All of the sensitive species discussed above may be indirectly affected by the introduction and spread of non-native invasive plants (Westbrooks, 1998). Forest Service Manual 2081.03 directs that whenever any ground disturbing action or activity is proposed, the Forest Service must determine the risk of introducing or spreading noxious weeds associated with the proposed action. For projects having moderate to high risk of introducing or spreading noxious weeds, the project decision document must identify noxious weed control measures that will be undertaken during project implementation. This analysis has been conducted, is located in the project file, and is summarized here.
Within the project area, weeds are most abundant in regularly disturbed areas, such as along the 16 miles of open system roads and 30 miles of closed system roads. Although a complete weed inventory has not been conducted for the project area, weeds were noted during the sensitive plant surveys within the project area. Observed weeds include wild carrot, spotted knapweed, Canada thistle, bull thistle, European swamp thistle, and hoary alyssum. There are no known infestations of highly invasive species such as purple loosestrife, Japanese barberry, leafy spurge, or garlic mustard. The most serious infestations appear to be of spotted knapweed, which was noted in clearings in Compartments 21 and 22, and with aspen and white pine in Compartment 7.
Timber harvest may increase noxious weed presence due to soil disturbance and introductions from uncleaned equipment. However, resulting weeds would be expected to be restricted to disturbed sites such as roadsides and would not persist within forested habitats. Logging machinery is expected to come from relatively local sources, which are unlikely to pick up weed seeds that do not already occur on the Forest. Establishment is most likely in road areas, skid trails, and landings, where the intact vegetation and soils may be disturbed. New road construction would lead to roadside weeds in sites that currently have none. Road reconstruction and maintenance may also result in disturbed roadside conditions that would also favor weeds. Road decommissioning would allow native vegetation to replace existing roadside weeds.
The proposed action includes measures to address the introduction and spread of weeds within the project area. All exposed mineral soil on log landings, skid roads, temporary roads, system roads that are opened and closed following operations, and newly constructed berms would be seeded with a native or non-invasive seed mix to prevent soil erosion and prevent the establishment of weeds.
Given the existing road system, the fact that most of the Ottawa National Forest weeds are widespread and often restricted to disturbed sites, and proposed measures to address reseeding, Alternative 2 was determined to present a low risk for introducing or spreading noxious weeds. There is therefore a low risk of indirect effects impacting sensitive plants.
Cumulative effects (sensitive plants)
Forest Service Manual Section 2672.42 directs that Biological Evaluations shall include “a discussion of cumulative effects resulting from the planned project in relationship to existing conditions and other related projects.” Forest Service Handbook section 1909.15 part 15.1 elaborates, “Individual actions when considered alone may not have a significant impact on the quality of the human environment. Groups of actions, when added together, may have collective or cumulative impacts which are significant. Cumulative effects which occur must be considered and analyzed without regard to land ownership boundaries. Consideration must be given to the incremental effects of past, present, and reasonably foreseeable related future actions of the Forest Service, as well as those of other agencies and individuals.” Concerning cumulative effects, the question then is what other past, present, and reasonably foreseeable future activities may also affect sensitive plant populations or habitat? Could the potential effects of the proposed action, when added to other past, present, and reasonably foreseeable future activities, produce a cumulative impact to any of the sensitive plants? As stated earlier, the analysis area for cumulative effects for plants is the entire Ottawa National Forest, since habitat occurs across the Forest and the plants are so sparse and widely scattered.
No past, present, or reasonably foreseeable actions specific to the project area are known that may affect rare plant populations or habitat. In other words, there are no other specific project proposals for land within the project area that may affect sensitive plants. However, the analysis area for cumulative effects is the entire Ottawa National Forest. Therefore, all past, present, and reasonably foreseeable future actions that are known or suspected to be contributing to the viability of native flora on the Ottawa National Forest are considered for this cumulative effects analysis. The information presented for each species in Biological Evaluation included, when known, what factors are thought to be placing each species at risk. Some species are naturally rare, or their habitat is uncommon on the Ottawa National Forest. In some cases, however, specific actions are suspected to have contributed to species being at risk. Ten different past, present, and reasonably foreseeable future actions have been identified that may be placing some plant species at risk on the Ottawa National Forest.
1. Vegetation management by the Ottawa National Forest.
The clearest set of past, present, and future actions which may affect the viability of sensitive plants on the Ottawa National Forest is other vegetation management projects by the Ottawa National Forest. Appendix H of the Final Environmental Impact Statement for the Ottawa National Forest Land and Resource Management Plan (USDA Forest Service, 1986) acknowledges that there are species where “maintenance of a viable population as required by NFMA regulations is in question” or for which “management programs have an adverse effect on the species’ Forest population.” Such species are designated by the Regional Forester as sensitive, and receive special management emphasis to ensure that the species will not become threatened or endangered because of Forest Service activities.
