Biodiversity and Transportation Infrastructure in the Republic of Korea: A Review on Impacts and Mitigation in Developing the Country

The construction and continued use of transportation infrastructure, specifically roads, has had a significant global impact on biodiversity and the environment. The Republic of Korea, or South Korea, has a road density of 1.13 km/km2. So far, three nationwide studies about vertebrate road-killed species have been reported, showing bias towards medium to large mammals, the most common victims being the Korean water deer (Hydropotes inermis), Korean hare (Lepus coreanus), Siberian roe deer (Capreolus pygargus), and the common raccoon dog (Nyctereutes procyonoides). Road-kills, or wildlife-vehicle collisions (WVCs), tend to occur in or near preferred habitat types or in highly fragmented areas, with roads additionally being linked to habitat fragmentation and loss. Alongside WVCs and habitat effects, information about other adverse effects on biodiversity is scant, although there are reports that heavy metals and other pollutants from road runoff impact marine biodiversity, vegetation, soil, and groundwater. Furthermore, roads have been linked to a prevalence of invasive plant species. To mitigate road impacts, the South Korean government has constructed, with mixed results, 530 wildlife crossing structures, mainly including overpasses and tunnels. To mitigate road impacts more effectively, the country will need more construction, monitoring, and consistent management of wildlife crossing structures. Further, incorporating plans for wildlife crossing structures in early stages of road development will be required.

The SLOSS dilemma of road ecology: Are several small wildlife crossing structures better than a single large?

Crossing structures for large wildlife are increasingly being constructed at major roads and railways in many countries, and current guidelines for wildlife mitigation at linear infrastructures tend to advocate for large crossing structures sited at major movement corridors for the target species. The concept of movement corridors has however been challenged, and pinching animal movements into bottlenecks entail risks. In this paper, I address the SLOSS dilemma of road ecology, i.e., the discussion whether a Single Large Or Several Small crossing structures along a linear barrier would produce the most benefit for wildlife. I point out risks, ecological as well as practical, with investing in one large crossing structure, and list a number of situations where it may be more beneficial to distribute the conservation efforts in the landscape by constructing several smaller crossing structures; for example when the ecological knowledge is insufficient, when animal interactions are expected to be significant, when the landscape changes over time, or when future human development cannot be controlled. I argue that such situations are often what infrastructure planning faces, and that the default strategy therefore should be to distribute rather than to concentrate passage opportunities along major transport infrastructures. I suggest that distributing passage opportunities over several smaller crossing structures would convey a risk diversification, and that this strategy could facilitate the planning of wildlife mitigation. What to choose would however depend on, i.a., landscape composition and ecology, and on relationships among target species. A single large should be selected where it is likely that it can serve a large proportion of target animals, and where the long-term functionality of the crossing structure can be guaranteed. I illustrate how species and regional differences may influence the choice, using the case of ungulates in Sweden. New research is needed to support trade-offs between size and number of crossing structures. Cost-effectiveness analyses of wildlife crossing structures are currently rare and need to be further explored. Camera trapping and video surveillance of crossing structures provide opportunities to analyze details concerning, for example, any individual biases according to sex, age, status and grouping, and any antagonism between species and individuals. Wildlife ecology research need to better address questions posed by road and railway planning regarding the importance of specific movement routes and movement distances.

Getting From Here To There - Mainstreaming Wildlife Crossing Structures Through Transdisciplinary Design Approaches To Collaborative Planning

The effectiveness of wildlife crossing structures in mitigating the impacts of roads on species and ecosystems have been well-documented in scientific literature. Despite this, there are challenges associated with translating ecological knowledge into policy and practice. The study examines the planning process for wildlife crossing infrastructure using a case study in the context of the Greater Toronto and Hamilton Area and explored the potential of transdisciplinary collaboration and design thinking to enhance landscape connectivity. The study followed an iterative design research method incorporating knowledge from literature review, policy analysis and subject matter professional expertise derived through participant observation through work with the Toronto and Region Conservation Authority. This supported the development of a conceptual framework for actionable research to encourage the co-creation of practical knowledge and specific planning solutions. In addition, the study contributes valuable insight to the broader literature of sustainable landscape planning, road ecology and transportation planning.

How to get the salamander across the road: exploring the policy intersection of biodiversity conservation and road projects in Ontario

Connecting landscapes around roads is an important element in a broader strategy to help protect and recover biodiversity. In regions like southern Ontario and the Greater Golden Horseshoe, growing urban footprints are leading to an expansion of road networks. Road planning and design has historically fragmented natural habitat and created barriers for wildlife movement. The negative impacts of roads can be mitigated through the creation of wildlife crossing structures that enable safe passage of wildlife over or under roads. This Major Research Paper will investigate key Ontario land use and regulatory policies that intersect with both road projects and biodiversity recovery to evaluate their effectiveness in recognizing biodiversity values and enabling the creation of wildlife crossing structures. Key words: landscape connectivity, wildlife crossing, safe passage, biodiversity, conservation, policy, planning, Ontario, Greater Golden Horseshoe

How to get the salamander across the road: exploring the policy intersection of biodiversity conservation and road projects in Ontario

