Friday, January 13, 2017

87 years ago, in ecology

Louis Emberger was an important French plant ecologist in the first half of the last century, known for his work on the assemblages of plants in the mediterranean.

For example, the plot below is his published diagram showing minimum temperature of the coolest month versus a 'pluviometric quotient' capturing several aspects of temperature and precipitation from:

Emberger; La végétation de la région méditerranienne. Rev. Gén. Bot., 42 (1930)

Note this wasn't an unappreciated or ignored paper - it received a couple hundred citations, up until present day. Further, updated versions have appeared in more recent years (see bottom).

So it's fascinating to see the eraser marks and crossed out lines, this visualisation of scientific uncertainty. The final message from this probably depends on your perspective and personality:
  • Does it show that plant-environment modelling has changed a lot or that plant environmental modelling is still asking about the same underlying processes in similar ways?
  • Does this highlight the value of expert knowledge (still cited) or the limitations of expert knowledge (eraser marks)? 
It's certainly a reminder of how lucky we are to have modern graphical software :)

E.g. updated in Hobbs, Richard J., D. M. Richardson, and G. W. Davis. "Mediterranean-type ecosystems: opportunities and constraints for studying the function of biodiversity." Mediterranean-Type Ecosystems. Springer Berlin Heidelberg, 1995. 1-42.

Thanks to Eric Garnier, for finding and sharing the original Emberger diagram and the more recent versions.


Hans Castorp said...

We have the equivalent of erased marks in every computer statistical model - only we are often not unaware of it

moreover I think the lesson is that modeling of vegetation is higly nonlinear (the sinous lines), something we can account in our models but often do not

Caroline Tucker said...