Maintenance of Natural Sustainable Riparian Communities Located Within the Middle Sheyenne Watershed

View the project final report

• 2010 annual report

Commodities

• Additional Plants: native plants
• Animals: bovine

Practices

• Animal Production: grazing management, grazing - continuous, grazing - rotational, range improvement, stocking rate, watering systems
• Crop Production: agroforestry, forestry
• Education and Training: demonstration, extension, on-farm/ranch research
• Natural Resources/Environment: riverbank protection
• Production Systems: agroecosystems, holistic management
• Sustainable Communities: sustainability measures

Geologic features of the Middle Sheyenne River Valley located within Eddy and Nelson counties in eastern North Dakota are dominated by alluvial terraces and flood plains, characteristic of valley type VIII as described by Rosgen. Valley type VIII supports stream types C, D, E, F, and G. Nine cross-sections were sampled to identify stream type using Rosgen’s classification of natural rivers. Classification of these cross-sections resulted in seven C5/6 and two E5/6 channels. The results of our stream classification lead us to conclude that stream type succession scenario 1 is most appropriate for the Middle Sheyenne River. The stable reference reach is an E channel; when stability is lost it first becomes a C channel, which is transformed into a Gc channel, followed by a F channel. As it begins to stabilize and a new floodplain is established a Bc channel forms, then an entrenched C channel, and finally it becomes an entrenched E channel. In the state-and-transition model the E and C channels, the potential natural channels, form state one. State two is comprised of the unstable Gc and F channels. State three is comprised of the Bc and the entrenched C and E channels that have restabilized the system.

Plant communities associated with the riparian ecosystem of the Middle Sheyenne River include: 1) the greenline, 2) woodlands, 3) shrublands, 4) grasslands and 5) wetlands. Plant communities were evaluated using a modified Whittaker plot to determine species composition and cover. The greenline community is a water sedge community that is subject to invasion by reed canarygrass. The woodland communities found within the floodplain are American elm/Sprengel’s sedge, green ash/Sprengel’s sedge, and bur oak/Spengel’s sedge. When changes occur in the canopy of woodlands the understory is vulnerable to invasion by Kentucky bluegrass or smooth bromegrass. Due to Dutch elm disease the American elm/Sprengel’s sedge community has been lost or compromised. The shrublands are dominated by northern hawthorn and Sprengel’s sedge with canopies subject to invasion by buckthorn and understory subject to invasion by Kentucky bluegrass. Prairie communities within the floodplain were warm season graminoid/western snowberry, now dominated by Kentucky bluegrass or smooth bromegrass. Wetland communities are characterized by a native sedge community; however, when compromised are dominated by reed canarygrass.

Introduction:

Ecological site descriptions (ESDs) are reports that characterize a site by documenting the site’s resources (USDA, NRCS 2003; Bestelmeyer and Brown 2010). Resources that are required to be documented within an ESD include physiographic features, climate, water features that are influencing the management of the site, soil features that are representative of the site, ecological dynamics of the site in the form of a state-and-transition model (STM), vegetation dynamics, and supporting information (USDA, NRCS 2010a). According to the USDA, NRCS (2003), an ecological site is “a distinctive kind of land with specific physical characteristics that differs from other kinds of land in its ability to produce a distinctive kind and amount of vegetation.” STMs are developed in conjunction with ecological site descriptions, defining alternative plant communities occurring within a site and possible drivers of transitions between both states and communities (Bestelmeyer et al. 2003; Bestelmeyer et al. 2004; Bestelmeyer et al. 2009; Bestelmeyer and Brown 2010; USDA, NRCS 2010a).

Riparian ecosystems are transitional ecosystems occurring between terrestrial ecosystems, where hydrology has little influence, and aquatic ecosystems where hydrology has a significant impact on ecosystem function and formation (Gregory et al. 1991; Naiman et al. 1993; Svejcar 1997). The stream channel and its associated floodplain that is influenced by the stream’s hydrology, specifically the water table and high flow events, are the primary components comprising a riparian ecosystem (Naiman et al. 1993). In addition to hydrology, riparian ecosystems are also influenced by geomorphology, climate, soils, vegetation, ecological processes, and management (Kovalchik and Chitwood 1990; Gregory et al. 1991; Niaman et al. 1993; Svejcar 1997; Lytle and Poff 2004).

Standard ESDs and STMs fail to adequately describe the complex ecological processes and vegetative dynamics of riparian ecosystems (Leonard et al. 1992). In order for ESDs to adequately describe riparian system’s geomorphology, specifically valley type and stream channel classification (Leonard et al. 1992; Stringham and Repp 2010), and the riparian complex need to be incorporated (Winward 2000; Stringham and Repp 2010). Similar to standard STMs, riparian STMs are used to describe ecosystem dynamics (Stringham and Repp 2010). However, due to the influence of hydrology in riparian ecosystems some adaptations must be made to adequately describe ecological processes and predict responses to disturbance. According to Zweig and Kitchens (2009) hydrology is the major factor driving transitions between states within riparian ecosystems. Riparian STMs need to include channel classification, channel evolution models, description of fluvial landforms, plant community phases comprised of multiple community components, and soil-water-vegetation dynamics taking place within the ecosystem.

The development of ESDs and STMs for riparian ecosystems is a relatively new endeavor, with a meager three drafts being completed by the NRCS for the entire nation that still need to be approved (Repp et al. 2011a; Repp and Boyer 2011; Repp et al. 2011b). Within North Dakota a riparian ESD and associated STM is currently being drafted for Magpie Creek in the western portion of the state (Repp 2010); however, no work has been conducted on perennial systems in the state.

The objectives of this project are: 1) identify the natural sustainable plant communities and best management practices of the above watershed through Ecological Site Description development, and 2) provide rangeland technical assistance through media development and consultation with relevant land managers. The ESD and STM will describe channel morphology, community phases, and plant community components associated with each state. In addition a description of environmental and anthropogenic disturbances triggering transitions between states and community phases within the riparian ecosystem of the Middle Shyenne River in eastern North Dakota, aiding in the establishment of realistic goals for restoration and maintenance of natural sustainable communities. Development of riparian range and forestry management recommendations targeted at restoring proper ecosystem function. Development of educational media including brochures, pamphlets, extension manuals, and meetings/ field days/ workshops with ranchers to review grazing recommendations for riparian ecosystems.