Decadal fates and impacts of nitrogen additions on temperate forest carbon storage:a data-model comparison
| Autor: | Peter Hess, Marie-Cécile Gruselle, Danica Lombardozzi, Christine L. Goodale, William R. Wieder, Per Gundersen, Filip Moldan, R. Quinn Thomas, Ivan J. Fernandez, Susan J. Cheng, J. Vira, Patrick Schleppi, Knute J. Nadelhoffer |
|---|---|
| Přispěvatelé: | Forest Resources and Environmental Conservation |
| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
0106 biological sciences
010504 meteorology & atmospheric sciences 04 Earth Sciences 05 Environmental Sciences lcsh:Life chemistry.chemical_element Environmental Sciences & Ecology engineering.material SCOTS PINE FOREST Atmospheric sciences 010603 evolutionary biology 01 natural sciences lcsh:QH540-549.5 TRACER Meteorology & Atmospheric Sciences Ecosystem Geosciences Multidisciplinary REACTIVE GASES Ecology Evolution Behavior and Systematics 0105 earth and related environmental sciences Earth-Surface Processes GLOBAL PATTERNS CLIMATE-CHANGE Ecology N-15 TRACERS ECOSYSTEM RESPONSE lcsh:QE1-996.5 Temperate forest NORWAY SPRUCE Geology Soil carbon 06 Biological Sciences Nitrogen lcsh:Geology lcsh:QH501-531 chemistry Soil water Physical Sciences engineering lcsh:Ecology Fertilizer Cycling SOIL CARBON Life Sciences & Biomedicine N-2 FIXATION NUTRIENT COMPETITION |
| Zdroj: | Cheng, S J, Hess, P G, Wieder, W R, Thomas, R Q, Nadelhoffer, K J, Vira, J, Lombardozzi, D L, Gundersen, P, Fernandez, I J, Schleppi, P, Gruselle, M-C, Moldan, F & Goodale, C L 2019, ' Decadal fates and impacts of nitrogen additions on temperate forest carbon storage : a data-model comparison ', Biogeosciences, vol. 16, no. 13, pp. 2771-2793 . https://doi.org/10.5194/bg-16-2771-2019 Biogeosciences, Vol 16, Pp 2771-2793 (2019) |
| DOI: | 10.5194/bg-16-2771-2019 |
| Popis: | To accurately capture the impacts of nitrogen (N) on the land carbon (C) sink in Earth system models, model responses to both N limitation and ecosystem N additions (e.g., from atmospheric N deposition and fertilizer) need to be evaluated. The response of the land C sink to N additions depends on the fate of these additions: that is, how much of the added N is lost from the ecosystem through N loss pathways or recovered and used to increase C storage in plants and soils. Here, we evaluate the C–N dynamics of the latest version of a global land model, the Community Land Model version 5 (CLM5), and how they vary when ecosystems have large N inputs and losses (i.e., an open N cycle) or small N inputs and losses (i.e., a closed N cycle). This comparison allows us to identify potential improvements to CLM5 that would apply to simulated N cycles along the open-to-closed spectrum. We also compare the short- (15N tracer addition experiments at eight temperate forest sites. Simulations using both open and closed N cycles overestimated plant N recovery following N additions. In particular, the model configuration with a closed N cycle simulated that plants acquired more than twice the amount of added N recovered in 15N tracer studies on short timescales (CLM5: 46±12 %; observations: 18±12 %; mean across sites ±1 standard deviation) and almost twice as much on longer timescales (CLM5: 23±6 %; observations: 13±5 %). Soil N recoveries in simulations with closed N cycles were closer to observations in the short term (CLM5: 40±10 %; observations: 54±22 %) but smaller than observations in the long term (CLM5: 59±15 %; observations: 69±18 %). Simulations with open N cycles estimated similar patterns in plant and soil N recovery, except that soil N recovery was also smaller than observations in the short term. In both open and closed sets of simulations, soil N recoveries in CLM5 occurred from the cycling of N through plants rather than through direct immobilization in the soil, as is often indicated by tracer studies. Although CLM5 greatly overestimated plant N recovery, the simulated increase in C stocks to recovered N was not much larger than estimated by observations, largely because the model's assumed C:N ratio for wood was nearly half that suggested by measurements at the field sites. Overall, results suggest that simulating accurate ecosystem responses to changes in N additions requires increasing soil competition for N relative to plants and examining model assumptions of C:N stoichiometry, which should also improve model estimates of other terrestrial C–N processes and interactions. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|