I am currently in New Orleans, Louisiana, on the shores of the Mississippi river, at a gathering of several thousands of ecologists: the annual meeting of the Ecological Society of America (ESA).

The city of New Orleans by night

This year’s theme of the conference is an especially fascinating one, and closely intertwined with the recent history of this beautiful city: extreme events, ecosystem resilience and human well-being. More specifically, these thousands of ecologists ask the question how the world bounces back when it gets an uppercut, how humans affect this ability to bounce back, and how this in return affects us humans.

Human and natural structures in New Orleans

Critical questions, and dramatically illustrated by the aftermath of hurricane Katrina, a true exemple of such an extreme event that devastated the city of New Orleans more than a decade ago. A lot of bouncing back happened since that day, but it took an extraordinary amount of time and resources, and it made apparent that when people alter the environment too much, resilience drops.

The swamps, marshes and bayous of Louisiana protect the shores against extreme events like hurricane Katrina, yet they are increasingly under threat.

A lot of what we are working on fits neatly into this theme. Right at this moment, for example, one of our PhD-students is monitoring the effects of Urban Heat Islands on non-native plant species in Flanders, right in the driest summer Western Europe has seen in a very very long time.

Little (Dichondra?) leaves in a hole in the streets in New Orleans. People and the environment are closely intertwined, and despite the dramatic changes in nature’s status quo that this gives, we will have to learn to deal with it.

Assessing the combination of the direct effects of humans (in cities, yet also along roads and trails, etc.) and the indirect ones (through climate change, for example) on plant species is indeed an important cornerstone of our work. I will be presenting a lot more ideas on that matter on Thursday morning in my talk, which will focus on how these direct anthropogenic disturbances are overruling all other possible drivers of plant species distribution changes in mountains. For those of you in New Orleans: you do not want to miss that!

he ability of ecosystems to respond to extreme events requires their resilience mechanisms to be intact. However, these have often been severely undermined by land-use practices that increase effects of extreme conditions, a thought not hard to believe amidst the giant human-made structures in a large city like New Orleans.