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Hartley, Dawn A., Janice L Thomson, Pete Morton, and Erik Schlenker-Goodrich. 2003. Ecological Effects of a Transportation Network on Wildlife: A Spatial Analysis of the Upper Missouri River Breaks National Monument. The Wilderness Society. http://www.tws.org/Library/Documents/MissouriBreaksTransportationEffects.cfm

 

RELEVANT TO:	ROADS/OFF-ROAD VEHICLES
	SPECIES
	CULTURAL AND HISTORICAL SITES
	INVASIVE SPECIES
	SOILS

DESCRIPTION

This report employs spatial analysis techniques for informing the design of transportation plans. Used in this case for the Missouri River Breaks National Monument, the techniques minimize impacts on the ecological and cultural resources of protected areas, while still allowing adequate access. Spatial analysis is predicated on the recognition that roads, vehicle trails, and other linear transportation features must be managed as a cohesive and interwoven system embedded within a landscape and not as a disjointed aggregation of individual access points. This report presents three landscape fragmentation analysis steps that agencies can use to plan ecologically viable transportation networks: (1) density analysis of existing transportation network features, (2) buffer analysis to examine the effect zone of the transportation network, and (3) core area analysis to identify habitat that remains unaffected by a given transportation network alternative. This report does not make specific route closure recommendations, but it does present a list of actions to ensure that the transportation plan will enhance, not degrade, the values of the monument.

• The study selected three landscape metrics: (1) density of roads and other linear features in the transportation network, (2) amount of habitat within the transportation effect zone, and (3) size of core areas.
• Density analysis. Density is a measure of the number of miles of linear transportation features per square mile. This analysis is important to gauge the effects of fragmentation on different species. (p. 12)
• Analysis of the transportation effect zone. The width of the zone depends on the effects measured e.g., noise, dust, erosion, human presence, etc., and the activity that is affected (for example, greater sage-grouse breeding, elk calving, or wilderness experience for hikers).
• To the extent that transportation effects on different species are understood,. analysis of transportation effect zones can disclose direct, indirect, and cumulative impacts of fragmentation across the landscape. Transportation effect zone data layers were generated by applying widths of 1/4 mile, 1/2 mile, 1 mile, and 2 miles to the transportation features. The zone widths were selected to represent a range of potential impacts, including noise and hunting.
• Analysis of core area--portions of the landscape that are sufficiently far from transportation corridors to be relatively unaffected by them.

MAJOR FINDINGS

• Wildlife populations are threatened by landscape fragmentation attributable to existing transportation features.
• The results of analyses point out the need for route closures to mitigate current and potential impacts of the transportation network on resources.
• The transportation plan should consist of two components: (1) a baseline transportation network and (2) an adaptive ecosystem management framework to guide all future transportation management decisions.
• In developing the baseline transportation network, the agency should conduct a habitat fragmentation analysis that overlays spatial data for key resources with transportation analysis layers.
• Relevant literature concerning the impacts of routes on wildlife should be used to inform habitat fragmentation analysis.
• All routes designated as open should be geographically distributed in a manner that reduces habitat fragmentation and human contact with sensitive resources to a minimum threshold.
• Once routes are identified for closure, the Travel Plan should include a detailed route closure and restoration strategy including timelines and budget commitments.

QUESTIONS RAISED FOR THE THREE FORESTS

• What spatial analysis will you use in developing a transportation plan?

RELEVANCE TO FOREST MANAGEMENT

• Establish criteria to identify routes necessary for access and use of the Forest.
• Ensure that the Forest protects and restores key resources by minimizing routes to only those necessary for use of and access to the Forests and which cause no unnecessary or undue degradation. Specifically:
• Routes should be evaluated in light of ground-truthed digital spatial data that indicate overall land health and integrity or otherwise require protection.
• Designated routes should be geographically distributed in a manner that reduces habitat fragmentation and contact with key resources.
• The Travel Plan must identify the allowable uses of designated routes and the allowable intensity of that use.
• Motorized and mechanized travel must be confined to designated roads/routes.
• Use of administrative routes including rights of way for lessees and private inholdings should be limited to the stated administrative purpose and the route automatically closed and scheduled for reclamation once the administrative purpose ends.
• Each road not deemed necessary for specified and defined uses of the Forest, must be closed.
• All routes not incorporated into the final transportation system must be closed and scheduled for decommissioning. This requires a detailed route closure and restoration strategy, with timelines and a stated commitment to devote staff and a portion of annual budgets to restoration of closed routes. Routes scheduled for decommissioning should not be placed on official Forest maps.
• To protect Forest values and comply with NEPA,, the Forest should conduct spatial analyses of the potential negative effects of transportation features on key resources and values that serve as an overall measure of the Forest's health and integrity.
• Aggregate in digital format and ground-truth existing data concerning key resources. As needed, inventory the Forest to obtain such data.
• Devise several alternative transportation networks based on the evaluation of existing routes. Roads or other transportation features that adversely impact key resources or otherwise unnecessarily or unduly degrade the landscape must automatically be excluded from each of the alternatives.
• Evaluation of each alternative transportation network must take the following findings of this report into account:
• The effects of transportation features on terrestrial and aquatic wildlife include habitat loss and fragmentation; diminished animal use of habitats because of noise, dust emissions, and the presence of humans; loss of forage for herbivores; interference with wildlife life-history functions (for example, courtship, nesting, and migration); spread of non-native species carried by vehicles; increased poaching or unethical hunting practices; increased recreation, particularly by off-road vehicles; and degradation of aquatic habitats through alteration of stream banks and increased sediment loads. Transportation access also increases vandalism, theft, and damage to archaeological and cultural sites. (p. 19)
• Reductions in the number and size of core areas and increased edge habitat created by transportation features lead to a series of potentially intersecting and cumulative adverse effects on species that depend on natural interior landscapes. (p.15)
• Routes running near or through riparian strips can lead to fragmentation of riparian habitat. Near streams they can change the patterns of flow, increase stream sedimentation and turbidity, and reduce fish productivity. Altered hydrodynamics and sedimentation can impact shorelines, change wildlife migration patterns and aquatic plant assemblage. (p.19)
• Remote wildlands provide a range of benefits to outdoor enthusiasts, including "personal development; social bonding; therapeutic and healing benefits; and social benefits (increased national pride)" (p.23).
• It is important to consider the connectivity of patches when assessing fragmentation because the size and number of core areas may matter little to a species if it cannot migrate among them.
• Make the results publicly available, subject them to peer review, and summarize them in the Environmental Impact Statement accompanying the Resource Management Plan.
• Establish an adaptive ecosystem management framework to implement the transportation system and to guide and inform the public and the Forest with regard to all future transportation-related decisions.