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Contrasting effects of nitrogen addition on soil respiration in two Mediterranean ecosystems
- Source :
- Digital.CSIC. Repositorio Institucional del CSIC, instname
- Publication Year :
- 2016
-
Abstract
- Increased atmospheric nitrogen (N) deposition is known to alter ecosystem carbon source-sink dynamics through changes in soil CO2 fluxes. However, a limited number of experiments have been conducted to assess the effects of realistic N deposition in the Mediterranean Basin, and none of them have explored the effects of N addition on soil respiration (R s ). To fill this gap, we assessed the effects of N supply on R s dynamics in the following two Mediterranean sites: Capo Caccia (Italy), where 30kgha-1year-1 was supplied for 3years, and El Regajal (Spain), where plots were treated with 10, 20, or 50kg Nha-1year-1 for 8years. Results show a complex, non-linear response of soil respiration (R s ) to N additions with R s overall increasing at Capo Caccia and decreasing at El Regajal. This suggests that the response of R s to N addition depends on dose and duration of N supply, and the existence of a threshold above which the N introduced in the ecosystem can affect the ecosystem's functioning. Soil cover and seasonality of precipitations also play a key role in determining the effects of N on R s as shown by the different responses observed across seasons and in bare soil vs. the soil under canopy of the dominant species. These results show how increasing rates of N addition may influence soil C dynamics in semiarid ecosystems in the Mediterranean Basin and represent a valuable contribution for the understanding and the protection of Mediterranean ecosystems.<br />This research was also financially supported by a research grant of the Spanish Ministerio de Economía y Competitividad (BIOMOD CGL-2013-44661-R). Comunidad de Madrid also funded this work through REMEDINAL-3 project (S2013/MAE-2719)
- Subjects :
- Mediterranean climate
Canopy
Soil nutrients
Spatial-temporal variability
Carbon Sequestration
010504 meteorology & atmospheric sciences
Nitrogen
Health, Toxicology and Mutagenesis
Air pollution
Carbon and nitrogen interaction
Carbon sequestration
CO2 emissions
01 natural sciences
Mediterranean Basin
Soil respiration
Soil
Environmental Chemistry
Ecosystem
Carbon use efficiency (CUE)
Global change
Soil Microbiology
0105 earth and related environmental sciences
Ecology
Soil classification
04 agricultural and veterinary sciences
General Medicine
Plants
Pollution
Italy
Spain
040103 agronomy & agriculture
0401 agriculture, forestry, and fisheries
Environmental science
Seasons
Soil microbiology
Fertilization experiment
Subjects
Details
- ISSN :
- 16147499
- Volume :
- 24
- Issue :
- 34
- Database :
- OpenAIRE
- Journal :
- Environmental science and pollution research international
- Accession number :
- edsair.doi.dedup.....2a2faa71c668eea0a09350a382414458