Dr. Ir. J.C. (Bob) Douma

!!! NEW MAIL ADDRESS: Bob.Douma@wur.nl!!! 

My research interests focus on understanding and quantifying community assembly rules. My ultimate aim is to use to these assembly rules to develop a new class of vegetation models which are able to predict the effects of climate change on community composition and functioning.

During my PhD I developed a new type of habitat distribution model that predicts vegetation distribution by several important environmental drivers via plant traits. The model consists of two steps. In the first step, a combination of plant traits is predicted based on a set of environmental variables. Plant traits are crucial in this model, since the assembly theory predicts that species’ traits reflect the way in which species are adapted to the local conditions. Moreover, the relationship between plant traits and environmental drivers is a functional relationship that can be used in a changing climate. In the second step a combination of plant traits is used to calculate an occurrence probability of vegetation types.

Expertise: Data management and analysis using various statistical (modeling) techniques, including multivariate analysis, structural equation models and (linear) mixed models.

Research project

Predicting the effects of climate change on the vegetation distribution is not an easy task. Particularly since extreme (weather) events may play a much larger role than the average meteorological conditions in shaping plant communities. In this project I will investigate if a trait-based approach can be used to detect effects of weather extremes by studying ecosystems with a high inter- and intra-annual variability in moisture conditions. Any ideas, help or collaboration is welcomed!

Participants

Peter van Bodegom, Rien Aerts and Flip Witte

Selected Publications

Douma, J.C., de Haan, M.W.A., Aerts, R., Witte, J.P.M., van Bodegom, P. M. Succession-induced trait shifts across a wide range of NW-European ecosystems are driven by light and modulated by initial abiotic conditions Journal of Ecology (in press)

Douma, J.C., Shipley, B., Witte, J.P.M., Aerts, R. & van Bodegom, P.M. Disturbance and resource availability act differently on the same suite of plant traits; revisiting assembly hypotheses. Ecology (in press)

Douma, J.C. (2011) Putting assembly rules to work: predicting vegetation distribution through plant traits. PhD Thesis. VU University Amsterdam. ISBN: 978-90-6464-494-8

van Bodegom, P.M., Douma, J. C., Ordonez, J. C., Bartholomeus, R. P., Witte, J. P. M. & Aerts, R. (2011) Exploring the merits of trait-based concepts to improve predictions of ecosystem-atmosphere fluxes in dynamic global vegetation models. Global Ecology and Biogeography, (in press).

Douma, J.C.,  Aerts, R., Witte, J.P.M., Bekker, R.M., Kunzmann, D., Metselaar, K. van Bodegom, P.M. (2011) A combination of functionally different plant traits provides a means to quantitatively predict a broad range of species assemblages in NW Europe. Ecography.  DOI: 10.1111/j.1600-0587.2011.07068.x

van Ommen Kloeke, A. E. E., Douma, J. C., Ordoñez, J. C., Reich, P. B. & van Bodegom, P. M. (2011) Global quantification of contrasting leaf life span strategies for deciduous and evergreen species in response to environmental conditions. Global Ecology and Biogeography, DOI: 10.1111/j.1466-8238.2011.00667.x

Soudzilovskaia, N. A., Graae, B. J., Douma, J. C., Grau, O., Milbau, A., Shevtsova, A., Wolters, L. & Cornelissen, J. H. C. (2011) How do bryophytes govern generative recruitment of vascular plants? New Phytologist,190, 1019-1031

Douma, J. C., Van Wijk, M. T., Lang, S. I. & Shaver, G. R. (2007) The contribution of mosses to the carbon and water exchange of arctic ecosystems: quantification and relationships with system properties. Plant Cell and Environment,30, 1205-1215.