华南潮间带矮大叶藻海草的生长动态研究
文献类型：学位论文
| 作者 | 邱广龙 |
| 学位类别 | 博士 |
| 答辩日期 | 2015-05 |
| 授予单位 | 中国科学院研究生院 |
| 授予地点 | 北京 |
| 导师 | 刘国华 |
| 关键词 | 海草斑块，无性系，叶绿素荧光，群落结构动态，海草生产力，深度 梯度，seagrass patch, clone, chlorophyll fluorescence, community structure dynamics, seagrass producitivity, depth gradient |
| 其他题名 | Growth dynamics of seagrass Zostera japonica in the intertidal zone of Southern China |
| 学位专业 | 生态学 |
| 中文摘要 | 海草床的保护和恢复是近年来国际上开始关注的问题，探讨海草的生长动态规律和主要影响因素，是进行海草生境有效保护和管理的关键。矮大叶藻（Zostera japonica Aschers & Graebner）是中国唯一同时在温带和亚热带都有分布的海草种类，是中国沿海最主要的海草种类之一。当前，我国的矮大叶藻资源正面临着快速衰退的困境。为了充分了解潮间带海草矮大叶藻在重直分布上不同时间尺度的生长动态差异，辨析控制矮大叶藻海草生态动态的主导因素，本文以广西珍珠湾交东海草场为研究样地，在三个不同高程布设不同类型的研究样地（围隔天然海草斑块、开放天然海草斑块以及移植形成的海草斑块），从2010 年10 月至2013 年10 月，开展了每月调查。本文主要研究内容包括：①不同季节、不同潮区、斑块内部不同位置矮大叶藻无性系结构特征的差异；②不同季节、不同潮区、斑块内部不同位置的矮大叶藻生产力；③不同季节、不同潮区的矮大叶藻叶绿素荧光光合特征；④不同季节、不同潮区的矮大叶藻海草群落结构；⑤相关的环境因素。 主要结果和结论如下： （1）研究区不同季节、不同潮区的海草生产力有显著差异。控制研究区矮大叶藻海草生产力的主要因素有光照、温度和风速。然而，不同植物性状对相同的环境因素的响应差别较大。另外，潮汐通过改变研究区的温度、光照、水动力而对海草的生产力产生影响，是矮大叶藻植物个体生长动态重要的间接影响因素。 （2）研究区矮大叶藻海草的全年平均生产力为1.05±0.06 g/m2·d（即383g/m2·y）。由于采样目标的选择、研究方法的限制、以及未能对源于高温灼伤、动物采食或机械损伤造成的生产量丧失的定量估算，造成了生产力估算的结果的偏低。依照方法差异对结果进行修正，研究区矮大叶藻的生产力应大于1.60g/m2·d（即584 g/m2·y）。 （3）无论是潮区间、季节间、或是年际间，研究区矮大叶藻海草的多项群落结构性状均表现出明显的差异。但在不同的潮区，影响海草群落结构动态的主要因素也不一样。在高潮区，温度是影响研究区矮大叶藻群落结构动态的主要影响因子；在中潮区，光照是影响群落结构动态的主要影响因子；而在低潮区，风速（水动力）是影响群落结构动态的重要因子。但无论在哪个潮区，温度始终对叶宽有显著的正相关影响。 （4）位于海草斑块内部的海草通常比斑块边缘的海草有更长的叶片和根状茎节间，同时也有更高的生产力、叶片产量和根状茎伸长率。 （5）个体水平与群落水平的植物性状相对于同一环境因素并不总是表现出一致的响应，主要原因为：a）采样的对象不一样。个体水平的研究对象都是处于根状茎末端、“较新”的植物片断；而群落水平的研究对象是海草斑块中随机选择的植物部分，即有可能包括了海草植物无性系中“较老”的部分，也可能包括“较新”的部分。b）只有群落水平才表现出的“涌现特征(emergent properties)”，即个体之间通过非线性的相互作用所形成的特征。 （6）台风/暴风潮的袭击很可能是华南潮间带海草面积大规模快速减少（或海草场的快速消失）的主要原因。而人为的物理干扰并非研究区海草群落结构动态的主导因素。 （7）在高潮区，最大光照和叶长为负相关关系，表明在高潮区海草容易出 现光抑制或高强光照对植物叶片造成了伤害；在中潮区，光照和叶长没有显著相关性；然而在低潮区，平均光照和叶长变为了正相关，表明在低潮区，光照成为了叶片生长重要的限制因子。 （8）太阳黑子的数量和高潮区诸多海草植物性状有显著相关性，具体机理有待进一步探讨。例如，太阳黑子数据和海草覆盖度、叶面积、叶片生物量、叶鞘生物量、地上生物量、叶长、叶宽、总生物量以及地上/地下生物比值等都有显著的相关性。 本研究展示了潮间带海草生长的高度动态性，表明了在没有任何人为物理干扰下海草斑块的动态变化以及快速消失。研究强调了潮间带海草自然生长的波动性、光照的重要性，以及台风暴潮在迅速改变海草生境中的可能影响，为华南潮间带海草的保护与管理提供了重要的科学依据。 |
| 英文摘要 | The conservation and restoration of seagrass bed are getting more and more attentions globally, and to understand the growth dynamics of seagrasses and their influential factors is essential for effective conservation and management of seagrass habitats. Zostera japonica Aschers & Graebner is among the main seagrass species found along China coastline and found to occur in both temperate and subtropical regions of China, but is currently in a bad situation of rapid degradation. Growth dynamics of Z. japonica at different vertical distribution were explored at different temporal scale to discover the factors that regulate the growth dynamics of the seagrass by monitoring the seagrasses in three kinds of monitoring plots(i.e. protective natural plots (natural seagrasses which are free of human’s physical disturbances), open natural plots (natural seagrasses exposed to anthropogenic physical disturbances, e.g. digging for clam harvest), and protective transplanting plots (transplanted seagrasses under protection from human’s physical disturbances)) which have been deployed at upper zone, middle zone and lower zone in Jiaodong seagrass meadow, Pearl Bay, Guangxi,. Monthly surveys were carried out from Oct 2010 to Oct 2013, focusing on: ① clone architectural features of Z. japonica at different elevations, seasons and locations within the patch; ②productivities of Z. japonica at different elevations, seasons, and locations within the patch; ③ chlorophyll fluorescence characteristics of Z. japonica leaves at different elevations and seasons;④community structural variations at different elevations, seasons and years; and ⑤relevant environmental factors (light, temperature, etc.) The primary results and conclusions are as follows: (1) There were significantly differences between seasons and zones for productivity of Z. japonica in Jiaodong seagrass meadow, and the primary factors affecting seagrass productivities in the research sites were temperature, available light and wind speed. However, the responses of seagrass plant to same environmental factors were greatly different and depending on the community features as well as the depths in which seagrasses inhabited. Tide