摘要

臺灣孕育五種特有種山椒魚，分佈在海拔1200公尺以上高山溪流源頭的潮濕的森林底層或是箭竹草原。棲地呈現不連續的族群分佈。棲息於亞熱帶冰河孑遺的臺灣原生山椒魚對於環境變化極為敏感，易於受到人為活動與環境改變而影響。其中棲地地表的無脊椎動物相與土壤性質影響山椒魚的生存甚巨。太魯閣國家公園中是臺灣的國家公園山椒魚物種多樣性最高，包括臺灣山椒魚、南湖山椒魚與楚南氏山椒魚。園區的合歡山地區（820林道）是上述三種山椒魚臨域或共域的區域，這樣的物種分佈模式，提供了一個研究臺灣的山椒魚演化的重要模型。另外，太魯閣國家公園園區內南湖山屋、成功山屋緊鄰山椒魚棲地，分別位於南湖山椒魚及楚南氏山椒魚棲地內，族群極易受到人為活動干擾。其中南湖山椒魚被國際自然保育聯盟（IUCN）列為極度瀕危物種（critical endangered），加上棲地範圍小，因此評估山屋旁山椒魚數量變化與棲地的品質尤為重要，可提供未來平衡遊憩活動、山椒魚保育與科普教育的策略制定依據。

因此，本計畫執行兩年，完成包括：（一）總計17次太魯閣國家公園園內與園區周邊山域之山椒魚族群數量調查，並進行山椒魚永久樣區，包含南湖圈谷、820林道、合歡山武嶺與成功山屋，每年4至8月期間每兩個月進行人為活動與山椒魚棲地重疊區域之保育監測，完成標放南湖圈谷10隻南湖山椒魚、成功山屋16隻楚南氏山椒魚、合歡山武嶺地區24隻楚南氏山椒魚，與820林道144隻山椒魚；（二）探討人為活動影響山椒魚棲地之環境因子，持續進行太魯閣國家公園園區內山椒魚為棲地資料收集與分析，範圍涵蓋820林道、南湖群峰、合歡山武嶺、成功山屋等區域，自2017年以來已累計收集1031筆資料，並指出820林道分布的山椒魚物種與利用之基質底層種類具有潛在關聯性，另針對南湖圈谷進行土壤硬度與酸鹼值資料收集與分析，顯示相對高人為踩踏區（南湖山屋旁步道）在步道中心顯著較步道兩旁具有較高的土壤硬度表現，且土壤酸鹼值檢出結果顯示pH值4.9至6.4之間；（三）研究與山椒魚棲地相關之可持續監測重要因子，以南湖圈谷為調查中心，於山椒魚每年高頻度活動期（四月至八月）於南湖圈谷架設掉落式陷阱，探討人為活動、山椒魚分布與無脊椎動物相之間的關聯性；（四）分析太魯閣國家公園內山椒魚族群之遺傳結構與地理的關係，於本期計畫完成收集26份山椒魚遺傳樣本，並結合自2017年以來的分析記錄，取得187種粒線體cytochrome b單套型，另完成20組核基因微衛星標記對偶基因型多樣性分析，針對太魯閣國家公園園區內與園區周遭之楚南氏山椒魚、臺灣山椒魚及南湖山椒魚，檢視地理分布與遺傳上的關聯性，結果顯示820林道分布的南湖山椒魚核基因組成與鄰近南湖圈谷分布的族群具有遺傳差異，臺灣山椒魚族群於核基因分析中則可分為二至三個次類群，且次類群的遺傳結構變化與族群所在之地景變化狀態一致，於820林道上分布的三種山椒魚，亦有檢測到核基因與粒線體不一致的現象，暗示三物種過去曾發生的基因交流與雜交可能性；（五）完成分析高人為活動區與低人為活動區之水鹿排遺分析，探討受塑膠微粒汙染狀況，收集包含波浪山、大濁水南溪、小風口與南湖圈谷之7份水鹿排遺，檢視塑膠微粒數量與型態的差異，結果顯示南湖圈谷、大濁水南溪與波浪山的水鹿排遺，則分別檢出25塊、24塊與1塊數量不等的塑膠微粒，涵蓋粒子、纖維與碎片等型態；（六）提供太魯閣國家公園內山椒魚之重要保育單位與經營管理策略。

