I must admit I rarely call myself an ecohydrologist, or a hydrologist for that matter, despite the fact that a large part of my research looks at the interactions and feedbacks between ecological processes and the hydrological cycle. Nor do I seek out ecohydrological conferences or workshops: I am an omnivorous kind of scientist and anything goes as long as it touches upon the soil-plant-atmosphere continuum and how it interacts with the hydrological cycle.
What are your undergraduate and graduate degrees in?
I did a combined BSc/MSc degree in Soil Science, at the University of Wageningen, the Netherlands. I specialized in Soil Physics, because it immediately appealed to me with its clear links to hydrology, meteorology and ecology. I am one of those few lucky people who realized quite early on what their vocation was: I decided to study Soil Science when I was around 15 years old. My PhD was in Micrometeorology, also in Wageningen, under the supervision of Henk de Bruin. I was really interested in the interactions in the soil-plant-atmosphere system, so this seemed a logical next step in my scientific career.
How did you arrive at working in/thinking about ecohydrology?
This really was during my PhD fieldwork in Central Spain and Niger, during the EFEDA (ECHIVAL Field Experiment in a Desertification Threatened Area) and HAPEX-Sahel (Hydrologic Atmospheric Pilot EXperiment in the Sahel) campaigns in 1991 and 1992, respectively. These were international studies with all kinds of scientists involved, including (ecohydrologists). We learned a great deal from each another and I have very fond memories of those campaigns and related workshops. More recently, I have greatly enjoyed working on the Oxford (UK) floodplains to study the sensitivity of communities of rare plant species, including the Snakeshead fritillary, to small changes in groundwater levels. I also had the privilege to be involved in a project on Caatinga dryland forest ecosystems in the semi-arid area of Northeastern Brazil. The intricate ways in which the many tree-and shrub species in these forests interact with the environment, in particular the very limited soil water stores, and with each other is fascinating. The big challenge is how to model this comprehensively.
What do you see as an important emerging area of ecohydrology?
I am not an expert in this particular area, but the use of stable Isotopes in Ecohydrology have already brought us important new insights. Now the challenge lies in further developing and testing in situ methods (such as those that sample soil water vapor) to capture the temporal dynamics in the isotopic signature of the various hydrological compartments. Another challenge is how to incorporate this information reliably into ecohydrological and land surface models. I also think there is still scope for further exploring coupled heat and water transport experiments and related modelling, especially with distributed temperature sensing becoming more widely available.
Finally, models that use optimization theory and mechanistic approaches of plant water transport and photosynthesis will help us to get a better handle of the effects of plant water stress on vegetation functioning under changing climatic conditions.
Do you have a favorite ecohydrology paper? Describe/explain.
I rarely read pure ecohydrological papers, but there are a number written by Simone Fatichi and colleagues on ecohydrological modelling that I greatly enjoyed. I am more familiar with the seminal papers in the micrometeorological arena (e.g., on turbulence in plant canopies) that also cross over to plant physiology, such as those by Finnigan, McNaughton, Monteith and Raupach. The papers by J.R. Philip (1927-1999), an Australian soil physicist and hydrologist, are close to my heart because he made both his mark on micrometeorology (e.g., advection, evaporation, canopy resistances) as well as on soil physics (infiltration).
What do you do for fun (apart from ecohydrology)?
Unfortunately, there is generally very little time left for fun stuff, but I really enjoy hiking, brushing up on or learning new languages (this is also a good excuse to watch foreign-language Netflix series in the evenings), and anything to do with the architecture and applied arts of the Art Nouveau period.