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Article Breakdown: The Value of Trail Corridors for Conservation Planning (Wilson & Belote, 2022)

Summary and Application By: Kelsey Johansen

Boardwalks over Fragile Environments Promote Nature Conservation and Recreational Access

Article Summary


In this Article Breakdown, I explore the key findings of Wilson and Belote's (2022) journal article on The Value of Trails for Bold Conservation Planning published in Land and talk about how their findings can be applied to trail organizations in Canada. If you're interested in reading the original, full, academic article, you can access it here.


As the world grapples with increasing challenges presented by climate change, forest fires, coastal eroision, and severe weather events, a growing number of conservationists and other scientists are recommending that up to 50% of all lands be held within protected area networks to maintain biodiversity and promote ecosystem health (Wilson & Belote, 2022). One way to achieve this, and to safeguard the recreational and economic value of our public lands to to create wildlife, conservation, and coastal zone management corridors along existing recreational infrastructure like trails (ibid).


Wilson and Belote (2022) explore the feasibility of this, looking at two case studies: the Pactific Crest Trail (PCT) and the Continental Divide Trail (CDT) who, along with the Appalachian Trail (AT) make up the Triple Crown of Thru-Hiking in the United States. In their article, Wilson and Belote (2022) assess the lands adjacent to these trails to determine whether they cam be used "as possible wildlife corridors to connect protected areas in the American West" (p. 1). The PCT and CDT were selected as case studies because of their length (the PCT is 4265 kilometers long, and the CDT is 7842 kilometers long) which allows them to "connect 95 protected areas creating two linear protected area chains from Mexico to Canada" (Wilson & Belote, 2022, p. 1). Both trails also coincide with the best wildlife corridor routes established in the literature, and have high wildland conservation values (ibid). Furthermore, "the majority of land units around the modeled PCT (88%) and CDT (90%) corridor" (Wilson & Belote, 2022, p. 1) are already owned by the American public, making it easy to convert them into conservation corridors without having to go through various land acquisition processes.


Why is this important?

Many animal species migrate, including species of fish, crustaceans, amphibians, reptiles, insects, and mammals. These animals might journey by land, sea, or air to reach their destination, often crossing vast distances and in large numbers. But, as the human footprint expands through development pressures like urban sprawl, and as a result of climate changes, many animal species live in increasingly fragmented habitats, seperated by roads and other infrastructure, including human settlements, from the places they meet their mates, raise young, foreage for food in winter, etc. (Wilson & Belote, 2022).


Thus, facilitating movement for wildlife is essential to the surival of many species, and has become increasingly important as the climate changes (Wilson & Belote, 2022). Addressing this pressing need is essential. Connectivity planning has therefore accelerated, with connectivity from protected area to protected area accerating, and connectivity from isolated areas, or remnants, being increasingly fostered through purposefully created wildlife corridors and urban greenways that promote migrations, dispersal, and gene flow for wildlife (ibid). One practical way this is accomplished is through wildlife overpasses such as the one in Banff National Park (see image below).


Another way is through the establishment of conservation corridors.

What is a Wildlife Corridor?

Wildlife corridors are connections across the landscape that link up areas of habitat. When establishing wildlife corridors, a 2 kilometer corridor width is recommended because it allows the corridor to accommodate large megafauna like moose and bison (Wilson & Belote, 2022).


Wildlife corridors support natural processes that occur in a healthy environment, including the movement of species to find resources, such as food and water. Corridors can also contribute to the resilience of the landscape in changing climates and can help to reduce future greenhouse gas emissions by storing carbon in native vegetation. Wildlife and Conservation Corridors can also support multiple land uses such as conservation, farming and forestry, and recreational access.


Wildlife corridors can range in size – from small corridors created by local communities to large corridors that stretch across many different landscapes.


For example, a small corridor might be an area along a creek that has been re-planted with native plants by a local community group to link two patches of forest. Animals can then move more freely between these forests to find food, shelter and opportunities to breed, and pollinators (like bees) are able to travel larger distances while still having access to food.


Large-scale corridors might span tens or hundreds of kilometres across multiple landscape types and jurisdictions. Typically a large-scale corridor requires collaboration between a wide range of groups, and stakeholders, working in partnership to designate, develop, and manage it.


Wildlife corridors can also also be categorized based on their width, with wider corridors being beneficial more diverse species. The following are three divisions in corridor widths:


  • Regional – (>500 metres (1,600 ft) wide); connect major ecological gradients such as migratory pathways.

  • Sub-regional – (>300 metres (980 ft) wide); connect larger vegetated landscape features such as ridge lines and valley floors.

  • Local – (some <50 metres (160 ft)); connect remnant patches of gullies, wetlands, ridge lines, etc.

However, overall corridor quality depends more on design and connectivity than corridor width. One way this is achieved is by combining many smaller wildlife corridor projects together to create an interconnected larger corridor initiative, each making an important contribution to connecting the landscape. This requires local champions to steward each section of the corridor - just like regional and municipal trails that interconnect to form an intra-regional or national trail network.


