1. What compels you to find these tallest trees, and why are they important?

These ancient giants are awe-inspiring — towering, stalwart, and wind-firm, they’ve endured fires, storms, and the axe. Discovering “extreme trees” — the biggest/tallest trees — is a new frontier. We learn from them because these trees define a “Boundary Condition” — that is, the limit of what that species can do when left alone. Changes in the environment will be seen first in the tallest trees. The biggest, tallest and oldest trees of a given species likely have good genetics that allowed them to become exceptional.

2. How does your research contribute to forest management?

The oldest, tallest trees are often the only survivors of ultrahot wildfires, thanks to their thick bark and branchless lower trunks. In fires like the Rim, Caldor, Ranch, and Dixie, mostly the largest and tallest trees survived while younger ones did not. These old trees are crucial seed sources for regrowth after fires. Giant trees also provide wind protection and homes for countless animals and unique plants. This shows us what we need to manage for to reduce fire impacts and promote more fully functioning forests.

3. Why is protecting big, old trees important for people?

Giant trees inspire people — most have no idea how immense trees like redwoods, giant sequoias, sugar pines, and ponderosa pines can be. Big, old trees sequester far more atmospheric carbon, stabilize more topsoil, keep surface temperatures lower, and hold more surface water than for smaller trees. 

4. How do you locate and measure champion trees?

I use LiDAR (Light Detection and Ranging — a remote sensing system), both ground- and aerial-based, to locate them. We also climb these trees using ropes, not spurs, to get accurate volume estimates of their crown, branches, and foliage for total mass.

5. What are the biggest threats facing the tallest, oldest trees today?

These trees are largely in protected areas, but climate changes and extremes, diseases and exotic pests pose the greatest threats, weakening and destabilizing forests in the Pacific Northwest, Eastern U.S., and globally.

6. Does old growth need to be managed?

The big old trees should be left alone to support wildlife and forest regeneration for future generations. Mature trees should be cultivated and selectively cut on long rotations, allowing many to mature into old growth. The largest dead trees should be left for wildlife habitats.

7. How can people help protect and manage for these old giants?

Landowners can conserve their forested lands to save their oldest trees, prevent overharvesting and development, and manage for mature forests, in the future, really old trees. As part of that, selective harvest and controlled burns help reduce fuel loads and return nutrients to the topsoil. These actions are key steps to protect these old giants.