(Fig. 3b) Spore and pollen frequency classes in sediment core Messel 2001@en

To detect significant quantitative changes within the palynomorph spectra, the percentage values of individual taxa or 'variables' were assigned to frequency classes to minimize the effect of minor fluctuations. These are probably due to regular variation in pollen precipitation and therefore do not reflect true changes in the frequency of the parent plants within the vegetation. Nevertheless, at the same time significant changes in the palynomorph spectra are preserved or even emphasized. Following Gauch (1982), 8 frequency classes - 0: 0%; 1: <0.5%; 2: <1%; 3: <2%; 4: <4%; 5: <8%; 6: <16%; 7: <32%; 8: >32% - were defined for the palynomorph percentages.为检测孢粉形态（palynomorph）谱内的显著数量变化，我们将单个分类群（taxa）或‘变量’的百分比值划分为频次等级，以最小化微小波动的影响。这类波动大概率源于花粉沉降的周期性变化，并非反映植被中母本植物频率的真实改变。然而在此过程中，孢粉形态谱内的显著变化非但得以保留，甚至会被进一步凸显。参考Gauch（1982）的研究方法，我们为孢粉百分比设定了8个频次等级：0：0%；1：<0.5%；2：<1%；3：<2%；4：<4%；5：<8%；6：<16%；7：<32%；8：>32%。