The Importance of Native Trees
You don’t have to be a tree-hugger to appreciate the benefit of trees. Just look at the children, the birds, and the butterflies. I always pause to consider the expression ‘preserving our way of life’ and how relevant that is when speaking of the conservation mission of the SCNPS and so many other great organizations. Trees are quite literally a part of our ‘way-of-life’. We humans and the wildlife so necessary to our own existence are imperiled hand-in-glove with that of our tree population.
Most of us are aware today that the incredibly rapid economic growth in the world, and that however unwittingly or unintentioned, that development has and continues to seriously degrade the earth’s capacity to sustain its plants and animals. In doing so, we threaten our own well-being today and our children’s future.
This essay then, addresses the question we so often ask ourselves; “What can I do?”.
The Back Story: Why Trees are Important?
The City of Greenville, SC does a pretty good job of summing up the benefit of trees in their recent posting https://www.greenvillesc.gov/201/Landscaping-Trees summarized here:
- Preserves habitat
- Reduces soil erosion
- Improves water quality
- Reduces energy costs
- Increases property value
- Improves air quality
- Promotes mental and physical well-being
Douglas Tallamy is professor of Entomology and Wildlife Ecology at Univ of Delaware and author of Bringing Nature Home and Nature’s Best Hope. His reports on the subject find that our residential landscapes today can average as much as 92% turf grass lawn. In the remaining 8% is shared by trees, shrubs, perennials and annuals, with only 20% of those native plants. It’s worse, of course, in commercial, and municipal areas.
Do the math: Consider if you will that the Arthropods are the largest group in the Animal Kingdom, including insects like beetles, moths & butterflies, spiders and other such critters. Collectively this group are responsible for the pollination of 87.5% of all plants, and the number of arthropods has reduced globally by 45% since 1974. Science has evidenced that the disappearance of these pollinators would result in the collateral disappearance of 87-90% of our plants. Now add to that the further realization that many, if not most pollinators have a narrow band of ‘host’ plants which are critical to their reproduction cycle. This unique combination of realities is one of the driving motivations behind our own SC Native Plant Society, and others, to prevent further loss of habitat and promote the restoration of natives species. This is a very serious challenge and one that’s catching fire in the form of a cultural revolution in our own society today.
From that broader perspective of habitat loss, let’s drill down a bit into the role of trees generally and native trees specifically in this worthwhile effort. While we usually think of perennials like our native asters as important for our pollinators, in fact oak trees rank 1stor 2ndin wildlife food production for 84% of all U.S. counties. And it’s not just oaks, here’s a short-list of the highest impact pollinator plants in our ecosystem:
- Oak trees host >500 species
- Black cherry host > 300 species
- Willow trees host >250
- Hickory & Maples host >200 species each
After trees, then next plant species in line would be Asters hosting over 80 species so there’s a tremendous gap between the benefit of trees and perennials. It’s also very important to match up the wildlife in the area with the plants that they recognize as a food source. In other words, indiginous species, or ‘natives’. For more about native trees in South Carolina click HERE.
The take-away here is that habitat loss is a critical issue and trees are at the forefront of benefit in many ways; especially in the contribution of critical food webs for our wildlife.
Tree Economics 101:
Okay, so set-aside bugs for a minute and let’s talk economics. Let’s turn now to the area of economics to broaden our awareness of the benefit of trees. In 2006 the U.S. Forestry Service launched the Urban Tree Assessment which provided a protocol and tools for cities and counties across the country to obtain factual data regarding the tree canopy in their area.
By way of example, overflights by the USFS for the city of Greenville reflected a loss of approximately 33.1 million square feet of tree canopy between 2001 and 2011. Using this data and growth mapping for the city, it’s projected that without some changes to planning and codes, that loss could grow to 59.6 million square feet by 2021; meaning 75% of the city could be covered in asphalt. If you have any doubts about that, look-up Greenville 2040 Plan https://greenvillesc.gov/1398/GVL-2040-Comprehensive-Plan to see what kind of changes are under discussion for the next 20 years here. Clearly, our city planners are getting a grasp on the importance of this situation.
