Drought, fire management and land use changes have led to denser forests in California

“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. In their paper published in Proceedings of the National Academy of Sciences, the researchers describe how they compared forest surveys over the past century and the changes they noted and what it might mean for the future of forest management in the state.

“In the past, before people arrived, fires, generally due to lightening strikes would start, and burn thousands of acres before dying natural deaths. That would allow for new growth, which would eventually lead to tall tree growth. Now, whenever a fire starts, it is put out as quickly as possible to protect homes and businesses in the area. The result is highly dense forests with dry small trees—the perfect conditions for fires to start and spread very quickly. The researchers also found that oak trees have grown more numerous while pine populations have declined—another result of the drier climate.”
Read more at: http://phys.org/news/2015-01-drought-denser-forests-california.html#jCp

GR: The researchers need to test their assumption that fire prevention and suppression have been effective. Even though fire-fighting budgets are growing, fire size is increasing.

It is interesting that large trees are fewer now. Could that be because of logging? And the spread of oak trees, is that influenced by logging or cattle grazing? The research conclusions seem to suggest that things are going to get back to what the researchers consider normal now that fires are becoming larger and more frequent. All that small growth that is preventing large trees will get burned up.