Contract Description:
Project Objectives:
1. Develop guidelines for re-vegetation of constructed meadow channels using environmental, physical and biotic factors as determinates for appropriate species combinations, planting location and timing and frequency of planting sequences.
2. Develop a long-term, effectiveness monitoring method that is robust, repeatable and requires minimal training in plant identification and stream channel surveying.
3. Develop a data recording program that provides electronic field data collection (PDA) capabilities with a smooth transition to office-based summarization and analysis of monitoring data.
Project Description:
Introduction
The Longley Meadows Restoration Project was initiated in 1999 by the CTUIR, ODFW, NRCS, and Alta Cunha Ranches to restore instream, riparian, and wetland habitat along Bear Creek, Jordan Creek, Moss Creek and the mainstem Grande Ronde River (Grande Ronde Model Watershed Program, Longley Meadows Report 2005). The overarching goal of the project was to restore the natural character and function of Longley Meadows with accompanying wetlands, floodplain, and stable channel morphology. Key drivers were water quality and fish habitat improvement goals. Bear Creek downstream of Highway 244 to the confluence with the Grande Ronde River was in poor condition due to historic channelization. In March 2003, approximately 5,500 feet of Bear Creek Restoration Channel construction was completed. Vegetation plantings for channel stabilization followed in summer 2003. Data on channel dimensions and groundwater response before and after restoration is available, however, data concerning vegetation planting response and success is limited.
The importance of woody riparian vegetation for streambank stabilization, fisheries habitat and ecosystem function has long been acknowledged within the scientific and lay literature. A brief search of over 2500 references on riparian ecology yielded in excess of 300 articles on willow ecology with 50 references dedicated to where and how to plant willow cuttings. However, a similar search on sedges, an important bank stabilization species in meadow systems, yielded approximately 50 articles on sedge ecology and only two on re-vegetation efforts using Carex species. The role of sedges in streambank stabilization for low gradient, fine substrate channels cannot be understated. Manning et al. (1989) found Nebraska sedge to have, on average, 9.2 miles of roots in the top four inches of a cubic foot of soil. Despite their importance to stream channel function, little is known about revegetation strategies for sedges in restoration projects. Sedges generally reproduce vegetatively, although establishment from seed may occur on disturbed areas if a seedbank is present and environmental conditions are favorable (van der Valk et al. 1999). In restoration projects where the planting site may be subject to high physical stress, such as erosion and siltation, seeding is less likely to be successful than transplanting (Steed and DeWald 2003). Because sedge reproduction is generally more successful via rhizomes in unstable environments, planting sedge plugs (root plus shoot material) may be an effective method for reestablishing these species. Depth to groundwater during the growing season has been identified as a key determinant of herbaceous species patterns within riparian meadows (Castelli et al. 2000), and its influence on sedge transplants has been documented in Minnesota (Yetka and Galatowitsch 1999). Research to-date has focused on meadow restoration using sedge wildlings or plugs and has not addressed the issues surrounding channel reconstruction and subsequent revegetation. Determining the appropriate location, timing and density of sedge plantings within a channel restoration project is a question yet to be answered. The need for this knowledge within the restoration community is vast and immediate. Bear Creek within the Longley Meadow restoration project is an ideal location to implement research into these restoration questions.
In order to determine if restoration or management efforts are effective a well thought out monitoring program must be designed, implemented and results integrated into conservation decisions. Central to any useful monitoring program are understandable, repeatable, and affordable monitoring methods that produce useful data within timeframes required for adaptive management decisions. Thus, the goal of long-term trend monitoring in riparian areas is to 1) determine trend over time and 2) to provide information useful in guiding restoration and/or management decisions. In response to concerns from field practitioners attempting to develop effective, repeatable and defensible riparian monitoring the National Riparian Service Team, an interagency team of experts in riparian ecology, fisheries, hydrology and livestock management, convened a group of representatives from the Bureau of Land Management (BLM), U.S. Forest Service (USFS), Oregon State University and University of Nevada-Reno at Logan, Utah, September 21-23, 2004. The group was hosted by the Forest Service Fish and Aquatic Ecology Unit. The goal was to facilitate learning, allow riparian monitoring experts to share ideas, and address issues that field practitioners are struggling with when attempting to determine and implement riparian vegetation monitoring. The group concluded that the pioneering work of Winward (2000) provides the basis for understanding riparian monitoring, however the Greenline method along with the other three proctocols reviewed required extensive knowledge in the area of species identification. Repeatability among observers for all four methods was of concern and the participants suggested further research into the utilization of plant functional groups may provide riparian monitoring protocols with increased accuracy at a lower cost.
Bear Creek, within the Longley Meadow restoration project provides an ideal location to test the plant functional group concept within the context of monitoring. In addition, the youth of the channel has the added benefit of providing a platform for studying time-frames in which vegetation and channel attributes can be expected to change. This information is important in determining the necessary frequency of long-term monitoring; an attribute that is poorly understood. Furthermore, the NRST review group acknowledged that the Winward (2000) greenline method may not be an appropriate tool for channels that have not yet established a well defined greenline. Bear Creek in 2005 exhibits an undefined greenline for the majority of the reach (see photo 1).
Monitoring of channel and vegetation response to restoration efforts involving channel reconstruction and vegetation planting provides a unique set of monitoring questions that have not been addressed in the riparian literature to-date. Development of effective, low-cost methods for determining restoration success in these highly manipulated systems is equally as important as the restoration effort itself. Furthermore, protocols developed for these systems have the potential to transfer easily to highly degraded meadow channels that are expected to respond to a change in management without reconstruction.
Existing condition
Bear Creek within the Longley Meadow restoration project is a channel type that should support a healthy and dense sedge community. The channel currently exhibits fluvial landforms devoid of vegetation that should support a sedge community. The lack of bank and bed stabilizing sedges within the bankfull channel indicates a channel at risk for bank and/or bed erosion. Although sedge plugs were initially planted along the Bear Creek Restoration Channel observations in August 2005 indicate limited planting success. Determining the appropriate location, timing and density of sedge plantings within a channel restoration project is a question yet to be answered. The need for this knowledge within the restoration community is vast and immediate. Bear Creek within the Longley Meadow restoration project is an ideal location to implement research into these restoration questions.