提供經營管理單位建議如下：（一）南湖大山地區南湖山椒魚遺傳獨特、但面臨棲地範圍小，族群小，人為活動干擾棲地且逐年數量遞減。建議圈谷內山椒魚棲地，溪溝兩側特定地區，植樁限制人為進入棲地活動；（二）南湖圈谷棲地、畢祿林道（820林道）沿線、成功山屋周遭棲地常有山椒魚躲藏的遮蔽物受到人為翻動且頻率頗大，建議在這些棲地內架設自動相機，頻估人為干擾樣態，作為日後保育政策擬定依據；（三）建議在南湖圈谷山屋與成功山屋內設置「野生動物保育」、「無痕山林」、「國家公園法」、「野生動物保育法」與「中高海拔生態系重要性」等文宣，強化遊客守法觀念；（四）南湖圈谷山屋與審馬陣山屋周遭活動步道動線（如到廁所的步道）需要規劃更清楚，也需要定期維護，以讓路徑清晰。如此，遊客才不會誤闖野生動物棲地，也可減少隨地大小便的行為；（五）選定南湖圈谷樣區、成功山屋樣區與武嶺樣區為南湖山椒魚與楚南氏山椒魚樣區進行永久監測，建立長期山椒魚族群數量變動數據；（六）建議定期對保育志工、解說志工、步道志工與處內同仁進行園區內重要野生動物（如山椒魚、水鹿）保育與研究進展教育訓練，以增進志工與同仁在棲地執勤時解說深度。

 

關鍵字：太魯閣國家公園、南湖山椒魚、楚南氏山椒魚、臺灣山椒魚

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Abstract

Taiwan is the habitat of five endemic salamander species, inhabiting the moist forest floor or bamboo grasslands at the headwaters of mountain streams above 1,200 meters in elevation. Their habitats exhibit a discontinuous population distribution. As subtropical glacial relict species, Taiwan's native salamanders are highly sensitive to environmental changes and are easily affected by human activities and habitat alterations. In particular, invertebrate fauna on the forest floor and soil properties greatly influence their survival. Taroko National Park, boasts the highest salamander species diversity among Taiwan’s national parks, including the Taiwan Salamander (Hynobius formosanus), Nanhu Salamander (H. glacialis), and Sonan Salamander (H. sonani). Around the National Park, the Hehuan Mountain region as well as 820 Forest Road, existed a contact zone where these three species distributed overlap, providing a significant model for studying the evolution of Taiwanese salamanders. Additionally, the Nanhuta Cabin and Chenggong Cabin in the park are located near salamander habitats, within the ranges of the Hynobius glacialis and Hynobius sonani, respectively. These populations are highly susceptible to disturbances from human activities. The Hynobius glacialis is listed as Critically Endangered by the International Union for Conservation of Nature (IUCN) due to its extremely limited habitat range. Therefore, monitoring salamander population changes and habitat quality near these cabins is crucial. Such assessments can inform strategies for balancing recreational activities, salamander conservation, and public education in the future.

