Understanding the biogeochemical cycling of an element through the traditional flux and pool methods has been an effective strategy for decades. It allows us to approximate steady state and if pools are increasing or depleting. 

Isotopes are an important tool to actually determine if the added element is in fact being stabilized or if the older material is remaining while and new material flows out rapidly. 

We were very fortunate to be able to collaborate with Dr. John Higgins at Princeton University for his expertise for measuring isotopes. 

Alex and Justin had a wonderful tour of the facilities and are excited to measure the isotopic ratio of nutrient elements to truly see their rate of cycling in forests of Vermont and New Hampshire.