GREAT BASIN TREE-RING RECORDS FROM LOWER-FOREST-BORDER SITES
BIONDI, FRANCO (1); STRACHAN, D.J. SCOTTY (1); KOZUBOWSKI, TOMASZ J. (2), AND
PANORSKA, ANNA K. (2)
(1) DendroLab, Department of Geography, University of Nevada, Reno, NV 89557, (2)
Department of Mathematics and Statistics, University of Nevada, Reno, NV 89557
In the Great Basin of North America, long records of fire frequency, drought, and species
distribution are important not only for fire management, but also for restoration efforts aimed at
reducing the recent expansion of piñon-juniper woodland into sagebrush and other types of
vegetation. Ecotonal environments characterized as lower forest border sites are ideally suited for
tree-ring reconstructions of hydroclimatic variability. Piñon trees from about 10 different sites in
the Great Basin were sampled to develop a network of moisture-sensitive chronologies spanning
the past few centuries. Principal component analysis was used to identify climatic signals, and to
develop spatially explicit records of past wet and dry episodes. Applications of the tree-ring
network to water resources research are investigated using stochastic models of episode duration
and magnitude that can produce probabilistic estimates for the likelihood of severe and sustained
drought.