- 期刊
水牛在擎天崗地景的覓食生態研究
ECOLOGICAL STUDY OF WATER BUFFALO GRAZING ON QINGTIANG LANDSCAPE
摘要
本研究探討北臺灣氣候、擎天崗野化水牛與闊葉林／草地的生態互動過程。擎天崗海拔為770 m，原匿居溪谷的水牛自2016年開始重新活躍於連峰稜線間。自2019年1月至2020年10月，每月進行穿越線約2.2 km之水牛族群調查，紀錄牛群之成／幼數量，與所在林區之覓食偏好。結果發現2019年秋季水牛族群總數最高可達35隻，2020年10月水牛族群總數則達39隻，然而2020年1～10月仔、幼牛死亡7隻，為過去4年中死亡數最多的1年。由於擎天崗40 ha林／草地涵蓋三種植被型：紅楠優勢森林型、高草灌叢型（如白背芒等）與低草型（如地毯草等）；藉由地理資訊系統套疊美國大地衛星（Landsat）多頻譜感測資料，可運用每季植生指數（NDVI）區辨草原地景的生態變動，遂以主成分分析水牛棲地各植被型與季節植生增減之關係。2019年春／夏季的植生指數都在0.6以上，顯示植被豐富度高；但至2019年秋季植被豐度增幅不夠，加上當年冬季只增加低草區域植物量，且非水牛越冬所常用的棲地，可能關聯到2020年春季連續4隻小牛死亡。整體說來，擎天崗林／草地受季節氣候的影響巨大，水牛春夏聚集於擎天崗草原創造濕地，周邊並有45種植物提供廣泛營養。水牛群於秋末及越冬關鍵期，跨越稜線廣泛搜食纖維食源，需仰賴多元棲地提供足夠食物；除林下取食高草植物外，也剝食長葉木薑子、米碎柃木、燈稱花等嫩葉。特定越冬需求地形上，霧谷具水源和豐富植被，是附近草食獸的避難所。擎天崗地區在經營上亟需調控遊憩壓力，以尊重動物如水牛與水鹿的生存權，並維護山間草原地景與生態功能，才能讓動物族群在歷史文化空間上永續發展。
並列摘要
This study compares the ecological effects of water buffalo (Bubalus bulalis) grazing on Qingtiangang landscape of the northern Taiwan. Feral water buffalo is mainly inherited from the historically domesticated swamp buffalo that re-colonized into the mountain ridges at an altitude of 770 m since 2016. From January 2019 to October 2020, the buffalo population has been surveyed monthly by counting the maximum number of the herd along a 2.2-kilometer transect, as well as by checking forested habitat. The results found that: the plant growth index in spring/summer of 2019 was above 0.6, indicating that the vegetation abundance was high; but the increase in vegetation abundance by the autumn of 2019 was not enough, and the limited increase of NDVI was only in the low-grass area in the winter of that year, which was not supportive for buffalo overwintering. The degraded habitat may be related to the death of 4 calves in the spring of 2020. As limited factors, Qingtiangang forest/grassland is greatly affected by the seasonal impacts. Buffaloes gather in Qingtiangang grassland to create water holes in spring and summer, with at least 45 species of plants to provide a wide range of nutrients. At the end of autumn and the critical period of overwintering, the herd relies crude fiber food sources in accompany of grazing seedlings, including Litsea acuminata, Eurya chinensis, and Ilex asprella. On the terrain with specific wintering requirements, the valley with water holes becomes a refuge for nearby herbivores. The Qingtiangang area urgently needs to regulate the human recreational activities in order to respect the survival rights of animals such as buffalo and sambar, and maintain the ecological functions of the degrading grassland, so that the animal population can survive in the cultural landscape historically.