Lennart Persson

Contact Information

Position:

Professor emeritus

personbild

Works at:

Ecology and Environmental Sciences

Address:

Umeå universitet
SE-901 87 Umeå
Sverige

Visiting Address:

KBC-huset, plan 4, Linnaeus väg 6, Umeå, A4-34-15

Tel:

+46 90 786 63 16

Email:

lennart.persson@emg.umu.seEmail 1

lennart.persson@umu.seEmail 2

Lync:

Get in touch via Lync

Web Page:

http://www.emg.umu.se/om-institutionen/personal/persson-lennart Web Page
http://www.emg.umu.se/english/about-the-department/staff/persson-lennart Web Page

Research

Most organisms on Earth undergo major changes in size and/or morphology over their life cycle and the rate by which these changes occur is generally dependent on food supply. In many organisms this involves a change in individual weight many orders of magnitude from that the individual starts to search for resources independently until it reaches maturity. In fact, even in unicellular organisms will the individual cell exhibit at least a doubling (often more) in weight from cell division up to mitosis. This ubiquitous presence of ontogenetic development among organisms sharply contrasts to contemporary ecological theory as presented in standard textbooks where population dynamics is defined as fluctuations in time and space in number of individuals only and ontogenetic variation is totally ignored.

My research interest has over my whole scientific career delt with the implications of ontogenetic variation on population and community processes. Research approaches used include experimental studies from laboratory systems to whole lake experiments, long-term field studies and theoretical modeling. My research has since more than 20 years been carried out in close collaboration with my colleague and friend André M. de Roos, a theoretical biologist at the University of Amsterdam.

Our research has now reached a state of conceptualization where we propose a novel general theory of ecology. In this generic theory, contemporary unstructured ecological theory represents a limiting case only with ontogenetic symmetry within a richer generic theory that also includes ontogenetic asymmetry. Ontogenetic symmetry is defined as the special case when mass-specific rates of biomass production through somatic growth and reproduction and biomass loss through mortality are independent of body size. In all other cases ontogenetic asymmetry prevails. Ontogenetic asymmetry has major implications for both community structure and population dynamics. You can read more about this in our book Population and Community Ecology of Ontogenetic Development recently published in the Princeton University, Monographs in Population Biology Series.

You can also view a seminar (YouTube) entitled Symmetry breaking in ecological systems through different energetic efficiencies of juveniles and adults – a new paradigm unfolds? where I synthesize the main aspects of our present thinking. Also check 4 webinars by André De Roos that cover the most salient results of our book (http://staff.science.uva.nl/~aroos/Research/Webinars/index.html).


Page Editor: Elisabet Carlborg
2013-04-02

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Research area

Freshwater ecology

Video:Symmetry breaking in ecological systems

Seminar:

Symmetry breaking in ecological systems through different energetic efficiencies of juveniles and adults – a new paradigm unfolds?

Lennart Persson, professor in Aquatic Ecology, Umeå university.