Hedvig Nenzen - Forest Ecology Lab

Whittier College, Whittier, CA



Measuring details of Forest Structure with Portable LIDAR

The 3-dimensional organization of the canopy is very important in determining its function.  The forest structure influences rates of photosynthesis, microclimate, carbon sequestration and habitat quality, among other things.  Previous techniques for measuring canopies have been slow and labor intensive, whereas the LIDAR (Light Detection and Ranging) system is quick and yields large amount of data. The method generates a density distribution of objects in the forest transect, data which is then used to quantify the structure. Some indices calculated include the local outer height, a measure of the variation in the canopy called rugosity, the average height, and the Canopy Area Index (CAI), which measures the density of the forest. We believed that as forests age, many of these characteristics change. This has already been shown in different communities of forests, but not for very similarly aged forests. Therefore, I established transects in two types of forests, intermediate (62-85 years old) and mature (107-126 years old), with two replicates for each type with three transects. The results were mixed, with most values too close to be distinguishable by age. New indices to express the difference in the forest should be developed. However, some transects did follow the hypothesis and the technique promises to be very powerful for differentiating different forests.

After going to ESA in August, I will start working as an environmental education instructor at a 4-H center in Georgia. I plan to continue to work within field biology, and eventually go to graduate school within Ecology.

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