Soils in depositional floodplains are the vigilant recordkeepers of watershed conditions,
recording changes across long timespans. Pennsylvania’s floodplains, mostly river-wetland
corridors, had functioned in a quasinaturally stable state without substantial human
intervention for over 10,000 years until European settlement in the late 17th and early 18th
Centuries. These natural, stable floodplain ecosystems were quickly and severely altered
following European settlement. Colonization ushered a wave of land clearing and
industrialization that reduced the quality and quantity of modern stream and wetland functions
to a mere shadow of the functions provided in the prior natural condition. If stream
restoration is to fulfill its obligation to return an aquatic ecosystem to a condition close to its
natural state, then it is critical to be able to identify the divergence between the natural
condition and the degraded condition, particularly when evaluating modern aquatic resources
and proposing restoration designs.
Field observations, analytical data, and digital examples of various floodplain soil profiles will
be presented to: 1) evaluate the common floodplain soil forming processes and 2) identify the
environmental conditions that formed each soil layer. Results from additional laboratory
analysis procedures such as organic matter content, radiocarbon dating, scanning electron
microscopy, and paleo-botanical seed analysis will also be presented to further enhance field
observations.
Attendees will be able to utilize this information to quickly identify common floodplain
degradations in modern landscapes and find in-situ evidence of the natural condition. This
information is critical in identifying the departure in the form and function of degraded aquatic
resources.
