Jan 20, 2015
Some press on our PNAS paper: Twentieth-century shifts in forest structure in California: Denser forests, smaller trees, and increased dominance of oaks.
- Berkeley News http://newscenter.berkeley.edu/2015/01/20/warmer-drier-climate-altering-forests-statewide/
- National Geographic http://news.nationalgeographic.com/news/2015/01/150119-california-forests-shrinking-climate-drought-science/
- LA Times http://www.latimes.com/local/lanow/la-me-ln-forest-study-20150119-story.html
- KTVU SF news http://wn.ktvu.com/clip/11049705/berkeley-drought-to-impact-climate-change-in-forests
In the paper we document changes in forest structure between historical (1930s) and contemporary (2000s) surveys of California vegetation. The shorthand is:
- Statewide, tree density in forested regions increased by 30% between the two time periods, and forest biomass declined by 19%.
- Larger trees (>60 cm diameter at breast height) declined, whereas smaller trees (<30 cm) have increased.
- Large tree declines were more severe in areas experiencing greater increases in climatic water deficit since the 1930s.
- Forest composition in California in the last century has also shifted toward increased dominance by oaks relative to pines, a pattern consistent with warming and increased water stress, and also with paleohistoric shifts in vegetation in California over the last 150,000 years.