Research
Theme 2
www.darwincenter.nl
Program 2040

Niche engineering and the evolution of biogeochemical cycles through time
Program coordinator(s): Prof. dr. G. J. van der Zwaan
Theme(s): 2
Funding date: 4-jul-05

Abstract
In marine and terrestrial environments animals and plants segregate into different sections of ecospace through competition for both space and resources. This leads to sometimes well-defined tiers; for instance, modern marine environments are characterized by a complex infaunal system with densities and diversities that vary depending on sediment type, availability of oxygen and organic matter load arriving at the sea bottom. In this system some infaunal species are keystone taxa in the sense that they play an extraordinary role in creating suitable environments for (sometimes many) other taxa. These keystone taxa should be regarded as veritable niche engineers and they are of profound interest from an evolutionary perspective: over time origination of niche engineers would lead to sudden bursts in evolution. Indeed, data suggests that the tiering history of Phaenerozoic marine substrates took place with discrete steps. In this program we propose to study the effects of the presence of various key types of infaunal taxa, in various substrates and under different levels of organic matter load. We want to assess the effects of these bioirrigators on the surrounding biodiversity, in particular the foraminiferal patterns, and assess the effects on biogeochemical cycling. We expect that we can associate a predictable foraminiferal assemblage with model-types of (often softbodied and thus non-preservable) infauna and with the co-occurring biogeochemical state of the sedimentary environment. Since foraminifera are extremely good index fossils, they allow us to detect the introduction of various key types of tiering over geologic (Mesozoic and particularly Cenozoic) time. The program is designed in such a way that eventually we hope to answer the following key questions: how did the world look under conditions when deep burrowers, larger invertebrates, complex ecological and food chains, were not yet present? How did this affect the biogeochemical cycling?How did the present day biogeochemical cycling evolve?

This program contains the following projects:
2041: Niche engineering and the evolution of marine biogeochemical cycles through time: the effects of bioirrogation on bacteria and foraminifera
2042: Niche engineering and the evolution of marine biogeochemical cycles through timean experimental study of the effects of diffusive and advective bio-irrigation on bacteria and meiofauna

Publications
De Nooijer L.J., Reichart G.J., Duenas-Bohorquez A., Wolthers M., Ernst S.R., Mason P.R.D., Van Der Zwaan G.J. (2007). Copper incorporation in foraminiferal calcite: Results from culturing experiments . Biogeosciences4: 493-504.
Darwin Center authors: Reichart G. J., van der Zwaan G. J.

Van Lith, Y., Langezaal, A.M., De Nooijer, L.J., Van Der Zwaan, G.J. (2009). Benthic foraminiferal effect on nitrogen and carbon cycling . Journal of Foraminiferal Research39 (2): 97-111.
Darwin Center authors: van der Zwaan G. J.

Johan Van Frausum, Jack J. Middelburgb, Karline Soetaert, Filip J.R. Meysman (2010). Different proxies for the reactivity of aquatic sediments towards oxygen: A model assessment. Ecological Modelling221: 2054-2067.
Darwin Center authors: van Frausum J., Meysman F., Middelburg J.J., Soetaert K. E. R.