硬基质海堤对中国岩相潮间带生物地理格局影响机制的研究

With economic development and population increase, the demand for land is increasing world widely. Land reclamation is important for compensating for the shortage of lands in many countries, for example in Netherlands, Singapore, Japan and United Arab Emirates. Intensive land reclamation also occurs in China, especially in recent 100 years, and more and more hard-substrate defense structures appear in China coast with the expansion of land reclamation. The threats of sea levels rise, coastal erosion and flooding also lead to a growth demanding for the hard-substrate defense structures. Hard-substrate seawalls play important roles in species compositions and structure of rocky shore communities. Seawalls provide suitable habitats for rocky shore species and can provide stepping-stones facilities the spread of rocky shore species. With expansion of seawalls, the related ecological problems arise, including species invasion and distribution shift of marine organisms. In the scenario of climate change, the pole-ward shifts in geographic ranges of marine organisms can also affect the roles of hard-substrate seawalls as stepping-stones. The fauna and flora on the rocky shore along China mainland coast have clear biogeographic patterns and can be divided into two biotic regions, North Pacific Temperature Biotic Region, East Asia Warm-temperate Subregion and Indo-West Pacific Warm-water Biotic Region, China-Japan Subtropical Subregion. Previous phylogeographic studies also showed that there are distinct divergences between south and north groups in many rocky shore species. Ocean current, freshwater discharge, climate and historical events have significant impact on the biogeographic patterns of these species. Besides these factors, substrate is another crucial factor controlling the biogeographic patterns of rocky shores species. The expansion of seawalls provides suitable habitat for some rocky shores animals. Therefore, it is reasonable to assume that the biogeographic patterns of rocky shore species will experience dramatic transform under pressures from both climate change and human activity. In order to understand the impacts of hard-substrate seawalls on the rocky shore community along China coast, integrative studies, including field ecological survey, phylogeographic study and comparative physiological study, will be carried out in this project. The field ecological survey will be preceded in four consecutive years in the hard-substrate seawalls in Yangtze River Delta. The phylogeographic patterns of some rocky shore species (periwinkle and limpets) were studied in both seawalls and natural rocky shores using mitochondrial and nuclear DNA. The thermal limits and physiological plasticity of animals in different clades are also comparatively studied to investigate whether animals can occupy the new habitats or not. This project will be important to know the future biogeographic patterns of the rocky shore species along China coast.

随着滩涂围垦规模的扩大和海平面上升等威胁的增加，海岸防护工程的标准随之提高，使得石块和混凝土等材料在海堤建设中大量使用，硬基底人工岸线长度随之延长，这改变了滩涂景观结构，为岩相潮间带生物提供了栖息地，成为其分布区迁移的"阶梯"。本项目以查明硬基质人工海堤的修建对中国岩相潮间带生物地理格局的影响为目标，整合生态调查、系统地理学和比较生理学研究手段，系统分析人工海堤生物群落动态及其演替规律；测定具有不同地理分布的物种（群体）对环境温度耐受和生理调节能力的差异，对岩相潮间带群落的动态做出合理预测。本项目对于了解全球变化背景下我国岩相潮间带生物地理格局的变化具有重要意义，同时还可丰富景观生态学和生理生态学基础知识，并可为海岸防护工程生态效应的评估提供理论支持。

随着滩涂围垦规模的扩大和海平面上升等威胁的增加，海岸防护工程的标准随之提高，使得石块和混凝土等材料在海堤建设中大量使用，硬基底人工岸线长度随之延长，这改变了滩涂景观结构，为岩相潮间带生物提供了栖息地，成为其分布区迁移的“跳板”。本项目整合生态调查、系统地理学和比较生理学研究手段，系统分析人工海堤生物群落动态及其演替规律；测定具有不同地理分布的物种（群体）对环境温度耐受和生理调节能力的差异。5年生态调查的结果显示，人工海堤和自然岩相之间存在良好的种群联通性，大部分人工海堤群落的物种组成与南方自然岩相较为一致，物种多样性随着与自然岩相距离的增加而减少，且在人工海堤建成的10年内显著增加。表明在硬基质人工海堤提供合适的栖息地后，来自南方的自然岩相潮间带生物迅速建立种群，人工海堤成为潮间带生物分布区向北迁移的“跳板”。系统地理学的结果显示，我国岩相潮间带生物原本存在以长江口为中心的生物地理学和系统地理学隔离。对种群遗传结构分析表明，人工海堤上的多个物种的种群的遗传结构与南方自然岩相的较为相近，进一步证实人工海堤的修建打破了原本的隔离，改变了我国岩相潮间带生物的格局。通过比较生物学，探讨潮间带环境温度耐受和生理调节能力对其分布区的影响。多种潮间带生物的不同分布区的种群之间温度耐受阈值大都不存在显著差异，但分子调控机制存在显著差异。微环境和生理多态性，无氧呼吸能力以及生化适应机制都是潮间带贝类能够成功应对热胁迫，占领广大分布区的重要因素。本项目对于了解全球变化背景下我国岩相潮间带生物地理格局的变化具有重要意义，同时还可丰富景观生态学和生理生态学基础知识，并可为海岸防护工程生态效应的评估提供理论支持。在项目支持下，目前已发表SCI收录论文16篇；培养博士研究生6名，硕士研究生4名；邀请外国专家进行学术交流10人次；在厦门大学组织国际学术研讨会3次；参加国内外会议29次。