刘利丹^1,,
介冬梅^2,3,4,5,,,
刘洪妍⁶,
高桂在^2,3,4,5,
李德晖^2,3,4,5,
李楠楠^2,3,4,5
1. 湖南师范大学资源与环境科学学院, 湖南 长沙 410001
2. 长白山地理过程与生态安全教育部重点实验室, 吉林 长春 130024
3. 东北师范大学泥炭沼泽研究所和环境保护湿地生态与植被恢复重点实验室, 吉林 长春 130024
4. 植被生态科学教育部重点实验室, 吉林 长春 130024
5. 东北师范大学地理科学学院, 吉林 长春 130024
6. 安阳师范学院资源环境与旅游学院, 河南 安阳 455000

基金项目: 国家自然科学基金项目(批准号:41901097、41771214、41971100和41471164)、湖南省自然科学基金青年项目(批准号:2019JJ50371)、湖南省教育厅科学研究项目(优秀青年项目)(批准号:18B029)和湖南省地理学一流学科建设项目共同资助


详细信息

作者简介: 刘利丹, 女, 31岁, 讲师, 自然地理学专业, E-mail:liulidan@hunnu.edu.cn

通讯作者: 介冬梅, E-mail:jiedongmei@nenu.edu.cn

中图分类号: P92;949.71⁺4.2;Q948.3

收稿日期:2019-12-17
修回日期:2020-03-15
刊出日期:2020-09-30

Representativeness of soil phytoliths for plant communities in the forest and grassland regions of Northeast China

Liu Lidan^1,,
Jie Dongmei^2,3,4,5,,,
Liu Hongyan⁶,
Gao Guizai^2,3,4,5,
Li Dehui^2,3,4,5,
Li Nannan^2,3,4,5
1. College of Resources and Environmental Science, Hunan Normal University, Changsha 410001, Hunan
2. Key Laboratory of Geographical Processes and Ecological Security in Changbai Mountains, Ministry of Education, Changchun 130024, Jilin
3. Institute for Peat and Mire Research, State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, Changchun 130024, Jilin
4. Key Laboratory of Vegetation Ecology, Ministry of Education, Changchun 130024, Jilin
5. School of Geographic Sciences, Northeast Normal University, Changchun 130024, Jilin
6. School of Resources Environment & Tourism, Anyang Normal University, Anyang 455000, Henan


More Information

Corresponding author: Jie Dongmei,E-mail:jiedongmei@nenu.edu.cn

MSC: P92;949.71⁺4.2;Q948.3

--> Received Date: 17 December 2019
Revised Date: 15 March 2020
Publish Date: 30 September 2020


摘要
摘要:文章系统研究了东北地区东部森林区和西部草原区41个样点表土植硅体及相应植物群落植硅体的关系，并据此定量校正了表土植硅体与植被、气候的数量关系。结果表明，不同植物群落下表土植硅体的组合特征与其地上植物群落间存在密切关联，依据表土植硅体可明显区分森林区木本群落和草原区草本群落。但表土中不同植硅体类型对地上植物群落的代表性不同。表土中帽型、哑铃型、尖型、扁平状、块状和扇型的含量高估了其在对应植物群落中的含量，在土壤中保存较好；毛发状、硅质突起型、硅化气孔、表皮植硅体对植物群落的代表性刚好与此相反；鞍型、齿型和棒型能够较准确地反映地上植物群落的信息，在土壤中保存较好。同时，东部森林区和西部草原区不同植物群落下表土中同一植硅体类型对地上植物群落的代表性也有所差别。东部森林区表土中帽型的含量高估了其在对应群落中的含量，棒型、块状和扇型可准确指示地上植物群落的信息，但西部草原区却与此刚好相反。基于此，依据植硅体的R值（表土植硅体含量与地上植物群落植硅体含量之比）校正了表土植硅体的含量，校正后的表土植硅体特征和干旱指数对地上植物群落特征和区域降水的响应更为敏感，表土植硅体组合特征能够更好地指示地上植物群落和气候信息的变化。因此，利用植硅体记录重建古植被、古气候时，需参考表土植硅体对地上植物群落的代表性校正沉积物植硅体，以提高植硅体-古环境重建的精度。
关键词: 植硅体/
代表性/
校正/
古气候/
东北地区

