Trees and Climate Change

With a dry winter forecast, city wells at historically low levels, and water rates poised to rise again, South Pasadena needs to develop an action plan for maintaining and replanting its tree canopy that takes into account the growing impacts of climate change. Days when temperatures rise above 95 degrees are expected to more than double in the San Gabriel Valley, from 32 to 74 over the next 20 years. This will make it more difficult to maintain adequate soil moisture for new trees planted to replace dying trees. It will require more watering than in the past to maintain the health of existing trees.

At the same time, without efforts to convert dark roofs, street pavement, and other hard surfaces to whiter materials that increase reflectivity, or albedo, the urban heat island effect will compound future temperature increases. Converting landscape to drought tolerant varieties that require less water also can reduce soil moisture and evaporative cooling, which compounds loss of soil moisture. Landscapes featuring cactus and stone, not only do this, but also act as heat sinks, similar to asphalt.

Catch the full story in this week’s print edition of The South Pasadena Review, 2.23.18. Never miss an issue of The South Pasadena Review. For subscription information click here.