms, creating a need to find plants and trees that can withstand greater heat, humidity and increased rainfall.

Flourishing Pond

At the Tregaron Conservancy, Belt helped coordinate the clean-up and revitalization of the estate’s pond which was once in a state of decay. She worked as part of a multi-disciplinary team that included botanists, pond specialists, historic preservationists and donors, among others, who pulled together to revitalize the pond in a historically responsible way.

In the process, the team perpetuated the vision of Ellen Biddle Shipman, a leading landscape architect who designed the Tregaron Estate and its pond with architect Charles Adams Platt in 1912.

The revitalization of the pond adhered to current ecological conditions, introducing new native species to make the pond area more resilient to climate shocks. The pond’s rehabilitation also supported local wildlife such as the American bullfrog, Mallard ducks, numerous pollinators and small mammals.

Belt showed a recent picture of the pond, comparing it to pictures of the pond more than 100 years ago. In both pictures, the pond is flourishing, surrounded by plants and flowers and evergreens lining the water. Bull frogs now inhabit the pond area, a sure sign the pond has made a recovery, blossoming into a vibrant wildlife oasis.

The plant palette has definitely changed over the past century because of the effects of the changing climate, Belt noted. But the spirit of the pond has remained intact, characterized by over-story trees, flowering shrubs, colorful perennials and bulbs as well as encroaching groundcovers. In many ways, the transformation has turned the pond into a magical space, Belt said.

“We want to keep this pond looking like this in perpetuity so hopefully when your children and grandchildren come to visit you will be able to see the same pond you are seeing now,” commented Belt.

Shipman planted a lot of azaleas and Rhododendrons in the Tregaron more than 100 years ago, and her plants still exist today, providing great shade and vibrant colors in the spring.

“We would like to plant more Rhododendrons, but they have diminished survivability,” Belt said. “Nonetheless we are still trying, and are testing different Rhododendron cultivators to see if we can find one that can handle the evolving site conditions.”

Plant Native

Belt urged webinar viewers to plant more native trees and plants that can withstand the warmer, hotter, and wetter weather.

“Native plans tend to be more adaptable, and they provide more cover for bees, other small pollinators, and birds,” she said. “They are also a good food source for small mammals.”

When planting trees, homeowners need to make sure the trees will be able to withstand ongoing climate change, which is likely to accelerate during the next 40 to 60 years, she said.

Gleeson, like Belt, also urged webinar viewers to go native by planting indigenous trees and plants. One of the overriding goals is to create native and thriving habitats for bees, butterflies, and other small pollinators.

She urged the audience to avoid using pesticides on their lawns which kill bees and other pollinators. Instead of pesticides, Gleeson said residents could use Mosquito Dunks®, donut-shaped disks made of natural mosquito larvicide that float on water, releasing bacterium that kills mosquito larvae. The dunks are harmless to humans and other forms of life.

Bee-Keeping Journey

Gleeson talked about her “journey” as a hobby beekeeper, explaining that her interest in beekeeping began many years ago while helping mountain communities in Nepal with the development of beehives and the cultivation of honey.

“In Nepal, honey can be a major source of income for mountain communities,” she explained.

Gleeson eventually settled in Washington, D.C., where she started helping beekeeper Sean Kennedy with the management of beehives, which he kept on the roof of his town house in the city. The two of them still maintain three hives on the roof of the town house.

Gleeson and Kennedy soon encountered difficulties keeping numerous beehives in a densely-populated area – someone occasionally got stung, creating friction with the neighbors. Gleeson stressed, however, that the neighbors are generally supportive of the beekeeping efforts.

Gleeson and Kennedy, co-owners of Bee Curious LLC, decided they wanted to expand their operation. One day, Gleeson walked out of her apartment and looked up at a Swiss flag, which created a “weird déjà vu/light bulb moment.”

Gleeson formerly lived in Switzerland for 10 years, and after glancing at the Swiss flag she wondered whether she and Kennedy could keep bees at the Swiss Embassy. As it turns out, the Swiss ambassador to the United States is a serious birder who strives to maintain eco-friendly goals for the embassy grounds.

Kennedy arranged an interview with the Swiss ambassador who granted permission for the bee hives. Within a few days, Kennedy and Gleeson moved hives onto the Swiss Embassy grounds.

“We grew and grew and grew,” Gleeson said. “We kept rescuing swarms of bees. We currently have 25 hives between the embassy and the garage roof. If you walk down 29^th Street between Cathedral and Woodley, you will see those hives (at the Swiss embassy).”

Gleeson pointed out that spring marks the start of swarm season, meaning bees are “apartment hunting.”

“You might find clusters of bees in all sorts of locations – up in trees, on top of roofs, next to trees, on fences,” she said. “You might find one on the back of your car.”

Swarm Catchers

As beekeepers, Gleeson and Kennedy spend much of their time rescuing bees from precarious locations such as tree tops and the inside walls of houses. Gleeson explained how she and Kennedy rescue bees from these locations.

The key is to capture the queen – once the queen is caught, the other bees go marching into a box that Gleeson and Kennedy set up, following the queen as if they are being directed by remote control.

“Here I caught a swarm,” said Gleeson, showing the capture of a swarm. “I knew I had caught the queen because all of a sudden, the bees line up like magnetic fire ants and start marching in. It is super cool.”

Gleeson said it takes the lifetimes of 12 worker bees to produce a tablespoon of honey. She urged local residents to buy local and “pay for your honey because these bees are literally working their wings off.”

“The beekeepers work hard too – to make sure the bees stay healthy,” Gleeson added.

Editor’s Note: During her Tuesday Talk presentation, Tamara Belt, Ph.D., urged webinar viewers to plant more native trees and plants that can withstand the warmer, hotter, and wetter weather resulting from climate change. She provided a list of trees, shrubs and perennials that are likely to do well as the Washington, D.C. environment changes.

Trees, Shrubs and Perennials for the 21st Century:

Deciduous Trees for Wet Sites