Interview with Nicole Davey

Learning from Growth Rings: An Interview with Nicole Davey

This story is part of the Columbia Climate School’s series celebrating women’s work in honor of International Women’s Day on March 8, 2022.Read more about the day and our related blog post here.

When I was very young, maybe 6 or 7, I remember learning about tree rings and counting the number of rings to determine the age of a tree. However, it wasn’t until my current age of 22 that I learned that trees can tell us more than just age. Not only are they our lifelines, providing us with the oxygen and other vital environmental services we need to survive, but trees are our record-keepers.

The science of dendrochronology, founded by Andrew E. Douglass in the late 19th century, refers to the technique of using characteristic patterns of growth rings in wood and tree trunks to determine events and environmental changes. Douglas noticed a relationship between the size of tree rings and climatic factors such as humidity and altitude. This led him to invent a technique called cross-dating, which involves matching patterns from one tree to another.

Today, tree-ring analysis is used not only to determine past climate conditions, but also to predict future patterns.

Nicole K. Davi, a dendrochronological scientist at the university tree ring laboratory Lamont-Doherty Earth Observatory at Columbia University, Professor of Environmental Science at William Paterson University in New Jersey, and a science enthusiast. Her research focuses on developing and interpreting paleoclimate records to understand climate change over the past 2,000 years. Paleoclimatological data, derived from natural resources such as tree rings, ice cores, and ocean and lake sediments, can help scientists understand what and why Earth’s past climates have been.

Davi also leads a project that helps undergraduates develop key science and math skills using dendrochronology.This project is called Terex — Tree-Ring Expeditions developed a series of five publicly accessible labs for undergraduate courses. TREX is designed to introduce students to the study of tree rings and to immerse students in the field of dendrochronology.

To learn more about the scientific field of dendrochronology and why it’s important to make it accessible to all, I met with Davi via Zoom in early February of this year. Below is an edited version of that conversation.

When and where did you first learn about dendrochronology?

I’m an environmental science major, so I have a very broad view of environmental issues, but I don’t know much about paleoclimatology [the study of ancient climates].

Believe it or not, working at the Tree Ring Lab was my first job out of college. I start with a technician. After finishing the interview with the director of the lab at the time, I just thought it would be great to learn so much about the environmental conditions from an old-growth forest growing in a remote area.

Now you are a paleoclimate scientist and actively involved in the science of dendrochronology. What do you find most interesting about your job?

There’s a lot – questions to ask, applications, potential information and its usefulness to decision makers. But I think the most interesting thing for me is developing projects that are useful to the community.

How can dendrochronology help inform future decisions, especially in climate and natural resource management?

Using tree rings to record we often ask two questions. One is, how has our climate changed over the past few thousand years?

A good example of how tree ring records can be applied is Colorado River Compact (1922). Seven states (Arizona, California, Colorado, Nevada, New Mexico, Utah, and Wyoming) decide how to distribute the Colorado River’s water between states by looking at perhaps only 20 or 30 years of flow data. It looks good – they have enough water to separate. However, when you analyze the flow of the Colorado River using tree rings and reconstruct the flow for 400 or 500 years, you see that the period before the compact was very high. As a result, states overuse water. In subsequent decades, the river’s flow extended periods of much lower flow.

From tree ring records, we also know that droughts can last for a long time. For a long time, the human record may not be able to capture. This is important for understanding how to effectively manage our natural resources.

Another question we asked was how do individual tree species respond to climate? Are they doing well? Are they getting worse? What will the forest of the future look like?

There are many factors that affect how trees grow, so isolating climate signals is important.

Davey forcibly inserted a dedicated fortune-teller into the red cedar; the drill was hollow so she could core cross-section growth rings without harming the tree.

How are forests responding to climate change?

It can be very site specific. Warmer conditions and more rainfall will favor some species over others. It really depends on what the different tree species need. We don’t have all the answers.

For example, I am coastal forest. Most of the adult cherry trees in my site are dead or dying, so I don’t think they can tolerate increasingly salty conditions. In the Catskills, there are beech trees with beech bark disease, which is caused by an invasive insect that leaves the trees vulnerable to fungus. Those forests will change because of the disease. These trees will disappear within 10 years. I can’t imagine them surviving.So what happens [instead]? This is an open question.

What do these forest changes mean for humans? Can you talk more about our connection to trees?

Our connection to trees is an interesting question. A lot of the time I study forests and climate – I think about people and how people are affected. How do we deal with climate extremes? You also have to consider the resources people have.

But what do forests mean to humans? This is a really explosive topic. There are many studies showing how important it is for people to spend time in nature and forests – and how good it is for people’s emotions. There’s a lot of value out there that hasn’t been understood yet.

For me, the value is also cultural – being connected to a forest that has been growing for hundreds of years and knowing it’s there. Being able to experience and explore that forest, think about how the landscape has changed, and consider how people relate to that forest. It’s amazing. The value — we can quantify it, but it’s hard.

Your love for trees is obvious. If you had to choose one favorite tree species, what would it be?

species? ! My goodness. It’s like picking a favorite dog or something. I can not do it!

I love working with conifers. They are cork, so they won’t be too hard to core.

I live in Nyack, NY, there’s a 100-foot state park [tall] The cliff, at the top, has a small cedar tree. I can see that tree from many places in town, even from the Tappanzee Bridge. I like that. Above is the sentinel. My favorite tree in this area.

You mentioned that education is very important to you, that you are the principal investigator of the TREX project. Can you talk more about the program and your interest in undergraduate education?

I didn’t “find” science until my senior year of college, when I took an ecology course. It’s my language and everything makes sense. So, I decided to switch majors and stay for two more years.

For me, I’m really interested in what communication scientists do because it’s so exciting, so creative, so curious-driven. I didn’t know this until I actually worked in science. I think if I could learn more about what scientists actually do, I’d be drawn to it faster.

I’m trying to make what I do accessible to a large audience, and it should be accessible. Especially since there is so much misunderstanding and disinformation surrounding climate change. Everyone is familiar with trees, and most people are familiar with tree rings. They’re pretty intuitive – the idea of ​​ring width changing with climatic conditions is intuitive. People understand this. Even very young children understand this.

Natalie Williams is a graduate student at Columbia University Master of Sustainability Management program.