Soils are the most diverse ecosystem in the world and is the second largest sink for carbon following oceans. Soil is not considered to be an infinite resource which can take 100 to 500 years to form just one inch of topsoil. The United States will be celebrating its SemiquintenniaI (250 years) in 2026 and since the birth of this country, just a 1/2 inch of topsoil has been formed. Let’s pause and think about that …. all the historical events, within that span of time, just 1/2 inch of topsoil has been formed. Soils are a valuable resource and must be protected. Soils are the foundation of our daily lives; without soil we wouldn’t have antibiotics, in which 3/4 of clinical medications come from soil bacteria. Ninety-five percent of our food supply depends upon that four letter word…Soil. Soils are the least thought about when it comes to sustaining our environment and Carbon storage.
We often hear how agriculture management practices, e.g. tillage contributes to climate change. But, what about urban landscapes - have we really given much thought to the fate of urban soil when it’s disturbed for new neighborhoods? What happens to that soil and the diversity of species living within that soil.
During construction, heavy equipment used to clear and prepare the lot for construction can contribute to compaction which limits air and water in the soil. Construction debris may get buried, machinery may leak fuel or other fluids that could be harmful to the soil and the soils microbiome.
According to the U.S. Census Bureau and the U.S. Department of Housing and Urban Development, new residential construction completions for the month of September 2022 was 1.4 million. Presuming each of these houses had an average lawn size of 10,000 ft 2 - this would equilibrate to an additional 3.2 million acres in the month of September that the soil has been disturbed and/or removed.
Recently, more focus is taking place on urban landscapes and the carbon cycle. Andrew Hill, at the University of Delaware, reported on a study about Backyard Carbon. He stated, “Our work highlights that within highly anthropogenic systems such as cities and suburbs, factors regulating natural carbon cycling can become altered from changes in environmental conditions such as urban heat island effects, modified hydrology, soil disturbance and land development.” They found that lawns can emit over 1 kilogram of carbon per square meter per year, an amount larger than that emitted from forest floors, suggesting that urban lawns may be an important source of carbon to the atmosphere. But, there are things that can be done - until next time