Relation between modern pollen rain, vegetation and climate in northern China: Implications for quantitative vegetation reconstruction in a steppe environment
Relation between modern pollen rain, vegetation and climate in northern China: Implications for quantitative vegetation reconstruction in a steppe environment
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中国北方现代花粉雨、植被和气候之间的关系：对草原环境植被定量重建的启示
DOI：
10.1016/j.scitotenv.2017.02.027
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发表时间：
2017
影响因子：
9.8
通讯作者：
Wang Junting
中科院分区：
文献类型：
--
作者：
Ge Yawen;Li Yuecong;Bunting M. Jane;Li Bing;Li Zetao;Wang Junting
根据古生态记录重建植被依赖于对现代花粉、植被和气候之间关系的充分理解。定量植被重建的一个关键参数是相对花粉生产力（RPP）。已知环境和方法因素的差异会显著改变RPP估计值，因此很难确定潜在的花粉生产力是否实际上发生变化，如果是这样，为什么。本文介绍了2013年和2014年在中国北方典型草原区坝上草原区进行的重复研究结果。每年采集30个地表样本进行花粉分析，同时使用“Crackles遗赠项目”方法进行植被调查。这两年的抽样设计略有不同：2013年的抽样地点完全随机，而2014年的抽样地点被限制在距离道路几公里的范围内。有一个很强的年际变化的花粉和植被光谱，因此在RPPs，年降水量可能是一个关键的影响这些变化。两个年份的花粉组合均以蒿属、苋科、禾本科、菊科、莎草科、豆科和葱属等草本植物为主，蒿属和苋科花粉的代表性明显高于其他植物。禾本科，莎草科和豆科似乎有代表性不足的花粉与植被相应较低的RPPs。菊科似乎是很好的代表性，具有中等RPP和较少的年度变化。估计的花粉相关源区（RSAP）范围为2000 - 3000米。不同的抽样设计对RSAP和RPPs都有影响，随机抽样选择可能是获得稳健估计的最佳策略。研究结果对典型草原区和其他具有强烈年际变化的开放生境的花粉-植被关系和定量植被重建研究具有重要意义。
Vegetation reconstructions from palaeoecological records depend on adequate understanding of relationships between modern pollen, vegetation and climate. A key parameter for quantitative vegetation reconstructions is the Relative Pollen Productivity (RPP). Differences in both environmental and methodological factors are known to alter the RPP estimated significantly, making it difficult to determine whether the underlying pollen productivity does actually vary, and if so, why. In this paper, we present the results of a replication study for the Bashang steppe region, a typical steppe area in northern China, carried out in 2013 and 2014. In each year, 30 surface samples were collected for pollen analysis, with accompanying vegetation survey using the “Crackles Bequest Project” methodology. Sampling designs differed slightly between the two years: in 2013, sites were located completely randomly, whilst in 2014 sampling locations were constrained to be within a few km of roads. There is a strong inter-annual variability in both the pollen and the vegetation spectra therefore in RPPs, and annual precipitation may be a key influence on these variations. The pollen assemblages in both years are dominated by herbaceous taxa such asArtemisia, Amaranthaceae, Poaceae, Asteraceae, Cyperaceae, Fabaceae andAllium.Artemisiaand Amaranthaceae pollen are significantly over-represented for their vegetation abundance. Poaceae, Cyperaceae and Fabaceae seem to have under-represented pollen for vegetation with correspondingly lower RPPs. Asteraceae seems to be well-represented, with moderate RPPs and less annual variation. Estimated Relevant Source Area of Pollen (RSAP) ranges from 2000 to 3000 m. Different sampling designs have an effect both on RSAP and RPPs and random sample selection may be the best strategy for obtaining robust estimates. Our results have implications for further pollen-vegetation relationship and quantitative vegetation reconstruction research in typical steppe areas and in other open habitats with strong inter-annual variation.