We sampled and analyzed surface sediments from 31 lakes along a latitudinal transect crossing the coniferous treeline on the Kola Peninsula, Russia. The major vegetation zones along the transect were tundra, birch-forest tundra, pine-forest tundra, and forest. The results indicate that the major vegetation types in our study area have distinct pollen spectra. Sum-of-squares cluster analysis and principal components analysis (PCA) groupings of pollen sites correspond to the major vegetation zones. PCA ordination of taxa indicates that the first axis separates taxa typical of the forest zone (Pinus, Picea) from taxa typical of tundra and forest-tundra zones (Polypodiaceae, Ericaceae, and Betula). The current position of the coniferous treeline, defined in our region by Pinus sylvestris, occurs roughly where Pinus pollen values reach 35% or greater. Arboreal pollen (AP)/non-arboreal pollen (NAP) ratios were calculated for each site and plotted against geographic distance along the transect. AP/NAP ratios of 7 or greater are found within pine-forest tundra and forest vegetation zones. Pinus stomates (dispersed stomatal guard cells) are absent from sites north of the coniferous treeline and all but two samples from the forested sites contain stomates. Stomate concentrations among the samples are highly variable and range from 10 to 458 per ml and positively correlate with the changing Pinus pollen values.

中文翻译：

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俄罗斯科拉半岛林线对面湖面沉积物中的现代花粉和气孔沉积

我们沿着穿越俄罗斯科拉半岛针叶林线的横断面对 31 个湖泊的表层沉积物进行了采样和分析。断面主要植被区为苔原、桦林苔原、松林苔原和森林。结果表明，我们研究区的主要植被类型具有不同的花粉光谱。花粉位点的平方和聚类分析和主成分分析 (PCA) 分组对应于主要植被区。分类群的 PCA 排序表明，第一个轴将典型的森林区（松、云杉）分类群与典型的苔原和森林-苔原区（Polypodiaceae、杜鹃花科和桦木）的分类群分开。在我们地区由樟子松定义的针叶树线的当前位置大致发生在松树花粉值达到 35% 或更高的位置。计算每个地点的树栖花粉 (AP)/非树栖花粉 (NAP) 比率，并绘制沿横断面的地理距离。在松林苔原和森林植被区中发现 AP/NAP 比率为 7 或更高。针叶树线以北的地点没有松树气孔（分散的气孔保卫细胞），除了两个森林样本外，所有样本都含有气孔。样品中的气孔浓度变化很大，范围为每毫升 10 到 458 个，并且与不断变化的松花粉值呈正相关。针叶树线以北的地点没有松树气孔（分散的气孔保卫细胞），除了两个来自森林地点的样本外，所有样本都包含气孔。样品中的气孔浓度变化很大，范围为每毫升 10 到 458 个，并且与不断变化的松花粉值呈正相关。针叶树线以北的地点没有松树气孔（分散的气孔保卫细胞），除了两个来自森林地点的样本外，所有样本都包含气孔。样品中的气孔浓度变化很大，范围为每毫升 10 到 458 个，并且与不断变化的松花粉值呈正相关。