Counting, listening, and other ways of knowing
Some questions need a soil sample, others need two hours of listening. Following my curiosity, I published four studies using various quantitative and qualitative research methods: tracing nitrogen through a desert forest, hearing how people experience nature, setting eighteen city initiatives next to each other, and going back six years later to see what changed.
01TraceBayovar and Piura, northern Peru, 2009
Along the coast of Peru, seabirds carry nutrients from one of the richest oceans in the world onto some of the driest land.
Seabirds feed one tree and not the other
Guano from blue-footed boobies loads the coastal soil with nitrogen. Capparis scabrida, which cannot fix its own nitrogen, takes it up and dominates the first 50 metres from the shore. Prosopis pallida, a legume that makes its own, ignores it.
Quantitative: soil and leaf samples, stable isotopes, and a field experiment with 400 seedlings.
MSc thesis, Wageningen University. PLOS ONE, 2014, with Alessandro Catenazzi and Milena Holmgren.
The guano signature, from soil to leaf
Zero is the value of nitrogen in air.
Soil nutrients by distance from shore
| µg per gram | 10 m | 50 m | 100 m | 200 m |
|---|---|---|---|---|
| Nitrate | 94.5 | 6.9 | 1.8 | 0.7 |
| Ammonium | 267 | 43 | 67 | 51 |
| Phosphate | 79.2 | 1.9 | 1.3 | 1.0 |
| Potassium | 425 | 96 | 104 | 93 |
Medians of five transects, Table 1. In a field experiment, 400 seedlings were planted with and without protection from herbivorous lizards; keeping the lizards off made no significant difference.
02ListenUffelte, Amsterdam and beyond, 2010 to 2011
Research increasingly links time in nature to well-being, and more and more people look for spirituality outside traditional religion.
The place shapes the experience
Eighteen people from the Open Up festival in Uffelte, each interviewed at a natural site of their own choosing: in seven Dutch provinces, and once in Luxembourg. Three picked the same spot, the Vondelpark. What they felt mirrored the place: open land gave overview, the sea grandness, still water stillness.
Qualitative: 18 in-depth interviews, analysed with interpretative phenomenology.
MSc thesis, Wageningen University. Ecopsychology, 2015, with Birgit Elands and Kris van Koppen.
What in nature mattered, and what it gave
Number of the 18 participants who mentioned each feature, with how they described the experience. Table 3 of the paper.
“It isn’t that I believe that the tree whispers an answer in my ear, but I feel a broadening when I am with such a big tree. More clarity in myself.”
a big tree, Elisabeth, 30
“This is a beech … but it feels more like a grandma.”
Eliot, 36
“Those waves, the sound … It’s the sounds … and the air that bring me at ease.”
the sea, Betty, 50
“In living nature, you feel fluctuations of presence.”
Danny, 57
“It’s like a thundercloud that is blown apart, and turns into a group of fleecy clouds that you can watch in a far more relaxed way.”
Timothy, 35
“The forest has a very clear vibration.”
Carry, 46
“I feel welcome there. Safe. At home.”
his gathering places, Anthony, 47
Names are pseudonyms, as in the published paper (Ecopsychology, 2015).
03Compare18 citizen initiatives in 16 European cities, 2015
As European cities grow denser and public budgets come under pressure, residents increasingly create and care for green space themselves.
Enthusiasm is not enough
From participatory budgeting in Lisbon to a first community garden in Szeged and a park adopted by companies in Oradea. Citizen-led green spaces thrive on money, time and people who know how to organise, and those are unevenly spread across neighbourhoods. The report proposes mosaic governance, tuned to each place.
Qualitative: comparative case studies built on interviews, documents and websites.
GREEN SURGE, EU research project. Co-author of the report Innovative governance of urban green spaces, 2016.
Five kinds of citizen involvement
When each initiative started
Case table of the report (Tables 1.1 and 1.2).
04Return11 cities revisited, 2020 to 2021
Climate change, biodiversity loss and growing inequality all ask new things of the parks and green spaces in cities.
Greener plans, the same blind spot
Six years on, green space officials in eleven cities were interviewed again. Climate adaptation and biodiversity brought new plans nearly everywhere. Social justice and cultural diversity barely reached green space planning. Most change was piecemeal rather than transformative.
Mixed: structured interviews with closed and open questions, repeated after six years.
European Planning Studies, 2022, one of 27 co-authors.
How each theme changed since 2014
↑ more important, → unchanged, ↓ less important, blank: not rated. Rated by each city’s green space official. Table 2 of the paper. Budgets: up in 3 cities, stable in 5, down in 3.
Since then · Amsterdam
The questions kept coming
I never lost my interest in scientific work. In 2021 I completed a course in science journalism (SCW Wetenschapsjournalistiek), taught by national science journalists, including writers from NRC, de Volkskrant and Quest.
I took the same way of working into marketing, where a market is a system too: people, attention and choices. I trace the path from ad to booking across Google Ads, Meta, GA4, HubSpot and Eventbrite. I listen to what people search for and feed it back to the team that develops the courses. And I return to the same dashboards month after month, to see how the field evolves.