Restoration plan for a rare high elevation sloping fen (Ophir Pass fen), San Juan Mountains, Colorado. By Rod Chimner, Ph.D. (Michigan Technological University)

Project Summary and Objectives: We will restore 0.65 ha (1.6 acres) of a unique iron fen in the San Juan Mountains, Colorado. This large and very steep fen (up to 21% slope) has six ditches (a total combined length ~700 ft) that are having a severe impact on the fen by lowering the water table, eliminated plant cover from a large area, and is causing a reversal of peat accumulation. This site is also undergoing severe frost heave and erosion that is preventing colonization of plants, and allowing direct runoff of large amounts of sediments directly into the Middle Fork of Mineral Creek. Therefore, our objective is to restore natural hydrological and vegetation conditions by filling and blocking 6 ditches, replanting the large bare area, and eliminating sediment runoff into the stream. We will restore the Ophir Pass fen by plugging and filling all six ditches, planting Sphagnum and sedges in the restored ditches and bare areas, stabilize steep slopes with coir matting, straw wattles, and excelsior mulch, and conducting pre and post vegetation and hydrologic monitoring. Community and student volunteers will assist with vegetation planting and post monitoring. This project is a collaboration of Mountain Studies Institute, U.S. Forest Service, Michigan Technological University, and Durango Mountain Resort.

Project Description and Need: Fens have been thought to be rare in the continental Western U.S. because of the hot and dry climate. However, it has recently become apparent that fens are numerous in the higher elevations of the Rocky Mountains and they support endemic and widely disjunct taxa and unique communities (Cooper and Andrus 1994, Chimner et al. 2010). Fens require perennially saturated soils produced by nearly constant ground water inflow to accumulate peat. Even small water diversions or depletions can reverse the process of peat accumulation that has been ongoing in many fens for more than 10,000 years (Chimner and Cooper 2002) and lead to fen destruction (Chimner and Cooper 2003). Typical fens in the Southern Rocky Mountains have a pH that range from slightly acidic (~pH 5.5) to slightly basic (pH > 7.5) depending on the type of bedrock that groundwater comes in contact with (Chimner et al. 2010). However, there are some very rare and unique “iron fens” in the Southern Rocky Mountains that are very acidic (pH = 3.0 - 4.5) from the weathering of iron pyrite, which naturally creates acidic groundwater (Cooper et al. 2002, Simon 2004, Chimner et al. 2010). These iron fens have very unique plant communities that are usually dominated by Sphagnum mosses. For example, at Chattanooga Fen in the San Juan Mountains, a population of an arctic peat moss, Sphagnum balticum, occurs disjunct by more than 2000 kilometers from its main range near Hudson’s Bay in Canada (Cooper et al. 2002). Ophir Pass fen is one of the steepest and most visible fens in the San Juan Mountains (Fig. 1). Ophir Pass fen is located near the top of Ophir Pass Road, which is the main 4x4 road that thousands of visitors drive from Silverton to Telluride on each year. Despite that this fen is seen by thousands of tourists looking for beautiful mountain scenery, Ophir Pass fen is one of the most severely damaged fens in the San Juan Mountains (Fig. 1). Ophir Pass fen was recently ranked as very high priority for restoration by a San Juan Mountain assessment of fens (Chimner et al. 2010). Ophir Pass fen is 0.65 ha in size, with 0.21 ha unvegetated, and is one of the highest (3,517 m asl) and steepest fens (up to 21% slope) in the San Juan Mountains. The centroid location of Ophir Pass Fen is approximately at latitude 37_ 50’ 59” N and longitude 107_ 46’ 18” W. This large and very steep fen has six ditches that are having a severe impact on the fen by lowering the water table, eliminated plant cover from a large area, and is causing a reversal of peat accumulation (Fig. 2). This site is also undergoing severe frost heave and erosion that is preventing colonization of plants, and allowing direct runoff of large amounts of sediments directly into a creek (Fig. 3) (Chimner 2011). Therefore, our objective is to restore the natural hydrological and vegetative conditions in Ophir Pass fen. Restoration plan for Ophir Pass fen

Detailed Methods: The methods for restoring Ophir Pass fen will be described in three sections: upper ditches (ditches 1-4), lower ditches (ditches 5-6), and the bare area (see Fig. 2 for ditch numbers).

