10 minute read
The cold, hard truth about climate change
Climate change is happening right here in Cleveland, but we can make a difference.
By David J. Burke
It’s a beautiful, sunny day in late March, and the woods at Holden Arboretum are filling with bird song. On this day, the sound of birds, and a light breeze through the treetops, mixes with the crunch of leaves beneath our feet. We are walking through Bole Woods to one of Holden’s long-term research projects. When arriving at the site, you are greeted by many multicolored flags sticking out of the ground. This project is Holden’s woodland phenology project.
Phenology is the study of the timing of annual phenomena in nature, including plant emergence, growth and especially flowering, and is an important way to understand how plants may be responding to a warmer world.
“We monitor the phenology of spring ephemerals — the woodland wildflowers that grow in the spring when the forest canopy is still open. We watch trout lily, trillium, dutchman’s breeches and squirrel corn closely from late March onward to see when they’re coming up, flowering and producing seeds,” says Emma Dawson-Glass, a research specialist at Holden Forests & Gardens. “Spring ephemeral phenology is closely linked to weather, and in warmer years, flowers tend to emerge earlier. As the climate warms, these shifts in timing can have important effects for other organisms that interact with these wildflowers.”
Global climate change is in the news a lot these days and often seems controversial. But there is widespread agreement among scientists and scientific organizations that the climate is changing and that this change is the direct result of human activities. In fact, at least half of the warming observed in recent decades is the result of the human activities that produce greenhouse gases such as carbon dioxide from the burning of fossil fuels.
Although we may think of polar bears and melting ice floes, climate change is a global issue, and it’s impacting us right here at home. The city of Cleveland has warmed on average by 2.5 degrees Fahrenheit since the 1950s. And at current rates of greenhouse gas emission, Cleveland will warm by an additional 3 to 7 degrees Fahrenheit by 2050. Unless we take action to reduce greenhouse gas emissions, our grandchildren living in Northeast Ohio will experience average temperatures as much as 10 degrees warmer than what our parents experienced in the 1950s, with potentially serious environmental consequences. The most serious impact of warming temperatures will be on patterns of rainfall and snowfall during the year. Warmer winters may be accompanied by less snowfall and more rain, changing water levels in lakes and rivers. Reduced precipitation during the growing season can reduce crop yield on our farms and in our gardens. Lack of winter snowfall can lead to increases in freezing and thawing of soil, damaging plant roots and soil organisms.
The warming temperatures will also affect the timing of plant, insect and animal growth and reproduction (that is phenology). Winter warm spells can lead to early flowering and leaf out for many plants, which can be vulnerable to damage by spring frosts. Warming can also lead to plants flowering before the emergence of their insect pollinators, leading to reduced seed set and jeopardizing pollinator populations that emerge too late to take advantage of flower food sources (e.g. nectar and pollen, which are used as food).
Warmer winter temperatures can also lead to pest outbreaks, especially the migration of invasive pests into our region. For example, hemlock wooly adelgid is an invasive insect attacking hemlock trees, eventually leading to tree decline and death. In the past, our cold winters have excluded this pest from northern Ohio, but as winters have warmed, the insect has begun to invade our region and is now found in many of our region’s forests, including those at the Holden Arboretum.
So, what can we do as individuals or organizations to make a difference when it comes to climate change? First, we need to recognize that climate change is real and is the result of human actions. That’s both good and bad news; the bad news is that we have triggered this slew of serious changes in our climate and, subsequently, the environment. The good news is that we have the ability to change our behavior and have a positive impact.
This spring, HF&G adopted a climate change statement recognizing that climate change is real and providing facts and information about climate change, its implications and some ways we are working to mitigate climate change within the organization. We hope this can be a helpful resource for people still trying to understand this complicated topic. You can find the full statement at holdenfg.org/holden-forests-gardens-climate-changestatement/, along with additional resources.
In order for HF&G to reduce its own climate footprint, we completed a carbon audit using the U.S. Environmental Protection Agency’s Simplified Greenhouse Gas Emissions Calculator. Carbon audits allow organizations and small businesses to understand the sources of greenhouse gas emissions so that targeted action can be made to reduce those emissions. Two large sources of emissions at HF&G result from heating our buildings and employee commuting. To reduce our emissions in these areas, we have committed to ensure that all building renovations reduce energy consumption by 25%, and we are encouraging employees to work virtually from home at least two days each week to reduce transportation emissions.
As a guest to our campuses, you may notice that at least 40 percent of all food items offered at our café or food service are vegan or vegetarian, as plant-based diets generate less greenhouse gas than those containing animal products. You will also notice we no longer sell bottled water, but water bottle refilling stations are available at both campuses.
Other ways we combat climate change include — our favorite subject — trees! Surprised we would mention trees? For us it’s natural. We are the People for Trees, after all. Because trees take carbon dioxide (the dominant greenhouse gas) from the air and use it to make sugars through photosynthesis, trees and forests can reduce greenhouse gases in our atmosphere. In fact, trees and forests represent the best natural solution to combat climate change.
