Transportation and Natural Habitat Impact

I. Overview

Fragmentation of habitat has been one of the most common and widespread impacts of transportation on natural habitat and wildlife. That disruption and fragmentation of habitat is caused by the direct and indirect intervention of roads and other modes of transportation in the same geographic space used by wildlife. The result of increased networks of transportation is a fragmentation in habitat in two ways: 1) by reducing the overall amount available in naturally occurring fragments due to substituted transportation networks, and 2) to isolate habitat to such an extent that movement by natural wildlife among different isolated sections of habitat becomes difficult if not impossible.

Corridor building has been one of the most often proposed solutions for resolving the problem of fragmentation. The goal of corridor building is to permit newly isolated habitats, which have been surrounded by transportation networks and therefore proven barriers to the movement of natural wildlife. Isolated populations become weakened from reduced gene pools and from restricted access to a wide range of feeding and protective environments. Small changes in climate or seasonal changes can be difficult for a species to tolerate without movement to another habitat. The establishment of wildlife corridors are widely viewed as a solution to the fragmentation caused by human encroachment.

The introduction of exogenous species is a real threat to the Puget Sound region, especially in its aquatic realm. Worldwide shipping corridors permit species to be transplanted and to migrate into Puget Sound at a much more intense rate than in the past. In the aquatic examples, does not increased mobility due to more intensive use of world shipping lanes represent more of a threat than a beneficial result (as the corridor principle would recommend)? Will some species seize opportunities created by these transformations and flourish in the new environment, whereas other endemic species will be overpowered? Will such "synanthropes" eventually become the predominant species if the corridor principle is applied even more widely? These and other questions remain to be answered by even the most knowledgeable biologists.

Other considerations are also important. The creation of wildlife corridors may aggravate the sprawl problems of urban settings because residential areas must be built on a larger scale and further apart. In another way of thinking, would it not be more effective for conservation biologists, who do not even know "how large is large enough" to maintain a population of a species, not bother to go to such pains and expense to build wildlife corridors in an urban setting, and to concentrate instead on strict enforcement of growth management tools in order to prevent further consumption of more isolated natural habitat?

The argument that many planning "improvements" designed for people may also facilitate animal movements, for example on bicycle and foot paths and roads, deserves closer attention. Does the number of species that is blocked by such artificially constructed pathways really exceed the number of species which benefit from such pathways? This remains a question for further scientific investigation.

In one sense, values and priorities in selecting those forms of wildlife to be protected play the most critical role. Selection of those forms of wildlife which are to be preserved, and those which are to be ignored, is a fundamental question for conservation biologists in terms of environmental impact from transportation. If we are forced to choose among species, those in whose vicinity we would prefer not to live and those whom we would like to save, how are such decisions to be made? Will efforts not be based more on personal preferences for targeting those species toward which we are more sympathetic?

Do the economic costs of preserving certain species (including those whose presence is not consider innocuous) always justify gains in preserving greater biodiversity? This is perhaps the most critical question in an investigation of transportation and the environment. In the end, even small landscape transformations can obliterate the home of an endemic species. Yet if we do not

understand the linkages, how do we know that our enforcement of new intrusion and secondary impacts through corridor principle (we might think of such efforts as induced funneling) or other conservation techniques have been beneficial?

II. Guest Lecturer – Peter Singleton

On Monday, February 28, Peter Singleton came to class to speak to about issues related to wildlife assessment along the I-90 corridor. Mr. Singleton is a wildlife biologist working on forest ecology issues for the United States Forest Service and is based out of Wenatchee. He first described the three main issues of concern related to transportation and it's impact on wildlife. They are 1) the ecological functions of roads, 2) roadways serving as barriers to wildlife movement, and 3) the management of roadway barriers. The implications of roadways are this: they either effect intra-territorial movement (i.e. a road is in a species "home range"), seasonal migration, or the dispersal effect, a critical component to the health of any species because it provides genetic diversity.
In addition, Mr. Singleton identified five impacts of roads that affect wildlife in one way or another. First, roads are "Source Functions," meaning that the actual road and its purpose have a direct impact on wildlife. This impact might be from pollution or contaminants that eventually migrate into wildlife habitat. Roadways are also the source of much noise pollution, which falls into this category as well. Mitigating the impacts from noise pollution is especially important for species that use auditory functions for survival (i.e. locating food sources or mates).
Second, I-90 serves as a "habitat functions" because is creates a unique kind of habitat. In this situation the strip of lawn, or "right-of-way", along the highway becomes edge habitat for small mammals and their prey. These areas, known as "Roadside Residual Habitat Strips", are often the only habitat left for some species if much of the privately owned land is already developed. These strips have positive and negative functions on species: they serve as linear corridors of habitat for long distances, but they also are considerably degraded and generally would not be an animals first choice to live.
Next, roads move not only people, but also animals. It is logical to consider that roads are often planned in the same areas where animals would choose to travel, along a valley floor for example. The "Conduit Function" of roads can help some species travel great distances, often exceeding out of their original habitat. Singleton referenced a mole in Australia that expanded its range 500 miles because of the presence of a road network.

