news-July 6, 2023-written by:Joep van der Wal

How do the various food forest studies relate to each other? And what role does citizen science play in this? Jeroen Kruit explains how the pyramid of data forms and why each layer is essential.

Multi-year food forest studies: measure the same thing in the same way as much as possible

Jeroen Kruit

The WUR, the Lynx Foundation and Food from the Woods collaborated in the project "Measure your food forest harvest. The goal was to use four very simple citizen science methods to make every food forest owner, wherever they are on this planet, a 'scientist' by being able to monitor their food forest themselves. This data is then shared in an Open Data Resource, accessible to anyone who wants to do research on it.

This set-up makes the multi-year research independent of grants or other external funding and thus, at its core, robust enough to last as long as the food forests themselves.

Multiple multi-year studies

But this is not the only monitoring research on food forests. In addition to Measure Your Food Forest Harvest, there is the National Monitoring Program Food Forests and the Top Sector-funded research "Scientific Soil Formation Under Food Forestry. The former has just produced its first major report. This program conducts research at more than 30 food forests each year with the help of students and doctoral students. The Top Sector-funded research dives into depth for five years. The still young food forests Schijndel (Brabant) and Eemvallei (Almere) are research objects in this regard. To have sufficient data from older systems, 16 more older food forests in the Netherlands and Belgium will be investigated. Together, these studies form a pyramid, with at the bottom many food forests where light information is collected by enthusiastic food forest owners through the project Measure your food forest harvest, and at the top a small selection of food forests where a lot of information is collected.

Through Jeroen Kruit, of the WUR, all these studies stay in good touch with each other and, as much as possible, measure the same kinds of things in the same way. He does this work on behalf of the Green Deal Food Forests (now the Network Food Forests Netherlands) and the Agroforestry Network Netherlands.

Is that necessary, overlapping data?

These studies measure everything the same way as much as possible. Is that smart, you might ask, because then aren't we measuring everything twice? "No absolutely not" says Jeroen Kruit. "You need a lot of data as a scientist to be able to identify trends and make statements about, for example, plant combinations that work well. It really takes a long breath to get a good picture of important long-term trends. The relatively short lead times of scientific research only increases the relevance of citizen science research. The three-stage rocket that has now emerged generates large as well as in-depth data sets. The longer citizen scientists continue to collect data and the scientists manage to bring in new research projects, the more valuable these datasets become. And then there is the classic saying, one study is no study!

What does this data tell us?

We know that current systems to farm arable crops and manage grasslands rely heavily on external inputs of nitrogen, phosphorus and potassium. Food forests operate without external inputs and without pesticides. So what we want to discover is exactly how that will work. We know that food forests can provide a variety of harvestable products year round. They become richer as a system over the years because of, among other things, the fixation of carbon from the air through photosynthesis and the much more diverse soil life.

And what do all these aspects look like for the different successional stages of a system that gradually becomes richer and more diverse over time? And how does succession occur in food forests at different sites and substrates?

"The longer you are engaged in research, the more questions arise." The method of food production without inputs and without chemical control and according to natural principles is so complex that we researchers also have to partially redevelop our thinking and research methodology, so to speak. And then when you as a researcher start looking for answers, really all data are welcome.

Are there developments in data collection?

Yes, we expect more affordably generated data in the not too distant future. For example through remote sensing with drones and satellites, or eDNA where you put all biodiversity in a "blender" and then you can measure everything, or even airDNA, where you can measure, among other things, the presence of all life via traces that life leaves behind in the air. But yes, a practical application may still be a long way off, because with this method you now also measure the animals in a nearby zoo.

This year, a new 2-year WUR research has started that focuses precisely on these new ways of measuring. This research focuses on exploring the possibilities of using modern technology to monitor biodiversity efficiently and affordably. One of the goals is to lay a foundation for the economic valuation of ecosystem services. The citizen science approach of Food from the Forest explicitly contributes to the development of measurable ecosystem services through the many measuring citizens/food forest owners.

Reason for optimism, then?

"Sometimes it seems that integrating trees into agriculture is only about food forests" says Jeroen, but of course that is not true. There are several other forms of agroforestry being experimented with. Food forests do live tremendously among a very wide audience and slowly the concept is also gaining a foothold in production-oriented agriculture. And more and more often you also meet someone in unexpected corners of science who is also completely enthusiastic about food forests. I think we can say that we have a healthy and growing food forest movement in the Netherlands that is being watched with increasing curiosity from abroad. In terms of area versus conventional monoculture-oriented agriculture, the actual number of acres of food forests is still very small. But, together, we do have a growing influence in the discussion about the transition to more sustainable forms of agriculture. The mycelium (underground fungal thread network) is steadily expanding!

Are you measuring too?

Join us and contribute to a powerful "three-stage rocket" through Food from the Forest. Together, we are generating large amounts of data from all different soil types, baseline situations and types of food forests. Measure with us and contribute to the health of your own forest, and that of the movement as a whole. Learn more about the measurements here.

And then there's the Food Forestcast, where we speak to Jeroen Kruit in episode #16. You can listen to this one here.

Ir. Jeroen Kruit is a (participatory) action researcher whose research practice focuses on facilitating, advising, evaluating and coaching (policy) professionals, grassroot initiatives and students at Wageningen University.

Project Measure Your Food Forest Harvest

Monitoring my forest

The Food Forestcast with Jeroen Kruit

Listen to episode