生物多样性 ›› 2008, Vol. 16 ›› Issue (3): 236-244.DOI: 10.3724/SP.J.1003.2008.07326

• 论文 • 上一篇    下一篇

深圳湾引种红树植物海桑的幼苗发生和扩散格局的生态响应

曾雪琴1,2,3, 陈鹭真1,3,4,*(), 谭凤仪3,5, 黄建辉1, 徐华林6, 林光辉1,4   

  1. 1 中国科学院植物研究所植被与环境变化国家重点实验室, 北京 100093
    2 中国科学院研究生院, 北京 100049
    3 深圳福田-城大红树林研发中心, 深圳 518040
    4 亚热带湿地生态系统研究教育部重点实验室/厦门大学生命科学学院, 厦门 361005
    5 香港城市大学生物及化学系, 香港
    6 广东内伶仃福田国家级自然保护区管理局, 深圳 518040
  • 收稿日期:2007-10-31 接受日期:2008-04-22 出版日期:2008-05-20 发布日期:2008-05-20
  • 通讯作者: 陈鹭真
  • 作者简介:*E-mail:luzhenchen@xmu.edu.cn
  • 基金资助:
    中国科学院“百人计划”资助项目;国家自然科学基金(30700092);中国博士后科学基金(20060400529)

Seedling emergence and dispersal pattern of the introduced Sonneratia caseolaris in Shenzhen Bay, China

Xueqin Zeng1,2,3, Luzhen Chen1,3,4,*(), Nora FungYee Tam3,5, Jianhui Huang1, Hualin Xu6, Guanghui Lin1,4   

  1. 1 State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093
    2 Graduate University of Chinese Academy of Sciences, Beijing 100049
    3 Futian-CityU Mangrove Research and Development Centre, Shenzhen 518040
    4 Key Laboratory for Subtropical Wetland Ecosystem Research, Ministry of Education / School of Life Sciences, Xiamen University, Xiamen 361005
    5 Department of Biology and Chemistry, City University of Hong Kong, Hong Kong SAR, China
    6 Administrative Bureau of Neilingding Futian National Nature Reserve, Shenzhen 518040
  • Received:2007-10-31 Accepted:2008-04-22 Online:2008-05-20 Published:2008-05-20
  • Contact: Luzhen Chen

摘要:

海桑(Sonneratia caseolaris)是我国华南沿海主要红树林造林树种, 在深圳湾引种造林15年后, 在天然红树林和光滩中出现了大面积的扩散。为了研究深圳湾红树植物海桑的幼苗扩散及其与生态因子的关系, 作者采用样线和样方调查法于2006年9月至2007年9月对深圳福田红树林内天然扩散的海桑幼苗的密度、高度和盖度及其相关生态因子(包括种间竞争、群落类型、光照、扩散距离与滩面高程)进行了6次调查。天然红树林和人工海桑林林下海桑幼苗密度在调查初期分别为24.7棵/m2和19.7棵/m2, 到2007年9月林下的一年生海桑幼苗全部死亡, 说明林下的弱光生境显著抑制了海桑幼苗的早期生长和自然更新。不同林型下(包括天然白骨壤林和秋茄林、人工海桑林)的海桑幼苗的密度、高度、盖度差异不显著(P>0.05); 而林中空地各指标显著高于林下(P<0.05)。虽然深圳福田红树林滩面高程介于1.12-2.10 m(黄海平均海平面)之间, 海桑幼苗自然扩散分布的最适滩面高程是1.40-1.60 m, 属于深圳湾红树林的中高潮滩, 但幼苗密度与滩面高程之间相关性较小。海桑具有一定的长距离扩散能力, 天然白骨壤林和秋茄林下海桑幼苗密度与其扩散距离(距最近母树的距离)之间呈显著负相关。天然白骨壤林和秋茄林下海桑幼苗密度与光照强度相关性不显著(P>0.05),而人工海桑林林下的海桑幼苗密度与光照强度呈显著正相关, 且相关系数逐次增大, 说明海桑幼苗的早期生长受到光照强度的影响极为显著。因此, 深圳湾引种海桑的繁殖体在天然白骨壤林和秋茄林下的扩散主要受与母树距离的影响, 但在海桑人工林下光照强度是影响幼苗分布的最重要生态因子。

关键词: 红树林, Sonneratia caseolaris, 幼苗扩散, 光照强度, 滩面高程, 扩散距离

Abstract

Due to its rapid growth,Sonneratia caseolaris, a mangrove species indigenous to Hainan, was introduced to Shenzhen Bay, Guangdong for afforestation purpose during the early 1990s. The seedling emergence, early growth and dispersal pattern of S. caseolaris and their responses to environmental factors have not been well studied in the new habitat. In this study, we evaluated the density, height and coverage of S. caseolaris seedlings underneath the canopies of various mangrove forests (including both natural Kandelia candel and Avicennia marina communities and introduced S. caseolariscommunities) and on the mudflats without canopy, in Futian Mangroves Natural Reserve of Shenzhen Bay from September 2006 to September 2007. Line intercept and square intercept methods were used in the survey. Tidal elevation, light intensity, community types and the distance between the sample squares and the nearest adult S. caseolaris were also recorded. The mean densities of S. caseolaris seedlings under the canopies of both the introduced and natural mangrove forests decreased from September 2006 (24.7 seedlings per m2and 19.7 seedlings per m2, respectively) to September 2007 (no seedlings survived). No significant differences were found in the seedling density, height or coverage of S. caseolaris among different mangrove communities. However, the density, height and coverage of S. caseolaris seedlings were significantly higher on the mudflats without canopy than under the mangrove canopies, indicating that higher light intensity in on the mudflats without canopy promoted the dispersal and vertical growth of S. caseolaris seedlings. Although the optimal tidal elevation for S. caseolaris seedlings in Shenzhen Bay was between 1.40 m and 1.60 m, an area that falls within the mid-to-high intertidal zones, seedling density and tidal elevation were weakly correlated. The seedling density under the native mangrove canopies was negatively related to dispersal distance. However seedling density were positively correlated with light intensity(P<0.05), and the correlation coefficients for the introducedS. caseolaris forest increased through time with successive surveys. In contrast, there was no significant correlation founded between seedling density and light intensity under native mangrove canopies. We concluded that distance to mother tree was the most important factor determining S. caseolaris seedling density under native mangrove canopies, whereas the light intensity was the most important environmental factor for controlling seedling dispersal pattern under the canopy of the introduced S. caseolaris forest.

Key words: mangroves, Sonneratia caseolaris, seedling dispersal, light intensity, elevation, dispersal distance