ripples Frithjof Lutscher

Research


(this site is permanently under construction, just as research itself)
OttawaU

  1. Modeling River Ecosystems
  2. Invasion and Conservation Biology
  3. Individual Movement Behavior and pattern formation

Modeling River Ecosystems

Individuals in rivers are constantly subject to unidirectional flow. However, populations persist in the face of this potential wash-out ("drift paradox"). I model dispersal mechanisms of individuals in rivers and study the effect of different mechanisms on the dynamics of populations. When can populations invade against the flow and how fast? How far upstream can a population invade? What are the effects of environmental heterogeneity? How are two competitors affected by drift?

The following results on this topic are available at my publications page:
Vasilyeva and Lutscher (accepted)
Lutscher et al. (2010) Theor Ecol
Lewis et al. (2009) Park City Mathematics Series 14
Pringle et al. (2009) MEPS
Lutscher et al. (2007) TPB
Lutscher et al. (2006) BMB
Pachepsky et al. (2005) TPB
Lutscher et al. (2005) SIAP/SIAM REV


Coexistence in Rivers
Invasion and Conservation Biology:
Modeling Dispersal in Discrete-Time Systems

Dispersal is often modeled by reaction-diffusion equations in continuous time. But many species have distinct dispersal stages and dispersal times. The better modeling framework for these populations are integrodifference equations (IDEs). I am interested in the following questions. How does dispersal behavior influence invasion speeds? Which dispersal mechanisms allow population persistence? How big a habitat patch is required for persistence? How does dispersal influence the  dynamics of interacting populations?

The following results on this topic are available at my publications page:
Samia and Lutscher (2010) BMB
Lutscher (2010) Applicable Analysis
Dewhirst and Lutscher (2009) Ecology
Lutscher and Petrovskii (2008) J. Biol. Dynamics
Lutscher (2008) JMB
Fagan et al. (2007) Am. Nat.
Lutscher (2007) BMB
Fagan and Lutscher (2006) Ecol. Appl.
Cobbold et al. (2005) TPB
Lutscher and Lewis (2004) JMB


r0
Individual Movement Behavior, Random Walks and Pattern Formation

Diffusion equations result from position-jump processes. These might not always be a good description of the mechanisms of movement. Other processes that were suggested are for example velocity jump processes, which lead to transport equations, or the Langevin equations. I study the differences and similarities that result from these different processes, and in scaling relationships between them. I am particularly interested in pattern formation in these systems, such as alignment, aggregation, or rippling (myxobacteria).

The following results on this topic are available at my publications page:
Eftimie et al. (2007) BMB
Hadeler et al. (2004) M3AS
Lutscher (2003) Proceedings
Lutscher and Stevens (2002) JNS
Lutscher (2002) JMB
Lutscher (2003) EJAM
Hillen et al. (2001) JMAA


Schooling and Predation

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