In a previous blog, we discussed how home lawns are misrepresented to the public in the media. In this post, we will focus on all of the beneficial aspects that lawns bring to our increasingly urbanized landscapes. According to The Lawn Institute, there are now more people living in urban areas than rural areas, and by 2030 the United Nations projects that up to 60% of the world’s population could be living in urban areas. Urban ecosystems, which include lawns and parks, contribute to public health and increase the quality of life of urban citizens (Boland and Hunhammar, 1999). Lawns provide ecosystem services that seem to be discussed sparingly by opponents of home lawns.
Ecosystem services refer to the many and various life-sustaining benefits that are provided to humankind by the natural environment and healthy ecosystems. Consider how plant roots stabilize our soils and prevent erosion, or how plants remove CO2 and other contaminants from the atmosphere. These are examples of beneficial services provided to us by various ecosystems in our environment. We argue that properly managed lawns, including green spaces composed primarily of managed turfgrass systems, provide numerous ecosystem services that make them vital components of our ever-urbanizing landscape. The societal benefits of lawns and turfgrass systems have been well-documented (Beard and Green, 1994; Stier et al., 2013; Christians, Patton, and Law, 2017; Brosnan et al., 2020). The primary ecosystem services associated with lawns are air filtering, noise reduction, microclimate regulation, rainwater drainage, and recreation and cultural value (Boland and Hunhammar, 1999). Let’s take a closer look at some of these benefits.
Keeping Cool
Evapotranspiration (ET) from lawns can modify temperatures and reduce energy requirements. In Los Angeles and Paris, the temperatures at parks and golf courses inside city limits have been documented to be 3-3.8 degrees Celsius, cooler than in the center of downtown (Dousset and Gourmelon, 2003). Landscaped areas, including lawns, have been shown to have the potential to reduce the energy used for air conditioning by up to 50% in a hot, humid environment like that of Miami, FL (Parker, 1983). McPherson et al. (1989) showed that turf reduced energy use for air conditioning compared to rock-based landscaping in Phoenix, AR by as much as 30%. The urban heat island effect is a real thing and lawns and landscapes in urban environments provide a means to combat this.
Air Purification
Did you know that 25 square feet of turfgrass can produce enough oxygen for one person for an entire day (Watschke, 1990 in Christians, Patton, and Law, 2017)? Lawns are able to absorb atmospheric pollutants and trap dust. Due to the complete coverage of soil by a healthy lawn, soil particles are prevented from becoming airborne and being carried to other areas. As your lawn conducts the process of photosynthesis, it’s removing CO2 from the atmosphere and giving us back O2 as a waste product of photosynthesis. The CO2 removed from the atmosphere is stored underground as organic carbon. Grasses are also able to absorb ozone, sulfur dioxide, nitrogen dioxide, ammonia, carbon monoxide, lead, and other volatile organic compounds, removing them from the atmosphere (Christians, Patton, and Law, 2017). So breathe easier when you’re out enjoying your lawn.
Happy Soil
Simply put, lawns add organic matter to the soil through the cycle of plant tissue turnover. The increased organic matter results in increased soil carbon and nitrogen, and better soil fertility. Soil organic matter also increases the soil's water-holding capacity and cation exchange capacity. Soil carbon is also associated with soil aggregate stability, decreased runoff, improved water infiltration, and decreased soil bulk density (Christians, Patton, and Law, 2017). Your lawn’s soil also provides a habitat for numerous soil-dwellers, like arthropods and countless microorganisms.
Water Filter
Lawns are very effective at reducing surface water runoff. The macropores created by turfgrass root systems create channels that allow for water infiltration. The hydraulic resistance and increased water infiltration allow for increased groundwater recharge. Additionally, microorganisms in lawn ecosystems can filter and cleanse water by digesting and degrading chemicals and pollutants (Beard and Green, 1994).
