Tree-Ring Talk

Do the tree rings of African Terminalia sericera record a chemical signal from coal-fueled power plants?

South Africa relies on a primarily coal-based power supply.  The national power provider, Eskom, currently operates approximately 20 plants, and is now constructing the largest coal-fueled power plant in the southern hemisphere (5800 Megawatts) to meet growing demand.  The new plant, Medupi, will be located near coal fields in the Waterberg region and will burn high-sulfur coal.  Although there are several large coal-based plants in the Waterberg area that have operated for the last 30 years, very little environmental monitoring related to emissions was ever conducted, and retrospective ana

Tree-Ring Network and Climate in the Mediterranean Region

Drought is a focal point in the assessment of hydroclimatic variability in the MediterraneanBasin. Droughts can have drastic social and economic impacts, particularly in North Africa (NA)and Eastern Mediterranean (EM) where population is increasing rapidly and water supplies areextremely limited. Knowledge of drought variability on time scales of decades to centuries isneeded to understand and prepare for dry and wet conditions in the region. Drought-sensitivetree-ring records are a valuable resource for extending knowledge of hydroclimatic variabilityboth in space and time.

Florida tree rings and shipwreck rates reflect Caribbean hurricane activity since 1500

The observational record of North Atlantic tropical cyclones (TCs) is too short to inform our understanding of decadal-scale climatic controls on TC regimes. We combined two new annual-resolution proxies of Atlantic storm activity to extend the observational TC record back to the 16th Century. A tree-growth suppression chronology (1707–2010 CE) from the Florida Keys captures 91% of observed North Atlantic TCs (1850–2010 CE) and shares significant peak events with a documentary time series of Spanish shipwrecks in the Caribbean (1495–1820).

An integrated field data collection system for dendrochronology

A wide variety of information or 'metadata' is required when undertaking dendrochronological sampling.  Traditionally, researchers record observations and measurements on field notebooks and/or paper recording forms, and use digital cameras and hand-held GPS devices to capture images and record locations.  In the lab, field notes are often manually entered into spreadsheets or personal databases, which are then sometimes linked to images and GPS waypoints. This process is both time consuming and prone to human and instrument error.

Climate Response of Four Tree Species from the East-German Low Rainfall Area

Climate response was investigated for four tree species in the East German low rainfall area in Thuringia where average annual precipitation falls below 600 mm. Black Pine (Pinus nigra) has large semi-natural stands on calcareous soils far north of its natural distribution, Common Ash (Fraxinus excelsior) reaches its physiological limit along calcareous slopes.

Sky Island Investigators: Where Students Become Scientists

We offer a diverse variety of science field classes – on the UA Campus at the Bryant Bannister Tree Ring Building, at Tumamoc Hill, and at field sites in the Catalina Mountains - where students learn that science is a dynamic process of gathering and evaluating information. We adapt our innovative approach to work with teachers and students of all ages and grade levels, depending on the needs of your students.

Dendroecology 2014 Course Presentations

Hear presentations on the Dendroecology 2014 pre-session course research topics.

Higher temperatures negatively affect tree growth at multiple spatial scales in the western United States

Annual tree growth is tightly regulated by climate.  As air temperature increases, evaporative demand also increases, changing the dynamics of water availability in forest ecosystems.  By correlating tree growth with precipitation, temperature, climatic water deficit, and vapor pressure deficit, we show that higher temperatures decrease tree growth across all spatial scales and regions.  We use a novel dataset of Douglas-fir chronologies from 122 sites distributed throughout all mountain regions and a broad range of climate regimes in the western United States.  By sampling throughout “clim

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