Regional N&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt;O fluxes in Amazonia derived from aircraft vertical profiles

D’Amelio, Monica Taís Siqueira; Gatti, Luciana V.; Miller, J. B.; Tans, P. P.

doi:10.5194/acp-9-8785-2009

Cited by 35 publications

(25 citation statements)

References 51 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The global source strength is estimated to be 17.7 Tg N yr −1 , with agriculture contributing 2.8 (1.7-4.8) Tg N yr −1 and soils under natural vegetation 6.6 (3.3-9.0) Tg N yr −1 (IPCC, 2007;Hirsch et al, 2006). Both estimates based on bottom-up approaches (Stehfest and Bouwman, 2006) and on observations of the N 2 O atmospheric column (Kort et al, 2011;D'Amelio et al, 2009;Hirsch et al, 2006) suggest that 50-64 % of the atmospheric N 2 O derive from the (sub)tropical zone 0 • to 30 • N. Much of the N 2 O attributable to this zone is emitted from forest soils (Melillo et al, 2001;Werner et al, 2007a;Rowlings et al, 2012). So far, N 2 O flux data from subtropical forests are scarce making this biome an underinvestigated component of the global N 2 O budget.…”

Section: Introductionmentioning

confidence: 99%

Spatial and temporal variability of N<sub>2</sub>O emissions in a subtropical forest catchment in China

Zhu

Mulder

et al. 2013

Biogeosciences

View full text Add to dashboard Cite

Abstract. Subtropical forests in southern China have received chronically large amounts of atmogenic nitrogen (N), causing N saturation. Recent studies suggest that a significant proportion of the N input is returned to the atmosphere, in part as nitrous oxide (N2O). We measured N2O emission fluxes by closed chamber technique throughout two years in a Masson pine-dominated headwater catchment with acrisols (pH ~ 4) at Tieshanping (Chongqing, SW China) and assessed the spatial and temporal variability in two landscape elements typical for this region: a mesic forested hillslope (HS) and a hydrologically connected, terraced groundwater discharge zone (GDZ) in the valley bottom. High emission rates of up to 1800 μg N2O-N m−2 h−1 were recorded on the HS shortly after rain storms during monsoonal summer, whereas emission fluxes during the dry winter season were generally low. Overall, N2O emission was lower in GDZ than on HS, rendering the mesic HS the dominant source of N2O in this landscape. Temporal variability of N2O emissions on HS was largely explained by soil temperature (ST) and moisture, pointing at denitrification as a major process for N removal and N2O production. The concentration of nitrate (NO3−) in pore water on HS was high even in the rainy season, apparently never limiting denitrification and N2O production. The concentration of NO3− decreased along the terraced GDZ, indicating efficient N removal, but with moderate N2O-N loss. The extrapolated annual N2O fluxes from soils on HS (0.54 and 0.43 g N2O-N m−2 yr−1 for a year with a wet and a dry summer, respectively) are among the highest N2O fluxes reported from subtropical forests so far. Annual N2O-N emissions amounted to 8–10% of the annual atmogenic N deposition, suggesting that forests on acid soils in southern China are an important, hitherto overlooked component of the anthropogenic N2O budget.

show abstract

Section: Introductionmentioning

confidence: 99%

Spatial and temporal variability of N<sub>2</sub>O emissions in a subtropical forest catchment in China

Zhu

Mulder

et al. 2013

Biogeosciences

View full text Add to dashboard Cite

show abstract

“…[3] Top-down approaches take different forms. Regional studies, typically of limited spatial and/or temporal scale, have employed total column [Wunch et al, 2009], surface [Thompson et al, 2010], satellite [Bergamaschi et al, 2007], and aircraft observations [Kort et al, 2008;D'Amelio et al, 2009]. Global studies make use of data from surface stations and/or satellite observations to invert for surface fluxes, with aircraft data typically only used for post-inversion comparisons [Stephens et al, 2007;Chevallier et al, 2010] due to limited spatial and temporal coverage, with a recent exception where upper tropospheric data are used in an inversion [Patra et al, 2011].…”

Section: Introductionmentioning

confidence: 99%

Tropospheric distribution and variability of N₂O: Evidence for strong tropical emissions

Kort

Patra

Ishijima

et al. 2011

Geophysical Research Letters

View full text Add to dashboard Cite

[1] Measurements of atmospheric N 2 O spanning altitudes from the surface to 14 km, and latitudes from 67°S to 85°N, show high concentrations in the tropics and subtropics, with strong maxima in the middle and upper troposphere. The pattern varies significantly over time scales of a few weeks. Global simulations do not accurately capture observed distributions with latitude, altitude, or time. Inversion results indicate strong, episodic inputs of nitrous oxide from tropical regions (as large as 1 Tg N-N 2 O over 9 weeks) are necessary to produce observed vertical and latitudinal distributions. These findings highlight strong tropical sources of N 2 O with high temporal variability, and the necessity of using full vertical profile observations in deriving emissions from atmospheric measurements. Citation: Kort,

show abstract

“…While we have a relatively strong understanding of the role that the Amazon plays in regional and global atmospheric budgets of these gases, one of the key gaps in knowledge is the contribution of specific ecosystem types to regional fluxes of GHGs (Huang et al, 2008;Saikawa et al, 2013Saikawa et al, , 2014. In particular, our understanding of the contribution of Amazonian wetlands to regional C and GHG budgets is weak, as the majority of past ecosystem-scale studies have focused on terra firme forests and savannas (D'Amelio et al, 2009;Saikawa et al, 2013;Wilson et al, 2016;Kirschke et al, 2013;Nisbet et al, 2014). Empirical studies of GHG fluxes from Amazonian wetlands are more limited in geographic scope and have focused on three major areas: wetlands in the state of Amazonas near the city of Manaus (Devol et al, 1990;Bartlett et al, 1988Bartlett et al, , 1990Keller et al, 1986), the Pantanal region (Melack et al, 2004;Marani and Alvalá, 2007;Liengaard et al, 2013), and the Orinoco River basin (Smith et al, 2000;Lavelle et al, 2014).…”

