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Defining the Effects of Stand-replacing
Wildfire on Stream Ecosystems
Proposal Title:
Development of indicators and monitoring approaches to defining the effects of stand-replacing wildfire on stream ecosystems in forested landscapes
Contacts: James Clayton, Bruce Rieman, Charlie Luce, Jason Dunham, Alan Barta, Jack King, RMRS-Boise
What are the critical management questions to answer:
Fires are known to have dramatic effects on aquatic ecosystems, but our ability to predict, monitor, and manage effects is very limited (Rieman and Clayton 1997; Peterson and Wollrab 1999). Furthermore, the effects of fire may be very different when considered in the short-term versus longer-term. For example, the fires of 2000 burned extensively across NFS lands, and intensive efforts to mitigate fire effects have been initiated. While the short-term effects of these fires appear to be obvious, the longer-term responses of aquatic ecosystems are poorly understood. A better understanding of the effects of fire in the context of time is needed to support assessments of management alternatives. An efficient approach to understanding fire effects is to study responses of aquatic ecosystems in relation to known fire histories. Thus, the fires of 2000 can be put into the context of historical fire occurrences and fire regimes throughout the region. We propose to develop methods to measure and monitor the effects of fire on key stream ecosystem attributes to address the following specific questions:
1) What are the short and long-term effects of fires on stream ecosystems?
2) Are effects of fire predictable?
3) What kinds of indicators and monitoring approaches are useful for detecting fire effects?
Project Description:
In the immediate aftermath of a large severe fire, aquatic ecosystems may be at great risk of damage. If riparian forests have burned, increased solar radiation warms the streams, and some large woody debris in and around the channel is consumed. Hillslopes are at risk of surface erosion and gullies during thunderstorms for a few years while fire-induced water repellency persists (DeBano 1981), and decaying root strength opens a window of vulnerability to landslides for up to 15 years following the fire (Burroughs and Thomas 1977). Over time the more positive values of these events may be realized as the wood and gravel inputs become arranged into complex habitats and increased solar radiation increases productivity without severely raising temperatures (Reeves et al. 1995). Important questions for managing aquatic habitats are, "How likely is it that this succession of events comes to pass from a given fire?" and "Over what period of time do these patterns unfold?"
We plan to use information on fire occurrence and history with existing and new stream inventory data to address the three questions posed above. Information on fire occurrences and histories are available for many areas within Regions 1 and 4 (see Current Work below). Information on past fires provides the basis for evaluating fire effects, including those from the 2000 fires, by substituting space for time. Basic indicators of stream ecosystem responses to fires include stream channel morphology, patterns in the distribution and abundance of large wood and sediment, and stream temperature. Previous work (e.g., Reeves et al. 1995) suggests a succession of stream channel responses related to fire regimes, with predictable distributions of stream habitats, sediments, and large wood. This work, with other recent reviews (e.g., Rieman and Clayton 1997; Benda et al. 1998), forms the basis for developing models to predict fire effects.
We will work in a variety of stream environments to consider a range of potential covariates and confounding effects. Field sampling of streams will be conducted to aid in the design of effective monitoring methods to detect fire effects. Our field sampling will be focused to relatively small (<1000 ha) basins in montane coniferous forests that have experienced relatively large (>70 percent burned area) stand-replacing fires in the past. This general forest type predominates on NFS lands in Regions 1 and 4. Our point is not to compare burned and unburned basins, but rather to look at the temporal dynamics of natural recovery of stream ecosystems from the effects of severe fire. This provides an essential context for developing pre- and post-fire management responses.
Timeframes:
We anticipate two years of field operations during summer/fall, followed by data entry, analysis, and report preparation in the winter and spring. The project would begin immediately following disbursement of funding (i.e. spring of 2001) and conclude the spring following the second summer of field operations (spring of 2003).
