Posted by Jim:
Here’s a new paper I was lucky to join. It’s based on the incredible plant database generated by the folks behind the “Leaf Economics Spectrum”. It’s of some considerable interest I think. Using 9300 observations of folar N and P contents we show that, as overall nutrient content increases, P content increases FASTER than N content, such that a plot of log(N) vs log(P) has a slope of 2/3. This means that nutrient-rich (fast-growing) plants have lower N:P ratio than low-nutrient (slow-growing) plants, consistent with the Growth Rate Hypothesis. This is supported by other metrics in the leaf economics spectrum, such as the scaling of photosynthetic capacity and such which are known to scale with growth rate. Furthermore, the scaling is completely independent of plant phylogenetic group or biome.