Phylogenetic measures of biodiversity uncover pteridophyte centres of diversity and hotspots in Tuscany

Biodiversity studies traditionally use species as their analysis unit. However, observed biodiversity is not necessarily an indicator of significant biodiversity and therefore, should not be used alone, particularly when the results will be employed for conservation planning. Here, we examine pteridophyte diversity in Tuscany using 4668 geo-referenced pteridophyte records stored in Wikiplantbase #Toscana and calculating standard richness measures and phylogenetic indices; in addition, we assessed the environmental predictors of each diversity metric. Finally, we identified which areas hosting significantly high diversity are not adequately covered by protected areas or intersected by human activities. Although considerable diversity is distributed along Tuscany within areas traditionally recognised as biodiversity hotspots, important areas of diversity are identified only after the application of randomisation tests and through the phylogenetic metrics. Topographic ruggedness resulted the single most important variable predicting high value of all indices; temperature seasonality and temperature continentality resulted the secondary explanatory variables with a significant negative effect on most diversity indices.

传统生物多样性研究通常以物种作为核心分析单元。然而，观测得到的生物多样性未必能作为具有保护价值的生物多样性的有效指示指标，因此不宜单独使用，尤其当研究结果将用于保护规划时。本研究以意大利托斯卡纳地区为研究区域，依托存储于Wikiplantbase #托斯卡纳（Wikiplantbase #Toscana）中的4668条带地理参考坐标的蕨类植物记录，计算标准物种丰富度指标与系统发育多样性指数；此外，本研究还评估了各多样性指标的环境预测因子。最后，本研究识别出那些生物多样性显著较高，但未得到保护地充分覆盖或受到人类活动干扰的区域。尽管托斯卡纳地区有相当规模的生物多样性分布于传统上被认定为生物多样性热点的区域，但关键的多样性富集区域仅能通过随机化检验与系统发育多样性指标方可被识别。地形粗糙度是预测所有多样性指标高值的最关键变量；温度季节性波动与温度大陆性则为次要解释变量，对多数多样性指标具有显著负向影响。