Weighing trees with lasers: new 3D measurements and models of tropical forests

Measuring forest structure – the size and location of leaves, branches and trunks – allows us to estimate the amount of biomass stored in a forest. This is a key property as it indicates the size and variability of forests as a store (and flux) of atmospheric CO2. Our current best estimates of forest C stocks are based on empirical extrapolations of the masses of a small number of trees that have been destructively harvested. Due to the difficulty of weighing trees, these measurements are also heavily biased towards smaller, non-tropical trees. As a result our knowledge of forest C stocks are highly uncertain. Mathias will show how new observations, using lasers in particular, are providing us with a new way to estimate the mass of trees. These measurements also provide a wealth of other information that allows us to build new 3D models to better exploit satellite and airborne observations and explore theories of metabolic scaling. He will also show how these highly-detailed 3D models, based on film industry animation techniques, can give us a ‘virtual laboratory’ for testing simpler models and methods, and are being used for a variety of applications. He will present results from recent tropical expeditions in Africa, Australia and Brazil, as well as a new view of the English oak, a bit closer to home.