本研究旨在瞭解鴛鴦湖自然保留區未受人為幹攏的溫帶針、闊葉混合林中，枯倒木對於臺灣扁柏(Chamaecyparis obtuse var. formosana)及闊葉樹種的更新及樹種共存的重要性。在保留區內攫取一個0.25公頃的樣區，記錄區內所有胸高直徑大於1公分的木本植物，在湖區附近另外選取九根倒木，記錄倒木上所有木本植物的地侄。在樣區內，只有少數的闊葉樹種高度超過10公尺，臺灣扁柏是主要構成樹冠層的種類。樣區內的木本植物種類與九根倒木上的木本植物小苗種類完全相同，表示在倒木上生辰的木本植物小苗，就足以維持森林內樹種的更新，包括森林的樹種組成、樹冠層結構及種多樣性。除此之外，臺灣扁柏及闊葉樹種，兩者在倒木上的生長有時間和空間分化的現象。大部分臺灣扁柏的種子會在新形成倒木的樹種及樹枝區發芽，小苗密度相當高，只有少數會在根強畫發芽。經過一段時間俊，扁柏小苗生長以填補倒木在樹冠曾留下的冠曾空隙，同疇小苗在倒木上的密度可能由放幢簡兢爭而逐漸降低。年輕枯倒木上附生的苔藤可能提供臺灣扁柏種子適當的生育地環境。闊葉樹種則不同，他擁大多分佈在新形成倒木的根張區，隨著時間，再慢慢入侵到老的枯倒木的樹幹及樹枝區。台漫扁柏及闊葉樹種在倒木上的兢爭可能與苔蒸所提供的營養臥臨有關。由於此兩群植物在倒木上生辰位置及入侵時間的分化，故可以用生態棲位分配假貌(niche partition hypothesis)來解釋雨者在森林中的共存現象。
The importance of down logs in forest gaps for forest development, tree regeneration, and the co-existence of yellow cypress (Chamaecyparis obtusa Sieb. & Zucc. var. formosana (Hayata) Rehder) and broadleaf trees was studied in the temperate forest of Yuanyang Lake Nature Reserve (YYL), Taiwan. On nine down logs in a plot of 0.25-ha, seedlings with diameter at breast height larger than 1cm were recorded. It was found that the species occur- ring on the sampled down logs were the same as those in the studied area. Few broadleaf trees could reach the height of 10m necessary to change the current canopy layer, which mainly consisted of yellow cypress. Regeneration of trees on down logs was sufficient to maintain the forest community, including its floristic composition, canopy structure, and species diversity. Tree seedlings of different species also varied in their distribution patterns on down logs. Yellow cypress seeds germinated on new down logs, but not on root swellings. The seedlings grew to fill gaps, while density was reduced from young to old down logs, possibly due to intra-species competition. Epiphytic bryo-phytes on new down logs seemed to provide a suitable habitat for the germination of yellow cypress seeds. In contrast, broadleaf trees grew mainly on the base and root swellings of new down logs and gradually recruited their seedlings onto other parts of older down logs. Availability of nutrient resources seemed to be the important determi-nant for the competition between seedlings of cypress and broadleaf plants. The niche partition hypothesis was employed to explain the regeneration of cypress plants in this nature preserve.
關聯:
Botanical Bulletin of Academia Sinica ； 44卷3期 (2003 / 07 / 01) ， P229 - 238
