臺灣北部插天山自然保留區的空中花粉散播：特別著重於臺灣水青岡

Dispersal of Airborne Pollen in Chatienshan Nature Reserve, Northern Taiwan, with Emphasis on Taiwan Beech

本文為首篇以花粉收集器探討臺灣森林中花粉雨的研究，特別著重於臺灣水青岡及一些主要物種的花粉散播型式，並嘗試釐清花粉組合與周圍植被之間的關係。共有十七個花粉收集器於2008年三月二十一日至五月十日，設置在北臺灣的北插天山西側。一共鑑定出37科43屬植物的花粉及孢子。對應分析的結果顯示，十七個樣點依花粉組合可分為三個垂直帶，對應三種不同的植被類型。主要的花粉分類群可分為三種出現型式，普遍出現型、局部出現型及高峰出現型。臺灣水青岡屬於局部出現型，在距離純林200公尺以外的花粉通量遠小於純林內的通量。這意味著現生臺灣水青岡族群間不太可能有以花粉為媒介的基因流。本研究除提供臺灣中海拔一些重要分類群花粉散播的基本資料外，也指出一些在解讀沉積物花粉百分率資料時所須注意的地方。

In this first study on the pollen rain in natural forest in Taiwan using pollen traps, the dispersal patterns of airborne pollen were determined, with emphasis on Fagus hayatae and some major plant species, and the relationship between pollen assemblages and vegetation was elucidated. Seventeen pollen traps were installed on the western slope of Mt. Takai, northern Taiwan, from March 21 to May 10, 2008. Pollen and spores belonging to 37 families and 43 genera were identified. The results of correspondence analysis suggested differentiation of three vertical zones of pollen assemblages that corresponded to three vegetation types. Three patterns of occurrence were identified for the major pollen taxa, namely ubiquitous occurrence, local occurrence, and peak occurrence. The pollen influx of F. hayatae, a taxon characterized by local occurrence, was remarkably lower at a distance of over 200 m away from the pure stands. This suggests that pollen-mediated gene flow between the beech populations in Taiwan is unlikely. Besides providing basic data on the pollen dispersal of some important taxa in the middle altitudes of Taiwan, the present study also points out that caution should be taken in interpreting pollen percentage data from sediments.