Roads also can become "Filters of Landscape" for many species. In other words, they become barriers to the animal, either physically or behaviorally. A physical barrier might mean that an animal cannot move physically across the road because of a concrete barrier, for example. Visual barriers prevent an animal from seeing across from one side or another, thus either putting them at risk if they do attempt to cross or preventing them from crossing at all. Behavior barriers discourage movement by the animal because it associates has learned to associate human presence, from developments for example, with roads.
Lastly, roads serve as "Population Sink Effects" because they have a direct mortality rate on some species. Another term to think of this is simply road kill. Species populations most vulnerable to road mortality are those that exhibit low density/long distance movements, have patchy habitat distribution, or those that have behavior that puts an entire population at risk.
Most important to address these impacts, Singleton says, is to look at habitat in terms of multiple scales. Habitats are not uniform, nor are given species. It's important to take a step index and look at the bigger picture; one healthy patch of habitat is not enough, if there are not others to which species can move. In other words, it's important to think in scales and look at how one spot of habitat relates to everything else. Only after doing this should specific areas of habitat be addressed. By this he means that when habitat patches are isolated, that impairs an animals ability to move around from healthy habitat areas and will contribute to a species decline. This concept is "metapopulation dynamics."

Moreover this is an especially important practice in the Pacific Northwest because of the 1864 Checkerboard Project. This land grant program that gave alternating blocks of land to private holdings to encourage railroad expansion. This policy has been contributed greatly to habitat fragmentation in Washington’s forests. It will also be especially important to address "metapopulation dynamics" and wildlife habitat connectivity on multiple scales because of global warming; it will be important to provide enough connectivity to allow ecosystems to shift North.

The following graph illustrates the important components to consider when assessing a habitat linkage area:






I-90 Corridor Modeling
In 1994 under the Northwest Forest Plan and mandated by the United States Congress, ten adaptive management areas were designated, the section of Interstate 90, along Snoqualmie Pass is one of them. Interstate 90 is an interesting section of highway because it crosses through several different ecosystems. Different points along the highway are home to different kinds of species, each having unique habitat needs that are necessary to coexist with a busy interstate. Management efforts at one point along the highway might be successful for certain species, but irrelevant for others. The five components used in the assessment were: 1) landscape modeling, 2) GIS analysis of ungulate road-kill distribution, 3) monitoring of existing highway structures that may provide crossing opportunities for wildlife, 4) automatic camera station documentation of species found near the highway, and 5) winter snow tracking transects to document highway crossings and animal distribution along the highway. (See paper at www.fs.fed.us/pnw/wenlab/research/projects/wildlife/index.html for specific information regarding the study)
Singleton found that the I-90 Corridor modeling project became a good hypothesis tool, but ground truthing proved that other factors were also important to look at wildlife habitat connectivity in the area. Ground truthing also proved to that the model was most accurate for assessing habitat for high and moderate mobility species like ungulates.

III. Links

National
The Sierra Club works to protect the wild places of the earth and promotes responsible use of the earth's. It is long involved in transportation issues related to growth/sprawl and impacts on the natural environment. (Links to local chapters available.)

Trout Unlimited (national and local chapters) works to promote quality trout and salmon fisheries both in their intrinsic value and as reminders of watershed health. Currently it supports the removal of the lower Snake River dams so the region can ensure the restoration of ecological processes consistent with native fish needs.

The National Wetlands inventory was established to generate information about the characteristics, extent and status of the Nation's wetlands and deep water habitats. Impacts due to marine transport can be found here.

Founded in 1935, The Wilderness Society works to protect America's wilderness and to develop a nation-wide network of wild lands through public education, scientific analysis and advocacy. Their goal is to ensure that future generations will enjoy the clean air and water, wildlife, beauty and opportunities for recreation and renewal that pristine forests, rivers, deserts and mountains provide.

The mission of the Audubon Society is to conserve and restore natural ecosystems, focusing on birds and other wildlife for the benefit of humanity and the earth's biological diversity.

