Thursday, January 14, 2010

A new Whittaker biome diagram


Whittaker biome diagram from Chapin, Matson, Mooney Ecosystem Ecology text.

Whittaker long ago attempted to explain the major patterns of vegetation in the world with combinations of temperature and precipitation. The Whittaker biome diagram is a fundamental starting point for understanding the vegetation of the world.

There are general questions about the overarching role of climate in determining biomes vs. other state and interactive factors, as well as what the boundaries should be and how much to subdivide biomes.

With recent advances in our understanding of the distribution of climate across the globe, we can now see that some of the patterns were not detailed initially correctly. Andrew Elmore and I redrew the Whittaker biome diagram to also include the actual distribution of land area for each combination of temperature and precipitation.


A few major things change.

1) Tropical forests exist in areas much wetter than originally detailed. Much forest exists between 4.5 and 7 m of rain.

2) Most of the world's temperate wet forests are at about 4°C. Whittaker would have lopped off much of them.

3) There are scattered high precipitation areas between what was considered temperate and tropical wet forests. This happens to largely be Hawaii. These have never been classified into temperate vs. tropical biomes.


4 comments:

  1. You also changed the division between deserts and grasslands (i.e. at 30 ºC deserts were below 500 mm for Whittaker but your line cuts 30 ºC at about 600 or 700 mm) ¿Why?
    I have extracted values from your whittaker plot and have modelled the biomas (for my biogeography classes) using worldclim maps. Deserts apeared a bit larger than in other biome maps. Ana Cingolani

    ReplyDelete
    Replies
    1. I'm not sure we meant to shift that boundary. It was never meant to be super-quantitative, so feel free to adjust it back. I remember Terry adjusting the demarcation for tundra and boreal, that's about it. --Joe

      Delete
  2. The change in the classification of temperate rain forests is very interesting. Would it be possible to obtain the data you used to produce that figure? Thanks

    ReplyDelete