Topics / ENVIRONMENT : Scientists Continue Study Into Plants’ Effects on Climate

Researchers returned to the San Gabriel Valley this month for the second phase of their study on the effects of transpiration--the moisture given off by plants--on climate temperatures.

Southern California Edison Co. sponsored the project conducted by the U.S. Forest Service and Indiana University researchers to determine whether the moisture would cool the neighborhood and result in less need for air conditioning.

This summer, researchers will gauge the wind speed, humidity and temperatures from eight 10-foot climate stations placed in the back yards of Arcadia and San Gabriel residents, and compare the results to the same statistics gathered from those stations last summer. Arcadia has more vegetation than San Gabriel, which researchers expect will lower the temperatures in the Arcadia yards.

Researchers will also compare the back-yard information to the yearlong statistics gathered from a 100-foot station that monitors Arcadia’s climate in general. Researchers were unable to put a similar station in San Gabriel for a year, so they will only monitor that neighborhood’s climate from a 100-foot station for one month.

Jim Simpson, who works for the Forest Service and coordinates the study, said the absence of yearlong data from the neighborhood station in San Gabriel would hinder the results, but that data from a summer month was the most crucial.

Researchers will conclude their study in San Gabriel Valley next month with results in six months to a year. They will move on to San Bernardino and Long Beach for similar tests and plan to finish the entire project in 1997.