Part of this special management emphasis is preparation of Biological Evaluations such as this one. Like the current proposed action, all major Forest Service on-the-ground activities are evaluated for effects to TES species. Projects that are determined to adversely affect Threatened or Endangered species, or contribute to a trend towards federal listing for Sensitive species, are usually modified so that potential harmful effects to populations or their habitat are mitigated. However, many determinations of effect depend on the result of field surveys. Field surveys of a given area often verify that suitable habitat is present for a particular TES species, but the TES species is not observed during the survey. It is possible that sensitive species are being missed during some field surveys. Cumulatively, the fate of most TES species will depend on either a sufficient number of populations being found and protected, or in the long-term retaining or promoting of sufficient suitable habitat. The Forest Service is actively preparing Conservation Assessments and Conservation Approaches to insure that Forest Service management is compatible with maintaining the viability of rare species (USDA Forest Service, 2002). The Ottawa National Forest Land and Resource Management Plan is scheduled to be revised within the next few years. Changes in the management of the Forest’s vegetation could have effects on rare plants. However, existing regulations will continue to ensure that habitats for all existing native and desired non-native plants, fish, and wildlife species are managed to maintain at least viable populations of such species (USDA Regulation 9500-004).
2. Land management activities by private and other agencies.
Within the proclamation boundary of the Ottawa National Forest, only approximately 63% of the land is managed by the Ottawa National Forest. The remaining areas are a mixture of corporate, private, county, and other land. Land uses include forestry, recreation, residences, and other activities. Non-National Forest system lands include habitat and known locations of sensitive plants, which could be affected by associated land management. Sensitive plant sites off of National Forest system land could serve as source populations for future new sites on National Forest system land. Generally, land management by private landowners and other agencies within the Forest boundary is similar to that of the Ottawa National Forest.
The Ottawa National Forest has no authority over sensitive plant populations within the Forest boundary but not on National Forest lands. However, the State of Michigan prohibits the taking of state-listed threatened and endangered plants and wildlife (Michigan Compiled Laws, 1994b). Of the 59 sensitive plants on the Ottawa National Forest, three are state-endangered, nineteen are state-threatened, ten are special concern (state-tracked but not legally protected), and 27 are not considered to be at risk in the State. Michigan protections for threatened and endangered species may help protect those sensitive species most at risk on land not managed by the Forest Service.
3. Habitat loss due to permanent development, including homes, roads, boat launches, and other construction.
Within the reasonably foreseeable future, and within the boundaries of the Ottawa National Forest, one could expect that there would be some loss of current or potential sensitive species habitat to permanent development, including homes, roads, boat launches, and other construction. The Forest Service generally allows only a small amount of National Forest land to be permanently developed. Examples include roads, new recreation sites, and administrative sites. Overall, land managed by the Ottawa National Forest has been increasing due to land acquisition. However, approximately 37% of the land within the proclamation boundary of the Ottawa National Forest is a mixture of mostly privately-owned land. Most of this land is undeveloped, supports occasional timber harvest and recreation, and generally resembles Ottawa National Forest land. Private land is more likely to be developed, and generally has less review for impacts to rare plants, although the amount of development is considered to be low. US Census data for the six counties that interest the Forest show that populations have been decreasing in four counties, stable in one county, and increasing in one county (US Census, 2000). The potential direct and indirect effects of the proposed action, when added to the effects of habitat loss to permanent development, are not expected to create a significant cumulative impact to any sensitive plant species.
Other than the proposed management actions, just about the only recent past, present, or reasonably foreseeable future human activity within the project area is recreation. The recreation section of the Environmental Assessment identifies hunting, fishing, driving for pleasure, snowmobiling, and the use off-road vehicles as the primary uses of the project area. The project area includes twenty-three leased recreational cabins, used primarily during deer hunting seasons but throughout the year as recreational retreats. Most of the recreational activities are confined to existing road corridors. None of the above recreation activities would be likely to directly adversely affect any sensitive plant populations or habitat. Indirect effects would include keeping travel corridors in an open condition and the potential for introduction or spread of exotic species.
5. Non-native invasive plants
The indirect effects of the proposed action from introducing and spreading weeds are discussed above. Cumulative effects to sensitive plants would include the loss of habitat from the past, present, and reasonably foreseeable spread of non-native invasive plants by wind, wildlife, and non-project human activities. Although weeds are a growing problem on the Forest, most of the known sensitive plant locations on the Ottawa National Forest are not judged to be at risk in the foreseeable future due to invasive plants. There is one Orobanche uniflora site and one Petasites sagitattus site where associated exotic species are a concern. Weeds on the Ottawa National Forest largely remain a problem of disturbed sites, and are uncommon in most natural habitats.
