New approach to predicting climate from leaf traits . . .
How much can a leaf tell you about the environment in which is grows? Can ecology become more predictive? We have been working on a variety of approaches to assess the ‘predictive nature’ of leaves. The idea is that that the constellation of traits that define a leaf actually reflect a set of coordinated shifts to maximize carbon gain and minimize a set of trade offs (for example see Blonder et al. 2011). In particular, in our recent paper because plant growth requires water loss through transpiration in the leaves, and transpiration requires water supply, which is provided by the leaf veins, then shifts in climate will then influence the rate of transport through venation networks. So, if natural selection has honed plant growth rate and water loss rate across different environments, then only certain leaf venation networks should be viable in each environment.
In work spearheaded by Benjamin Blonder we just published a new paper arguing that it may actually be possible to predict the local climate and atmospheric conditions by measuring traits associated with the venation network.
The paper “Inferring climate from angiosperm leaf venation networks” argues that that one can use the community-mean vein density to predict growing season temperature and atmospheric CO2 concentration. The key assumption is that leaf water supply is matched to water demand in the local environment. We tested the model predictions using leaves from 17 temperate and tropical sites that span broad climatic gradients. Overall, we find quantitative agreement between predicted and observed climate values. We also highlight additional leaf traits that may improve predictions.
The theory developed in the paper provides a set of mechanistic equations that help to link leaf traits and climate. Because these leaf traits are tightly linked to the flux of carbon and water these traits could be used to better assess the ecosystem implications for changing climate, the reconstruction of past paleo climates, and for understanding why shifts in certain traits in ecological communities are more tightly linked to broad scale climate gradients . Ben wrote a nice piece summarizing the paper that you can read here on his blog.