Development and Evaluation of Seed Dispersal Functions in the Kenting Forest Dynamics Plot

墾丁森林動態樣區種子傳播模式之發展與評估

10.7075/TJFS.201003.0053

林葭瑀(Chia-Yu Lin)；林宜靜(Yi-Ching Lin)；林佩蓉(Pei-Jung Lin)；王相華(Hsiang-Hua Wang)；孫義方(I-Fang Sun)

傳播媒介 ； 森林動態樣區 ； 逆向模式分析法 ； 種子傳播 ； dispersal agents ； forest dynamics plot ； inverse modeling ； seed dispersal

臺灣林業科學

25卷1期（2010 / 03 / 01）

53 - 62

英文

發展合適的種子傳播模式，量化種子傳播特性，是植物生態學研究上的重要課題，因為，種子經傳播後的空間分布，代表植物族群之啟始分布，將顯著影響許多後續的生態過程。本研究的目標在於使用逆向模式法，發展墾丁高位珊瑚礁森林動態樣區內，4種樹種的種子傳播模式，將種子傳播之特性量化。此外，我們並比較風力與動物傳播物種於種子散布模式上的差異。自2006年8月至2009年4月，每週於墾丁高位珊瑚礁10公頃森林動態樣區中，4條穿越線上所設置的72個種子網內，收集種子，所得種子予以分類與計算數量。本研究利用逆向模式分析法(inverse modeling analysis)，分析2種藉動物傳播、2種藉風力傳播之樹種。種子散布模式採用韋伯(Weibull)、對數常態分布(lognormal)與二維t分布(2-dimensional t model, 2Dt)3種模式進行模擬，以最大概似度法(maximum likelihood methods)估算參數，並利用AIC準則(Akaike's Information Criterion)決定最適模式。結果顯示，對數常態分布與二維t分布為較好模式，最適模式並未因種子傳播媒介不同而有差異，但模式適合度以風力傳播的樹種較動物傳播的樹種高。未來，我們計劃發展混合或機制模式，將種子傳播者之行為加入種子傳播模式，以改善模式的適合度。

Developing appropriate seed dispersal functions to quantify seed dispersal is one of the important themes in plant ecology, because the post-dispersal distributions of seeds translate spatial patterns of parent plants to offspring and result in significant ecological consequences. In this study, the best-fitting seed dispersal functions were identified for 4 tree species in the Kenting forest dynamics plot in Taiwan. Dispersal functions between animal- and wind-dispersed species were also compared. Seed rain data were collected weekly from 72 seed traps (0.5 m^2) along 4 transects within a 10-ha permanent plot (400×250 m) in Kenting from August 2006 to April 2009. We chose 2 animal-dispersed species, and 2 wind-dispersed counterparts for this study. Applying the inversemodeling approach, we developed seed dispersal functions via maximum likelihood methods. Weibull, lognormal, and 2-dimensional t (2Dt) models with negative binomial errors were used. Akaike's Information Criterion was used to determine the best-fitting model. The results indicated that the lognormal and 2Dt models were the best-fitting models for the studied species. The bestfitting models did not differ between the 2 dispersal modes since they were equally represented for animal- and wind-dispersed species. However, the level of goodness-of-fit was higher for winddispersed than animal-dispersed species. In the future, mechanistic models should incorporate the behavior of seed dispersers to improve model fitting.