posed impacts on seagrasses’ production via altering the ambient temperature, available light and hydrodynamic force. Therefore it should be treated as a significant indirect factor affecting seagrass productivity in the study area. (2) Average productivity of Z. japonica in Jiaodong, Guangxi was 1.05±0.06 g/m2·d (i.e, 383 g/m2·y). It is believed that the productivity of seagrass was underestimated because of: a) the inappropriate selection of targeted sampling-plants, b) the limitation of adopted-methods, and c) without a quantitative assessment on the loss of production caused by herbivory and physical damage. Based on the quantitative differences between research methods, the productivity of Z. japonica in Jiaodong meadow was revised to >1.60 g/m2·d (584 g/m2·y). (3) Changes in clone architectural features (e.g. rhizome internodal length, rhizome diameter, leaf length, sheath length, shoot weight, etc.) and dynamics properties (e.g. rhizome horizontal elongation rate, leaf production rate, lateral branching rate, etc.) of Z. japonica at different tidal zones were obvious in temporal and spatial scale. Influential factors of seagrass community structure dynamics differ in different tidal zones. Temperature, light and hydrodynamic force were major influential factors at the upper zone, middle zone, and lower zone respectively. Temperature was found to be significantly correlated with leaf width of seagrasses in all tidal zones. (4) Generally, seagrasses at the inner parts of seagrass patches had longer leaf and sheath, and also larger productivity, leaf yield and rhizome horizontal elongation rate than seagrasses at the margin of the patches. (5) Responses of plant traits to the same environmental factors were not always consistent at clone level and community level. The reasons were as follows: a) the target samples selected for productivity experiments and analysis of clone architectural features were relatively ‘new’ ramets close to the apical meristem. Samples for study of community structure were randomly-selected regardless of the plants were ‘new’ or ‘old’. b) Some ‘emergent properties’ only appeared at community level (nonlinear interactions among seagrass ramets) and didn’t exist in separated seagrass individuals. (6) Typhoon/storm was probably the major cause for abrut degradation of intertidal seagrasses in Southern China at large scale. It is also concluded that dynamics of seagrass communities in the Jiaodong seagrass meadow were not induced by human physical disturbance. (7) The maximum light was negatively correlated with leaf length at the upper zone, indicating that photoinhibitions might occur or strong light might damage seagrass leaf blades at the upper zone. There was no significant correlation between light irradiation and leaf length at the middle zone. In contrast, mean light irradiation was positively significant correlated with leaf length at the lower zone, implying light might be a limiting factor of leaf growth at deeper water. (8) Sunspot amounts were significantly correlated with some plant traits such as seagrass cover, leaf area, leaf biomass, sheath biomass, above-ground biomass, leaf length, leaf width, total biomass and the ratio of above-ground:below-ground biomass of seagrass at the upper zone. However, the mechanisms behind these phenomena remain unknown and require further study. The present research demonstrated the highly dynamics of growth in the intertidal seagrasses, and illustrated the variations and abrupt disappearance of intertidal seagrasses in southern China without any anthropogenic physical disturbance. This study also highlighted the marked temporal and spatial variations of growth in the intertidal seagrasses, the significance of light in seagrass growth and influence of typhoon/storm in rapidly shaping intertidal seagrass community. In conclusion, this study can provide valuable and essential scientific data for the smart conservation and effective administration of intertidal seagrass habitats in Southern China. |
| 源URL | [http://ir.rcees.ac.cn/handle/311016/34363]  |
| 专题 | 生态环境研究中心_城市与区域生态国家重点实验室 |
| 推荐引用方式 GB/T 7714 | 邱广龙. 华南潮间带矮大叶藻海草的生长动态研究[D]. 北京. 中国科学院研究生院. 2015. |
入库方式： OAI收割
来源：生态环境研究中心
浏览0
下载0
收藏0
其他版本
除非特别说明，本系统中所有内容都受版权保护，并保留所有权利。