Abstract:Phytolith records have provided a new perspective on the reconstruction and interpretation of palaeovegetation and paleoclimate. However, the reliability of soil phytoliths for representing phytolith assemblages from archaeological and palaeoecological contexts has not been fully determined, and it needs to be assessed and calibrated before they can be used in palaeoecological contexts.
In this study, we collected plant samples and topsoil samples from a total of 41 sites in Northeast China (39°40'~53°30'N, 115°05'~135°02'E), representing 13 sites in woody communities and 28 sites in herbaceous communities. A total of 93 topsoil samples (including dark brown soil, chernozem, chestnut soil, meadow soil, eolian sandy soil, wetland soil, alluvial soil, and albic soil) and 93 community samples were sampled, respectively. The NE China is influenced by the East Asian monsoon and has four distinct seasons, with a long winter and a short summer. The annual average temperature ranges from-5℃ to 10℃. The temperature in January and July ranges from-24℃ to 9℃ and from 21~26℃, respectively. The average annual precipitation ranges from 400~1000 mm and is concentrated in summer and autumn.
Phytoliths were extracted using the wet ashing method and heavy liquid flotation. At least 300 phytolith grains were counted for each sample. Correlation coefficient (C) and Similarity coefficient (CC) were calculated to assess the similarity between phytoliths from soil samples and community samples. R-values were also calculated to assess the soil phytolith preservation, using the percentage of each morphotype for all of the grassland or forested samples, respectively. Then principal components analysis (PCA) and discriminant analysis (DA), implemented with Canoco 4.5, were used to determine the morphotype associations in grassland and forested region respectively. Correlation analysis was used to assess the correlation between Iph values and the mean annual precipitation (MAP).
The phytolith morphotypes extracted from community samples and corresponding topsoil samples in NE China are various and could be divided into seven categories according to anatomical items:short cell (rondel, saddle, bilobate, cross, cylindrical polylobate, trapeziform sinuate), elongate, lanceolate, blocky, bulliform, tabular, epidermal phytolith, stomata, tracheid, and others. And there is a reasonable correspondence between phytolith morphotypes from topsoils and those from the corresponding plant communities. In the grassland and forested region, the CC-values all exceeded 56%, and the C-values of different phytolith morphotypes all exceeded 36%. Principal components analysis (PCA) and discriminant analysis (DA) further confirm the correlation between phytolith morphotypes from topsoils and those from the corresponding plant communities. Topsoil phytolith assemblages could reliably differentiate samples from herbaceous and woody communities. Additionally, there is slight difference on the topsoil phytolith morphotypes between grassland and forested region. All the phytolith morphotypes, except for margin scuniform, blocky scrobiculate and blocky ridged, occur in both forested and grassland regions.
Notably, different phytolith morphotypes exhibit varying degrees of representational bias in terms of the aboveground plant community. Some morphotypes (e.g. rondel, bilobate, lanceolate, blocky, tabular and bulliform) with R-values greater than six over-represent the abundance of the associated plant taxa; morphotypes such as microhair, conical epidermal, silicified stomata and epidermal phytoliths with R-values less than one under-represent the parent plant abundance; and other morphotypes (e.g. saddle, trapeziform sinuate and elongate) are in good agreement with the numbers of individual plant taxa, with R-values varying from 1 to 4. Additionally, the representational bias of some phytolith types, such as rondel, elongate, blocky and bulliform, for reflecting the aboveground plant communities differed between the woody community and herbaceous communities. Specifically, in the woody communities, rondel in topsoil over-represented the numbers of individuals of the corresponding plant taxa; whereas elongate, blocky and bulliform could well represent the aboveground communities. However, the reverse has taken place in the herbaceous communities.
Based on R value, soil phytolith indices with known vegetation compositions and precipitation change was calibrated, and the corrected phytolith contents of the herbaceous plants from most sites are greater than 10% in grassland samples and but remain less than 6% in the forest samples. The corrected Iph values of grassland samples are higher than those of forest samples, and the corrected Iph values of grassland samples from most sites are greater than 0.45 in grassland samples and but remain less than 0.45 in the forest samples. And Iph values between 40% and 45% tend to correspond to grassland. Thus the frequencies of corrected soil phytolith indices are moderately consistent with actual plant richness and climatic changes. Overall, our findings provide new perspectives on the reliability of phytoliths for reconstructing climatic changes in the northern temperate region.
Key words:soil phytoliths/
representativeness/
calibration/
paleoclimate/
Northeast China



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