Upper Ditch Restoration: Ditches 1-4 are ditches that cut across the upper portion of the fen (Fig. 2). They are very shallow and fully vegetated, a testament to how old they are. Despite how old and shallow they are, the ditches are still capturing groundwater, and funneling water and sediments into the adjacent stream. Because the ditches are shallow and fully vegetated, I propose that ditches 1-4 be restored by ditch blocking. Ditch plugs will be constructed by using a combination of peat bags (filled with bare peat on site) and Excelsior bales. Ditch plugs will be constructed by first digging a trench across the ditch (width of an Excelsior bale). Sod will be set aside to be used in the re -vegetation. After the trench is dug, Excelsior bales will be laid end to end in the trench so it traverses the length of the ditch. The Excelsior bale will stick up roughly 1 ft (~30 cm) above the soil surface. Filled peat bags will be placed end to end around the excelsior bales. This will create a more mounded plug vs. a vertical wall from using just Excelsior alone. Once the Excelsior bales and peat bags are in place, bare peat will be used to cover the entire plug (a few inches deep), then the sod will be placed on the bare peat. Once the ditch plugs are fully vegetated, they should last indefinitely; allowing the ditches to slowly fill in over time. Once in place, the ditch plugs would keep water from flowing down the ditches and into the Middle Fork of Mineral Creek, and instead will flow down the wetland, keeping it wet. The number of ditch plugs per ditch varies with the length and steepness of the ditch. Ditch 1 is a small ditch that should only require 1 ditch plug at the lower end of the ditch. Ditch 2 is the deepest of the upper ditches, but is also the shortest. Ditch 2 will require 2 ditch plugs, one in the middle and one in the end. Ditches 3 and 4 are long and shallow ditches. Both ditches will require 4 ditch plugs spaced out evenly along the ditches. Each ditch plug will require 2 excelsior bales and 10 peat bags. In total, the four upper ditches will require 11 ditch plugs, 22 excelsior bales, and 110 peat bags.

Lower Ditches: We will restore the lower ditches (ditches 5 & 6) of Ophir Pass fen by filling them. Ditches 5 & 6 are much deeper then the upper ditches, averaging about 1 m in depth and 2 meters wide for a total combined length of ~225 ft. Soil from the original ditch digging was placed along side the ditch and now forms a spoil pile berm along the ditches. A survey of the site (Fig. 2), indicated that there is not enough fill in the spoil pile to completely fill in either ditch 5 or 6. However, ditch 5 is a very short ditch that is adjacent to a large mound of dried out peat. That mound of peat needs to be removed to make a level slope, allowing for natural water flow. So we will use the extra dried peat next to the ditch, along with the spoil pile, to completely fill in ditch 5 using a small backhoe. Ditch 6 the most destructive ditch because it is a long (175’), deep, and is perpendicular to the groundwater flow. It is also too big for ditch plugs and there is not enough spoil material along the ditch available for filling. Therefore, out best option for restoring ditch 6 is to fill with Excelsior bales, topped with peat. This technique was successfully tested in Chattanooga fen in 2009. For this method, all sedges will be first scraped off from in the ditches and on the berms. The scraped off plant sod will be carefully set aside and placed back on the bare soil when backfilling in that section is completed. After the plants are removed, bales of Excelsior will be placed by hand into the ditch. Given the length of the ditch, roughly 150 bales will be required to fill in this ditch. After the bales are in place, peat from the ditch berm and from the nearby bare area (see methods below) will be used to pack around the bales. We will also put at least 6 inches on top of the bales for the plants to grow into. Unlike the Chattanooga ditch that is on a slope, this ditch is flat. So I do not think that plywood will be needed. However, if we feel that wood is needed, we will insert pieces of plywood, perpendicular across the ditch, to keep the new fill from moving. Plant sod will then be placed on top of the ditch fill, which will revegetate most of the ditch. Any remaining bare areas will be planted by hand (see below for methods).

