Landscape and Ecology

Ecological Restoration

To execute the mission assigned by the Biodiversity Group of the National Council for Sustainable Development and understand the influence of National Freeway facilities and landscaping on the ecology of the environment along the freeways, the Bureau developed a strategy for the sustainable development. Since 2008, it began the National Freeway Eco-friendly Environment Restoration Project, which has now entered its 4th phase. A task force with members from all departments within the Bureau was formed, while a team of ecology experts from academia and private sectors was commissioned to continue related work over the long term, accruing promising results. The details are as follows:
1. The classification, management and survey of ecologically sensitive sections along the freeways
No legal ecological protected or reserved areas are designated around the freeways; however, the surroundings of the freeway are interspersed with a variety of natural environments. To ensure that the diverse utilization of the right-of-way within Freeway Bureau authority is balanced between ecology and local economic development, the Bureau has consolidated landscape data from area within 5km on both sides of the freeways using a geographical information system. The Bureau was able to graph 40 blocks of large area forest, and then superimposed on the graph areas of concern and ecological survey data from the government, private sector, and academia. The resulting data was used to determine and classify the level of ecological sensitivity of those areas into three categories and design relevant regulations. The regulations provide rules and recommendations for the use of land in each category of ecological sensitivity from the perspective of new construction, maintenance and management and restoration. For example, if a new interchange were to be built in the class 1 ecologically sensitive section, it is required that an analysis of the changes of land use of surrounding land within 15 km diameter be done, and that the predicted impact and countermeasures be proposed, and that the ecology of protected or rare species in the area be studied. In terms of maintenance and management, ecological issues should be prioritized with consideration for issues ranging from the methods and frequency of maintenance to the ecological function of the plants on the slopes. With regards to restoration, emphasis should be put on reducing the number of roadkill and the implementation of ecologically friendly measures within Bureau authority, as well as on performing periodic survey of biological resources which can serve as feedback for future review. In the first 5 years since the classification rules for ecologically sensitive areas have been in effect, an ecological resource survey of all class 1 sections has been completed and a standardized method of investigation and long-term monitoring mechanism established. In a four-season survey of 17 animal regions within 1 km of the freeways, a total of 148 species of birds, 32 species of mammals, 25 species of amphibians, 24 species of reptiles, 155 species of butterflies and 72 species of Odanatas have been recorded, including 43 protected species of different statuses and 85 endemic species and subspecies. To determine plant species suitable for growing alongside the freeway, analysis was done based on geography and climate. A total of 22 areas were surveyed, with 1079 species of vascular plants recorded, including 81 endemic species and 680 native species. The survey results were added to the database for long-term monitoring in addition to being used to determine the most pressing ecological issues and as a reference for choosing suitable native species for planting.
2. From reducing roadkill events to reestablishing habitat connectivity
Traffic accidents involving wild animals, namely roadkill, is an issue that all countries pay attention to for new roads as well as those in operation. Aside from the large number of animal death affecting the survival of the species and reducing biodiversity, striking animals can pose a risk to the life and property of the road users. In addition, roadkill carcasses are unappealing and is a detriment to the recreation quality of the area.
(A) Euploea Conservation
The Bureau first began its efforts in reducing roadkill in 2007, when promoting the Freeway for Butterflies conservation plan. At the time, volunteers from the Taiwan Butterfly Conservation Society found that the migration path of Euploeas (crow butterflies) intersect the freeway around the 251k mark on Freeway No. 3. Every year around the beginning of April, large numbers of migratory butterflies died because they cannot dodge the traffic. The Bureau invited scholars and experts to devise a plan and began the Freeway for Butterflies project. Conservation measures were also added to the annual list of tasks that continue to run, including setting protective nets 4 meters wide by 1,010 meters long around the beginning of April to help Euploeas fly at a higher altitude. Staff are also stationed at the site to close off the outer lanes when the number of butterflies passing through exceed 300 per minute. Monitoring the results show that the roadkill rate of Euploeas have gone down from 3~4% in 2007 to 0.275% in 2016. The efforts of the Bureau in helping Euploeas clear the freeway during migratory periods have garnered positive response from the public and media coverage, both local and international.
(B) Roadkill investigation
The first step to reducing roadkill numbers is to systematically collect roadkill data in a standardized way. The analysis of roadkill species, location, and time can determine the priority and provide performance evaluation.
