Lab Overviews

Lab 1. Launching an Expedition

In Part 1, you will be introduced to the science of dendrochronology. You will see how tree core samples are obtained and processed, and take a virtual tour of a tree-ring laboratory.

In Part 2, you will hear two accomplished dendrochronologists describe their career paths and the role serendipity has played in their work. Then you will explore four important tree-ring research sites around the world and consider what types of research sites and trees scientists seek to help them answer questions about how our climate has changed in the past.

In Part 3, you will explore publicly available tree-ring datasets from the International Tree-Ring Databank (ITRDB). You will then focus on the work of one of the science investigators and their peer-reviewed research to help you understand how science works and how necessary collaboration is to doing meaningful research in tree-ring science.

Lab 2. Humpty Dumpty and Drought in the Hudson Valley, NY

In Part 1 of this lab, you will go on a virtual expedition to study drought in the Hudson Valley using some of same tools and analysis methods as tree-ring scientists. You will explore the Humpty Dumpty Talus Slope site with Google Maps and learn about the importance of picking study sites where climate-sensitive trees are growing.

In Part 2, you will learn how to evaluate patterns in tree-ring records by observing and comparing core samples. You will then identify marker years in your cores to decipher the climate record and determine when severe droughts occurred in the Hudson Valley.

In Part 3, you will use Climate Explorer, a powerful online tool that will let you map and evaluate recorded meteorological data. With this tool, you'll see if you can confirm that the cored trees are recording climate information by comparing your analysis of tree-ring data and observations of 'marker years' to the recorded data from Climate Explorer for those same years.

Lab 3. Tree Rings and the Ancestral People of Pueblo Bonito: Uncovering the Past

In Part 1 of the lab, you will go on a virtual expedition to New Mexico and visit Pueblo Bonito, an ancient ruin that was occupied between 750 and 1250 AD by the Ancestral Pueblo people. You will explore the region with Google Maps and search for samples of wood to analyze.

In Part 2, you will use a qualitative methodology to create a skeleton plot, a graphical method for accurately marking and dating tree-ring cores, from the scanned image of a portion of a Western Juniper sample and use it to date the site.

In Part 3, you will use ImageJ software to measure tree-ring data, produce a graph, and combine your data with those of your classmates to determine how the climate of Pueblo Bonito changed in the past. Did an extreme period of drought force inhabitants to leave the pueblo, or might there be a different reason for the abandonment of the village?

In Part 4, you will investigate a long-term data set produced by tree-ring records to identify the existence of megadroughts and other drastic climate changes that affected the ancestral people of Pueblo Bonito.

Lab 4. Sharing a River: The Colorado River Story

In Part 1, you will take a journey down the Colorado River to give you perspective on the scope of the watershed and how various stakeholders have drawn water from the river to meet the needs of seven western states. Then you will collect data on where the water comes from, who is using the water and how much they are using, and what the future may hold for the people living in the basin.

In Part 2 of this lab, you will explore aspects of the Colorado River Basin using a variety of resources, interactives and tools such as Google Maps.

In Part 3, you will work in small groups and use a quantitative method to analyze the ring patterns of samples of wood collected from sites in the basin and produce a graph to determine tree-growth in the region over the past century. Then, you will evaluate a 2000 year tree-ring based Colorado River streamflow reconstruction to determine how often major droughts occurred in the past.

Lab 5. Warming around the Northern Hemisphere: Reconstructing Temperature

In Part 1, you will explore the tree-ring datasets available from the International Tree-Ring Databank (ITRDB). You will then focus on the work of a dendrochronologist to help you understand how science works and how important and necessary collaboration is for doing meaningful research in tree-ring science

In Part 2, you will explore three different tree-ring research sites using Google Maps in order to understand the setting and ecology of the regions you will be studying in Parts 3 and 4.

In Part 3, you will use a quantitative method to measure rings from a tree core sample and produce a time-series graph from these measurements. You will then combine your measurements with those of your classmates to produce a preliminary tree-ring record for different regions around the globe.

In Part 4, you will use a time-series graph that shows a very long tree-ring chronology developed from many tree-ring sites across the Northern Hemisphere to identify periods of extreme cold and warmth in the past 2,000 years.

Lab 6. Climate Extremes and Impacts on People

This lab is designed as a supplement to TREX Lab 5.

In Part 1, you will identify cold extremes from tree-ring records during the end of the "Little Ice Age" (the late 1700s to early 1800s), and explore regional and societal impacts.

In Part 2, you will turn your attention to recent climate changes in the Arctic, and the impacts of temperature extremes over the last few decades on Indigenous communities.

In Part 3, you will learn about climate projections in northwestern North America and your own backyard, and you will consider the implications of future climate change.