- Utility Costs: According to Dr. Puskar Khanal, Associate Professor, Dept of Forestry & Environmental Conservation at Clemson, every $1 invested in trees can provide a potential return of $6in economic value to the community. In cities like Greenville, where future development forecasts reflect an ever-increasing population density and traffic, this density alone could increase the ‘heat island’ impact by as much as +5°F in temperatures, resulting in higher energy costs.
- Property Values: Real estate values are typically thought to be 8-20% higher in areas adjoining naturalist settings like parks and tree-lined streets.
- Income and Tax Revenue: The net value of the tree industry SC is about $1.35 billion annually, including about $30 million in salaries and operating spend for tree maintenance which in turn generates about $15.3 million in tax revenue.
- Retail Sales: In central business districts with tree-line streets and canopies like our downtown Main Street, shoppers confess to spending 9-12% more.
One final point on tree economics. I took UpstateTrees Tree Keepers course on tree care and planting last year and learned that the average life-expectancy of an urban tree is only 15 years. Those wonderful heritage trees that grace our communities today, are a dying breed. And if urban trees are averaging only 15 years life, that means they will be smaller, and require a much greater commitment to planting in series. To replace one might 150 year old oak; an estimated 40 smaller trees. There are numerous factors contributing to that, but one of the most common is that most trees today are often planted improperly by homeowners and far too many professionals. The TreesUpstate website has a wealth of knowledge on the subject at https://www.treesupstate.org/resources/
What Can I Do?
Okay, okay, so we have a problem; but let’s think of it as a collective challenge. Hugging a tree may be spiritually rewarding, but
it’s going to take more than that.
Becoming more aware is the first step, and then, helping to make incremental changes around you. Here are some thoughts:
- Visit the SCNPS website EDUCATION page to find a listing of native trees for our state ecosystems HERE.
- Tune in to the TreesUpstate organization at https://www.treesupstate.org/. They are a terrific group of enthusiastic people with a goal of installing thousands annually here in the Upstate. They also work with Duke Power to give away free trees several times a year, and they offer an outstanding educational program in tree pruning and planting.
- Take the City of Greenville’s survey on updating the Urban Tree Ordinance. https://publicinput.com/K1373. It’s open now through October 13th
- We have outstanding professionally trained arborists in our city and we need to utilize them. To find a list of the companies that employ certified arborists in SC go to the SC Forestry Commission’s link at https://www.state.sc.us/forest/ptreeservice.pdf
- Educate yourself by visiting any of the amazing programs easily available online, including:
- The 1 Trillion Trees campaign which aims to “grow, restore and conserve one trillion trees around the world in a bid to restore biodiversity and help fight climate change,” https://www.trilliontrees.org/
- The National Wildlife Federation’s Certified Wildlife Habitat program at https://www.nwf.org/CertifiedWildlifeHabitat
- The Audubon Society’s Backyard Habitat Certification program http://aswp.org/pages/backyard-habitat-program
- The Clemson Carolina Yards Program https://www.clemson.edu/extension/carolinayards/certify-yard.html
We need to change the paradigm on how we, as a society, think of trees. Trees are a common resource essential to life as we know
it and we it’s time to re-think our role as ‘stewards-of-the-land’ to embrace individual trees as a shared resource, much the same way we do air and water. We need to also look more critically at the role of government in assuring this shared resource is not denied us by non-sustainable development.
Sheila Stanbeck founded the Oshun Mountain Sanctuary, a 42 acres of cove and oak urban forest boardering the French Broad River near Asheville to preserve native habitat that’s becoming scarce, placing many of the native flora and fauna at risk. I leave you with her fitting words, just replace ‘natural spaces’ with the word ‘trees’:
“Natural places are essential for human health. Once they are lost to development, they are gone forever. We must preserve them now and for our sake, and for the sake of the future.”
- Douglas Tallamy, professor of Entomology and Wildlife Ecology at Univ of Delaware and author of Nature’s Best Hope.