How can a stream running through the hot desert of eastern Oregon have occasional cold spots, with warm water both upstream and down? This anomaly showed up in 1994 when fisheries biologist Bruce McIntosh (Forest Science) started working with forward-looking infrared (FLIR) sensor images representing the surface temperatures of stream, vegetation, and soil. Puzzled, McIntosh went to hydrologist Bob Beschta (Forest Engineering). They discussed the anomalies but could reach no conclusion without more data. At about that time, they responded to a call for proposals from the Environmental Protection Agency (EPA) and the National Science Foundation (NSF) Joint Watershed Research Program and developed a project that would help in understanding stream temperatures and factors affecting them in eastern Oregon.

Their initial concern was that thermal patterns of streams and adjacent land were anomalous. In some places the water seemed to be too cool, given adjacent temperatures, and those places, termed thermal refuges, are preferred by chinook salmon. That seems understandable, since at the hottest time of the year, stream temperatures might be at or above lethal temperatures for spring chinook salmon. The questions to be addressed were how the anomalies occur and whether they are natural or reflect human practices.

Given the complexity of the issues, the project is led by multiple principal investigators, each bringing a different expertise, along with a love for eastern Oregon. In addition to McIntosh and Beschta, biologists Hiram and Judy Li and Boone Kauffman (all in Fisheries and Wildlife) are investigating the distributions of fish, invertebrates, and vegetation. Geomorphologist Pat McDowell from the University of Oregon adds her skills in interpreting the geology.

Similar anomalies show up in other Oregon streams, even on the bigger ones, such as the Klamath River. But because many eastside streams have both high temperatures and limited salmon populations, research is being conducted on the Middle Fork of the John Day River. One of the reasons for choosing this area is that fish are holding on in these streams, and so the area offers hope for restoration of fish populations. However, much of the best fish habitat on the east side is in private ownership. This means that researchers are working on private lands, and management research is inappropriate. On the other hand, their work here helps to fill a research void; eastern Oregon has long been bypassed by researchers in favor of westside streams.

The researchers are examining a number of possible causes for the stream temperature anomalies. For instance, denser or different vegetation might shade some areas. Cool water from underground sources and springs might enter the stream at certain points. Many of the research methods involve high technology. They continue to use FLIR, a Department of Defense-developed imaging technology that offers great precision and accuracy. Ground-penetrating radar allows them to sense the depth to bedrock. Comparison of aerial photographs taken in 1939 and 1990 has allowed them to track historical changes in the environment and land use. Some 126 wells along three river reaches make it possible to trace patterns in groundwater temperatures. Researchers have also collected soil and vegetation data in the well fields. In addition, they have done traditional counts of fish and invertebrates along various reaches of the river, both warm and cool. Geographic information systems (GISs) let them overlay the different kinds of data, to make common patterns apparent.

As they learn about the local environmental patterns, the researchers have revised their hypotheses. For instance, some of the research effort has shifted direction to consider evaporative heat transfer. As afternoon winds come up, a local microclimate involving the wind and dry air often develops. To investigate this possibility, in 1998 researchers made micrometeorological measurements of relative humidity, wind, and air temperature, in the stream channel and in nearby riparian areas.

With these different kinds of research going on, coordination becomes important. It can be difficult to get all investigators out at once, and they have to be ready for anything because of the down time imposed by travel distances. Compensating for that are the advantages of collaboration. If they were not all working at the same sites, they would never be sure whether apparent differences were real or just the result of their different perspectives. By working together they can discuss issues across disciplines. Typically, when the collaborators reach a conclusion, it has inherent backing of all the disciplines. That not only grants it much greater credibility but also increases the likelihood that such conclusions will have an effect on future management of stream and riparian resources.