This study by Wessely et al. is groundbreaking in that it warns of climate change posing a greater risk for the preservation of European forests -and their ability to provide services- than previously thought. When it comes to predicting which species in each territory may encounter suitable climatic conditions in the future, the traditional approach is often limited to modeling a 'snapshot' of a given date. In contrast, this work adopts a dynamic perspective that takes both the rate at which climate change is progressing and the longevity of trees into account. Therefore, the study considers that tree species must tolerate the full range of climatic conditions that occur between now and the end of the century, to successfully reach the end of the century. Which translates into much gloomier predictions on the number of tree species available in the future.  

Although the work is of great importance for future forest management, it focuses too much on an alarmism that results from the way in which species distribution models (SDMs) oversimplify reality and yield predictions that are largely the result of the assumptions that were made at the start. Some of the limitations are the following:  

• SDMs predict the suitable area for each species based on average climate data (current and future). However, the species niche has other components, such as soil conditions, species interactions, dispersal/migration ability of species, etc. The effect of extreme events, which causes both massive tree mortality and recruitment, is not considered either.  

• The MOEs do not consider the ability of species to adapt or acclimatize to changing environmental conditions. Several studies have found that species' resistance to climate change varies among populations, being sometimes higher in populations that are closer to the species' distribution limits, due to local adaptations to adverse conditions.    

•  The microclimatic variability that exists at a local scale is lost by using a scale of 1 km2, which may be key to explain the existence of climatic refugia for species. For example, if microclimatic variations between sunny and shady slopes are not considered, it is difficult to explain the existence of Atlantic trees (beech, linden or sessile oak) in the center of the Iberian Peninsula.    

• The initial pool of species used to estimate which of them are capable of reaching the end of the century, only includes the most abundant native trees currently found in European forests. It does not consider the ones that are now rare but could expand in the future, the ones that could migrate from other territories, or the exotic trees that humans have been planting for decades in Europe to provide services. This greatly limits the possibilities of real replacement of species during climate change.    

• Assuming that species must be climatically suitable throughout the whole 21st century is a very demanding criterion that does not consider that species can replace each other throughout the process of climate change.    

• Finally, the reduction in the capacity of future forests to provide ecosystem services is also magnified. Thus, only three of the many services provided by forests are considered, these are considered on the species (and not landscape) scale, and no account is taken of the fact that the benefits that humans get from forests also change over time.  

Many of these limitations are acknowledged and discussed at the end of the article, but with a cursory reading it is hard to grasp these nuances, and the reader will be left with the doomsday message only. It is true that any attempt at modeling necessarily simplifies reality, so it must be assumed that models are more useful for understanding processes than for making predictions. All in all, it is an important wake-up call for forest managers in Europe".