Connecting landscapes around roads is an important element in a broader strategy to help protect and recover biodiversity. In regions like southern Ontario and the Greater Golden Horseshoe, growing urban footprints are leading to an expansion of road networks. Road planning and design has historically fragmented natural habitat and created barriers for wildlife movement. The negative impacts of roads can be mitigated through the creation of wildlife crossing structures that enable safe passage of wildlife over or under roads. This Major Research Paper will investigate key Ontario land use and regulatory policies that intersect with both road projects and biodiversity recovery to evaluate their effectiveness in recognizing biodiversity values and enabling the creation of wildlife crossing structures. Key words: landscape connectivity, wildlife crossing, safe passage, biodiversity, conservation, policy, planning, Ontario, Greater Golden Horseshoe

Getting From Here To There - Mainstreaming Wildlife Crossing Structures Through Transdisciplinary Design Approaches To Collaborative Planning

The effectiveness of wildlife crossing structures in mitigating the impacts of roads on species and ecosystems have been well-documented in scientific literature. Despite this, there are challenges associated with translating ecological knowledge into policy and practice. The study examines the planning process for wildlife crossing infrastructure using a case study in the context of the Greater Toronto and Hamilton Area and explored the potential of transdisciplinary collaboration and design thinking to enhance landscape connectivity. The study followed an iterative design research method incorporating knowledge from literature review, policy analysis and subject matter professional expertise derived through participant observation through work with the Toronto and Region Conservation Authority. This supported the development of a conceptual framework for actionable research to encourage the co-creation of practical knowledge and specific planning solutions. In addition, the study contributes valuable insight to the broader literature of sustainable landscape planning, road ecology and transportation planning.

Landscape Characteristics Based on Effectiveness of Wildlife Crossing Structures in South Korea

Roads are notable and responsible for the loss of biodiversity and disruption of wildlife habitats connectivity. Wildlife crossing structures (WCS) help wildlife move between habitats by connecting fragmented habitats. Their effectiveness is affected by various factors. Here, to identify methods for improving the effectiveness of wildlife crossing structures, we controlled the effect of intrinsic factors, such as size, that are difficult to improve in an already installed area, and then, evaluated the differences in extrinsic factors using 12 landscape characteristics. Our results show that 18 wildlife crossing structures were selected with propensity-score (PS) matching method. The surrounding landscape characteristics differed between high-effectiveness wildlife crossing structures and low-effectiveness wildlife crossing structures. Particularly, there was a significant difference between the ‘statutory protected area’ and the ‘edge’ index of the morphological spatial pattern analysis among the landscape characteristic variables derived within 1 km2 of wildlife crossing structures. We empirically demonstrate that characteristics around highly effective WCS, statutory protected areas are widely distributed, and the ratio of edge of MSPA is low (within 1 km2). Therefore, an important outcome of our research is the demonstration that management of WCS itself is important, but conservation of surrounding habitats and landscape management plans are also significant.

Mammal use of wildlife crossing structures along a new motorway in an area recently recolonized by wolves

Wildlife crossing structures (WCSs) enhance connectivity between habitats of wild animals fragmented by fenced motorways, but factors affecting their use by targeted species remain understudied, particularly in areas recently recolonized by large carnivores. We investigated the use of WCS—6 overpasses (width 30-45m), 5 large underpasses (width 33–114 m) and 4 small underpasses (width 15–19 m)—located along the A4 motorway in the Lower Silesian Forest (western Poland), a large forest tract recently recolonised by wolves (Canis lupus). Identifying and counting tracks of mammals left on sand-beds as well as individuals recorded by camera traps were used to determine species diversity, number and activity patterns of mammals on WCS, and to reveal seasonal and temporal changes of WCS use over 3 years of study (2010–2013). WCSs were mostly used by wild species (51.5%), followed by humans (34.8%), livestock and pets (13.7%). Among wild species, ungulates were the most common (77.4% of crossings), while lagomorphs and carnivores were recorded less often (15% and 7.6% of crossings, respectively). The number of species and crossings of wild mammals, especially wild ungulates and wolves, was substantially higher on overpasses (mean effective number of species (Hill numbers): 0D = 7.8, 1D = 4.1 and 2D = 3.3) than on underpasses (0D = 6.3, 1D = 2.9 and 2D = 2.3) and was not affected by distance between WCS and human settlements or WCS width. There was a higher diversity of wild species and more crossings under large extended bridges than on smaller underpasses. The number of species and number of crossings of wild mammals, domestic animals and people increased from 2010 to 2013. There was a significant difference in activity patterns, with almost all wild species being nocturnal, in contrast to people and dogs. There was no relationship between crossing time and rates of wild carnivores and potential prey. We conclude that overpasses, even with steep entrance slopes (25–26.5%) or integrated with moderately used gravel roads, maintain movement of wild terrestrial mammals much better than underpasses, and the presence of wolves does not hamper the movement of other wild species. As there are significant temporal changes in use of WCS by mammals, we recommend monitoring WCS in all seasons for at least 3 years as a minimum standard for the post-investment assessment of WCS utilization by animals.