The four miles of road maintenance (FR 6950) in this alternative will not have any effects on stream water quality because this road does not cross any permanent stream or river in the project area. This road will not contribute sediment to any permanent stream in the project area. There are some road crossing that will go unattended in this alternative and some of these crossings are contributing sediment to stream and rivers. Tthe most noteable is the FR 6987 crossing of Redlight creek. Sediment is entering the stream at this crossing and represents a negative impact to mollusks downstream of the culvert. The sediments may bury riffle habitat where the mollusks feed, or a large addition of sediment may actually bury the mollusks faster than they can move and end up killing them. Sedimentation in the stream can affect mollusks indirectly by changing habitat conditions for the host fish species in the stream, and without the hosts mollusks cannot successfully reproduce. There is also one small (currently an ATV crossing) on Choate creek. FR6975-E7 crosses Choate creek and the crossing is by ATVs. there is some potential for sediment to enter the stream at this crossing. The other road crossings are crossings at intermittant streams and drainages. Any sediment moving into these intermittant drainages will not have a direct impact on potential mollusk habitat in the permanent streams, the effect will be indirect as some of the sediment maybe trapped in the intermittant drainages, but some sediments may make its way to the perennial streams over a long period of time.
Cumulative effects were assessed at the project area scale. In the last fifteen years (1987-2002) approximately 214 acres of aspen has been harvested in the project area. These harvest were all clear cuts and this amounts to only 2 1/2% of the project area in 15 years. This is a minor amount of area and the harvests revegetate in a short period of time, about three years. The cumulative effects past harvest actions are thought to be indirect and minimal.
The maintenance of FR 6950 would not produce any cumulative effects because the road does not cross any streams. The greatest input of sediment into streams that has the potential to enter the streams are the undersized culverts associated with Redlight creek. There are other culvert needs associated with the exisitng transportation system that will not be addressed in alternative 1. These will continue to cause some cumulative effects to potential mollusk habitat in the project area.
Alterntive 2 (Modified Proposed Action)
The modified clear cuts on 1,027 acres would remove the mature aspen, which would remove the canopy to stimulate growth aspen suckers and regenerate a new stand. A stand of new trees rapidly occupies the site in 1 to 3 year, and there is growth of herbaceous material rapidly covers the exposed soil surfaces. None of the proposed aspen harvests are located with the Wild and Scenic River corridors for the Cisco Branch or the South Branch of the Ontonagon River. None of the modified clear cuts extend to the edge of Choate, Relight or Sucker creeks. There will be untreated stands of trees between the edge of the modified clear cuts and the stream bank, the actual distances described in design criteria in Chapter 3 of the EA. There are also riparian design criteria to mitigate the effects of the modified clear cuts the intermittent drainages adjacent to or within some of the modified clear -cut units. Most of the modified aspen clear cuts will be harvested either during the winter or during the dry summer months of mid-July to September, which would limit the exposure of the harvest units to surface disturbance and reduce the amount of exposed bare soil to erosive processes. The rapid re-vegetation, season of operation, layout of the harvest units and use of BMPs and riparian design criteria will limit amount of bare surface exposed to erosional processes and mitigate any potential sedimentation risks. The modified aspen clear cuts will not produce any direct effects that would negatively alter stream water quality or increase stream sedimentation in any potential mollusk habitat in the project area.
Under Alternative 2, about 256 acres would receive management treatment. Individual tree selection harvest in northern hardwood stands would not affect potential mollusk habitat because these treatments will retain an overstory canopy and are not located adjacent to any permanent stream, and riparian design criteria and BMPs will be applied as necessary. Treatmentof these stands would not have any direct or indirect effects on potential mollusk habitat in the project area.
Thinnings in 309 acres in in northern hardwood stands, and red pine plantations would open the canopy considerably, which would result in increased understory growth of trees, shrubs, and forbs. For the same reasons listed in the preceeding paragraph the 309 acres of thinning harvest cuts should not have any direct or indirect effects on potential mollusk habitat in the project area.
The maintenance of 362 acres of upland openings will involve the hand cutting and removal of woody shrubs and some tree saplings vegetation to maintain the open condition. The work will involve handcutting of woody. Surface disturbance would not part of the opening maintenance prescription and with no bare soil,there is no chance of soil entering any of the intermittant drainages or permanent streams.
There will be 162 acres of understory scarification for natural conifer regeneration. This work is ground disturbing, many on the seedling and sapling hardwood will be removed. The litter layer will be disturbed and mixed with underlaying mineral soil to provide a seed bed for conifer seed germination and seedling establishment. None of the proposed treatment areas are within the Wild and Scenic River corridor or near any other permanent streams. By following riparian design criteria and BMPs the indirect effects of soil reaching any intermittant drainage can be mitigated and avoided.