The National Park Service preserves unimpaired the natural and cultural resources and values of the national park system for the enjoyment, education, and inspiration of this and future generations. The Park Service cooperates with partners to extend the benefits of natural and cultural resource conservation and outdoor recreation throughout this country and the world. Because the mission’s purpose is dual fold, protecting natural/cultural resources and providing educational/recreational opportunities for the general public, the agency monitors human-induced impacts to wildlife habitat closely. (See individual parks for site specific information)

USGS Urban Dynamics Research studies and determines trends of the nation’s largest metropolitan areas and land use change. Information is located here that assesses human-induced impacts like transportation on ecosystems and natural resources.

Rails to Trails is an organization is dedicated to enriching America's communities and countryside by creating a nationwide network of public trails from former rail lines and connecting corridors. This site also includes research on the efforts to use highway funds to enhance water quality, wetlands, and habitat connections.

State

The Nature Conservancy is a private, non-profit conservation organization committed to preserving plants, animals and natural communities that represent the diversity of life on Earth by protecting the lands and waters they need to survive.

The Washington Wilderness Coalition a statewide coalition of individuals and groups dedicated to preserving wilderness and biodiversity for the benefit of future generations. WWC works to protect and restore wildlands and waters through outreach, public education, organizing, and support of grassroots conservation groups.

Watch over Washington is a joint program between Washington State Department of Ecology and the Governor’s Council on Environmental Education. This site contains data on watersheds and habitat collected by local volunteers.

Washington State Wetlands Network is the local branch of the Audubon Society (see above). "WETNET’s" mission is "to protect, preserve, enhance and restore wetlands and watersheds for the benefit of birds and other wildlife and for human health and well being"

Washington State Department of Transportation has a program, Biology Projects, that works closely with WSDOT designers and permit staff and resource agencies to assess potential environmental impacts of transportation projects, and find ways to avoid or minimize those impacts. Tasks include: Wildlife habitat studies, Wetland inventory and delineation, Stream surveys, Endangered species studies, and Project impact analysis. Also included is a Wetland Strategic Plan.

Washington DNR http://www.wa.gov/dnr/ website will provide you with information on the agencey’s program, Natural Areas of Washington State. This program works to protect outstanding examples of the state's extraordinary diversity. These lands represent the finest natural, undisturbed ecosystems in state ownership, often protecting one of a kind features

which are unique to this region. Natural Resources Conservation Areas (NRCA) and Natural Areas Preserves (NAP) are the two types of natural areas managed by the Department of Natural Resources.

Washington GAP Analysis Project. Gap Analysis is a process of identifying areas of high conservation priority. It is designed to be a proactive approach to conservation. Gap relies on information about current landcover and terrestrial vertebrates to identify habitat types and species that are poorly represented on reserves. The resulting maps are combined to provide maps showing centers of diversity, which can be overlaid with land ownership maps to determine areas of need for preserving all species. The point of Gap Analysis is to try to determine critical habitat before it becomes 'critical', and before its fauna becomes endangered. The project is funded by the United States Geological Survey (USGS) Biological Resources Division, through the Washington Cooperative Fish and Wildlife Research Unit at the University of Washington.

Washington State Department of Fish and Wildlife works to provide sound stewardship of fish and wildlife. The health and well-being of fish and wildlife is important not only to the species themselves, but to humans as well. Often, when fish and wildlife populations are threatened, their decline can predict environmental hazards or patterns that also may have a negative impact on people.

Today, public interest in wildlife viewing as a recreational activity is continually growing. The traveling public is demanding more information and guidance about where to go and what to do. Watchable Wildlife is a unique national program that seeks to make exceptional wildlife viewing areas easily accessible to the traveling public. The National Watchable Wildlife Program was established in 1990 by a memorandum of understanding among eight federal land management agencies, four national conservation groups, and the International Association of Fish and Wildlife. The desired outcome of this program is a series of statewide guidebooks to wildlife viewing opportunities and a consistent system of directional signing along transportation routes.

Tucked into The Wilderness Society's Seattle office are staff on the cutting edge of environmental high-tech. They are the geographic information systems (GIS) and remote sensing team, the core of our Center for Landscape Analysis. These people use remote sensing from satellites and GIS data to create maps, handbooks, reports and computer models that show the location and condition of natural resources. These products establish a scientific basis for land protection. For example, the results of the team's work with old growth forest and salmon habitat were used by the Clinton Administration to draw management boundaries for the Northwest Forest Plan.

County

Puget Sound Green Pages This is an excellent resource of internet links for people who are interested in environmental issues around the Puget Sound Region.

