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.

Effectiveness of aerial wildlife crossings: Do wildlife use rope bridges more than hazardous structures to cross roads?

Introduction: Although wildlife crossing structures have proven successful at reducing wildlife-vehicle collisions and linking fragmented habitat, their ability to prevent electrocutions of arboreal wildlife has not been closely examined. Objective: To evaluate the effectiveness of aerial rope bridges in restoring habitat connectivity for arboreal species in Manuel Antonio, Costa Rica, while preventing electrocutions by determining 1) what species are using the rope bridges and 2) whether wildlife prefer to use rope bridges instead of other hazardous structures that cross the roads (such as telephone cables, which are often in close proximity to electric wires). Methods: From January to May 2016, nine rope bridges along the highly-trafficked main road that extends from Quepos to Manuel Antonio, Costa Rica, were monitored using camera traps, and ten rope bridges were observed directly along a paved side road off the main road. Results: A total of 11 species were seen using the bridges, and 1 540 crossings were witnessed via camera traps and observations (1 234 via camera traps, 306 during observations). Results from a paired t-test showed no significant difference in the average number of individuals crossing the road via rope bridges versus telephone cables (t(8) = 1.027, P = 0.334). Conclusions: Rope bridges are used by a variety of arboreal wildlife species with a high degree of frequency; however, due to the equally high usage of telephone cables by arboreal wildlife, they are insufficient to prevent wildlife electrocutions on their own. Rope bridges should be installed in tandem with other methods to prevent electrocutions, such as insulating electric wires, to facilitate the safe passage of wildlife over roads.

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.

How do King Cobras move across a major highway? Unintentional wildlife crossing structures may facilitate movement.

Global road networks continue to expand, and the wildlife responses to these landscape-level changes need to be understood to advise long-term management decisions. Roads have high mortality risk to snakes because snakes typically move slowly and can be intentionally targeted by drivers. We investigated how radio-tracked King Cobras (Ophiophagus hannah) traverse a major highway in northeast Thailand, and if reproductive cycles were associated with road hazards. We surveyed a 15.3km stretch of Highway 304 to determine if there were any locations where snakes, and other wildlife, could safely move across the road (e.g., culverts, bridges). We used recurse analysis to detect possible road-crossing events, and used subsets of King Cobra movement data to create dynamic Brownian Bridge Movement Models (dBBMM) in an attempt to show movement pathways association with possible unintentional crossing structures. We further used Integrated Step Selection Functions (ISSF) to assess seasonal differences in avoidance of major roads for adult King Cobras in relation to reproductive state. We discovered 32 unintentional wildlife crossing locations capable of facilitating King Cobra movement across the highway. Our dBBMMs failed to show if underpasses were being used by telemetered individuals; however, the tracking locations pre- and post-crossing provided strong evidence of underpass use. Our ISSF suggested a lower avoidance of roads during the breeding season, though the results were inconclusive. With the high volume of traffic, large size of King Cobras and a 98.8% success rate of crossing the road in our study, we strongly suspect that individuals are using the unintentional crossing structures to safely traverse the road. Further research is needed to determine the extent of wildlife underpass use at our study site and globally, alongside using previously proven fencing to facilitate their use. We propose that more consistent integration of drainage culverts and bridges could help mitigate the impacts of roads on some terrestrial wildlife, particularly in areas where roads fragment forests and wildlife corridors.

Wildlife Crossings at Felda Aring - Tasik Kenyir Road, Malaysia

The Felda Aring - Tasik Kenyir Road was identified as one of the most threatening roads to wildlife in Malaysia. The present study was conducted to assess the road crossing activities involving the medium- to large-mammal species due to the problem stated. The objectives of this study were to (1) predict the suitability of the road and its surroundings as the roaming areas for the Asian elephant (Elephas maximus, n = 104) and Malayan tapir (Tapirus indicus, n = 66), (2) identify the mammalian species inhabiting the forest beside the road, (3) compare the forest’s common species [photographic capture rate index (PCRI) > 10/ detection probability (P) ≥ 0.05] with the ones utilising the road crossing structures; the viaducts and the bridges, and (4) determine the most impacted species from traffic collisions. The road and its surroundings were classified as moderately suitable to the elephant and tapir (suitability values = 0.4 - 0.8). A total of 16 mammal species were recorded at the forest edges, in which the wild pig (Sus scrofa) (PCRI = 118.96, P = 0.3719 ± 0.027), barking deer (Muntiacus muntjak) (PCRI = 68.89, P = 0.2219 ± 0.0232), sun bear (Helarctos malayanus) (PCRI = 11.13, P = 0.0507 ± 0.0159), tapir (PCRI = 11.13, P = 0.0469 ± 0.0118), elephant (PCRI = 10.7, P = 0.0787 ± 0.0195) and Malayan porcupine (Hystrix brachyura) (PCRI = 10.7, P = 0.103 ± 0.0252) were the common species utilising the crossing structures. In contrast, the Asian palm civet (Paradoxurus hermaphroditus) and leopard cat (Prionailurus bengalensis) were the most frequently hit species on the road [F(7,398) = 28.53, p < 0.0005]. The present study found that large-mammal species were utilising the crossing structures at a higher frequency, whereas more medium-mammal species were involved in traffic collisions.

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.