Differences in Seedling and Sapling Densities and Species Composition between Canopy Gaps and Forest Understories in a Subtropical Forest in Bangladesh  

孟加拉国亚热带森林中林冠间隙与林下层之间幼苗和幼树密度及物种组成的差异

作　　者：Tarit Kumar BAUL Anwarul Islam CHOWDHURY Md Jamal UDDIN Mohammad Kamrul HASAN Tapan Kumar NATH Lars Holger SCHMIDT Tarit Kumar BAUL;Anwarul Islam CHOWDHURY;Md Jamal UDDIN;Mohammad Kamrul HASAN;Tapan Kumar NATH;Lars Holger SCHMIDT(吉大港大学林业与环境科学研究所,孟加拉国吉大港4331;东部大学(UEF)林业学院科学,林业与技术部,芬兰约恩苏80101;莱里达大学农业与林业科学与工程学院,西班牙莱里达25001;自然资源研究所(Luke),芬兰赫尔辛基00790;诺丁汉大学科学与工程学院,马来西亚布罗加街43500;哥本哈根大学地球科学与自然资源管理系,丹麦腓特烈堡C1958)

机构地区：[1]Institute of Forestry and Environmental Sciences,University of Chittagong,Chittagong 4331,Bangladesh [2]Faculty of Science,Forestry and Technology,School of Forest Sciences,University of Eastern Finland,Joensuu 80101,Finland [3]Department of Agricultural and Forest Sciences and Engineering,University of Lleida,Lleida 25001,Spain [4]Natural Resources Institute Finland(Luke),Helsinki 00790,Finland [5]Faculty of Science and Engineering,University of Nottingham Malaysia,Jalan Broga 43500,Malaysia [6]Department of Geoscience and Natural Resource Management,University of Copenhagen,Frederiksberg C 1958,Denmark

出　　处：《Journal of Resources and Ecology》2025年第1期105-114,共10页资源与生态学报(英文版)

摘　　要：Canopy openings have a vital role in forest structure,regeneration,and plant composition.In this study,we investigated and compared the species composition and densities of seedlings and saplings between canopy gaps(openings)and forest understories(in dense canopies)in a sub-tropical forest of Bangladesh.We objectively identified 42 canopy openings between transect lines and 42 main plots in dense canopies,sampled for regeneration and young tree patterns.For the regeneration study,we placed 2 m×2 m four subplots in each canopy opening and the main plot of dense canopy,thus making a total of 336 subplots.The species diversity of seedlings,saplings,and trees were significantly(P≤0.05)higher in the dense canopy than in the canopy opening.Although,most dominant and frequent regenerating species such as Diospyros pilosula,Garcinia cowa,Brownlowia elata,and Lithocarpus polystachya were common in both dense canopy and openings,the canopy openings had the highest Importance Value Index,suggesting the significance of gap dynamics in the dominance of native floral species.The dense canopy played an important role in forest compositions because 12 regenerating species,including Stereospermum suaveolens and Diospyros montana,were not found in the canopy openings,implying that rain forests must maintain a high canopy cover for regeneration.林冠空隙对森林结构、更新和植物组成具有重要作用。本研究选择了42个林冠开口和42个密集林冠的主样地,调查并比较了孟加拉国亚热带森林中林冠空隙(开口)和林下层(密集林冠下)之间的物种组成和幼苗及幼树的密度。在更新研究中,在每个林冠开口和密集林冠的主样地中放置了2 m×2 m四个子样地,总共有336个子样地。幼苗、幼树和树木的物种多样性在密集林冠中显著(P≤0.05)高于林冠开口。尽管大多数优势和频繁再生的物种,如毛柿、加尔西牛、布朗洛瓦和多毛石栎在密集林冠和开口中都很常见,但林冠开口具有最高的重要值指数,表明间隙动态在本地植物物种优势中的重要性。密集林冠在森林组成中起到了非常重要的作用,在林冠开口中未发现包括斯氏木和蒙大拿柿在内的12个再生物种,表明雨林必须保持高林冠覆盖以进行更新。

关 键 词：canopy opening disturbance forest dynamics native flora SEEDLING SAPLING 

分 类 号：S718.5[农业科学—林学]