6. Exotic earthworms
The indirect effects of the proposed action from introducing and spreading exotic earthworms are discussed above with northern mesic forest species. Sensitive plants that may be affected by the spread of exotic earthworms include Botrychium hesperium, B. mormo, B. pallidum, B. oneidense, Cardamine maxima, Disporum hookeri, Erythronium albidum, Juglans cinerea, Orobanche unfilora, Panax quinquefolius, Phegopteris hexagonoptera, and Tiarella cordifolia. Although the status of earthworms within the project area is unknown, cumulative effects to sensitive plants would include the continued changes to soil profiles from the spread of exotic earthworms. Earthworms are spread by their own movement within the soil and by the movement of soil on vehicles or as fishing bait. As stated earlier, none of the project are is considered to be secure from earthworm invasion. There may be future effects from exotic earthworms within northern mesic forest within the project area, but these effects would occur independent of the direct and indirect effects of the proposed action.
7. Fire suppression
Turn-of-the century logging followed by catastrophic fires, and the later advent of fire suppression have affected plant community composition and distribution in many areas of the Lake States forest (Seymour and Hunter, 1999; Spies and Turner, 1999). In the western Upper Peninsula of Michigan and northern Wisconsin, fire-dependent communities occur on droughty outwash plains, bedrock ridges, and conifer-dominated wetlands (Albert, 1995; Curtis, 1971). Sensitive plants whose habitats include dry northern forests may be at risk in part due to fire suppression in portions of their range. On the Ottawa National Forest, these may include Vaccinium cespitosum, Cynoglossum boreale, Oryzopsis canadensis, and Pterospora andromedea. The Choate project area is not thought to contain any fire-dependent communities. The potential direct and indirect effects of the proposed action, when added to the effects of fire suppression, are not expected to create a significant cumulative impact to any sensitive plant species.
8. Forest pests and disease
Exotic forest pathogens and pests such as Dutch elm disease, white pine blister rust, and gypsy moth have changed the composition of many native plant communities in the Lake States. Increased movement of people and material around the world will likely lead to the spread of existing pests and the introduction of new non-native pathogens in the future. At this time, the only one of the 59 species of sensitive plant that is known to be at risk due to exotic forest pests or disease is Juglans cinerea, which is subject to Butternut canker (Sirococcus clavigignenti-juglandacearum), a non-native fungus that causes stem cankers (NatureServe, 2002). If there are any naturally-occurring and disease-free butternut trees on the Ottawa National Forest, the proposed actions are not expected to contribute to the likelihood of their being infected with Butternut canker.
9. Natural succession. Sensitive plants that occur in open or early-successional habitats include Astragalus canadensis, Astragalus neglectus, Botrychium hesperium, Botrychium lunaria, Botrychium pallidum, Botrychium rugulosum, Crataegus douglasii, Cynoglossum boreale, Geocaulon lividum, Muhlenbergia uniflora, Orobanche uniflora, Oryzopsis canadensis, Polygonum careyi, Vaccinium cespitosum, and Viola lanceolata. Some sites that may provide suitable habitat at one time may change to an unsuitable condition as natural forest succession occurs. However, suitable habitat would be expected to occur elsewhere on the landscape due to natural and human-caused events. The Ottawa National Forest is managed to provide a diversity of age classes. Abundant potential habitat for species needing open and early-successional features is expected to remain throughout the planning area.
10. Effects from wildlife
Wildlife are involved in the lives of many species of plants, such as through pollination and seed dispersal. The past, present, and reasonably foreseeable activities of beaver and deer, in particular, may have affects on the viability of rare plants. The resurgence of beaver has led to increased flooding in riparian habitats, which may adversely affect some species but likely has an overall positive influence on biodiversity (Brinson and Verhoeven, 1999). Herbivory of plants by animals is also a natural part of ecosystem function, although increased numbers of white-tailed deer are affecting the composition and distribution of some native plant communities. In the Lake States, browsing by white-tail deer has contributed to a lack of regeneration of white pine, white cedar, and hemlock (Frelich and Puettmann, 1999; Waller et al., 1996; Saunders, 1999). Decreased regeneration of these canopy trees may impair the long-term viability of their respective plant communities. Deer abundance is the result of landscape-level decisions, State game management, and other factors beyond the scope of the proposed management actions. At this time, none of the 59 species of sensitive plant are known to be at risk due to effects of deer, beaver, or other wildlife.