Kilian Perrelet

Last week, I defended my PhD thesis! 🎉

4 years diving into blue-green infrastructure, biodiversity, food webs, eDNA, and above all, amazing collaboration between engineers and ecologists 🏣🌱🐞🧬

Big thanks to @laurenmcook.bsky.social, Marco Moretti, and @florianaltermatt.bsky.social!

Green roofs ≠ ground habitats. 🌿🏙️
Only 10% of invertebrate species on the ground are found on nearby rooftops. Green roofs host distinct species that need tailored design to thrive.
Treat them as ecosystems, not substitutes.
📄 doi.org/10.1016/j.je...

#GreenInfrastructure #Biodiversity #GreenRoofs

Huge thanks to the co-authors: Marco Moretti, Océane Inglard, @florianaltermatt.bsky.social, and @laurenmcook.bsky.social

And to the #BGB initiative @eawag.bsky.social @wslresearch.bsky.social

6/6

The good news: small design changes = big ecological impact. In particular, let's favor...

✅ Deeper substrate
✅ Organic-rich soils
✅ Higher vegetation cover

... to benefit species with varying dispersal abilities! 🦋🐞🦗

5/6

As expected, flying invertebrates 🦋🐝 thrived on green roofs. But even ground-dwelling species 🕷️ made it up there!

However, species that live within the soil (e.g., springtails) didn’t do as well, probably due their limited dispersal and challenging environmental conditions ☀️

4/6

Surprising finding: very few species were shared between roofs and ground-level sites.

📍 Spatial isolation didn’t matter much.

🏙️ Instead, green roofs hosted distinct communities, though a bit less species-rich overall.

3/6

We collected soil samples from 50+ pairs of green roofs and ground-level green spaces across Zurich, Switzerland.

Using eDNA metabarcoding 🧬, we identified invertebrates with different dispersal abilities to see who’s living where.

2/6

Fresh off the press! 🚨

What happens to species with different mobility when we replace urban green spaces with green roofs? Can they migrate to rooftops? 🏙️

TL;DR: Not really, but green roofs still offer unique and improvable habitats!

Now out: www.sciencedirect.com/science/arti...

1/6

Big congrats to @merinrejichacko.bsky.social and colleagues on the release of this incredible dataset! Amazing to see such large-scale collaboration come to fruition.

Very grateful for early access! It allowed us to demonstrate how #urbanization reshapes and homogenizes multitrophic food webs 🏙️

A collaboration between @eawag.bsky.social and @wslresearch.bsky.social with @laurenmcook.bsky.social, @adietzel.bsky.social & @florianaltermatt.bsky.social!

Aquatic and terrestrial environmental DNA signals reveal decoupling of blue-green communities along an urbanization gradient Urban blue and green spaces, like ponds and parks, can mitigate the negative effects of urbanization on biodiversity by providing diverse, connected h…

🚨New paper alert🚨

Exploring urban #aquatic & #terrestrial biodiversity with #eDNA 🧬

❗ #Urbanization weakens land–water linkages
❗ Aquatic & terrestrial communities follow distinct drivers 🐞🦟
❗ Adapted primers for aquatic & terrestrial invertebrates 🧬

www.sciencedirect.com/science/arti...

Thank you so much! It was great to meet you!

Thanks a lot! Could you eventually add me?

Interested in #foodwebs, #urbanization, or #eDNA metabarcoding? Then come to my talk tomorrow (Friday 13th, 11:30 am) in the Community Ecology Mixed Bag session!