Other factors, such as landscape elements, that contribute to wildlife corridors viability include:

  • Native grasslands that provide habitat and pasture;

  • Linear strips of roadside and fence line vegetation that form important links in the landscape, and provide pollen and seeds for pollinators and migration birds;

  • 'Stepping stones' of native vegetation such as paddock trees that link larger patches (especially important for migratory pollinators and bird species);

  • Sensitively designed urban parks and gardens that contribute habitat for native species and which are managed without pesticides;

  • Free-flowing rivers that transport nutrients and sediment to the sea;

  • Installation of fish ladders and elevators along rivers and streams to allow fish who travel between fresh and saltwater environments at different lifecycle stages to migrate around dams and other human infrastructure;

  • Interconnected wetland and shore habitats that migratory bird species rely on;

  • Pollen and seed dispersal assisted by animals and insects moving through the landscape;

  • Floodplain inundation that triggers plant regeneration and provides habitat for aquatic species;

  • Large patches of native vegetation that provides core habitat;

  • 'Buffers' around natural areas that protect them from external threats; and,

  • Corridors that guarantee food, water, and shelter, thus making long-distance movement of migratory species easier.

Land use practices contributing to wildlife corridors also include:

  • Indigenous Protected Areas managed for cultural and ecological values;

  • Restoration efforts such as revegetation projects that link core habitat patches;

  • National parks managed to preserve values and minimise impacts of invasive species;

  • Private land conservation and stewardship;

  • Development offsets that contribute to habitat restoration and management;

  • Periodic wetland inundation from environmental flows;

  • Landcare and coastcare groups managing local areas;

  • Local governments incorporating connectivity conservation into land planning and management;

  • Urban landholders that create biodiverse gardens or pollinator / butterfly gardens that are friendly to wildlife;

  • Natural resource management grants and other incentives that assist landholders to manage lands, and waterways, combat threats, and restore habitat;

  • Roadside vegetation managed by regional and local governments that connect core habitat patches;

  • Holistic farm management plans that assist private landholders to manage their agricultural lands for long term soil health, and conservation value;

  • Biodiverse plantings by landholders that contribute to long-term carbon stores;

  • Paddock tree protection programs that help to ensure natural regeneration; and,

  • Invasive species management that keeps landscapes and waterways healthy.

By implementing some of these practices, or adjusting existing land use practices, wildlife and conservation corridors can be created to help retain, restore, and manage natural connections and interactions across the landscape.


Can Trails, like the PCT and CDT, act as Conservation Corridors?

Returning to Wilson and Belotte's (2022) question, can trails, like the PCT and CDT, act as conservation corridors? Well, both greenways and trails have multi-faceted benefits and have large public appeal, which has only increased since the COVID-19 pandemic, making them easier to develop, fund, and manage (Wilson & Belote, 2022). As such, trails and greenways can and do provide meaningful opportunities for conservation planners to connect habitats while providing people with access to nature-based recreation (i.e., hiking, biking, walking, paddling, etc.) provided that there is a "friendly" legislative, regulatory, and funding framework in place.


In the United States, special federal legislation called the National Trail Systems Act (16 U.S.C. § 1241) was passed in 1968. This legislation allows "nationally significant recreational trails [to be set aside] for their historic, recreational, scenic, and cultural values. According to the act, scenic trails are conserved for human recreation and conservation" (Wilson & Belote, 2022, p. 2). Both the PCT and CDT are national scenic trails. "The PCT was designated in 1968 and completed in 1993, while the CDT was designated in 1978 and is unfinished" (Wilson & Belote, 2022, p. 2).


Due to their length, and the fact that they traverse many states and regions, the conservation status of both the CDT and PCT, and their surrounding landscapes, are complicated (Wilson & Belote, 2022). For example, the trail tread, or physical width of the footpath, of the PCT and the CDT trails is between 45–121 cm and is managed by U.S. Forest Service. While the landscape surrounding the trail tread (known as the trail corridor) is managed by a variety of public agencies and private stakeholders.


Protocols and best practices for using trail corridors or the linear landscapes around recreational trails as wildlife corridors are currently underdeveloped though some of the design and land use planning considerations above support corridor development. Furthermore, trails generally occur in areas conducive to important ecological flows such as riparian zones that represent hydrological flows and/or within mountain ranges, along which humans and animals migrate, and trails typically traverse landscapes with high scenic and aesthetic values.


To assess the potential of the CDT and PCT as wildlife corridors, Wilson and Belote (2022) modeled and evaluted the trail corridor using geospatial analysis in ArcGIS by buffering the PCT and CDT tread routes ( 45 to 121 cm wide) with a 1 kilometer buffer on either side of the trail's centerline to model a 2-km wide trail corridor.


Next, they buffered the PCT and CDT trail corridor map layers to extract values from seven other map layers to determine their wildland conservation value, conservation status, and management status. With these maps, and layers, they were able to quantitatively evaluate the wildland conservation value for:

  1. high wildness,

  2. high connectivity value for land to serve as a corridor between protected areas,

  3. high ecosystem representation within protected areas, and

  4. land that was rich in endemic species that are not well protected in conservation reserves.

