Tree-Ring Talk

The National Forest Inventory and Analysis Program (FIA) conducts a congressionally mandated repeat forest inventory implemented on all lands in the conterminous United States. Forested plots (~125,000 nationwide) are revisited on a 5- or 10-year basis for data collection. As part of baseline protocols on initial visits increment cores were collected. Cores were used for aging stands, determining potential productivity in timber forest types and to quantify growth increment.

The southernmost European conifers forests are considered vulnerable areas to climate change. Recent climatic trends towards warmer and drier conditions across the Mediterranean Basin might render some of these populations more vulnerable to drought-induced growth decline at the southernmost limit of the species distribution and in relict forests. In addition to climate drivers, the land use changes and past management drive the growth response to climate change effects.

The 1970s were a period of intense activity in the Gallina heartland of north-central New Mexico. Excavations by James Mackey and Sally Holbrook and by Herb Dick documented dozens of Gallina sites and structures in the Llaves Valley alone. Unfortunately, analysis and publication did not always follow excavations, particularly in Herb Dick’s case.  His untimely death in 1993 left much of his excavated material in disarray.

The relatively muted warming of the surface and lower troposphere since 1998 has attracted considerable attention. One contributory factor to this “warming hiatus” is an increase in volcanic cooling over the early 21st century. Our recent research has identified the signals of late 20th and early 21st century volcanic activity in multiple observed climate variables. Volcanic signals are statistically discernible in spatial averages of tropical and near-global sea-surface temperature, tropospheric temperature, net clear-sky short-wave radiation, and atmospheric water vapor.