My general interest is to understand how organisms interact with their biotic and abiotic environments. A comprehensive description of the biophysical mechanisms linking biotic and abiotic spaces is needed to forecast the effects of climate change to come. Such a perspective obviously appeals to a highly integrated and multidisciplinary approach. I have knowledge in physiological ecology of invertebrates and plants as well as in environmental biophysics.

During my master degree in France, I worked on the impact of physical environment on intra-specific relationships. I studied the impact of ambient light heterogeneity in a tropical rain forest on the efficiency of visual (colour) communication in some dung beetles of French Guiana, South America (Figure 1). The study shows how ambient light spectra, background reflectance, and dung beetle photoreceptor sensitivities determine the conspicuousness of body coloration to conspecifcs: the signal efficiency is maximal in the light environment actually used while searching for food or mate.

Figure 1. The largest dung beetle of South America, Coprophanaeus lancifer.

Eventually, I studied the impacts of physical environment on inter-specific relationships by focusing primarily on spatial (my PhD) and temporal (my postdoc in USA) patterns, and then in an evolutionary perspective (my current postdoc).

My PhD dealt with the thermal ecology of an intimate herbivore insect-plant interaction. The thermal environment of a leaf mining species was explicitly modelled in great details to reveal the biophysical mechanisms that set the temperature inside a mine (Figure 2). Micro-measurements indicated that the larva alters the properties of plant tissues, leading to a large temperature excess within the mine. The second trophic level manages and partially controls the first one, even to the point of one trophic partner co-opting the physiology of the other. The biophysical model of a mine was then connected to a physical model of radiative transfer in plant canopies to quantify precisely the spatial heterogeneity in mine temperature and insect performance at the canopy scale. This approach revealed the spatial dynamics of the canopy mosaic of favourable and risky microhabitats for the leaf miner as function of regional climate: location of the most favourable microhabitat for insect development is totally reversed during heat wave events compared to periods with more typical ambient temperatures.

Figure 2. The leaf mining moth Phyllonorycter blancardella develops within apple leaf tissues, inside a mine.

My postdoctoral project at the University of South Carolina (USA) looked at the impact of temporal pattern of thermal exposure on biotic interactions in the intertidal ecosystem, which is thought to be especially susceptible to climate change. The intertidal keystone predator, the ochre sea star (Figure 3), experiences frequent but short periods of exposure to high aerial body temperature (acute exposure) but avoids microhabitats where such exposure is chronic. Lab experiments showed otherwise that acute exposure leads to higher feeding rate and tends to increase growth rate. Under certain circumstances, environmental stress can have positive effects over organismal physiology and reinforces the strength of biotic interactions. Moreover, cold waters (when immersed at high tide) help the predator to recover relatively quickly from aerial thermal stress. The worst scenario for this top predator is when both aerial and water temperature warm up…

Figure 3. The top intertidal predator Pisaster ochraceus is an impressive sea star. It exerts a strong top-down control over community structure by feeding mostly on mussels which out-compete other invertebrates and algae for space.

How does the physical environment shape the design of the sensory structures used by organisms to sense their micro-environment? My current postdoctoral position at the Research Institute on Insect Biology wraps my interest in physical ecology in an evolutionary context. More specifically, I am looking at the air flow velocity and the pattern of turbulence within the litter boundary layer of temperate forests, to estimate the level of background noise for those insects that may escape from spider attack thanks to micro-hairs sensing air flows (Figure 4). This work is part of the CILIA European project.

Figure 4. Very few is known on the microclimate, and especially air flow velocities, experienced by organisms at the leaf litter surface. These conditions can strongly influence prey-predator relationships.

Publication List:

Pincebourde S., Sanford E. & Helmuth B. (2009). An intertidal sea star adjusts thermal inertia to avoid extreme body temperatures. The American Naturalist 174, in press.

Sinoquet, H., S. Pincebourde, B. Adam, N. Donès, J. Phattaralerphong, D. Combes, S. Ploquin, K. Sangsing, P. Kasemsap, S. Thanisawanyangkura, G. Groussier-Bout & J. Casas (2009). 3D maps of tree canopy geometries at leaf scale. Ecology (DataPaper) 90, 283 (archive E090-019).

Pincebourde S., Sanford E. & Helmuth B. (2008). Body temperature during low tide alters the feeding performance of a top intertidal predator. Limnology & Oceanography 53, 1562-1573.

Théry M., Pincebourde S. & Feer F. (2008). Dusk light environment optimizes visual perception of conspecifics in a crepuscular horned beetle. Behavioral Ecology 19, 627-634.

Pincebourde S., Sinoquet H., Combes D. & Casas J. (2007). Regional climate modulates the canopy mosaic of favourable and risky microclimate for insects. Journal of Animal Ecology 76, 424-438. This article has received the youth author award 2007 (Elton prize) from the British Ecological Society (BES) and the editors of the Journal of Animal Ecology.

Pincebourde S. & Casas J. (2006). Multitrophic biophysical budgets: Thermal ecology of an intimate herbivore insect plant interaction. Ecological Monographs 76, 175-194.

Pincebourde S., Frak E., Sinoquet H., Regnard J.L. & Casas J. (2006). Herbivory mitigation through increased water use efficiency in a leaf mining moth-apple tree relationship. Plant Cell and Environment 29, 2238-2247.

Pincebourde S. & Casas J. (2006). Leaf miner-induced changes in leaf transmittance cause variations in insect respiration rates. Journal of Insect Physiology 52, 194-201.

Casas J., Pincebourde S., Mandon N., Vannier F., Poujol R. & Giron D. (2005). Lifetime nutrient dynamics reveal simultaneous capital and income breeding in a parasitoid. Ecology 86, 545-554.

Loon J.J.A.v., Casas J. & Pincebourde S. (2005). Nutritional ecology of insect-plant interactions: persistent handicaps and the need for innovative approaches. Oikos 108, 194-201.

Feer F. & Pincebourde S. (2005). Diel flight activity and ecological segregation within an assemblage of tropical forest dung and carrion beetles. Journal of Tropical Ecology 21, 1-10.

Giron D., Pincebourde S. & Casas J. (2004). Lifetime gains of host-feeding in a synovigenic parasitic wasp. Physiological Entomology 29, 436-442.

PDF

Dr. Sylvain Pincebourde

2009-present. CNRS Research Scientist (CR2), IRBI (France).
2008- 2009. Postdoctoral position, IRBI (France).
2006-2007. Postdoctoral position, University South Carolina (USA).
2002-2005. PhD, IRBI (France).
2001-2002. Master, University François Rabelais (France).

Keywords:
Biotic interactions; Climate change; Environmental biophysics.

Physical ecology of trophic interactions

Back up

PDF