2 Restoration plan for Ophir Pass fen

Restoring the bare area: The first step in restoring the large bare area is contouring the slope. The bare area has three features of interest, a flat section, a very steep section and some large dried peat mounds (Fig. 4). The flat section and the steep section needs little contouring. However, the flat section quickly transitions to the very steep eroding section, with large dry peat mounds in the middle. The dried peat mounds are too high to become a functioning fen. The peat mounds hold an estimated 50 cubic yards that need to be removed. This fill will be used to help fill in ditch 6 (see methods above). The contouring will accomplish two things, 1) remove the high areas that are too dry for peatland plants (Fig. 4), and 2) create a surface less prone to erode. Our goal is to contour the bare area to be a more consistent slope without the sharp transition. The soil surface will be contoured by the backhoe on site and managed by the restoration ecologist to make sure contouring is conducted properly. Immediately after the bare area is contoured to our specifications, we will stabilize the soil to minimize erosion and facilitate planting. The first step will be to cover the steep lower section of the bare area with coir matting. After the coir matting is in place, 5 rows of straw wattles will be placed on the steep section perpendicular to the slope. The next step will be to plant sedges and mosses in all bare areas. We will use community and student (high school and college) volunteers organized by Mountain Studies Institute to help replant by hand. Volunteers will collect wild transplants of sedges (Carex aquatilis) and Sphagnum in the greater fen complex and immediately plant them. We will only collect a small amount of wild plants from any one area to minimize the damage to the surrounding fen. Sphagnum mosses will be revegetated by cutting off the tops of the mosses and scattering them on the soil. Planting the sedges and mosses are very important for fen ecosystem functioning, as they are the dominant peat forming plants. However, iron fens in the San Juan Mountains have unique plant communities (Chimner et al. 2010). We will therefore collect seeds from plants in other nearby iron fens and seed with the transplanted sedges and mosses. After planting, the entire bare area will be mulched with Excelsor bales. Chimner (2011) found that mulching is useful for restoring bare fens by decreasing temperature extremes, increasing humidity under the mulch, and decreasing frost heave. Mulch was absolutely required to regenerate moss fragments and was helpful in establishing sedges from transplants. Mulching with Excelsor bales was found to be more effective than straw mulch, especially in high snowfall areas. Sphagnum russowii and Polystrictum were the most successful moss species for restoring iron fens in the San Juan Mountains. This planting method has been found to be very successful in 3 fens in the San Juan’s, including Ophir Pass fen (Chimner 2011). In addition, the Excelsior mulch in combination with the coir matting and straw wattles will minimize erosion on the steep slope. The bare area also contains a small mineral soil outcrop that is surrounded by peat soil. Other non- disturbed parts of Ophir Pass fen has many such small outcrops of mineral soils that are vegetated by Engelmann spruce, Vaccinium species, mosses and several vascular plants. This upland area will be planted to similar plants as are found on other upland outcrops. A detailed vegetation survey will be underdone to determine the exact species composition. The outcrops will be restored by first mixing in some of the dried peat into the bare soil, than planting Engelmann spruce seedlings, mosses, and chosen vascular plants. The area will then be mulched with excelsior mulch.

Monitoring: We will conduct intensive plant monitoring to quantify plant species and cover after restoration. We will locate permanent transects and sampling points across the restored ditches. Point frames will be used to quantify species type and cover once a year. This data will allow us to monitor how the vegetation changes after restoration. Hydrological monitoring is already ongoing. Three groundwater wells were established in 2007 in the Ophir Pass fen (Chimner 2011), and 20 more were installed and monitored in 2009. The monitoring wells give us excellent pre and post restoration hydrologic data for the site. Long-term monitoring of the groundwater wells will be conducted by the USFS and MSI. We have two success criteria: 1) recovery of natural hydrologic conditions below the

