Last night brought extreme weather conditions to Belgium. After a hot summer day, hailstorms swept over the country, dropping hail stones of several centimeters.  

The storm resulted in a lot of economical, agricultural and natural damage, although it lasted not longer than fifteen minutes. Those fifteen minutes were however enough for the hailstones to perforate windows and greenhouses and many other unprotected things all over the country.

Such hail storms provide a good example of temporal variation in microclimate. I have been focussing on its spatial counterpart, which gives different climate over a distance of a few centimeters or meters. But it is not only on a spatial scale that we can see deviations from the average climate. Over time, extreme weather conditions may happen, that may differ a lot from the average Those extremes, like hail storms, long heat waves or large floodings, may be much more limiting for plant growth than the average climate ever will.

Climate change will most likely bring us more of these extreme weather events in the future. So even if the average climate would not change too drastically, those higher chance of extremes will still strongly influence species survival and distributions.

I have been focussing my research a lot on the spatial variation in microclimates, but this huge hail storm made me realize that the temporal variation can not be ignored. I did not have the opportunity to check what the hailstones did to my disturbance experiment, but it made me at least realize that all these extreme events should be taken into account to understand the results.