Expected Products:
We expect two major products to result from this work. The first would be development of methods to monitor fire effects on stream ecosystems within Regions 1 and 4. The second would be an analysis of fire effects on stream ecosystems, including an assessment of the relative severity and predictability of fire effects on different time scales.
Potential Partners:
National Forest resource specialists (e.g., Boise National Forest, Nez Perce National Forest) in Regions 1 and 4. We will work with local staffs to make full use of existing data, other sources of information, and staff resources to implement the study.
Current Work:
Several forests in collaboration with RMRS or PNW stations have or are building detailed coverages and understanding of fire history across large areas. For example, the Boise National Forest has maintained records on fire occurrences for over 50 years (Kathleen Geier-Hayes, personal communication). The Nez Perce National Forest has extensive fire history information for the Selway River basin (Patricia Green, personal communication). In addition, several Forests and RMRS Boise have conducted short-term (i.e. <20-year) evaluations of fish and channel response that provide perspective for the experimental design. We also plan to collaborate with researchers at the PNW station (Gordon Reeves, personal communication) to integrate our results with research in the Pacific Northwest region that provides both a template and a contrast for this work (e.g., Reeves et al. 1995; Benda et al. 1998). Other research at RMRS-Boise includes an inventory of landslides and debris flows on the Payette NF (in collaboration with Michael Dixon) to develop better tools for determining landslide and debris flow risk. One of the factors we are examining is the risk in burned versus unburned areas. On the Boise NF, several channels that had post-fire debris flows are being monitored for recovery with cross-section surveys and photographs. Risk-based models to evaluate post-wildfire landslide and debris flow risk are being developed at RMRS and in collaborative work with Utah State University (David Tarboton and Robert Pack) and Earth Systems Institute (Lee Benda and Daniel Miller).
| Project Activity Description | |
| FY 2001 Experimental design, site selection with collaborators, development of field methodology, pilot sampling |
| Salary (RA or Tech Specialist 6 mo) | $28,600 |
| Travel/Vehicle | 3,200 |
| Equipment and Supplies | 6,000 |
| FY 2002 Field sampling all sites, data synthesis, analysis and report |
| Salary (RA or Tech Specialist 6 mo; field crews) | 69,600 |
| Travel/Vehicle | 20,000 |
| Equipment and supplies | 1,750 |
| Administrative Overhead (FY01/02) @ 12 percent | * 15,498 |
| Total: | $144,648 |
| * 06/01 - Overhead charges are excluded due to the emergency fire funds not allowing | |
References:
Benda, L.E., D.J. Miller, T. Dunne, G.H. Reeves, and J.K. Agee. 1998. Dynamic landscape systems. Pages 261-288 in R.J. Naiman and R.E. Bilby, editors. River ecology and management: lessons from the Pacific coastal ecoregion. Springer-Verlag, New York.
DeBano, L. F. 1981. Water repellent soils: A state-of-the-art, USDA Forest Service General Technical Report PSW-46.
Burroughs, E. R., Jr., and B. R. Thomas. 1977. Declining root strength in Douglas-fir after felling as a factor in slope stability, USDA Forest Service Research Paper INT-190.
Peterson, J.T., and S.P. Wollrab. 1999. An analysis of potential stream fish and fish habitat monitoring procedures for the inland Northwest. Prepared for USDOE. BPA, Project Number 92-032-00, Contract Number 92AI25866.
Reeves, G.H., Benda, L.E., Burnett, K.M., Bisson, P.A. & Sedell, J.R. 1995. A disturbance-based ecosystem approach to maintaining and restoring freshwater habitats of evolutionarily significant units of anadromous salmonids in the Pacific Northwest. Pages 334-349 in J.L. Nielsen, editor. Evolution and the aquatic ecosystem: defining unique units in population conservation. American Fisheries Society Symposium 17. Bethesda, Maryland.
Rieman, B.E., and J.L. Clayton. 1997. Fire and fish: issues of forest health and conservation of native fishes. Fisheries 22(11):6-15.
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