Abstract To examine the relationship between plant presence and pollen presence, modern pollen samples were collected and counted from natural moss polsters in the UK uplands. The herbaceous pollen signal is difficult to interpret in paleoecological analysis as pollen presence is often rare for individual herb taxa. Indices of association have previously been used to determine association from over- and under-representation; however, previous surveys have used spatially limited single-source areas. Indices of Association (IOA) between pollen and plant presence at increasing distance from the pollen source, to 50 m, are presented in a new spatially extended IOA (SEIOA) method. For several pollen taxa, including Plantago lanceolata, Ranunculus acris-type, Rumex and the Cichorioideae family, association increased progressively, when plants at greater distance were included in the calculation, and over-representation was reduced. Other taxa become increasingly under-represented at the landscape scale, e.g., Filipendula, Apiaceae, Cerastium indicating true ultra-local source areas. A weak association and increasing under-representation indices, cautions that pollen absence of these types in paleoecological analysis is not a secure indicator of plant absence. Extended IOA values can aid the interpretation of the rare-type pollen spectra in paleoecological analyses. The method shows potential for developing individual pollen source areas (iPSAs) for herbaceous pollen types. These iPSAs together with the probability of correct application, determined by accuracy and association scores, are useful when applying pollen correction factors in pollen-derived vegetation community and landscape models. Further indices and significance testing are suggested to enhance understanding of the association and the rate of correct classification. The results can assist both interpretation of community composition from the herbaceous pollen spectra in local-scale paleoecological studies, and understanding the limits to this interpretation in paleoecological analysis.

中文翻译：

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古生态重建中草本花粉光谱的解释：关联指数的空间扩展和从二进制数据确定单个花粉源区

摘要 为了检查植物存在与花粉存在之间的关系，从英国高地的天然苔藓植物中收集和计数现代花粉样本。在古生态分析中很难解释草本花粉信号，因为单个草本分类群的花粉存在通常很少见。关联指数以前曾被用来确定与过度和代表性不足的关联；然而，以前的调查使用了空间有限的单一来源区域。在距离花粉源增加到 50 m 的距离处，花粉和植物存在之间的关联指数 (IOA) 以一种新的空间扩展 IOA (SEIOA) 方法呈现。对于几种花粉类群，包括车前草、毛茛类、Rumex 和 Cichorioideae 科，关联逐渐增加，当更远距离的植物被包括在计算中时，过度代表就会减少。其他分类群在景观尺度上的代表性越来越低，例如，Filipendula、伞形科、Cerastium 表明真正的超本地源区。弱关联和增加的代表性不足指数提醒说，古生态分析中这些类型的花粉的缺失并不是植物缺失的可靠指标。扩展的 IOA 值有助于解释古生态分析中的稀有型花粉光谱。该方法显示了为草本花粉类型开发单个花粉源区 (iPSA) 的潜力。这些 iPSA 连同正确应用的概率，由准确性和关联分数决定，在花粉衍生的植被群落和景观模型中应用花粉校正因子时非常有用。建议进一步的指标和显着性测试，以增强对关联和正确分类率的理解。结果有助于在局部尺度古生态研究中从草本花粉光谱解释群落组成，并了解在古生态分析中这种解释的局限性。