‘No measuring without modelling and also no modelling without measuring’. Throughout my career this has been the basic philosophy of my research, which focuses on patterns and processes at the earth surface, where abiotic and biotic components of the landscape interact at various temporal and spatial scales. How can we combine measurements and models to trace the lengthy chains of cause-and-effect relations in complex systems? What are relevant phenomena and what concepts do we need to model the spatial and temporal dynamics of these phenomena? How can we parameterise and validate our models? How can different model perspectives contribute to the increase of our insights? It is my ambition to merge theoretical ecology and field based descriptive ecology and to contribute to the development of predictive ecology.
It is my mission to promote and facilitate big-data and computationally intensive ecological research, what we call “e-Ecology” (technology enhanced ecology), not only for our own group but also in an (inter-) national context. Together with NLeSC and SURFsara we therefore build virtual laboratories to facilitate remote collaboration and use of research infrastructures for data acquisition, storage, visualization, exploration and analysis.
I am concerned about the future of our planet and I am not the only one. As involvement starts with education, I initiated a new educational program "Future Planet Studies", an interdisciplinary program in which developments in the coming 50 years are discussed from perspectives of demography, economics, and quality of life in the context of the earth's resources. In a world that generates ever more knowledge and where knowledge is ever more accessible, we train students to find and aggregate new knowledge and to develop their own views and not so much to reproduce knowledge. From 2006 to 2014, I was initiator, developer and director of the UvA BSc program Future Planet Studies. This program has grown from 45 students in the cohort of 2007 to almost 200 students in 2014. In 2017, I initiated the master track Future Planet Ecosystem Science, which I have coordinated until my retirement in September 2021.
Currently I am still involved in the following projects:
In the late eighties and early nineties, a huge research programme on acidification research was carried out by about 80 research institutes and university groups in the Netherlands. The research concentrated mainly on two Douglas fir forests with different vitality (Aciforn-project). Within this projectI co-operated with several others to assess the hydrological fluxes and states in these two forests. My main task was to monitor and model rainfall interception and throughfall dynamics, temporal and spatial patterns of soil water content and root water uptake, and transpiration dynamics. I very much enjoyed the development of a new technique to measure canopy water storage amounts. Two hoists, with a microwave transmitter and receiver, went up and down along two towers (everyfive minutes, 300 times a day and 100.000 times in a year), while measuring vertical profiles of microwave attenuation caused by intercepted water. Measurements and simulations showed that the canopy water storage was above the threshold value of 0.3 mm of water storage for 40% of the total time, thus enabling the co-deposition of ammonium sulphate (Bouten et al, 1991, Bouten & Bosveld, 1991, Bouten et al, 1996, Vrugt et al, 2003)
My MSc thesis was about remote sensing of surface roughness and top soil moisture of bare tilled soil with x-band radar. A scatterometer was mounted in a mast on a lorry that was moved along test sites with different soil roughness and water content. This enabled me to measure from different incidence angles and various polarizations (Janse and Bouten, 1980; Koolen et al., 1979) During my masters I also did minors in mathematics and theoretical production ecology where I worked on the development of algorithms to improve the calculation speed of a numerical crop micrometeorological modelby Goudriaan (1977)
Bird Tracking System
One of my main topics is currently the monitoring of bird behavior in the context of movement ecology. Together with Edwin Baaij of the Technology Center of our faculty, w e have designed, tested, produced and deployed a bird tracking system for studying the behaviour of free-ranging birds without the need to recapture them. The GPS tracker weighs only 12 grams and includes a GPS receiver, tri-axial accelerometer, microprocessor, 4MB memory for data storage, solar panel and battery. To maximize flexibility, it is equipped with a radio transceiver for bi-directional communication with a ground-based antenna network permitting not only the downloading of data but also the uploading of new measurement schemes remotely. The GPS system also comprisesa spatial database and web services for post-processing, visualizing and querying the data. More information can be found on www.UvA-BiTS.nl
Bayesian Inverse Modelling
Another main topic of interest is the use of Bayesian inverse modelling for improving theories of geo-ecological processes. The development of knowledge in Natural Sciences is an iterative process in which scientists confront their theories with observations. "Concept formulation (modeling) - experimental design - experiments and observations - data analyses" form the Iterative Research Cycle (IRC) that furthers the knowledge and the perception of natural systems. Inverse modeling, based on Bayesian statistics, is used to confront our theoretical concepts (models) with reality (observations) to identify errors in the model structure, model inputs or model parameters while taking uncertainties into account. I an especially intere sted to find out how inverse modelling techniques can inspire us to improve our theories of spatially explicit dynamic models.
A third topic which has my specific interest is the development of virtual laboratories to promote scientific collaboration. VLs are advanced interactive problem solving environments for (multi-disciplinary) user groups that facilitate (i) data access, either by communication links to sensors or through portals to a data base, (ii) data integrity and quality control, (iii) data post-processing, (iv) data storage and backup, (v) data merging, (vi) data sharing, (vii) interactive data visualization and exploration, (viii) data mining and annotation, and (ix) data analyses, model building and model improvement. It is our mission to promote and facilitate data and computationally intensive ecological research, what we call "e-Ecology".