Introduction to the field trips and labs on streams

The lab section for ESR220 will focus on problems associated with urban streams in the Portland area. The relationship between human and nature and the role of science in this relationship is illustrated by these problems and solutions that are being proposed. As humans take more and more control of natural systems (controlling over half of the total global primary productivity) we also need to take responsibility for protecting, managing or modifying ecosystems. We can and should debate, what the moral and philosophical issues this level of control or demand raises. But for our purposes in the class and in Portland, humans have a huge impact on the nature of urban streams and yet we have decided that we value some natural features or ecosystem services that they provide. Toward this end, Metro had worked very hard to protect and restore our streams.

Types of Streams and Restoration

We will have field trips to make preliminary observations on several different types of streams that we have near by:

• small little streams as they just start out in a neighborhood (Upper Fanno Creek, near Hillsdale)
• larger, low slope streams that have collected water (and been impacted by humans) for many miles (Mid Fanno Creek near 217, and Johnson Creek)
• streams that are almost wholly in natural areas (Balch Creek)
• streams that are fed by springs or ground water (Crystal Springs Creek)

We will also see different restoration efforts that are pushing streams back to more natural flow patterns and shape:

• Balch Creek and Johnson Creek have both had many channelizing or bank stablization structures removed
• Tidewood-Johnson Park and Brownwood area have both been stripped of non-natives and replanted

Purpose of the labs:

The impact of humans on streams is a very real problem. There are solutions being implemented and more being proposed, but it is an active area of research in science, management, and policy. It is often the case in science and management issues that determining the biogeochemical background conditions and processes (Millenium Ecosystem Assessment) which means that there should be more measurement, modeling and monitoring of these systems.

In these labs we will start by observing different streams and putting them in the context of the watersheds. Then you will learn to make measurements for key parameters for following streams; flow, temperature, dissolve ion load (conductivity), total dissolved load (including organics), suspended material and turbidity. These parameters are related to where the water came from and what processes it went through before you measured it. For example, rain water that hits the soil and slowly percolates to a stream will pick up a higher load of dissolved ions than rain water that falls directly on the stream or runs off the top of saturated soil. By understanding some of these processes, the source and transport of the water can be understood better.

After your lab has had time to make some beginning observations, study some of the available information, and learn some field techniques, you will form groups to gather more information and collect data yourself that you think will be helpful to address hypotheses related to management decisions. For example, you might come up with an explanation for high turbidity that could be due to direct runoff from a distrubed field or work site into one of the streams after particularly strong rains. You could determine a monitoring program that might include:

• upstream and downstream
• before, during and after heavy rains
• measurement of other confounding problems such as other erosion sites

(This is just one example.) Then you and your team will make the measurements and formulate an explanation for the impact. You will both write an individual paper on this topic and make a group presentation that will have at least:

• context
• hypothesis or hypotheses to be tested
  • that addresses a conceptual model of the watershed and processes
• methods and plan of research
• results
• discussion

This will be presented in a professional manner, using Powerpoint with graphics, maps, graphs, tables and pictures.