At the Holden Arboretum campus, HF&G manages 3,000 acres of natural areas, and these natural areas remove 14,000 tons of carbon dioxide from the atmosphere each year, which is far more than HF&G emits as an organization. Our research and conservation teams work to understand how we can better manage forests to enhance biodiversity and improve the ability of forests to remove carbon dioxide from the air. “Not only are we managing our forests to maximize health and resiliency now and into the future, but we’re also using these forests as living laboratories – a test bed where we can trial strategies for forest management,” says Holden scientist and research chair Katie Stuble. “And, of course, our Conservation and Community Forestry department is sharing our findings with the community, promoting and supporting trees throughout northeast Ohio.”
Green tree branches with leaves reduce heat and carbon dioxide.
In our urban and suburban communities, trees are not only important for removing carbon dioxide from the air but also for mitigating the effects of ongoing change. Their leafy canopies provide shade in the summer, cooling the air, a critical service aiding in keeping our urban spaces cool in the face of increasingly warm weather conditions. If you want to help, join our People for Trees campaign and check our website for important information on tree planting, care and selection.
Holden Forests & Gardens is uniquely positioned to tackle climate change on multiple fronts in Northeast Ohio. We’re managing our own forested lands to promote their ability to sequester carbon, as well as quantifying the impacts of management on the functioning and resiliency of these forests, all while supporting trees in the region more broadly. By embracing improved forest management, and tree planting within our communities, we can all work together to combat climate change.
MEET THE STAFF
David Burke, Ph.D., is the Vice President of Science and Conservation. David’s primary research interest as an ecologist has been the interaction between plants and soil microorganisms. Of special interest are mycorrhizal fungi that can enhance plant growth, disease resistance, drought tolerance, and affect plant community composition. David is an Adjunct Assistant Professor of Biology at Case Western Reserve University and an Adjunct Assistant Professor of Biological Sciences at Kent State University. He received his Ph.D. in Biology from Rutgers University.
Our beautiful displays of trees and plants also serve as a living museum.
Maintaining the Museum
Get to know Tom Arbor, Curator of Living Collections
What exactly is Holden Forests & Gardens’ Living Collection?
Our gardens offer beautiful displays of trees and plants, but did you know they also serve as a living museum? Each tree and perennial plant on display is carefully cataloged by our curation team. We know where each tree or plant came from, whether we received them as seeds or cuttings and exactly when we received them. All of these plants, including more than 20,000 individually tracked trees and plant groupings, make up our Living Collection.
So you’re the Curator of this Living Collection? How do you curate it?
With so many plants in our Living Collection, I can’t learn them all in such a short time. Fortunately, our plant records team led by Ethan Johnson has that responsibility, and they help me immensely. What I’m focusing on is identifying groupings of plants within our Living Collection. I’m evaluating these collections using a series of characteristics and metrics, including their importance to horticulture, research and conservation. These significant collections are where most of my curation efforts will be concentrated. The goal of this work is to seek Nationally Accredited Plant Collections status from the Plant Collections Network program of the American Public Gardens Association and the USDA Agricultural Research Service.
What is one of your first memories experiencing wonder with a plant or a tree?
When I was fairly young, my grandfather took me to a new park in Akron that featured an absolutely gigantic bur oak. But this oak was special — it was ringed by a split-rail fence, and instead of having a single stem, two additional arms split off to the left and right, from which two other massive trunks shot upward. Known as the “Signal Tree,” local legend held that the tree was shaped by native people to serve as a type of guidepost for those traveling along the Cuyahoga River. When they saw this tree, it was time to leave the river and carry their canoes south on foot via a portage path to the Tuscarawas River, allowing them to reach the Ohio Valley. While that story is considered dubious, and much of the tree has fallen since I originally saw it, it still holds a special place in the community 30 years later.
Why did you decide to devote your career to plants and trees?
I had an opportunity to do an internship with the Ohio Department of Natural Resources Division of Natural Areas and Preserves after my sophomore year of college. I maintained trails and eliminated invasive species in a system of preserves across Northeast Ohio. I was immersed in rare habitats and the rare plants that called them home, and these experiences got me hooked on all things that photosynthesize. Mentors like Emliss Ricks and Ron Etling helped me understand what I was seeing, and why these plants were so important.
What are some of your favorite books and/or films about nature?
I love field guides. Field guides are what got me into nature, and they took me to the next level to start putting names to the things I was seeing in nature. Field guides are being replaced by identification apps on smart phones, and I just don’t think they offer the same experience. Peterson Field Guides Eastern Trees got me started, and I still use that book.
And anything else you would like to share?
I absolutely love working at a place where trees and plants are the focus. I love the diversity of plants and plant communities we care for — rare natural areas, trees from around the world and tropical glasshouses. As Earth’s climate changes, holding plants in ex-situ living collections will become increasingly important.
