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 (Rs). To fill this gap, we assessed the effects of N supply on Rs dynamics in the following two Mediterranean sites: Capo Caccia (Italy), where 30 kg ha−1 year−1 was supplied for 3 years, and El Regajal (Spain), where plots were treated with 10, 20, or 50 kg N ha−1 year−1 for 8 years. Results show a complex, non-linear response of soil respiration (Rs) to N additions with Rs overall increasing at Capo Caccia and decreasing at El Regajal. This suggests that the response of Rs 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 Rs 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.

Contrasting effects of nitrogen addition on soil respiration in two Mediterranean ecosystems / Lo Cascio, Mauro; Morillas, Lourdes; Ochoa-Hueso, Raúl; Munzi, Silvana; Roales, Javier; Hasselquist, Niles J.; Manrique, Esteban; Spano, Donatella; ABOU JAOUDé, Renée; Mereu, Simone. - In: ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL. - ISSN 0944-1344. - 24:34(2017), pp. 26160-26171. [10.1007/s11356-017-8852-5]

Contrasting effects of nitrogen addition on soil respiration in two Mediterranean ecosystems

Lo Cascio, Mauro;Morillas, Lourdes;Spano, Donatella;ABOU JAOUDé, Renée;Mereu, Simone
2017

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 (Rs). To fill this gap, we assessed the effects of N supply on Rs dynamics in the following two Mediterranean sites: Capo Caccia (Italy), where 30 kg ha−1 year−1 was supplied for 3 years, and El Regajal (Spain), where plots were treated with 10, 20, or 50 kg N ha−1 year−1 for 8 years. Results show a complex, non-linear response of soil respiration (Rs) to N additions with Rs overall increasing at Capo Caccia and decreasing at El Regajal. This suggests that the response of Rs 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 Rs 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.
Contrasting effects of nitrogen addition on soil respiration in two Mediterranean ecosystems / Lo Cascio, Mauro; Morillas, Lourdes; Ochoa-Hueso, Raúl; Munzi, Silvana; Roales, Javier; Hasselquist, Niles J.; Manrique, Esteban; Spano, Donatella; ABOU JAOUDé, Renée; Mereu, Simone. - In: ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL. - ISSN 0944-1344. - 24:34(2017), pp. 26160-26171. [10.1007/s11356-017-8852-5]
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Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11388/220864
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