This is cross-view stereopair. To view this video in 3D you need to cross your eyes until you see three fuzzy images. Then try and focus the middle image. This takes a lot of patience to get right, but once you've done it once it gets easier. (There is a red-cyan anaglyph version over at flickr flickr.com/photos/firrs/2854954464/ )
This video shows the felling of two Sitka spruce trees in a Scottish plantation forest. Normally, commercial felling is done using harvesting machines, but these trees are being felled for a research project. The trees in this particular forest are about 40-years old and will soon be harvested and the logs sent to a sawmill. The land will then be replanted with new trees to provide timber in the future. Wood grown in this way can be used in place of materials that are not renewable, such as concrete and plastic.
Research helps us understand the factors that affect the properties of wood that are important for us, such as strength and stiffness.
To find out more about the science behind forestry and timber, visit: