Environmentally speaking, sacrificing turf by mandating native plants is a net negative.
All plants convert carbon dioxide to oxygen through photosynthesis. The rate of conversion is a function of leaf surface and growth rate. Lawn grasses have far higher leaf densities and growth rates than California native alternatives. For example, 2500 square feet of lawn absorb carbon dioxide from the atmosphere and release enough oxygen for a family of four to breathe. Turfgrass also absorbs particulates and some of the worst atmospheric pollutants from the air such as sulfur dioxide, ozone, hydrogen fluoride, and peroxyacetal nitrate.
Water Purification & Conservation
Turfgrasses have an extremely dense root system that is very effective in purifying runoff water as it leaches into underground aquifers. Turf roots act as a filter and in combination with soil biology make lawns a near ideal medium for the biodegradation of all sorts of environmental contamination. The high quantity of turf roots in the oxygen rich upper soil profile hosts greater numbers of beneficial soil microbes, which break down greater quantities of organic chemicals into harmless materials. Turf also prevents erosion and reduces runoff thereby increasing water infiltration and groundwater recharge.
Nature’s Air Conditioner
On a hot summer day, lawns will be 30 degrees cooler than asphalt, 14 degrees cooler than bare soil and significantly cooler than artificial turf. The average front lawn has the cooling effect of about 9 tons of air conditioning (a typical home-sized unit has a 3 to 4 ton capacity). The cooling effect of plants is a function of their transpiration rates. Turf has a high transpiration rate, thereby providing substantial cooling. Native California plants have a minimal cooling effect. Aside from creating a more comfortable setting, turf reduces energy demand.
Natural turf provides a safe, sanitary, self-renewing surface, while artificial turf may harbor harmful bacteria, retain dust and pollutants, and increase sports injuries. Healthy turf will not sustain fire, as will woody native shrubs. Lawns with tree shrub borders absorb sound while hard surfaces reflect it.
A Drop In The Bucket
Statewide Distribution Of Water
For more information on the environmental benefits of turf grass go to: The Lawn Institute