image: This is a high-severity burn where young trees that regenerated after the 2000 Glade Fire re-burned in the 2016 Berry Fire. view more
Credit: Monica G. Turner
A study assesses the impact of short-interval severe fires on the resilience of subalpine forests. Although the subalpine forests of the northern United States Rocky Mountains have survived severe forest fires on the timescale of 100-300 years, changing climatic conditions may reduce the interval between severe fires in the future. Monica G. Turner and colleagues examined 18 plots of 0.25 hectares each in forests that had burned in either 1988 or 2000 and subsequently experienced another severe fire in 2016. The plots were located in Yellowstone and Grand Teton National Parks, and were compared with nine plots that had burned in previous fires but did not burn in 2016. The authors found that in some re-burned plots, in which pre-fire trees were dense and small, nearly all biomass was consumed. Re-burned areas experienced a six-fold decrease in tree seedling density on average, and high-density stands of more than 40,000 stems per hectare were converted to sparse stands of less than 1,000 stems per hectare. The authors found that re-burning reduced the biomass and aboveground carbon of downed logs by 65% and 62% respectively, with simulations showing that re-burned forests would need more than 150 years to restore aboveground carbon stocks. According to the authors, future short fire intervals may adversely affect the resilience of subalpine forests.
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Article #19-02841: "Short-interval severe fire erodes the resilience of subalpine lodgepole pine forests," by Monica G. Turner, Kristin Braziunas, Winslow Hansen, and Brian Harvey.
MEDIA CONTACT: Monica G. Turner, University of Wisconsin-Madison, WI; tel: 608-262-2592, 608-833-4137; e-mail: turnermg@wisc.edu
Journal
Proceedings of the National Academy of Sciences