This two-year research project achieved the following objectives: (1) Salamander Population Surveys and Monitoring: we conducted 17 surveys in and around Taroko National Park to evaluate salamander population sizes. Established permanent monitoring plots in Nanhu Cirque, Hehuan Mountain, Wuling Campground, and Chenggong Cabin. Performed conservation monitoring every two months from April to August in areas where human activities overlapped with salamander habitats. We also mark-release 10 Nanhu Salamanders in Nanhuta Cirque, 16 Sonan Salamanders near Chenggong Cabin, 24 Sonan Salamanders in the Wuling, and 144 salamanders along 820 Forest Road; (2) Environmental Impact Analysis: we collected and analyzed habitat data for salamanders in areas such as 820 Forest Road, Nanhu, Wuling, and Chenggong Cabin, amassing 1,031 records since 2017. Identified potential links between salamander species distribution and substrate types along 820 Forest Road. Analyzed soil hardness and pH in Nanhuta Cirque, revealing significantly harder soil in heavily trodden trail centers near Nanhuta Cabin, with pH ranging from 4.9 to 6.4; (3) Sustainable Monitoring Factors: Investigated the relationship between human activity, salamander distribution, and invertebrate fauna in Nanhuta Cirque by setting up pitfall traps during the salamanders' active season (April–August). (4) Genetic Structure and Geographic Relationships: Collected 26 genetic samples from salamanders in Taroko National Park, adding to 187 mitochondrial cytochrome b haplotypes accumulated since 2017. Completed genetic diversity analysis using 20 markers to examine genetic and geographic correlations among Hynobius sonani, Hynobius formosanus, and Hynobius glacialis. Detect genetic differences between Nanhu Salamanders from 820 Forest Road and those from Nanhu Cirque. Nuclear gene analysis revealed 2–3 subgroups within Hynobius formosanus, with genetic structure reflecting landscape variations. Detected nuclear-mitochondrial discordance among the three species along 820 Forest Road, suggesting past gene flow and hybridization events. (5) Plastic Microbead Pollution Assessment: Analyzed sambar deer feces for microplastic pollution in high- and low-human activity areas, collecting seven samples from Bolangshan, Dazhuoshui South Creek, Xiaofengkou, and Nanhu Cirque. We detected varying amounts of microplastics (e.g., particles, fibers, fragments), with Nanhu Cirque, Dazhuoshui South Creek, and Bolangshan containing 25, 24, and 1 microplastic pieces, respectively. (6) Conservation and Management Recommendations: we provided critical conservation strategies and management plans for salamanders in Taroko National Park.

We provided the recommendations for the management authorities as follows: (1) Protecting salamander habitat in Nanhu Cirque: Hynobius glacialis exhibits unique genetic characteristics but faces challenges such as limited habitat range, small population size, habitat disturbances from human activities, and a yearly decline in numbers. It is recommended to install stakes in specific areas along both sides of the stream within the cirque to restrict human access to salamander habitats. (2) Monitoring human disturbances in key areas: Salamander habitats in the Nanhu Cirque, 820 Forest Road, and Chenggong Cabin are frequently disturbed by human activity, such as flipping over cover objects. Installing automatic cameras in these areas is advised to monitor human interference patterns, providing a basis for future conservation policies. (3) Raising awareness through educational materials: Educational materials covering topics such as "Wildlife Conservation," "Leave No Trace," "National Park Law," "Wildlife Conservation Law," and "The Importance of Mid-to-High Altitude Ecosystems" should be displayed in Nanhu Cirque Cabin and Chenggong Cabin to strengthen visitors’ understanding of compliance and conservation. (4) Trail planning and maintenance around cabins: Trails around Nanhu Cirque Cabin and Shanmachen Cabin, including paths to restrooms, need clearer planning and regular maintenance to ensure well-defined routes. This will help prevent visitors from accidentally entering wildlife habitats and reduce instances of improper waste disposal. (5) Long-term monitoring of salamander populations: Designate permanent monitoring plots in Nanhu Cirque, Chenggong Cabin, and Wuling areas for Hynobius glacialis and Hynobius sonani. Establish long-term population fluctuation data for these species. (6) Training for conservation and education volunteers: Regular training should be provided to conservation volunteers, interpretive guides, trail maintenance volunteers, and park staff on the conservation and research progress of key wildlife species (e.g., salamanders and sambar deer) within the park. This will enhance their ability to provide in-depth explanations while working in the field.

 

Key words: Taroko National Park, Hynobius glacialis, Hynobius sonani, Hynobius formosanus