Species distributions models (SDM) that rely on estimated relationships between present environmental conditions and species presence-absence are widely used to forecast changes of species distributions caused by global warming but far less to reconstruct historical assemblages. By compiling historical fish data from the turn to the middle of the twentieth century in a similar way for several European catchments (Rhône, Danube), and using already published SDMs based on current observations, we: (1) tested the predictive accuracy of such models for past climatic conditions, (2) compared observed and expected cumulated historical species occurrences at sub-catchment level, and (3) compared the annual variability in the predictions within one sub-catchment (Salzach) under a future climate scenario to the long-term variability of occurrences reconstructed during an extended historical period (1800–2000). We finally discuss the potential of these SDMs to define a “reference condition”, the possibility of a shift in baseline condition in relation with anthropogenic pressures, and past and future climate variability. The results of this study clearly highlight the potential of SDM to reconstruct the past composition of European fish assemblages and to analyze the historical ecological status of European rivers. Assessing the uncertainty associated with species distribution projections is of primary importance before evaluating and comparing the past and future distribution of species within a given catchment.

中文翻译：

---

鱼类分布的历史变化：参考条件的变化和全球变暖的影响

物种分布模型（SDM）依赖于当前环境条件和物种存在与不存在之间的估计关系，广泛用于预测由全球变暖引起的物种分布变化，但很少用于重建历史组合。通过以类似的方式编译几个欧洲流域（罗纳河、多瑙河）从二十世纪之交到中叶的历史鱼类数据，并使用基于当前观测的已发布的 SDM，我们：（1）测试了此类数据的预测准确性。过去气候条件的模型，(2) 比较在子流域一级观察到的和预期的累积历史物种发生情况，以及 (3) 将未来气候情景下一个子流域 (Salzach) 内预测的年度变化与长期气候情景进行比较-在较长的历史时期（1800-2000）期间重建的事件的术语变异性。最后，我们讨论了这些 SDM 定义“参考条件”的潜力、与人为压力有关的基线条件变化的可能性以及过去和未来的气候变化。这项研究的结果清楚地突出了SDM在重建欧洲鱼类组合过去的组成和分析欧洲河流的历史生态状况方面的潜力。在评估和比较给定流域内物种过去和未来的分布之前，评估与物种分布预测相关的不确定性至关重要。