Performing a systematic roadkill survey on the 1000-plus km of freeways is both highly difficult and dangerous. In 2007, the then Taiwan Area National Expressway Engineering Bureau began 2 years of research. Since then, the Freeway Bureau gradually established how its staff and the Engineering Bureau work together to investigate roadkill. After proper training each year, the staff gain the capability of investigating roadkill on the freeways while performing their routine tasks. Therefore, since 2009, cleaning personnel patrol the northbound and southbound shoulders along the thousand-kilometer freeways and record each and every incidence of roadkill. As of June 2016, they had accumulated over 55,000 records. Aside from regular surveys, when road users see animal carcasses, they can call the 1968 hotline. The accident response personnel from the respective branches will arrive promptly to process and record the scene. For issues that require in-depth research, the Bureau will commission experts to perform the study. This long-term, comprehensive, large-scale systematic survey of roadkill is unprecedented domestically or internationally. It also accumulates precious data that jump-start the effort to decrease the number of roadkill.
In the more than fifty thousand roadkill data accumulated over more than 8 years, a total of 82 species of birds, 17 species of mammals, 22 species of reptiles and 3 species of amphibians could be identified. The largest numbers come from small birds such as doves, pigeons, sparrows and Chinese bulbul, and dogs and cats. Approximately 25 protected species were recorded, of which medium sized mammals, such as the masked palm civet, and two birds: Otus lettia and crested goshawk, account for the most where attention needs to be prioritized.
Sometimes injured animals are encountered while surveying for roadkill. These animals are rescued then sent to the municipal government authorities or Endemic Species Research Institute to await care. Carcasses in good condition are donated to organizations such as the National Museum of Natural Science to add to their collection or used for research.
(C) Installing ecological corridors
The roadkill per kilometer of freeway is tallied for medium-sized mammals such as the masked palm civets, Lepus sinensis formosus, ferret-badgers, pangolins, and leopard cats. The annual improvement goals are set for hot zones with the highest roadkill density. Structures that may be suitable as ecological corridors such as culvert, viaducts, and overpasses, are first surveyed and selected before being modified. Protective nets and guiding nets are installed on the shoulders and slopes to prevent the animals from crossing on the freeways and guide them toward animal passages. The first ecological corridor on National Freeway was completed in April 2010. Since then, until mid-2016, a total of 8 km of National Freeway hot zones had been improved (17 km if northbound and southbound are counted separately). Follow-up studies found that the rate of roadkill for the target species in the hot zones have significantly decreased. The automatic infrared cameras installed in animal passages have also found that animals such as the masked palm civets are using the ecological corridor to cross freeways more and more frequently. Aside from Euploea and mammals, the Bureau has also completed parts of the improvement to roadkill hot zone sections for herons, dogs, and cats. Analysis for hot zones and reasons for roadkill raptors have also been conducted.
(D) Habitat connectivity
Aside from improving the roadkill hot zones along the freeways, the Bureau wants to further reduce the issue of fragmentation of habitats as a result of the freeways. One of the attempts is to reconnect the large forest areas on the two sides of the Freeway with a green corridor or animal passage. Foothill forests in Miaoli is a natural habitat for protected animals such as the leopard cats. The Tongxiao area through which Freeway No. 3 runs is found to be an area of high leopard cat density where the improvements are more feasible than neighboring Sanyi and Tongluo areas. Foreign studies have pointed out that installing overpassing corridors and connective landscape corridors are some of the most effective measures for reducing the effect of habitat fragmentation due to roads for regional terrestrial populations. Therefore, the Bureau began planning for overpassing corridors, with the Tongxiao No.1 overpass as the target for improvement. leopard cat conservation experts from Taiwan and abroad were invited to survey the site in 2012, followed by a feasibility meeting by the Forestry Bureau, Miaoli County Government, and scholars. In March 2013, the experimental multifunctional improvements to the Tongxiao No.1 overpass was completed, and it became the first overpassing animal passage in the country. Automatic infrared cameras showed that Lepus sinensis formosus began frequently using the overpass within 1 month of its completion. The following month saw ferret-badgers and masked palm civets using it. Then, traces of leopard cat activity and images of them around the bridges showed that the improved overpass served its role as the corridor connecting the foothills on the two sides of the Freeway. Overall habitat connectivity plans were made for the Tongxiao section, and the highest priority of them all: the habitat connectivity project below the Tongxiao No. 1 viaduct was completed at the end of 2016.
3. Ecological greening and its results
Ecological greening is greenification executed according to the rules of nature. The growth of plants is induced artificially according to the local vegetation, and succession is accelerated so that the plant community to quickly reach a status similar to the neighboring plant communities and ultimately reach climax. In recent years, as the concepts of ecological conservation and carbon reduction become entrenched in the public mind, ecological greening is gaining attention. More and more places are restoring their environment or creating habitats through methods of ecological greening such as planting native species, multilayer planting and mixed planting of multiple species. The right-of-way under the Freeway Bureau authority composes a green strip that runs through the entire length of Taiwan. Therefore, the Bureau is eager to create, improve, and restore the green belt along the freeways to create a stronghold for maintaining the biodiversity of the foothill areas of Taiwan.
