雪山雪東線步道種子植物開花物候之調查

Flowering phenology of East Xue Trail of Xue Mountain

高山植物的開花物候受限於惡劣的生育環境，長期以來為研究氣候變遷的重要題材。本研究於雪山雪東線步道，自海拔2,140 m登山口至海拔3,886 m雪山主峰沿線，包括中、高海拔生態系，橫跨高山植群帶、冷杉林帶、鐵杉雲杉林帶，以及櫟林帶上層等4個植群帶。由2012年3月起至同年12月止，每月觀察記錄步道兩旁種子植物之開花物候，提供保育及氣候變遷之訊息。共記錄45 科125屬172種維管束植物，主要物種以菊科、薔薇科及杜鵑花科等3科種數最優勢。研究區內花期自3月開始，夏季6-7月為花期高峰，11月多數物種花期結束進入休眠狀態，至12月已無植物開花。雪山雪東線沿線植物的開花物候與氣溫呈顯著相關，反映氣溫是高山植物開花重要的限制因子。4 個植群帶的逐月開花物候的種數模式相近，花期高峰皆在6-7月；其中，高山植群帶植物花期最短，自4月起至10月止，可能反映亞寒帶的氣溫相對較低，熱量累積較緩慢而致使植物之開花物候期程相對較短。本區物種花期的長度1-9個月不等，多數物種花期長2-3個月，其中多數大喬木的花期較短，約1-2個月。於生長季早期開花者有菫菜科、松科、楊柳科等，花期約在4-5月；於生長季晚期開花者有菊科、龍膽科、蓼科等，其花期多在8-9月。不同生長型中喬木、灌木植物花期較草本植物提早，推測其植株較高大可截取較多陽光有關。海拔廣泛分布的物種，分布於較低海拔的個體通常較高海拔者花期提早，花期開始時間延後1-4個月，少數種類如臺灣鬼督郵和一枝黃花則有提早現象。不同種類之花候差異可能與物種遺傳特性與熱量累積、以及環境的溫度變化及生育地異質性等有關。 This study is focus on flowering phenology of vascular plants in the East Xue Trail of Xue Mountain. The total observed 172 species belong to 125 genera and 45 families. The elevation of the study area was 2,140 to 3,886 m, belongs to cold harsh climate. Amount the observed species, the most dominant families were Compositae, Rosaceae and Ericaceae. Plant growth and reproduction was strictly controlled by the environment condition, the observed duration was between March to December 2012. The flowering period was from March to November, with a peak in June to July. Flowering phenology pattern was followed with the change of temperature in the study area. Due to Alpine vegetation zone at the highest altitude had the lowest temperature, the flowering duration of plants at community level was shortest. Flowering duration ranging from 1-9 months, most specieswas2-3 months, however, tree species had relatively shorter flowering period. Violaceae, Pinaceae and Salicaceae Species usually blooming centralized in April to May in early growing season. On the other hand, Compositae, Gentianaceae and Polygonaceae species often flowering in the late growing season in August to September. Trees and shrubs usually bloom earlier than herbs. Most species which the individuals grew in low altitude area blooming earlier about 1 to 4 months than those in high altitude. Otherwise, few species such as Solidago virgaurea and Ainsliaea latifolia ssp. henryi were flowering earlier at high altitude area than the lower ones. The flowering phenology differentiation of each species was influenced by genetic and environment heterogenetics.