Reevaluating the Theory of Gap Dynamics Using Studies of Typhoon Disturbance at the Fushan Experimental Forest, Northeastern Taiwa

以台灣東北部福山試驗林颱風研究重新評估孔隙動態理論

林登秋(Teng-Chiu Lin)

《台灣林業科學》 35卷1期 (2020/03) Pp. 97-102

https://doi.org/10.7075/TJFS.202003_35(1).0006

摘要

The theory of gap dynamics generalizes disturbance-diversity-forest dynamics relationships but is hotly debated. Studies of interactions between tropical cyclones and forest dynamics at the Fushan Long-term Ecological Research Site in northeastern Taiwan, where typhoon disturbances occur on an annual basis, indicate that gaps created by disturbances do not always differ from the non-gap understory in important physical conditions such as light availability and variability. Therefore, shade-tolerant and -intolerant species can coexist in both gaps and the non-gap understory. In such forests, gaps are not indispensable for the establishment and growth of shade-intolerant species as postulated by the theory of gap dynamics. Thus, it is important to focus on specific environmental conditions rather than the gap versus non-gap status when discussing gap-biodiversity-forest dynamics relationships. In the era of climate change characterized by more-frequent climate extremes and natural disturbances, we should move beyond generalizations and directly address the processes leading to the observed relationships among disturbance, diversity, and forest dynamics.

關鍵字

theory of gap dynamics ； disturbance-diversity-forest dynamics ； typhoon disturbance ； climate change ； Fushan Long-term Ecological Research

並列摘要

孔隙動態理論為擾動、生物多樣性與森林動態之間的關係提出通則性的論述，但引起了廣泛的爭論。在每年均有颱風擾動的台灣東北部福山長期生態研究站，對熱帶氣旋和森林動態關係的研究指出，擾動造成的林間孔隙與非孔隙在重要的物理條件，如林下光照量與其變異程度，未必有顯著差異。因此，耐陰和不耐陰的物種可以共存於孔隙和非孔隙的林下。在這類森林中，不耐陰樹種並非如孔隙動態理論所假定的一定得依靠孔隙才能在林內存活和生長。在討論孔隙、生物多樣性、和森林動態的關係時，焦點應集中在環境條件的差異而不是孔隙與非孔隙的區分。在氣候變遷使得極端氣候和自然擾動更為頻繁的年代，更應該超越一般通則，直接探討導致吾人所觀察到的擾動、生物多樣性和森林動態之間關係的過程。

並列關鍵字

孔隙動態理論 ； 擾動多樣性與森林動態 ； 颱風擾動 ； 氣候變遷 ； 福山長期生態研究