福山亞熱帶雨林林木之個體物種面積關係

Individual Species Area Relationship of Woody Plants in a Subtropical Rainforest at Fushan, Northern Taiwan

蔡政翰(Cheng-Han Tsai)

指導教授 ： 丁宗蘇

共同指導教授 ： 謝志豪

國立臺灣大學/生物資源暨農學院/森林環境暨資源學研究所/碩士(2009年)

https://doi.org/10.6342/NTU.2009.02534

摘要

儘管已有許多理論與假說解釋群集中眾多物種的共存現象，中性理論與棲位理論的爭議依然存在。因此以實證研究來檢測這些理論機制，便成為群落生態學中重要的一環。熱帶森林的地域性(< 1 km2)林木多樣性分布，是最早用來支持中性理論之實證研究。近年熱帶森林樣區之研究顯示，雖然在較大的空間尺度下(> 20 m)，所觀察到的現象支持中性理論，但是在極小的空間尺度下(< 20 m)卻是支持棲位理論。亞熱帶森林在這方面或許會有不同的現象，但尚未有亞熱帶森林研究驗證過這些理論。本研究探討福山25公頃亞熱帶森林長期動態樣區的林木物種多樣性，以及釐清不同空間尺度下林木種間關係所扮演的角色。藉由個體物種面積關係分析與蒙地卡羅模擬，我檢測個體觀點之物種面積關係，並由此將所有樹種區分為多樣性累積者、多樣性排斥者以及多樣性中性者三類，再以這些物種特徵來推論種間競爭作用的重要性。結果顯示，種間競爭作用在亞熱帶的福山森林樣區內的影響力比在熱帶樣區更為顯著，在< 50 m空間尺度下，所有檢驗的52種福山林木物種是多樣性排斥者，並且其中性性質並不會因空間尺度不同而變化。總結而言，由於福山森林樣區內樹種大多為多樣性排斥者，種間競爭關係的影響力應該相當重要。因此，與熱帶的森林樣區相比，種間競爭關係在福山林木物種多樣性上，可能扮演較重要的建構角色。此研究結果可以提供未來進一步探討種間競爭關係在亞熱帶森林所扮演機制的基礎。

關鍵字

福山森林動態樣區 ； 空間分析 ； 群落集合規則 ； 尺度相依

並列摘要

Although numerous mechanisms have been proposed to explain the coexistence of species in highly diversified communities, the niche/neutral controversy remains unsettled. Testing empirical evidence against theoretical mechanisms in explaining coexistence is important for understanding community ecology. Woody plants diversity pattern at local scales (< 1 km2) in tropics was firstly demonstrated as supports for neutral theory against niche driving assembly theory. Recent spatial analyses of tropical forest dynamic plots showed empirical evidences supporting the neutral theory at > 20 m scale but niche assembly theory at < 20 m scale. Thediversity pattern in subtropical forests might differ from the tropical plots; however, no study in subtropical forests has been carried out. This study aimed to explore the woody plants diversity pattern in the 25 hectare Fushan Subtropical Forest Dynamic Plot in northern Taiwan and elucidate the role of inter-specific interactions in different spatial scales. Through individual species-area relationship (ISAR) analysis and Monte Carlo simulation, the species-area patterns from individual view were estimated; as such, every woody species was distinguished as a diversity accumulator, repeller, or neutral species. These species specific characteristics then were treated as implication for the strength of competitive interactions in the study site. The results showed that the influence of negative interactions among woody species in this subtropical plot was greater than other studied tropical plots. All the 52 examined woody species at the Fushan plot behaved as diversity repeller within a 50 m scale and did not show scale-dependent neutral behavior. In conclusion, the high prevalence of diversity repeller suggests that negative inter-specific interactions were strong in this study site. Therefore, niche driving assembly processes may play a more important role in structuring the woody plants diversity pattern of Fushan subtropical plot than that in tropical plots. The results provide important basis for further investigation on the mechanisms of such negative inter-specific interactions in the subtropical forests.

並列關鍵字

Fushan Forest Dynamic Plot ； Spatial analysis ； Community assembly rules ； Scale-dependent

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