John Sakulich

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It has long been hypothesized that trees growing at range limits likely also occur near the limit of their ecological amplitude and thus, should be more sensitive to climate variability than individuals growing nearer the range core. We developed a tree-ring chronology using Tsuga canadensis individuals from three disjunct stands at the species’ southern(More)
Fire is a key disturbance agent in the fire-prone mixed conifer and ponderosa pine forests of the southwestern United States. Human activities (i.e., livestock grazing, logging, and fire suppression) have resulted in the exclusion of fire from these forests for the past century and fire exclusion has caused changes in forest structure and composition. This(More)
[1] Monsoon droughts, which often coincide with El Niño warm events, can have profound impacts on the populations of Southeast Asia. Improved understanding and prediction of such events can be aided by high-resolution proxy climate records, but these are scarce for the tropics. Here we reconstruct the boreal autumn (October–November) Palmer Drought Severity(More)
Extreme climate conditions have dramatic socio-economic impacts on human populations across the tropics. In Indonesia, severe drought and floods have been associated with El Niño-Southern Oscillation (ENSO) events that originate in the tropical Indo-Pacific region. Recently, an Indian Ocean dipole mode (IOD) in sea surface temperature (SST) has been(More)
disturbance was ice storms, which generally resulted in suppression of radial growth in pines and increased radial growth in oaks. Additionally, pulses of understory establishment coincided with major ice storms. The lack of understory disturbance such as fire may be allowing the establishment of shade tolerant understory species while limiting the(More)
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