North Cascades Conservation Council keeps government officials, environmental organizations, and the general public informed about issues affecting the Greater North Cascades Ecosystem. Action is pursued through legislative, legal, and public participation channels to protect the lands, waters, plants and wildlife.

Northwest Environment Watch explores the issue of roadbuilding in the region’s forests and assesses their impacts on wildlife habitat and their role in the local economy.

Interstate 90, Washington state's main east/west highway, crosses lands rich in natural beauty, from the shores of Puget Sound in Seattle to the Kittitas Valley and the small towns of Cle Elum and Thorp in eastern Washington. The Mountains to Sound Greenway encompasses farms and forests, urban and wilderness parks, historic towns and recreation opportunities along the 100-mile transportation corridor. Since 1991, the Greenway Trust has convened a remarkable coalition of people, representing all major land owners and managers along Interstate 90, together with foresters, business representatives, recreation groups, environmentalists and government agencies. This diverse group has forged a plan and a network of alliances that is, year by year, protecting more and of the scenic and recreational landscape along I-90.

The King County Wildlife Program was established in 1992 to respond to citizen concerns that wildlife habitats were not being adequately protected. The Wildlife Program has developed into a comprehensive program that addresses wildlife protection issues throughout the County. Through incentives, education, policy development, and implementation of regulations, the Wildlife Program works to integrate wildlife into the places where the people of King County live, work, and play.

King County Environmental Links webpage.

City

Seattle Public Utilities Habitat Conservation Plan for the Cedar Creek Watershed.

Other

Critter Crossings
http://www.fhwa.dot.gov///////environment//wildlifecrossings/
- This web site is sponsored by the Federal Highways Administration and
provides some examples of projects related to highways and wildlife habitat
connectivity. My I-90 project is profiled here.

The International Conference on Transportation and Ecology
http://www.itre.ncsu.edu/cte/ICOET2001.html
- The proceedings of the ICOET conferences are the best compilation of the
variety of research and management addressing transportation and wildlife
habitat impacts. The information here is more technical in nature. I have a
paper on the I-90 project posted in pdf format on the proceedings page for
the 1999 conference: http://www11.myflorida.com/emo/sched/icowetiii.htm.
There are a number of other interesting papers available as well.

The Infra Eco Network Europe
http://iene.instnat.be/
- The Europeans are the leaders in integrating transportation and natural
landscape design. The IENE is an international European organization
focused on addressing transportation network effects on wildlife habitat
connectivity. The pictures of the habitat linkage structures across
highways that have been implemented in many parts of Europe are
particularly interesting.

Trans-Canada Highway Banff National Park Twinning Project
http://www.hsctch-twinning.ca/Environmental/tchwildlifeintro.htm
- The wildlife habitat linkage mitigation that has been implemented along
the Trans-Canada Highway in Banff National Park is probably the most
extensive and best documented project addressing transportation network
impacts on wildlife habitat linkage in North America. The engineers in the
class will find this site particularly interesting because it includes the
technical design drawings for the wildlife crossing structures that have
been implemented along the highway.

Defenders of Wildlife Highways and Habitat Campaign
http://www.defenders.org/habitat/highways/
- This is the leading environmental advocacy effort on this issue.

Montana Highway 93
http://www.skillings.com/us93re-evaluation/index.html
- Once completed, this project will rival the Trans-Canada highway through
Banff. This one also provides an iteresting lesson on integrating
transportation networks with cultural landscapes, in this case the Flathead
Indian Nation.

Interagency Grizzly Bear Committee Wildlife Habitat Connectivity
http://www.fs.fed.us/r1/wildlife/igbc/
- Wildlife habitat connectivity is particularly an issue for wide-ranging
carnivores, including grizzly bears. This page has links to related
information.

British Columbia is endowed with amazing biological diversity and abundance. While habitat alteration of various kinds has many negative effects on our fish and wildlife resources, opportunities to protect, manage and even improve their habitat are numerous. The establishment of the Habitat Conservation Trust Fund was one of the most important conservation innovations ever introduced to protect these resources. To qualify for funding consideration, projects must pursue habitat restoration, species conservation, land stewardship, environmental education, or land acquisition. The largest part of the funds, about $5 million annually, is contributed by the consumptive users of fish and wildlife species through surcharges on hunting, fishing, trapping and guiding licenses. As well, money from the Crown Land Account, compensation funds from industry, donations, and cost sharing funds from co-operating groups contribute to the Trust Fund.

Naturescape British Columbia encourages restoration, preservation, and enhancement of wildlife habitat in our urban and rural landscapes throughout the province.

Prepared by Nathaniel Trumbull and Professor Christine Bae. Last updated 02/27/2000.