Aside from active ecological greening and forestation in the past 20 years, the Bureau has also exerted its effort in greenbelt management along the freeways. By consolidating the plant resource survey outside of its right-of-way, slope corridor investigation, and experience with ecological greening and evaluation, the Bureau has studied methods to inhibit, prevent, and remove foreign species and greening to propose different recommendations of native species based on different circumstances with consideration for biodiversity and forestation of slopes. The Bureau also consults and collaborates with organizations such as Endemic Species Research Institute to select endemic plant seedlings or seeds suitable for foothill ecologies. The seedling cultivation is done by branch staff, and the grown seedlings are planted at suitable slopes or interchanges. Meanwhile, a standard evaluation protocol was established to evaluate the result of ecological greening of areas from different years through the slope growth restoration indicator as well as seeing how animals are using the area. The result of the evaluation confirmed that the ecological greening has indeed provided a shortcut for the slopes along the freeways to become part of the eco-system of the foothill forests.
4. Joining forces with NGOs for habitat restoration
The land neighboring the freeways has complex right-of-way and diverse ecological issues. The Bureau realized whilst promoting ecological conservation along the freeways that the work requires the support and participation of parties from all circles to find the optimal solution for a complete and sustained progress toward the goal of conservation. As such, the Bureau is eager to offer its own resources to facilitate the collaboration of all parties involved.
The 000k+900 mark on Freeway No. 3A is adjacent to Taipei's Fuyang Eco Park. The right-of-way around this section is often illegally occupied for growing crops. Since the location is the water source for the Eco Park, the fertilizers, herbicides, and pesticides have an impact on the surrounding environment. The Society of Wilderness, which has been observing the Fuyang Eco Park for an extended period of time, has found after comparing ecological surveys of recent years that the number of Taipei Green Tree Frog (Rhacophorus taipeianus), a protected species, has dwindled possibly due to agricultural pollution. In July 2000, the Bureau inspected the illegally occupied land with the Society of Wilderness and decided to take back the land to build a habitat that is suitable for Taipei Green tree frogs and other animals while also establishing an educational environment. Then, in March of 2010, the Bureau and the Society visited the Parks and Street Light Office of the Public Works Department, Taipei City, and reached an agreement with the management authority of the Fuyang Eco Park for subsequent collaborations. In April of the same year, the Bureau and the Society confirmed items such as design principles, water source, and outsourcing the design. In May of 2013, the artificial wetland construction began. In January of 2014, continued monitoring after completion showed that the plants were growing well, and Taipei Green tree frogs thrived in the environment. The automatic infrared cameras also captured activities of wild animals in the wetland.
5. Freeway Foothill Environmental Restoration Program
The foothill ecosystem is the landscape type of focus of the Satoyama Initiative of the 2010 United Nations Biodiversity Treaty. The landscape type has been overlooked in the past and mostly not included regulated reserves. However, the foothills are a diverse landscape, characterized by a high biodiversity and use in the agriculture, forestry, husbandry, and fishing industries, and are often threatened by human development and interference.
Many sections of the freeways lie in the foothills, mainly in the Taoyuan, Hsinchu, Miaoli, New Taipei City, Yilan, Nantou, Tainan, and Kaohsiung areas. The green belt of the National Freeway serves as an opportunity to string together the foothill landscape and restore the habitats around the freeways to protect biodiversity. This is the unwavering mission of the Bureau in its operations. Therefore, aside from classifying and managing sensitive sections, reducing roadkill, and ecological greening, the Bureau is also researching and implementing environmental restoration in the foothill areas of Miaoli and Tongxiao, in which the grounds of the freeway is connected to natural and diverse habitats. The Bureau surveys the sensitive habitats and the issues at hand, plans improvements to the overall habitat connectivity, designs for ecofriendliness, and strategizes the mid-to-long term restoration in hopes of minimizing the negative impact of freeways on the foothill ecosystem. In addition, the Bureau hopes that these Freeway grounds can serve as an example of foothill biological corridor and shelter for the animals and plants for future implementation in other sections.