3 Restoration plan for Ophir Pass fen

ditches, and 2) returning of natural plant cover in the filled ditches and current bare areas. These success criteria will be documented by hydrologic and vegetation monitoring before and after restoration. This project is part of a larger fen effort in the region. MSI has administered EPA Region 8 grants entitled “Fen monitoring, assessment and protection, San Juan Mountains”, by Cooper and Chimner and “Regional Assessment of Fen Distribution, Condition, and Restoration Needs, San Juan Mountains, Colorado”, by Cooper, Chimner and Nydick. The goals of these projects were to identify and map fens, assess their condition and restoration potential, and teach land managers and the public about fens in the San Juan’s. As part of this project, we conducted two fen training sessions for interested land managers covering what fens are, how they work, and how to protect and manage them. MSI developed a “Wetlands of the San Juan Mountains” outreach booklet funded by EPA-Region 8 Wetlands Program Development grant. We also conducted a fen restoration workshop in 2010 training people on how to restore mountain fens. In all, we have trained over 100 people on fens in the San Juan nmountains. A fen restoration study also occurred with an agreement between Dr. Chimner and The San Juan National Forest. This project developed methodology for reestablishing vegetation and restoring ditches and gullies in San Juan fens (Chimner 2011). A part of that project occurred in Ophir Pass fen that is denuded of vegetation. This project has provided direct information on restoration methodology that we are using to increase the probability of success of this project. A partnership has also occurred with Durango Mountain Ski Resort. As part of their mitigation program, they funded addition ditch filling research in nearby Chattanooga fen. This project was also a great success and we developed a method of using Excelsior bales to fill in ditches. That technique will also be used for this restoration. Long- term management and protection will be accomplished by revising the Forest Plan to make Ophir Pass fen a "Theme 2"- a special emphasis area that will have unique management guidelines and protection. This will restore roughly 1.6 acres (0.65 ha) of wetland. All permits will be obtained by the San Juan Forest Service personal.

Literature Cited Chimner, R.A. and D.J. Cooper. 2002. Modeling carbon accumulation in Rocky Mountain fens. Wetlands 22: 100-110. Chimner, R.A. and, D.J. Cooper. 2003. Carbon balances of pristine and hydrologically modified southern Rocky Mountain fens. Canadian Journal of Botany 81: 477-491. Chimner, R.A. and, D.J. Cooper. 2006. A report on the restoration potential of Chattanooga Fen, San Juan’s, Colorado. Annual report to San Juan National Forest. Chimner, R. A., D. J. Cooper, and J. M. Lemly. 2010. Mountain fen distribution, types and restoration priorities, San Juan Mountains, Colorado, USA. Wetlands 30:763-771. Chimner, R.A. 2011. Restoring sedges and mosses into frost heaving iron fens, San Juan Mountains, Colorado. Submitted to Restoration Ecology. Cooper, D.J. and R. Andrus. 1994. Peatlands of the west-central Wind River Range, Wyoming: Vegetation, flora and water chemistry. Canadian Journal of Botany 72: 1586-1597.Cooper and Andrus 1994, Cooper, D.J., R.A. Andrus and C.D. Arp. 2002. Sphagnum balticum in a Southern Rocky Mountains iron fen. Madrono 49: 186-188. Simon, W. 2004. Preliminary characterization of fens in iron rich areas of Mineral Creek. Report to San Juan National Forest. Wolf, E. 2008. Fill volume survey of drainage features at Chattanooga and Ophir fens. Report to Mountain Studies Institute, Durango Mountain Resort, and the San Juan National Forest. 11 pages.

4 Restoration plan for Ophir Pass fen

Figure 1. View of Ophir Pass fen looking down from the north. This view shows several of the ditches and most of the bare unvegetated area. Almost all of this 0.65 ha fen is impacted by ditches. The top most section of the 0.21 ha bare areas is visible. Also visible is the highly popular Ophir Pass road that is traveled by thousands of visitors exploring the mountains.

5 Restoration plan for Ophir Pass fen

Figure 2. Map showing the I foot contour intervals of the existing ground surface at Ophir fen. The numbered red polygons outline the ditches to be filled and the inside of the blue polygon indicates bare soils (Wolf 2008).

6 Restoration plan for Ophir Pass fen

Figure 3. Photo showing sediment from the eroding fen entering the stream at the bottom end of the fen.

7 Restoration plan for Ophir Pass fen

Figure 4. View of two of the dried peat mounds (foreground and background) that need to be removed/countoured. Notice the two different bare areas. The left side of the photo the bare area is sloped only slightly. However, it quickly transitions to the very steep eroding section on the left side of the photo, with large dry peat mounds in the middle. We will contour the bare area to be a more consistent slope without the sharp transition.

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