Posted by Jim:
Here’s another neat one, this time from Mike Kaspari’s group. They show that fertilization of tropical detritus and such with sodium (Na) greatly stimulates its break-down. It also stimulated the abundance of termites and ants. Importantly, the stimulation effects was observed when Na was added as NaCl and as NaPO4, a cautionary tale to be careful with experimental controls when testing for P-limitation! It would be easy to misinterpret a response to a NaPO4 enrichment as a response to P if you didn’t have an appropriate sodium control. This is a very neat story, as the authors point out that plants have little use for Na (they generally use K for similar purposes in intracellular buffering and signalling) but heterotrophs do, including bacteria and animals. Thus, fundamental stoichiometric imbalance at the plant-“consumer” interface arises in various ways, not just because of the generally high C:nutrient ratios of plant biomass compared to animal biomass.