Liebergesell Mario, Reu Björn, Stahl Ulrike, Freiberg Martin, Welk Erik, Kattge Jens, Cornelissen J Hans C, Peñuelas Josep, Wirth Christian
Department of Special Botany and Functional Biodiversity, University of Leipzig, Leipzig, Germany.
Escuela de Biología, Universidad Industrial de Santander, Cra. 27 Calle 9, 680002, Bucaramanga, Colombia.
PLoS One. 2016 Feb 5;11(2):e0148607. doi: 10.1371/journal.pone.0148607. eCollection 2016.
Future global change scenarios predict a dramatic loss of biodiversity for many regions in the world, potentially reducing the resistance and resilience of ecosystem functions. Once before, during Plio-Pleistocene glaciations, harsher climatic conditions in Europe as compared to North America led to a more depauperate tree flora. Here we hypothesize that this climate driven species loss has also reduced functional diversity in Europe as compared to North America. We used variation in 26 traits for 154 North American and 66 European tree species and grid-based co-occurrences derived from distribution maps to compare functional diversity patterns of the two continents. First, we identified similar regions with respect to contemporary climate in the temperate zone of North America and Europe. Second, we compared the functional diversity of both continents and for the climatically similar sub-regions using the functional dispersion-index (FDis) and the functional richness index (FRic). Third, we accounted in these comparisons for grid-scale differences in species richness, and, fourth, investigated the associated trait spaces using dimensionality reduction. For gymnosperms we find similar functional diversity on both continents, whereas for angiosperms functional diversity is significantly greater in Europe than in North America. These results are consistent across different scales, for climatically similar regions and considering species richness patterns. We decomposed these differences in trait space occupation into differences in functional diversity vs. differences in functional identity. We show that climate-driven species loss on a continental scale might be decoupled from or at least not linearly related to changes in functional diversity. This might be important when analyzing the effects of climate-driven biodiversity change on ecosystem functioning.
未来全球变化情景预测，世界上许多地区的生物多样性将急剧丧失，这可能会降低生态系统功能的抵抗力和恢复力。曾有一次，在更新世-上新世冰川期，与北美相比，欧洲更为恶劣的气候条件导致了树木植物区系更为贫乏。在此，我们假设，与北美相比，这种由气候驱动的物种丧失也降低了欧洲的功能多样性。我们利用154种北美树种和66种欧洲树种的26个性状变异，以及从分布图中得出的基于网格的共现情况，来比较两大洲的功能多样性模式。首先，我们确定了北美和欧洲温带当代气候方面的相似区域。其次，我们使用功能离散指数（FDis）和功能丰富度指数（FRic）比较了两大洲以及气候相似的次区域的功能多样性。第三，在这些比较中，我们考虑了物种丰富度的网格尺度差异，第四，使用降维方法研究了相关的性状空间。对于裸子植物，我们发现两大洲的功能多样性相似，而对于被子植物，欧洲的功能多样性明显高于北美。这些结果在不同尺度、气候相似区域以及考虑物种丰富度模式的情况下都是一致的。我们将这些性状空间占据的差异分解为功能多样性的差异与功能特性的差异。我们表明，大陆尺度上由气候驱动的物种丧失可能与功能多样性的变化脱钩，或者至少不是线性相关的。这在分析气候驱动的生物多样性变化对生态系统功能的影响时可能很重要。
