【作者】 刘颖；

【导师】 介冬梅；

【作者基本信息】 东北师范大学 ， 自然地理学， 2021， 硕士

【摘要】 辽东半岛位于东亚季风区北段,是气候变化和植被变化的敏感区域,定量地重建该区域的古植被演化历史对解译过去植被和气候变化均有重要意义。本文以植硅体为指标,通过分析211个木本单种样品(81个树叶样品、73个树枝样品、57个树皮样品),90个典型群落样品(30个草本层样品、30个枯枝落叶层样品、30个草本层和枯枝落叶层混合样品),84个典型群落对应的表土样品,119个泥炭剖面样品,开展了植硅体的来源、群落植硅体对植物分类、表土植硅体对植被类型判别、表土植硅体与群落盖度间数量关系等一系列植硅体现代过程研究,将研究成果应用于集安剖面,重建了该剖面自中晚全新世以来的古植被演化过程,并结合周围区域的古植被重建资料验证了应用植硅体在该区域开展古植被重建工作的适用性。本文得到如下结论:1.辽东半岛常见的木本植物中树枝和树皮均不产生植硅体,树叶主要产生表皮植硅体、导管型、硅化气孔等植硅体;利用群落植硅体组合能够将辽东半岛典型植物群落分为松栎林、麻栎林、杂木林,证明植硅体有能力对植物群落进行分类;通过对枯枝落叶层和草本层植硅体组合对比确定了仅产生于木本植物的植硅体及仅产生于草本植物的植硅体,利用这两类植硅体的比值,即W/G可以确定植物群落结构的变化。2.不同群落下表土中植硅体产量和表土植硅体组合均不相同,利用所有表土植硅体的组合构建的判别函数能够有效地将松栎林、麻栎林、杂木林进行区分,判别准确率达80%;Ic指数和Iw指数在三类群落中均具有显著性差异,在该区域内适用;基于WAPLS建立表土植硅体组合-群落盖度数量关系,预测植被盖度与实测植被盖度有显著的线性相关关系,证明这种数量关系可以有效地应用于古植被盖度重建工作。3.利用群落-表土植硅体对应关系重建了集安剖面自中晚全新世以来的植被面貌演化过程:4961-4187cal a BP,植被类型为杂木林,盖度较小,C3草本植物较C4草本植物更有优势,林草比较大;4187-2400cal a BP,植被类型为杂木林-松栎林的转变,证明该阶段内松科植物相对增加,盖度较大,C4草本植物较C3草本植物更有优势,林草比较小;2400-590cal a BP,植被类型以松栎林和麻栎林为主,盖度较小,C3草本植物较C4草本植物更加占优势,林草比相对较大。对比周围区域的古植被类型演化结果、古植被盖度重建结果、古温度重建结果及植被周期性演变规律均证明集安剖面植硅体-古植被重建结果是准确的,植硅体在辽东半岛进行古植被重建是适用的。更多还原

【Abstract】 The Liaodong Peninsula is located in the north of the East Asian monsoon region,which is sensitive to climate and vegetation change.It is of great significance to quantitatively reconstruct the evolution history of palaeovegetation in this region for interpreting the past vegetation and climate change.In this paper,based on phytolith we analyzed 211 woody species samples(81 leaf samples,73 branch samples,57 bark sampels),90 typical community samples(30 herbaceous layer samples,30 litter layer samples,and 30 mixed samples of herb layer and litter layer),84 corresponding topsoil samples under typical communities,and 119 profile samples.And a series of phytolith modern processes,such as phytolith source,plant classification level of community phytolith assemblage,identification of vegetation types by topsoil phytolith,the quantitative relationship between topsoil phytolith and community density,have been studied.Then the results studies were applied to Ji An profile to reconstruct the evolution of paleo-vegetation since the middle and late Holocene,and the applicability of phytolith in the reconstruction of paleovegetation in this area was verified by combining with the paleovegetation reconstruction data in the surrounding area.This paper draws the following conclusions:1.In the common woody plants of Liaodong Peninsula,neither branches nor barks produce phytoliths,but leaves mainly produce epidermal phytolith,tracheary,and stomate.The phytolith assemblage can divide the typical plant communities into Pinus-Quercus forest,Quercus acutissima forest and broad leaved forest,which proves that phytolith has the ability to classify the plant communities.By comparing phytolith assemblages in litter layer and herbaceous layer,phytolith assemblages produced only in woody plants and phytolith assemblages produced only in herbaceous plants were determined.Using the ratio of phytolith assemblages(W/G)of the two types,the change of plant community structure could be determined.2.The phytolith production and phytolith assemblage in topsoil were different in different communities.The discriminant function based on all topsoil phytolith assemblage could distinguish Pinus-Quercus forest,Quercus acutissima forest and broad leaved forest effectively,and the discriminant accuracy reached 80%.The Ic index and Iw index had significant differences among the three communities,which were relatively applicable in this region.Based on WA-PLS method,the quantitative relationship between topsoil phytolith assemblage and community density was established,and the predicted vegetation density had a significant linear correlation with the measured vegetation density,which could effectively reconstruct the density of palaeovegetation.3.Based on the correspondence between plant community and topsoil phytolith assemblage,the evolution process of Ji An profile since the middle and late Holocene was reconstructed as follows: 4961-4187 cal a BP,The vegetation type was broad leaved forest with low density,C3 herbaceous plants had more advantages than C4 herbaceous plants,and the ratio of woody and herbaceous plants was relatively large;4187-2400 cal a BP,the change of vegetation type from the broad leaved forest to the Pinus-Quercus forest proved that the number of coniferous plants was relatively increased in this stage,the density was larger,C4 herbaceous plants had more advantages than C3 herbaceous plants,and the ratio of woody and herbaceous plants was relatively small;2400-590 cal a BP,the vegetation types were mainly Pinus-Quercus forest and Quercus acutissima forest,with low density.C3 herbaceous plants were more dominant than C4 herbaceous plants,and the ratio of woody and herbaceous plants was relatively large.The comparison of the palaeovegetation types evolution results,the reconstruction results of palaeovegetation density,the reconstruction results of palaeotemperature and the periodic evolution of vegetation in the surrounding area all proves that the phytolith-palaeovegetation reconstruction results in Ji An section are accurate,and the phytolith-palaeovegetation reconstruction is suitable for the Liaodong Peninsula.更多还原