Throwback to last summer fieldtrip in Belgian cities

Posted on December 11, 2020 by lembrechtsjonas

Guest post by Charly Géron, our urban ecologist!

Last summer was -normally- the last field season of my PhD which tries to better understand how cities influence alien plant invasions. One would think that the last field season would be easy and a bit melancholic, but actually it was most stressful to organize. Due to the Covid-19 situation, the trips I had to do between the Belgian cities but also the help of the students were maybe not possible which questioned my fieldwork organization.

However, I really cannot complain as we found ways to make it work, so I was really lucky compared to some less fortunate colleagues. Even better, the team we formed with the students was very efficient and the mood was always very positive!

We then began our quest for alien plants in urban and rural Belgium, driving more than 1700 km.

*Plants thrive in an abandoned factory under the sun (left), or along the railroad tracks with a grey sky (right). The one pictured here are native!*

I already hear what you are going to say, plants in cities are rare except in parks and gardens. Well, that is totally untrue! Actually, plants are everywhere, in every pavements cracks, walls, or road sides. As a plant lover this makes me very happy. The most fascinating point of this fieldwork is that alien plants grow in the most unexpected spots!

*Alien plant species enjoying concrete cracks (left), pavements (middle), or even walls (right)*

The elaborate look of these exotic species play with us. We tend to love those bright flowers and gigantic leaves, so we plant them and introduce them to new areas, from where they can escape and potentially impact native plants. That is one of the reasons why we need to better understand why and how they thrive in cities.

Another characteristic of urban areas is their perpetual evolution. A parking lot can become a chic housing estate within a year, when in the same time frame an old house becomes an abandoned brown site. With that in mind, some of the plants I studied simply disappeared… However, we had many good surprises, with tiny sprouts becoming lush and strong trees.

*Same place, but one year apart. The tiny sprout in 2019 (left) became a lush invader in 2020 (right).*

How amazing! Great for my experiment, not so much for the local environment. That is an important dilemma of being a biologist studying alien plant invasions, being amazed by a gigantic invader yet being concerned for the local ecosystem!