Field Studies: Bringing Historical Records Down to Earth
There are many field techniques that take research beyond what can be found in written documents. Clues to the past are hidden in such subtle (and not so subtle) features as topographic modifications, soils, and tree trunks. Field studies search for evidence of conditions and for their resultant effects through a variety of techniques. Features may be evident from a ground survey, located precisely through GPS. Remote imaging, using a variety of techniques from simple aerial photography to lidar, reveal hidden patterns, that may then be studied on the ground. Archeological study relates the patterns found on the ground to human activities, as they have changed over time. Dendroecology interprets records left in tree rings. Some studies look at stands of different ages to study change over time, and long-term studies trace change in individual stands. In these field studies that look at the past, soil characteristics and materials hidden in the soil, such as DNA, stable isotopes and charcoal, can reveal details of past processes and species. These methods are illustrated with examples from a wide range of biomes.