Ecosystem engineering and stream ecology
Ecosystem engineering is generally defined as the process by which organisms modify their physical environment from one physical state to another (Jones et al. 1994, 1997). It encompasses the construction, destruction, modification, and maintenance of habitats and can be directly induced via organisms’ physical structures (i.e., autogenic engineering, e.g., plants) or indirectly by affecting the physical state of living or dead material (i.e., allogenic engineering, e.g., beaver’s dam). The picture on the left is the biggest beaver dam in the world!
The picture on the right is from a seminal journal article by Vannote et al. (1980). Although it has been heavily discussed and argued about since then, in their article (The River Continuum Concept) the authors illustrated an important point --> a stream is made of interactions (be them in a continuum or in a more complex shape) between the organisms inhabiting the stream and the physical structure of this stream. Attention, when we say organisms we need to consider all of them, from the obvious fish and invertebrates populating the water to the less thought of (but as important) trees along the river banks, vertebrates (birds, mammals, etc.) visiting the stream!
My own research
Currently a Ph.D. student at the University of Kentucky, I am working on my dissertation, if it sounds like a daunting beast ... well it is! Joke aside, the primary goal of my dissertation is to quantify how an ecosystem engineer (crayfish) directly and indirectly modifies its habitat. For that purpose, I focus on how natural factors modulate those effects to better understand the full breadth of engineering properties. I've got different project that I worked on or that I am working on or that I will work on (hopefully soon).
First, I investigated the interactive effect of crayfish regeneration and predator exposure for crayfish-induced turbidity in streams. Second, I documented the impact of cheliped regeneration on burrowing structure and completion time. Third, I propose to extend this last project by studying the energetic costs associated with regeneration for crayfish burrowing. Finally, I intend to build a mathematical model of a stream community to describe how engineering works within freshwater communities including crayfish by capturing variability both of crayfish engineering and of processes influencing crayfish engineering.
Scientific papers you might want to look at ...
Because everyone should be able to read scientific papers for free, at least the old one, here are the ecosystem engineering seminal papers:
- Jones et al. - 1994 - Organisms as ecosystem engineers;
- Jones et al. - 1997 - Ecosystem engineering by organisms: Why semantics matters.
Now, you might want to check out my personal research ... if that's the case first thank you for your interest, I truly appreciate that someone else than my mom will read my work (although I suspect that my papers only end up stuck on her fridge under a magnet in France)! Oh, you're still here, well I guess you can check them out now:
- Dunoyer et al. - 2014 - Effects of crayfish on leaf litter breakdown and shredder prey: Are native and introduced species functionally redundant?
- Bichet et al. - 2014 - Females tend to prefer genetically similar mates in an island population of house sparrows.
- Garcia-Ramos et al. - 2015 - Evolution of resistance by a native competitor can lead to invasion collapse in disease-mediated invasions.