The demand for water from public lands, including National Forests, continues to
increase. Human demand for water resources inevitably alters the character of streams,
watersheds, ecosystems, and ultimately landscapes. The emerging emphasis on managing
entire ecosystems demands sophisticated integration of diverse professional disciplines.
Water is a connecting thread in the fabric of these disciplines. The anticipated
widespread increase in the alteration of flow regimes and the implications this has
for ecosystem management justifies a greatly expanded research emphasis.
The recent Rocky Mountain Forest and Range Experiment Station publication, A Research
Strategy for Understanding Stream Processes and the Effects of Altered Streamflow
Regimes, compiled by James Meiman and Larry Schmidt, proposes a strategy for addressing
these needs.
The strategy recognizes the link between physical stream processes and the habitat
and biology of the stream. Since most biological systems co-evolved with physical
systems, understanding physical processes provides essential knowledge for implementing
ecosystem management.
The Stream Systems Technology Center (STREAM) was established, in part, to help acquire
and assemble the knowledge needed to improve management of aquatic ecosystems.
Specific purposes of STREAM are:
· To improve ecosystem knowledge about stream systems and physical processes,
· Identify research needs,
· Develop operational tools, and
· Provide training and technical support so forest officers can manage National
Forest System ecosystems to secure favorable conditions of water flows.
The mandate for the Stream Systems Technology Center requires it to focus on the
physical characteristics of stream channels representative of those on USDA Forest
Service administered lands fully recognizing that physical processes are but one
component of ecosystem function.
The Stream Systems Technology Center's activities focus on the interface of
the channel with the stream, the aquatic system including fisheries, and the riparian
system.
Some fundamental questions that underlie many specific issues to be addressed by
this research strategy include:
· What type of streamflow regime is needed to maintain channel features plus
instream and riparian values for different channel types?
· What are the consequences of changed flow regimes to on-site and downstream
channel functions and values?
· How are instream flow needs affected by water diversions and land-use activities?
These kinds of questions require creativity from individual researchers, particularly with respect to formulating new paradigms for working with the steep-gradient, course-material streams often strongly influenced by woody debris, which are characteristic of the National Forests.
Streams are dynamic and vital components of several ecosystems. To be most
effective, a research program must be cognizant of all of these complex systems and
designed within the context of integrated system studies with interdisciplinary participation.
(1) At any given point in a channel, a stream represents the integrated effects of
the water, sediment, woody debris, and dissolved materials from the contributory
watershed above.
(2) Hillslopes contribute water and materials to stream sometimes directly and often
through a myriad of surface and subsurface pathways.
(3) An integral connection exists between the adjacent riparian area and the stream
and both surface and subsurface flows may travel in either direction. The riparian
system connects both with the channel immediately adjacent and up and down valley
via subsurface flow and sometimes (during floods) along the surface.
(4) Away from the direct influences of the stream at the groundwater/streamwater
interface, is the hyporheac zone with its own unique ecology.
A comprehensive research program looking at channels from three different interactive
approaches is recommended.
· Channel site and reach studies to increase our understanding of basic processes
of sedimentation and channel morphology. Emphasis is on determining the response
of channels to changes in sediment load, sediment size, and streamflow including
relationships between riparian vegetation and stream processes.
· Stream system studies to increase understanding of systems in dynamic equilibrium
and impacts of land and water use.
· Watershed studies to provide a framework for analyzing channel management
problems, integrating ecosystem knowledge, and identifying knowledge gaps for further
research.
Initial priority of STREAM is on Channel Site and Reach studies. An integrated interdisciplinary
program of collaborative
research and joint funding with interested partners is suggested.
Channel Site & Reach Study Priorities
Priority 1. Response of different channel types to changes in sediment and discharge.
Priority 2. Interrelationships between riparian vegetation and stream processes.
Priority 3. Flow frequency duration studies regionalized for application to stream
channel management problems.
Priority 4. Regionalized studies of major channel types and the distinguishing features
that separate significant differences in channel maintenance requirements.
Priority 5. Stream system studies of the continuity of streamflow-sediment dynamics
and channel form change in space and time.
