- Planting trees, mostly native ones, and taking good care of them are key actions individual gardeners and communities can take to limit the impacts of climate change and create beautiful, resilient homes and neighborhoods.
- Trees provide shading, cooling, cleaner air and water, habitat for wildlife, and stormwater management -- many essential benefits in our natural and built environments.
- Trees are “carbon sinks”-- they capture and store carbon dioxide, the primary climate-changing greenhouse gas.
- Maryland has a goal of planting 5 million native trees by 2031. Residents can receive support for purchasing and planting trees. The Maryland Department of Natural Resources and many Maryland county governments and organizations offer tree rebate programs.
The benefits of trees in our changing climate
In our changing climate, trees play an essential role both in mitigating climate-warming greenhouse gasses as well as supporting and improving the quality of life in our natural and built living spaces. These are the many benefits of planting and maintaining trees:
Shade & cool your living spaces. Trees help reduce the urban “heat island effect” - the higher temperature of cities due to the prevalence of hard surfaces like roads, parking lots, and buildings, all of which absorb and re-emit heat. In Baltimore City neighborhoods with no trees, for example, summer temperatures have been recorded as much as 10°F to 16°F hotter than surrounding areas that have abundant green spaces and parks. Trees make it cooler by providing shade and releasing water vapor.
Save energy. Trees that shade your home in the summer and block cold winds in the winter can help you reduce the costs of air conditioning and heating. Planting with energy conservation in mind can lower your energy bills by 3 to 30 percent, depending on the size of the tree, its location, and other factors such as home construction.
Increase property value. Various studies of single-family properties have shown that the presence of trees and neighborhood tree cover increase property value by 2% to 15%.
Sink carbon. Trees are champions when it comes to holding carbon out of the atmosphere. All plants use carbon dioxide (CO2) to generate their own food and energy. In trees, a portion of this energy builds wood which stores carbon for a long time. Trees are “carbon sinks.” They hold carbon inside while they are alive. When they die, some of the carbon gets stored in the soil through roots and decomposition, and some is released back into the air.
Improve health and well-being. Trees contribute to cleaner air by absorbing some air pollutants and capturing particles of dust and ash. Children living in communities with trees have less asthma. Trees improve community walkability, which is connected to a reduction in obesity. Studies also have shown that being around trees reduces stress and anxiety, lowers blood pressure, and increases feelings of calmness. More tree cover has even been associated with less crime.
Provide habitat. Do you enjoy birds? Butterflies? Fish? Trees provide nesting places as well as food for birds, butterflies,and small animals. Native bees and other insects and birds have evolved with native plants, which provide the specific food and habitats they need for survival. Twenty-seven percent (27%) of Maryland bees are pollen specialists, meaning they must have pollen from specific native plants to survive and raise their young. For fish: Tree roots stabilize stream banks, reduce erosion, and keep water clear; their canopies provide shade to regulate water temperature and dissolved oxygen – all important conditions for healthy populations of fish and other aquatic wildlife.
Reduce stormwater runoff. Trees help to intercept and soak up rainwater, stabilize the ground, reduce erosion, and keep water clean. Tree planting in urban and suburban areas is especially important to help minimize the amount of stormwater running over paved surfaces to storm drains and carrying pollution to streams, rivers, and the Chesapeake Bay.
Selecting trees with climate change in mind
All tree species have a natural habitat range where they can survive and thrive. As climate change accelerates, more severe weather (floods, droughts), higher temperatures, earlier springs interrupted by freezes, and new pest and disease pressures will put stress on trees in our forests and landscapes. By 2080, summer temperatures in Baltimore, Maryland may feel more like they do in Cleveland, Mississippi, about 6°F warmer. Some tree species will fare better than others in the future. Some tree populations will be able to adapt or migrate gradually to new habitat ranges, while others will not be able to. People can facilitate migration by planting a different palette of trees with climate change and species adaptability in mind. For more on this, refer to Native Plants and Climate Change.
Researchers are working on models to help predict which types of trees will be most adaptable to future climate conditions. These are several examples:
- The USDA Forest Service’s Climate Change Tree Atlas explores traits, habitat suitability, and adaptation potential for 125 tree species. The trees were given an “adaptability rating” to indicate how likely they will adjust to climate conditions in 2100 under low and high greenhouse gas emissions scenarios. In the Lower Chesapeake area, for example, oaks, red maple, black gum, and loblolly pine are among the species that are expected to be more adaptable.
- (PDF) Climate Change Projections for Individual Tree Species: Greater Baltimore, Maryland. This list provides a summary of tree adaptability for the Baltimore region, based on the Forest Service’s Climate Change Tree Atlas.
- (PDF) Climate Change Vulnerability of Urban Trees, Washington, DC is a similar assessment of tree adaptability for the nation’s capital. [Note: This list also gives ratings to some non-native species. Invasive ones (denoted with an *) should not be planted.]
Research is also underway on sourcing, trialing, and breeding new trees that will be suitable for our region’s hotter summers but still able to survive Mid-Atlantic winters. Some trees that are native to the Southern USA: Florida sugar maple (Acer saccharum ssp. floridanum), Florida anise (Illicium floridanum), and Mexican flowering dogwood (Cornus florida subsp. urbiniana), for example, have captured the interest of ornamental plant breeders at the University of Pennsylvania’s Morris Arboretum.
There will be trade-offs when it comes to selecting species from outside of our region vs. using regionally adapted native species. In urban areas with high heat, air pollution, and limited planting space, a non-native, non-invasive species might be tougher and better able to survive and provide benefits such as shading and cooling, but it may not support native wildlife as well as a native species, for example.
Questions to consider
With climate change in mind, how do you decide which trees to plant for the best chances of survivability and benefits provision? A piece of general guidance is: Plant mostly native trees. Choose ones best suited to your site and goals. And take good care of them. If you can only plant one tree, think about multiple benefits you could gain with your choice. Here are some questions to consider: