摘要
对植被历史变化过程的研究是理解现代植被组成、分布及其对全球变化响应的基础。近年来,随着分子古生态学的发展,分析沉积介质中的陆生植物古DNA信号,以研究植被及植物多样性演变的历史过程正在成为研究热点,湖泊沉积植物古DNA已成为古植被和古生态学研究的成熟代用指标。然而与第四纪孢粉分析相比较,湖泊沉积植物古DNA的现代过程依然不明确,成为其进一步发展和应用的限制因素。基于此,该文综述了湖泊沉积植物古DNA技术研究进展,尝试阐明湖泊沉积植物古DNA的现代过程,包括植物DNA的来源、沉积和保存过程及其影响因素,以及植物DNA与现代植被的关系等。已有研究表明,湖泊沉积植物古DNA主要来自湖泊周边或流域范围,其丰度和组成除受到源植物生物量的影响外,同样受到沉积物的搬运和沉积过程中DNA降解作用、土壤以及沉积物中颗粒的吸附过程和稀释作用等因素的影响。湖泊沉积物中植物DNA的保存则主要受到微生物活动、湖水的化学性质(电导率和pH值)、湖泊深度、沉积物组成等一系列生物与非生物因素的共同影响。湖泊沉积植物古DNA可以揭示其沉积时代的植物群落类型以及气候环境信息,但目前并不能够用来定量重建古植被变化过程。鉴于湖泊沉积植物古DNA现代过程的复杂性,对研究结果的解释要格外小心。与孢粉分析相比,湖泊沉积植物古DNA研究仍处于起步阶段,但随着分子生物技术的进步、实验设计的优化、物种条形码的扩充及参考数据库的完善等,以DNA宏条形码和宏基因组学为主要技术手段的植物古DNA技术,必将推动我国植物古生态研究的进一步发展。
Study on paleovegetation is with great significance on understanding the modern vegetation composition,distribution, and its responses to global change. During recent decades, it has been a rapidly developing field in molecular palaeoecology to track the long-term vegetation composition and plant diversity changes by using sedimentary ancient DNA. Meanwhile, the lacustrine sedimentary ancient plant DNA(PsedaDNA) is becoming a popular proxy for palaeovegetation and palaeoecological studies. However, the modern process of PsedaDNA remains unclear compared with pollen analysis, which limits its further application. Here, we reviewed the PsedaDNA researches and tried to elucidate the modern processes of PsedaDNA, including the source, deposition,and preservation processes, and to understand the relationships between the PsedaDNA and modern vegetation.Pseda DNA is mainly derived from the lake surroundings or within the catchment. The abundance and composition of PsedaDNA are influenced by the biomass of terrestrial plants, and factors such as DNA degradation, the adsorption, and dilution of particles in soils and sediments during the transportation and deposition. Moreover, the preservation of PsedaDNA is largely affected by both biotic and abiotic factors, including the microbial activity,chemical properties of lake water(conductivity and pH), and sediment composition. PsedaDNA can be used to reveal the contemporary vegetation and climate information but was incompetent to quantitatively palaeovegetation reconstruction. Considering the complexity of modern processes, the interpretation of PsedaDNA results should be done with extra caution. To sum up, PsedaDNA is still in its infancy, which has been benefiting from the progress of molecular biotechnology, optimization of experimental design, species barcodes, and sophistication of reference databases. The Pseda DNA technique including DNA metabarcoding and metagenomics will certainly promote the development of Chinese palaeophytoecology research.
作者
吴铠
李凯
贾伟瀚
廖梦娜
倪健
WU Kai;LI Kai;JIA Wei-Han;LIAO Meng-Na;NI Jian(College of Chemistry and Life Sciences,Zhejiang Normal University,Jinhua,Zhejiang 321004,China;Polar Terrestrial Environmental Systems Research Group,Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research,Potsdam 14473,Germany;Institute of Environmental Science and Geography,University of Potsdam,Potsdam 14476,Germany)
出处
《植物生态学报》
CAS
CSCD
北大核心
2022年第7期735-752,共18页
Chinese Journal of Plant Ecology
基金
国家自然科学基金(42177433)
浙江省自然科学基金(LY20D010002)。
关键词
湖泊沉积
植物古DNA
埋藏学
植被代表性
古植被
古生态学
lake sedimentation
ancient plant DNA
taphonomy
vegetation representativeness
palaeovegetation
palaeoecology
