|摘要: ||物候為植物生活週期在年間循環的現象，其變化可與環境因子相互反映，定期觀察可做為學術及監測氣候變遷的重要資料。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，由2012年3月起至2013年5月止，每月觀察記錄步道兩旁種子植物之開花物候，初步建立臺灣高山植物之開花物候資料，以提供了解物種保育及氣候變遷下對植物繁殖影響之訊息。開花物候觀察共記錄48科128屬175種，開花物候觀察與研究區主要物種組成相當，以菊科、薔薇科及杜鵑花科等3科植物種數最優勢。研究區含括中、高海拔生態系，生育地環境較嚴苛，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。整體而言，研究區內花期自3月開始，夏季6 - 7月為花期高峰，11月多數物種結束花期進入休眠狀態，至12月已無植物開花。雪山雪東線4個植群帶的逐月開花物種數相近，且均與氣溫呈顯著相關，反映出氣溫是高山植物開花重要的限制因子；其中，高山植群帶植物開花物候期最短，於5月起至10月止，可能反映亞寒帶熱量累積較緩慢，而致使植物之開花物候期程相對較短。物種花期的長度1 - 9個月不等，多數物種花期長2 - 3個月，其中大多喬木植物的花期較短，約1 - 2個月。於生長季早期開花者有菫菜科、松科，花期高峰4 - 5月；於生長季晚期開花者有柳葉菜科、龍膽科、蓼科等物種，其花期高峰8 - 9月。海拔廣泛分布的物種，大多數隨分布海拔上升，花期開始時間延後1 - 4個月。早花型物種於2012年較2013年進入花期時間提早，應與該年春季溫度較高有關。部分物種僅於2013年春季觀察到花期如薄葉柃木、菝葜及臺灣紅榨槭，其開花有年度之間均有豐欠年之差異，物種需累積足夠能量後方能進入開花狀態。生長型中木本植物花期較草本植物提早，推測其生長型利於截取較多陽光有關。雪東線植群與塔塔加及玉山主峰線植群花候比較，植群尺度之物種數花期分布相似，而單一物種於不同地區則有所差異，受當地微環境、氣候、植物遺傳生理等因子影響。|
This Study investigated the flowering phenology of vascular plants along the East Xue Trail of Xue Mountain from elevation 2,140 m to 3,886 m during March 2012 to May 2013; in order to establish the primary data of the Taiwan alpine plants’ flowering phenology and understand the effect of species protection and climate change on plant propagation. The vascular plants observed in this study contained 175 species, including three dominant families: Compositae, Rosaceae, and Ericaceae.
The study area belonged to medium and high - altitude ecological zone, covering Alpine Zone, Abies Zone, Tsuga - Picea Zone and Oak Zone. Overall, the main flowering period of this area was from March to November, with a blooming peak period during June to July. The flowering phenology pattern followed the change of temperature, showing that temperature is the most important limiting factor for flowering duration of alpine plant. Alpine Zone has shortest flowering phenology among these four zones, which was from May to October. The possible reason may be its slow heat buildup rate. Flowering duration of plants ranged from 1 - 9 months, and most species had flowering period from 2 - 3 months; however, tree species had relatively shorter flowering period which only had 1 - 2 months.
Species which usually blooming in early growing season (e.g. from April to May) included the family of Violaceae, Pinaceae and Salicaceae; and the species that blooming in the late growing season (e.g. from August to September) included the family of Compositae, Gentianaceae and Polygonaceae. Trees and shrubs usually bloom earlier than herbs due to its advantage of capturing more sunlight.
Most species grew in low altitude area had their blooming period 1 to 4 months earlier than the one grew in high altitude. The starting time of earliest flowering species in 2012 was earlier than 2013 due to the higher temperature in spring. In 2 years investigation, some species only flowered in spring 2013, such as Eurya leptophylla, Smilax china and Acer morrisonense, since they need to accumulate more energy from sunlight to bloom. Moreover, compared with other alpine flowering phenology research, we found that the flowering number distributions of species in different spots were similar in plant community scale but different in species scale, indicating the influence of local environment factors is significant. As altitude increases, the flowering time of the same species at different altitude were different, which indicated that the flowering phenology was influenced by species and environment factors such as temperature and habitat heterogeneities.