Tree abundance-elevation change
Changes in live tree abundances at low, middle, and high elevation in response to the 2011 freeze and drought event.
Climatic conditions from 2010-2012 in the Chisos Basin of Big Bend National Park, Texas (WRCC 2013) including A) monthly extreme low temperatures, B) mean monthly maximum temperatures, and C) mean monthly precipitation. The weather station is located within 0.25 km of the middle elevation sample sites in this study.
Stand structural data
Changes in forest stand structure due to drought and freezing in 2011 in the Chisos Mountains, Big Bend National Park, Texas. Mean values (+ S. E.) prior to the drought (2009) and after the drought (2011) are shown for A) seedlings by species, B) live trees (> 5 cm dbh) by species, C) live trees in 5 cm diameter classes, and D) standing dead trees. Significant changes between sampling intervals (P < 0.05) are indicated with an (*).
Tree size-mortality regression
Regression of tree dbh (cm) as a predictor of percentage tree mortality. Percentage mortality was significantly (P = 0.0016) correlated with tree size (y = 9.9538e-0.062x). Smaller trees suffered 2 to 5 times higher mortality than larger trees.