Do actively cycling C and N pools depend ultimately on soil P supply? Across-biome synthesis
In terrestrial systems the nitrogen cycle is more open than the phosphorus cycle. New N accumulates by biological N fixation and atmospheric deposition, and is readily lost from the system when N is in excess of biological demand. In contrast, available P is supplied from more slowly cycling soil pools already present in the system. Thus, long term rates of ecosystem N accumulation may be constrained by the rate at which available P is provided from stocks of slowly cycling P. In a related workshop at the LTER All Scientists’ Meeting (ASM), participants found soil N to be positively correlated with both total and slowly available soil P within each of nine long-term research sites across North America, including six LTER sites. The SPARC project includes ASM workshop participants as well as additional members. The objectives of this synthesis are to:
- produce a paper synthesizing the dependency of soil N accumulation on slowly cycling P within sites, based on the results of the ASM workshop,
- compile a comprehensive database for soil P stocks across terrestrial LTER sites including information on the availability of related datasets on productivity and nutrient cycling, and
- scope additional synthesis papers and potential activities.