Tree-Ring Talk

‘Blue rings’ in multi-century bristlecone pine from near upper tree limit in California and Nevada

Our strongly replicated collections of dendrochronologically dated tree-ring material of bristlecone pine (Pinus longaeva) from multiple locations in the high mountains of the Great Basin and nearby regions constitute a unique environmental archive. Their tree-ring widths have yielded multi-millennial histories of moisture availability, tree growth, temperature and tree-line elevation as well as of the chronology and influence of climatically effective, explosive volcanic eruptions.

Reconstruction of Ob River, Russia, discharge from ring widths of floodplain trees

The Ob River is the third largest Eurasian river supplying heat and freshwater to the Arctic Ocean. These inputs influence water salinity, ice coverage, ocean temperatures, ocean circulation, and ultimately the global climate system. Variability of discharge of the Ob River on long time scales is poorly understood because gaged flow records are short.

Multi-proxy Evidence for Sea-Level Changes at the Archaic-Woodland Transition on the Georgia Coast, USA

Tree-Ring Talk, topic to be decided

Drought, heat and cold stress...and bugs: the Mediterranean joy of tree life

Mediterranean forests provide multiple challenges and opportunities to dendroecology. I will cover some of these questions by presenting three examples we have studied. These study cases include different stressors such as drought-induced dieback affecting silver fir forests, winter drought involving Scots pine stands, and defoliations caused by the pine processionary moth. Tree rings allow addressing these disturbance factors following a retrospective approach. However, I will emphasize that such observational studies must be complemented by other sources of information (e.g.

Co-varying influences on growth of eastern U.S. deciduous hardwood trees

The assumption that a single dominant climatic factor (e.g. water balance or temperature) in extreme sites and locations limits tree growth allows for annually resolved climate reconstruction.

Fire history and fire-climate relationships of Buryatia, Siberia

Wildfire activity in the boreal forests of Siberia has been increasing over the past 20 years in response to warming temperatures, with several extreme fire years in the past decade.  While extreme fire yeas have a strong association with temperature and drought conditions, smaller human-ignited fires occur almost every year, related to agriculture and logging.  To better understand the longer-term context of wildfires and fire-climate relationships of central Siberia, we developed a fire history for the Buryatia province, where we collected 25 sites of fire-scarred material throughout the

Combining tree-ring and forest plot data to infer climatic niche: a hierarchical Bayesian approach

The forest biome is expected to shift geographically with anthropogenic climate change. To build species-specific, process-based models for forecasting how trees' geographic distributions will change under future climate scenarios, we see a need to combine two major, complementary sources of information on individual tree performance in response to climate variation: tree-ring and forest plot data.

Forest Inventory and Analysis Tree-Ring Data

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.

Effects of climate on Colorado River flow: perspectives from the past, present and future

Mountain snowpack is a critical factor for determining annual streamflow in the upper Colorado River, but other climatic factors can play an important role as well.  In particular, spring temperatures appear to be increasingly important, but antecedent fall moisture and early summer rainfall may also influence flows.  In the Colorado River basis, where water demand increasingly exceeds supply, water managers are interested in gaining insights on these additional climatic influences.

Subscribe to Tree-Ring Talk