大瑶山国家级自然保护区中山针阔混交林的植物多样性

【目的】阐明中山针阔混交林群落的物种多样性形成机理、分异规律及维持机制。【方法】在全面踏查的基础上,通过建立12块20m×20m的调查样地,研究中山针阔混交林的植物群落组成、植物多样性及分异规律。【结果】银杉混交林共有植物56科76属94种,长苞铁杉混交林共有植物51科78属103种,广东五针松混交林有30科43属66种,小叶罗汉松混交林有29科38属49种。银杉混交林的针阔叶树优势种分别是银杉(Cathaya argyrophylla,重要值IV为34.86)、长苞铁杉(Tsuga longibracteata,47.70)、五列木(Pentaphylax euryoides,27.69)、信宜杜鹃(Rhododendron faithiae,18.07);长苞铁杉混交林相应为长苞铁杉(63.44)、五列木(51.03)、马蹄荷(Exbucklandia populnea,13.24);广东五针松混交林为广东五针松(Pinus kwangtungensis,43.19)、五列木(59.09)、大头茶(Polyspora axillaris,44.49)、马蹄荷(26.10);小叶罗汉松混交林为小叶罗汉松(Podocarpus wangii,58.22)、福建柏(Fokienia hodginsii,32.89),南华杜鹃(Rhododendron simiarum,66.31)。中山区4种混交林中乔木层的物种丰富度没有显著差异(P0.05),而灌木层和草本层的物种丰富度存在显著差异(P0.05),乔木层和灌木层的植物多样性指数无显著差异(P0.05);长苞铁杉混交林中草本层的物种多样性指数显著高于广东五针松混交林(P0.05);其它类型间差异不显著(P0.05)。【结论】中山区特殊的气候和土壤条件是针阔混交林形成的主要原因,而作为优势种的针阔叶树种的生态生物学特性是维持中山区针阔混交林物种多样性的关键。

Plant Species Diversity of Mixed Broadleaf-conifer Forest in Mid Mountain Region of Dayaoshan State Natural Reserve,Guangxi

Objective] Plant species diversity of mixed broadleaf-conifer forest in mid mountain region of Dayaoshan state natural reserve was studied in order to illustrate their forming mechanism, changing law and maintaining regimes.Methods] Twelve investigation plots (20 m×20 m) were established based on all-round survey to study the plant community composition, diversity and changing law of the mixed broadleaf-conifer forest in mid mountain region.Results] There were 94 species falling into 56 families and 76 genera in the Cathaya argyrophylla mixed forest, 103 species belonging to 51 families and 78 genera in the Tsuga longibracteata mixed forest, 66 species falling into 30 families and 43 genera in the Pinus kwangtungensis mixed forest, and 49 species falling into 29 families and 38 genera in the Podocarpus wangii mixed forest.The dominant species were Cathaya argyrophylla (IV:34.86), Tsuga longibracteata (47.70), Pentaphylax euryoides(27.69)and Rhododendron faithiae(18.07)in the Cathaya argyrophylla mixed forest; Tsuga longibracteata (63.44), Pentaphylax euryoides(51.03)and Exbucklandia populnea(13.24)in the Tsuga longibracteata mixed forest; Pinus kwangtungensis(43.19), Pentaphylax euryoides(59.09), Polyspora axillaris(44.49)and Exbucklandia populnea(26.10);Podocarpus wangii(58.22), Fokienia hodginsii(32.89)and Rhododendron simiarum(66.31)in the Podocarpus wangii mixed forest. There was no significant difference in species richness in the tree layers of the four mixed forests in mid mountain(P>0.05), however significant difference existed between the woody and herbaceous layer(P<0.05).There was on significant difference in plant diversity index in the tree and shrub layers(P>0.05).The species diversity index of herbaceous layer in Tsuga longibracteata mixed forest significantly higher than that in the Pinus kwangtungensis mixed forest (P<0.05), and there were no significant differences in the other forests(P>0.05).Conclusion] This study suggested that the special climate and soil condition are primary cause of the formation of mixed broadleaf-conifer forest in the mid mountain, while the ecological and biological characters of the main conifer and broad-leaf tree species are critical for the maintaining of the species diversity.