MEXICO: A team of researchers with members from several institutions in the U.S. has found that compared to the beginning of the last century, California’s forests are more dense, with fewer large trees, more small growth and are a much bigger risk for fires.
Researchers from the USGS, UC Davis and UC Berkeley took modern tree surveys conducted from 2001 through 2010 and then compared them to those taken from 1929 and 1936, discovering that the density of large trees declined across the state, with the biggest drops – up to 50 percent – in Northern California, the south and central Coast Ranges and the Sierra Nevada highlands. Meanwhile, small tree density rose by a substantial margin between the older surveys and the newer ones.
The primary culprit is thought to be widespread drought, as less humid conditions will reduce the amount of water available for trees to grow. This results in more dense clumps of shorter trees – an unfortunate fact considering that these types of trees are much more susceptible to destruction by wildfire – something that the scientists involved in the study say could lead to different approaches when it comes to California’s forest land management policies.
Patrick McIntyre, the lead author from the survey, highlighted how important it is to understand how water balance plays a role in drought-affected systems – and how global temperature increases will affect the system as well. McIntyre said that California has a third of its land mass covered by forests and woodlands, making it a priority to understand the systems in play.
