Reacción a "Extreme droughts slow the carbon storage capacity of scrublands and grasslands"

This is a solid article, whose main values are:

• It is a global study carried out in scrublands and grasslands around the world, harmonising numerous small-scale experimental field studies on climate manipulation (plots of a few square metres). It is worth noting the difficulty of carrying out these studies, but they benefit from the networking of numerous scientific groups.
• It highlights the distinction between two components of droughts: their intensity and their duration. It should be emphasised that climate change scenarios point to an increase in the duration and intensity of droughts in many parts of the world. The study is therefore highly relevant and timely.
• The results show a certain capacity for adaptation to droughts on the part of the vegetation studied. However, there is a greater impact when the duration and intensity of the drought are combined. In other words, as the drought continues, the effect of the intensity of the drought is greater.
• These results provide evidence for relevant ecological hypotheses, such as the disproportionate increase in ecological impacts when different stress elements are combined.

As for limitations:

• This is a global study that shows general trends, but that does not mean that each specific situation will reproduce the results obtained. There is significant variability that deserves to be monitored at the local level.
• The duration of the experiments is limited (three to four years) and long-term experimental and monitoring studies harmonised across many sites are needed.
• The study assesses a single variable (net primary production or productivity) that describes the functioning of the system, as it integrates multiple ecological processes, but, for example, the impacts on nutrient balances or biodiversity are not assessed.
• Only certain types of terrestrial ecosystems are assessed: scrubland and grassland. Although these are important, it remains to be seen whether the results are consistent in other ecosystems, such as forests. In forests, climate manipulation experiments are more difficult and costly, but they are also carried out.