Noise and Glare Reduction
Replacing acoustically-hard ground (e.g. concrete) with porous soil (e.g. a lawn) offers substantial noise abatement while also preserving the openness of a landscape (Van Renterghem, 2015). The overall costs of noise have been estimated to be in the range of 0.2 –2% of GDP in the EU (Kömmunforbundet, 1998). Noise from traffic and other sources in urban areas creates health problems for inhabitants. Increasing the number of areas with soft ground and vegetation may decrease these noise levels. A soft lawn, rather than a concrete pavement, decreases urban noise levels by 3 dB(A) (Boland and Hunhammar, 1999). Planting grass along roadsides decreases noise levels by 40% compared to hard surfaces (Hoyle, 2017). Lawns also have the ability to reduce glare and light reflection. The multidirectional light reflectance, owing to the variability in the size, shape, and angle of individual grass plants, can reduce glare and increase visibility (Christians, Patton, and Law, 2017).
Erosion Control
Properly managed turfgrass systems, like lawns, can have an incredibly dense, fibrous root system. These dense roots are able to stabilize soil, which reduces erosion, mud, and dust. There is a reason that “contractor’s mix” grass seed is a thing. Quickly established, low-maintenance turfgrasses are the best and fastest way to stabilize soil and reduce erosion in new developments and newly built homes. According to Stier et al. (2013), “sediment losses from turfed areas are negligible compared with situations in which bare soil is exposed, such as in row-crop agriculture or construction sites.” Turfgrass sod has also been shown to be more effective than synthetic erosion-control materials at reducing sediment losses by delaying the initiation of runoff (Krenitsky et al., 1998).
Recreational and Cultural Value
Where do we begin with this section, with so much value added to our lives by having lawns? Landscapes, like lawns, improve emotional, mental, and physical health. Hospital patients with views of green spaces heal faster after an operation compared to those who don’t (Ulrich, 1984). Vandalism and graffiti tend to decrease in urban areas that invest in landscaping. Your backyard lawn can act as your sanctuary where the kids and pets have a safe, cushioned area for outdoor recreation. It can act as your space for quiet reflection away from the daily grind. Home values can be increased by up to 15% with the presence of a well-manicured lawn. Lawns provide an aesthetically pleasing backdrop or centerpiece in home landscapes. When you think of the recreational value of your lawn, what other surfaces can de described as permeable, non-heatable, injury protecting, impact cushioning, and relatively inexpensive (Monteiro, 2016)?
In order to ensure the long-term success of the American lawn and to enjoy its benefits, we may need to seriously rethink the standards of what we deem as an acceptable lawn. We also need to focus on good lawn care practices that are sustainable for both the homeowner, the lawn, and the environment.
It’s ok to let your lawn go dormant in the intense summer heat, it’s fine to have a smattering of weeds throughout your yard, and it’s not necessary to be constantly fertilizing your lawn. Many grass species evolved in some of the driest places on earth, browning and dormancy in times of stress are perfectly natural and don’t mean that your lawn is going to die. Choose to irrigate when your turf shows signs of stress rather than on a set schedule. Opting for mechanical control of weeds, like the old-fashioned “pull and twist”, before immediately resorting to herbicides is a great way to reduce inputs to your lawn. Responsibly applying fertilizers based on soil testing, or using non-fertilizer products that can reduce plant stress like Sea Hume, Soil Hume, or Root Hume is also a great way to make your lawn more sustainable so we can all continue to enjoy our lawns for years to come. Responsibly fertilizing your lawn is a great way to set it up for sustained success so that you can enjoy all of the previously mentioned benefits that your lawn can provide.
Curious to learn more about sustainable turfgrass? Check out this resource.
Unlinked Resources:
Brunson, L. (2001). Resident appropriation of defensible space in public housing. Doctoral Dissertation, University of Illinois, Champaign-Urbana, IL.
Christians, N. E., Patton, A. J., & Law, Q. D. (2017). Fundamentals of turfgrass management. Hoboken, NJ: John Wiley and Sons.
Kommunförbundet, 1998. Skönheten och oljudet (The Beauty and the noise). Handbok i trafikbuller skydd, Svenska Kommunförbundet, Stokholm, 132 pp. (in Swedish).
Stier, J. C., Steinke, K., Ervin, E. H., Higginson, F. R., & McMaugh, P. E. (2013). Turfgrass benefits and issues. In J. C. Stier, B. P. Horgan, & S. A. Bonos (Eds.), Turfgrass: Biology, use, and management. Madison, WI: ASA.
Watschke, T.L. 1990. The environmental benefits of turfgrass and their impact on the greenhouse effect. Golf Course Management. 58(2), 150-154.