Then, to understand the conservation status and land management of the PCT and CDT corridors they calculated the area of the trail corridor using different status codes applied by land managers (e.g., US Forest Service, National Park Service), and assessed the number of protected areas that the PCT and CDT corridors and calculated the percentage of GAP status lands alongside their land manager types using the tabulate intersection tool in ArcGIS (Wilson & Belote, 2022).


Based on their data, they found that:

  • 87% of the PCT corridor was in the top 50th percentile of the most valuable wildlands in the U.S.,

  • 18% of the PCT was in the top 5% of wildland conservation value in the country and fifty percent of the trail is in the top 25%,

  • The PCT corridor contained land with high wildness value (23% is in the top 95th percentile) and high corridor value (25% is in the top 95th percentile),

  • The CDT corridor had a high wildness value and 11% was in the top 95th percentile and 75% was in the top 50th percentile, and that

  • 95% of the CDT corridor was in the top 50 percent of the most valuable corridor lands (Wilson & Belotte, 2022, pp. 5 - 9).

Furthermore:

  • The PCT corridor was composed of 11% national park and 44% wilderness area, with 12% either known to be unmanaged or is uncategorized, and, unlike the PCT

  • 66% of the CDT corridor is currently not protected, and in addition, sections of the CDT are along roads or allow for motorized recreational vehicles.

As a result, Wilson and Belote (2022) concluded that the conservation infrastructure that both the modeled Pacific Crest Trail (PCT) and Continental Divide Trail (CDT) corridors provide is quite remarkable and that "landscapes that were once primarily preserved for their recreational value seem to also hold ecological integrity" (Wilson & Belote, 2022, p. 10).

To ensure that these trails can provide important ecosystem service, and act as wildlife and conservation corridors, Wilson and Belote (2022) recommended concentrating conservation efforts on unprotected lanscapes within the trail corridors, rather than on portions of the corridors and their ecosystems that are already protected. To support these efforts, they recommend establishing robust protocols for interagency cooperation and collaboration, and the procurement of additional land units (Wilson & Belote, 2022).


Application to Canadian Trails

Applying Wilson and Belotte's (2022) findings to Canadian trails, requires a modified approach, that reflects our different political, legislative, conservation, and trail development approaches employed in each country. Unlike the United States, which has federal legislation that supports the development and funding of their National Scenic Trails, there is no national trails act in Canada. Despite this, some provinces, like Ontario, and Alberta, have provincial Trails Acts, that could be leveraged to support the development of trails as conservation corridors.


Additionally, non-profit trail organizations in provinces like Ontario could benefit from working, not only with Ontario Parks and Parks Canada to create trail networks that service as conservation corridors connecting their parks and protected areas, but could also partner with Conservation Authorities. Unique to Ontario, Conservation Authorities are community-based local watershed management agencies, whose mandate is to undertake watershed-based programs to protect people and property from flooding, and other natural hazards, and to conserve natural resources for economic, social and environmental benefits. Conservation Authorities are legislated under the Conservation Authorities Act, 1946. Conservation Authorities promote an integrated watershed management approach balancing human, environmental and economic needs, making them uniquely qualified to partner with non-profit trail organizations on conservation issues that span an entire watershed.


This doesn't mean that trails in other provinces or territories cannot also modify Wilson and Belotte's approach. Instead, it likely means working with or establishing a provincial / territorial trail organization to engage with local stakeholders to develop a program that would help designate trails as conservation corridors, or other ecological management corridors (e.g. climate change adaptation or coastal erosion mitigation corridors). If this is of interest to you, we recommend at minimum:

  1. Working with or establishing a provincial / territorial trail organization to champion the cause;

  2. Identifying industry, governmental, and community experts who can help with conservation planning, and mapping of the conservation value of your trail corridor, including identify local species-at-risk, and invasive species, that need special management in your region, or watershed;

  3. Identifying industry, governmental, and community experts that can model the economic value of the ecosystem services provided by your trail corridor (e.g., carbon sequestering, flood and storm water management services, recreation value, etc.); and,

  4. Recruiting individual and organization-level stakeholders who willl advocate for the designation of your trail as a conservation corridor to the appropriate municipal, regional, or provincial / territorial authority.

While this may seem like a daunting task, it is another important layer of protection that you can provide for your trail network, and will enhance the recreational, educational, and conservation value of your trail / trail network.

Where To Go from Here

If you're looking for more information about trail planning, check out our earlier blog posts 'All Trails Should Have a 'Shovel-Ready' Project' by Kirsten Spence and Jane McCulloch, 'Recreation Ready or Tourism Ready: What Carrying Capacity Has To Do With It' by Kelsey Johansen, or 'Transformative Placemaking, Regenerative Tourism, and Trails' by Kelsey Johansen.


Get In Touch

If you have questions about how to leverage this information within your own trail organization, including how to apply any of the study's recommendations to your trail, how to design trails with conservation in mind, or how to being the process of designating them as conservation corridors, please reach out to us at: info@trailresearchhub.com.


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