Li Nannan, Yu Fengling, Sack Dorothy, Huang Zhaoquan, Tian Ganghua, Liu Shengtao
State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, China.
Department of Geography, Ohio University, Athens, OH, United States.
Front Plant Sci. 2022 Jun 20;13:912627. doi: 10.3389/fpls.2022.912627. eCollection 2022.
This study investigates the reliability of phytolith assemblage analysis for characterizing subtropical vegetation and explores the potential for using these modern phytolith-vegetation relationships for paleoenvironmental interpretation in southeastern China. The samples were collected from five common subtropical vegetation communities in the Daiyun Mountains, southeastern China, with the above-ground vegetation recorded at each plot. Constrained ordination analysis was used to determine the most important factor governing the variations in phytolith assemblages that could be quantitatively reconstructed with weighted averaging partial least squares regression (WAPLS). The relationship between modern phytolith assemblages and the parent vegetation, as well as production, dispersal, and taphonomic processes, was discussed. Results demonstrated that the main subtropical biomes in southeastern China could be well distinguished by soil phytolith assemblages. In particular, the overall amount of tree coverage was well represented by topsoil phytolith assemblages. Grass silica short cell phytoliths (GSSCP) tended to occur in higher proportions in open habitats (shrub-meadow) at higher elevations, whereas non-grass phytolith morphotypes attained higher frequencies under mixed and broadleaf forests at lower elevations. Human-induced deforestation might increase the frequency of GSSCP within the bulk phytolith assemblage. Our results constitute the primary phytolith reference data for the subtropical zone in southeastern Asia where vegetation change during the Holocene period, particularly forest shifts, anthropogenic deforestation, and early agriculture are poorly documented.
本研究调查了植硅体组合分析在表征亚热带植被方面的可靠性，并探索利用这些现代植硅体与植被的关系对中国东南部进行古环境解释的潜力。样本采集自中国东南部戴云山脉的五个常见亚热带植被群落，每个样地都记录了地上植被情况。使用受限排序分析来确定控制植硅体组合变化的最重要因素，这些变化可以通过加权平均偏最小二乘回归（WAPLS）进行定量重建。讨论了现代植硅体组合与原始植被以及生产、扩散和埋藏过程之间的关系。结果表明，中国东南部主要的亚热带生物群落可以通过土壤植硅体组合得到很好的区分。特别是，表土植硅体组合能很好地反映树木覆盖的总体数量。草硅短细胞植硅体（GSSCP）在海拔较高的开阔生境（灌丛草甸）中往往占更高比例，而非草植硅体形态类型在海拔较低的混交林和阔叶林林下出现的频率更高。人为砍伐森林可能会增加整体植硅体组合中GSSCP的频率。我们的研究结果构成了东南亚亚热带地区的主要植硅体参考数据，该地区全新世期间的植被变化，特别是森林变迁、人为砍伐森林和早期农业活动，记录较少。
