Distribution Patterns in the Native Vascular Flora of Iceland

The aim of our study was to reveal biogeographical patterns in the native vascular flora of Iceland and to define ecological factors responsible for these patterns. We analysed dataset of more than 500,000 records containing information on the occurrence of vascular plants. Analysis of ecological factors included climatic (derived from WORLDCLIM data), topographic (calculated from digital elevation model) and geological (bedrock characteristics) variables. Spherical k-means clustering and principal component analysis were used to detect biogeographical patterns and to study the factors responsible for them. We defined 10 biotic elements exhibiting different biogeographical patterns. We showed that climatic (temperature-related) and topographic variables were the most important factors contributing to the spatial patterns within the Icelandic vascular flora and that these patterns are almost completely independent of edaphic factors (bedrock type). Our study is the first one to analyse the biogeographical differentiation of the native vascular flora of Iceland.

本研究旨在揭示冰岛本土维管植物区系（native vascular flora）的生物地理格局（biogeographical patterns），并明确驱动该格局形成的生态因子。本研究分析了包含逾50万条维管植物分布记录的数据集。生态因子分析涵盖气候变量（源自WORLDCLIM数据集）、地形变量（基于数字高程模型（Digital Elevation Model）计算得到）以及地质变量（基岩特征）。本研究采用球形k均值聚类（spherical k-means clustering）与主成分分析（Principal Component Analysis）两种方法，以识别生物地理格局并探究其驱动因子。本研究共界定出10类具有独特生物地理特征的生物区系组分（biotic elements）。研究结果表明，与温度相关的气候变量及地形变量是塑造冰岛维管植物区系空间格局的关键驱动因子，且该空间格局几乎完全不受土壤因子（edaphic factors，基岩类型）的影响。本研究是首例针对冰岛本土维管植物区系生物地理分化展开的系统性分析。