Section: Introductionmentioning

confidence: 99%

Seasonal variability in methane and nitrous oxide fluxes from tropical peatlands in the western Amazon basin

et al. 2017

View full text Add to dashboard Cite

Abstract. The Amazon plays a critical role in global atmospheric budgets of methane (CH 4 ) and nitrous oxide (N 2 O). However, while we have a relatively good understanding of the continental-scale flux of these greenhouse gases (GHGs), one of the key gaps in knowledge is the specific contribution of peatland ecosystems to the regional budgets of these GHGs. Here we report CH 4 and N 2 O fluxes from lowland tropical peatlands in the Pastaza-Marañón foreland basin (PMFB) in Peru, one of the largest peatland complexes in the Amazon basin. The goal of this research was to quantify the range and magnitude of CH 4 and N 2 O fluxes from this region, assess seasonal trends in trace gas exchange, and determine the role of different environmental variables in driving GHG flux. Trace gas fluxes were determined from the most numerically dominant peatland vegetation types in the region: forested vegetation, forested (short pole) vegetation, Mauritia flexuosadominated palm swamp, and mixed palm swamp. Data were collected in both wet and dry seasons over the course of four field campaigns from 2012 to 2014. Diffusive CH 4 emissions averaged 36.05 ± 3.09 mg CH 4 -C m −2 day −1 across the entire dataset, with diffusive CH 4 flux varying significantly among vegetation types and between seasons. Net ebullition of CH 4 averaged 973.3 ± 161.4 mg CH 4 -C m −2 day −1 and did not vary significantly among vegetation types or between seasons. Diffusive CH 4 flux was greatest for mixed palm swamp (52.0 ± 16.0 mg CH 4 -C m −2 day −1 ), followed by M. flexuosa palm swamp (36.7 ± 3.9 mg CH 4 -C m −2 day −1 ), forested (short pole) vegetation (31.6 ± 6.6 mg CH 4 -C m −2 day −1 ), and forested vegetation (29.8 ± 10.0 mg CH 4 -C m −2 day −1 ). Diffusive CH 4 flux also showed marked seasonality, with divergent seasonal patterns among ecosystems. Forested vegetation and mixed palm swamp showed significantly higher dry season (47.2 ± 5.4 mg CH 4 -C m −2 day −1 and 85.5 ± 26.4 mg CH 4 -C m −2 day −1 , respectively) compared to wet season emissions (6.8 ± 1.0 mg CH 4 -C m −2 day −1 and 5.2 ± 2.7 mg CH 4 -C m −2 day −1 , respectively). In contrast, forested (short pole) vegetation and M. flexuosa palm swamp showed the opposite trend, with dry season flux of 9.6 ± 2.6 and 25.5 ± 2.9 mg CH 4 -C m −2 day −1 , respectively, versus wet season flux of 103.4 ± 13.6 and 53.4 ± 9.8 mg CH 4 -C m −2 day −1 , respectively. These divergent seasonal trends may be linked to very high water tables (> 1 m) in forested vegetation and mixed palm swamp during the wet season, which may have constrained CH 4 transport across the soil-atmosphere interface. Diffusive N 2 O flux was very low (0.70 ± 0.34 µg N 2 O-N m −2 day −1 ) and did not vary significantly among ecosystems or between seasons. We conclude that peatlands in the PMFB are large and regionally significant sources of atmospheric CH 4 that need to be better accounted for in regional emissions inventories. In contrast, N 2 O flux was negligible, suggesting that this region does not make a significant contribut...

show abstract

Regional N<sub>2</sub>O fluxes in Amazonia derived from aircraft vertical profiles

Cited by 35 publications

References 51 publications

Spatial and temporal variability of N<sub>2</sub>O emissions in a subtropical forest catchment in China

Spatial and temporal variability of N<sub>2</sub>O emissions in a subtropical forest catchment in China

Tropospheric distribution and variability of N₂O: Evidence for strong tropical emissions

Seasonal variability in methane and nitrous oxide fluxes from tropical peatlands in the western Amazon basin

Contact Info

Product

Resources

About

Regional N&lt;sub&gt;2&lt;/sub&gt;O fluxes in Amazonia derived from aircraft vertical profiles

Cited by 35 publications

References 51 publications

Spatial and temporal variability of N&lt;sub&gt;2&lt;/sub&gt;O emissions in a subtropical forest catchment in China

Spatial and temporal variability of N&lt;sub&gt;2&lt;/sub&gt;O emissions in a subtropical forest catchment in China

Tropospheric distribution and variability of N2O: Evidence for strong tropical emissions

Seasonal variability in methane and nitrous oxide fluxes from tropical peatlands in the western Amazon basin

Contact Info

Product

Resources

About

Regional N<sub>2</sub>O fluxes in Amazonia derived from aircraft vertical profiles

Spatial and temporal variability of N<sub>2</sub>O emissions in a subtropical forest catchment in China

Spatial and temporal variability of N<sub>2</sub>O emissions in a subtropical forest catchment in China

Tropospheric distribution and variability of N₂O: Evidence for strong tropical emissions