(A) A repository for rare plant species
On the hills in western Taiwan lies an important and special type of plant habitat—a vast meadow that is home to many rare plant resources. In the Hsinchu, Miaoli and Taichung sections of the freeways, parts of the grasslands were preserved during construction. These grasslands and the surrounding undisturbed meadows serve as refuges for the sensitive species. Species found here include the Syneilesis intermedia, which has not been collected in over a half century since it was first discovered; critically endangered species Stemmacantha uniflora; endangered species Cirsium lineare, Bupleurum kaoi, Aster ovalifolius, Chionanthus retusus, Centranthera cochinchinensis, Cynanchum atratum, Siphonostegia chinensis, Alloteropsis semialata, and Eriochloa villosa; and vulnerable species Aster shimadai, Styrax matsumuraei, Glochidion puber, Eupatorium lindleyanum, Laggera alata, and Ischaemum rugosum Salisb.. The Bureau has completed the survey of plants of interest in the foothills near the Tongxiao and Yuanli sections. In response to the threats of disappearing habitats and the dwindling population of these plants, the Bureau aspires to perform conservation and restoration work on the freeway grounds in addition to its existing habitat conservation work for the rare plants in need of restoration or can serve the purpose of greening. The ecological greening experience and technology the Bureau has accumulated over the years will be leveraged for the conservation efforts.
(B) Lethocerus indicus population and habitat survey
The residents of the foothills of Miaoli often use natural or artificial reservoirs for irrigation. The scattering of these pools throughout secondary forests and farmland have formed a special landscape that retains water and wetlands. Many aquatic plants, water birds, fish, shrimps, crabs, shellfish, and aquatic insects rely on the pools for survival, while the diverse organisms have made the place an important feeding ground for other animals. During an ecological survey of the class 1 ecologically sensitive areas in the Tongxiao section in 2012, the rare aquatic insect Lethocerus indicus was found in the pools by the freeway. It continued to be recorded for three years in a row. Further inspection of the several hundred pools in the 1 km periphery of the freeway gave a preliminary picture of the distribution of Lethocerus indicus and other aquatic organisms, as well as the habitat requirements of Lethocerus indicus. Aside from continuing to focus on the conservation of Lethocerus indicus, the Bureau has also looked at the possibility of converting the settling basins into habitats for Lethocerus indicus and other aquatic organisms that are under attention.
(C) Giving Bats a Home
Cave dwelling bats often use artificial structures such as bridges and culverts as alternative habitats. Some road structures can provide a space for bats to shelter them from the weather, hide from predators, and nurture their offspring. As natural habitats disappear gradually, these artificial structures have become essential for the bats.
While looking to alter existing structures to make animal passages, the Bureau found large numbers of bats inhabiting the culverts beneath the freeways in many locations, much to their surprise. Bats were similarly found to inhabit bridges and culvert during routine inspections. As such, a survey of bats in National Freeway structures has been launched. Currently, National Freeway structures in over 300 locations have been inspected, with over 3000 bats found to use these structures as their habitats to nurture their offspring and to pass winter. Of the bats found, the largest populations belong to Rhinolophus monoceros, Miniopterus schreibersii fuliginosus, and Hipposideros armiger terasensis, while other species have also been found, including those in the genus Pipistrellus and Myotis.
To enhance the Bureau colleagues’ understanding of bats, the Bureau invited Dr. Hsi-Chi Cheng of the Endemic Species Research Institute to talk about the ecology and diversity of bats during a National Freeway eco-friendliness seminar. To further understand the conflict that may arise between maintenance work on the structures, such as bridges, and the bat habitats, the Bureau also invited experts to give seminars. Aside from deciding to continue with surveys on how bats use National Freeway structures, recording bat habitat has been added to part of the routine work in bridge inspection. Staff has also been instructed not to close maintenance holes to provide bats with a safe habitat.
(D) Improvements to the ecological corridor and leopard cat conservation
To give more attention to the issue of the conservation of leopard cats, which include conserving habitats, building and maintaining ecological corridors, and reducing roadkill, complex maps of leopard cat activity were made to gain a preliminary understanding of the locations of their key habitats and corridors. Maps of habitat suitability, suitable habitats, and predicted corridors of the area between Freeway No. 1 and Freeway No. 3 in the Miaoli area are made from the perspective of landscape and habitat requirements using GIS data by taking into consideration factors such as land usage, terrain, and the distance from freeways, forests, and other transportation facilities.
To confirm the actual distribution of leopard cat populations and the possibility of their using culverts and bridges to cross the freeway, over 30 automatic infrared cameras were installed around the Tongxiao and Yuani sections of Freeway No. 3. The results showed that these key habitats were inhabited by the leopard cats and that they already use some existing structures less frequented by humans to cross the freeway. Analyzing the habitat, corridors, structure type and carnivorans distribution pinpointed the section that needed to be prioritized for restoration and overall habitat connectivity improvement. In 2016, the eco-friendliness project was completed for the top priority location beneath the Tongxiao No.1 viaduct. In the future, habitat conservation and ecological corridor installation for this section will continue to be actively pursued. Protective nets have also been installed in sections where roadkill rate was high. The hope is that these sections can become an important shelter for animals such as the leopard cat.

Date of Posting :2018-02-12
Source of Information:Construction Division
Last Updated:2018-02-12