Having recently observed Arbor Day and Earth Day, it is a good time to review the benefits that trees provide us in the Irvine community as well as other communities.

Landscaping maintained by the Irvine Public Works Department

First, a bit about Irvine and its history with trees: The Irvine's Public Works Department maintains over 63,000 trees, which includes over 30 eucalyptus windrows. These publically owned trees are pruned under the supervision of certified International Society of Arboriculture(ISA) arborists to comply with ISA standards. And, of course, many privately owned trees can be seen landscaping various Irvine yards. According to a City of Irvine press release, some of the most popular trees in Irvine are pines, sycamore, sweetgum, Crape Myrtle and ficus.

In addition,Irvine has been an Arbor Day Tree City for 24 years. Also, Shadetree Partnership  is located on UC Irvine's campus and has a partnership with the Irvine Ranch Water District. Shadetree is a non-profit, volunteer organization that plants and provides stewardship of shade trees that Shadetree donates to parks, schools, and other public property.

In some cases, the value of trees is obvious; in other cases, not so much. American Forest illuminates the benefits that trees provide by placing them into three main categories: economic, social, and environmental. (American Forest is the oldest nonprofit conservation organization in the country and has planted more than 45 million trees and restored watersheds to help provide clean drinking water.) Many of the benefits could fit into more that one of these categories, but here is some of what American Forest says concerning the benefits that trees provide:

Economic benefits are both direct and indirect. Depending on where trees are planted, they can reduce air-conditioning and heating cost. The aesthetics that trees provide increases property values of not only individual homes, but also neighborhoods, and business districts. In addition, trees can control storm water and flooding, thereby saving the community money.

Social benefits include increased health, aesthetic, and recreational opportunities. Trees provide protection from harsh sunlight and ultraviolet rays, reduce noise pollution, and provide areas that encourage outdoor activities as well as relaxation.

Environmental benefits include improved climate and air quality, as well as preventing water runoff and improving water quality.

Trees absorb pollutants from the air, with the main pollutant being carbon dioxide. A mature tree absorbs approximately 48 pounds per year of carbon dioxide. In addition, tree release oxygen, which, of course, is the stuff we need for breathing.

Trees hold topsoil in place, and since healthy topsoil retains more water than eroded soil, ground water evaporation is greatly reduced.* The shade from the trees also plays a part in preventing water evaporation. This reduction in evaporation is especially useful during a drought and good for the budget in the form of lower water bills whether there is a drought or not. Also, tree roots filter pollution from groundwater. The results are improved groundwater quality as well as healthier rivers and streams.

*The following quotes were noted in a previous post (Irvine Farmer Markets, National Ag Week, and a Few More Thoughts), but they are relevant to this subject and worth repeating here:

"Absent carbon and critical microbes, soil becomes mere dirt, a process of deterioration that's been rampant around the globe. Many scientists say that regenerative agricultural practices can turn back the carbon clock, reducing atmospheric CO2 while also boosting soil productivity and increasing resilience to floods and drought."—Soil as Carbon Storehouse: New Weapon in Climate Fight?

"According to the Ohio State University Extension, the number of microbes in a teaspoon of [healthy] soil is larger than that of people on Earth. Microbes in the soil are important in providing organic nutrition to plants, allowing them to grow." —Microbes in the Soil