Syed had always been fascinated by the way forests seemed to have their own personalities. Growing up, he loved exploring the forest near his home, where each tree seemed to tell its own story of growth and struggle. Now, as a researcher, Syed found himself in an incredible position: using cutting-edge technology to “listen” to forests across the globe—from the chilly Boreal forests to the sunny Mediterranean and misty Atlantic woodlands.
The project Syed was working on had a straightforward goal: to understand the “types” of forest structures and classify them in a way that could be applied anywhere. Why? Because knowing a forest’s structure is essential for making smart decisions about how to protect it and use its resources sustainably.
But here’s where it got tricky. Forests are wildly diverse, with some towering like skyscrapers and others dense and scrappy. How do you develop a method that works everywhere? Syed and his team began by diving various forest attributes into numbers. They used detailed forest inventory data to look at four key traits of a forest’s structure:
Average tree size (because size matters in forests!),
Tree size inequality (do a few giant trees dominate, or are they evenly distributed?),
Tree density (how crowded is the forest?), and
Basal area larger than mean (essentially, how much space the bigger trees take up).
They ran these numbers through a method called hierarchical clustering, which grouped forests based on their similarities. They found three major types of forest structures:
Simple forests with just one layer, like a tidy lawn but with trees.
Multi-layered forests, where trees of all sizes competed for sunlight.
Reversed-J forests, where small trees were common, and big ones were rare.
Within each group, they further sorted forests into young and old, or sparse and dense. It was like creating a universal “family tree” for forests.
Next came the exciting part—could they use airborne laser scanning (ALS) to identify these types without stepping foot into the forest? ALS is like giving a forest an X-ray from above, using lasers to map the height, density, and shape of trees. Syed compared ALS data with the detailed ground measurements and taught a computer to recognize forest types using a method called nearest neighbor analysis.
The results amazed Syed. The computer could classify deciduous forests with nearly perfect accuracy (87%) and coniferous forests pretty well (72%). The most important clues turned out to be tree height and how unevenly the canopy was distributed.
Syed thought about what this meant. With just a plane and a laser, anyone could classify forests anywhere in the world—no need for weeks of exhausting fieldwork. This method could help countries work together to manage their forests, no matter how different they are.
But what Syed loved most was the realization that forests, no matter where they were, spoke a universal language. And through science, he had found a way to hear them.