Ecosystems are composed of plants, animals, and microscopic organisms that live in the soil, of which we cannot see, yet they drive nutrient cycling. These soil microbes transform detritus into usable reactive forms that fuel plants and microbes. In this system microbes specifically transform N from deposition into usable forms.
- The levels of ammonium (NH4+) were greater in snowpack than nitrate (NO3-) suggesting that the N from deposition is of agricultural origin.
- Microbial biomass was greater in the early communities followed by mid then late. This indicates high amounts of microbial activity in soil and processing of N.
- Soil microbial communities readily use this N and release nitrous oxide (N2O) and carbon dioxide (CO2) during metabolism, both of which are greenhouse gases (Figure 1).
- Leaching is a physical process that occurs when there is excess N in the system. Leaching can cause the soil to become acidified altering soil microbes, plant nutrition, and plant health. Leaching is particular. High levels of N can adversely affect oxygen levels for humans and aquatic systems. Early snow release sites had higher leaching of NH4+ than mid or late sites.
In 2014 Dr. Poinsatte furthered his study by applying N in amounts mimicking potential future deposition (+0.3, +0.5, and +1 g N/m2/yr) at the research sites.