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Michalzik, Beate; Kalbitz, Karsten; Park, Ji‐Hyung; Solinger, Stephan; Matzner, Egbert

doi:10.1023/a:1006441620810

Cited by 525 publications

(138 citation statements)

References 59 publications

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“…Reported average rain DOC concentrations in the Amazon basin are significant with 1.3 to 3.9 mg C L −1 (Table 5; in most temperate regions average concentrations < 1 mg C L −1 are common, see Michalzik et al 2001), of the same magnitude as observed concentrations in white and clear-water Floodh 95th [m] No value 0-10 10-50 50-100 100-500 500-1000 > 1000…”

Section: Doc In Precipitation and Throughfallmentioning

confidence: 91%

“…rivers of the region (Moreira-Turcq et al, 2003). The spatial variation in rain DOC concentration is unknown and we thus assumed a constant value of 2.4 mg C L −1 throughout the Amazon basin, from the average of reported literature values (Table 5).…”

Section: S Riverh2o90th [Mm]mentioning

confidence: 99%

“…Another specific challenge is the reproduction of the different DOC loadings from the different sub-basins of the Amazon. While most of the major tributaries are white or clear-water rivers with low to moderate average DOC concentrations of up to 6 mg C L −1 , the Rio Negro, which after the Rio Madeira is the second largest tributary of the Amazon, is a black-water river with twice the concentrations of DOC (Moreira-Turcq et al, 2003).…”

Section: Introductionmentioning

confidence: 99%

“…We simulate all C fluxes and stocks at half-hourly to daily time steps, which allows the representation of seasonal and inter-annual variations. We focus on the lateral transfer of dissolved CO 2 and dissolved organic C (DOC), which represents the major and more reactive proportion of TOC exports to the coasts in the Amazon basin (Moreira-Turcq et al, 2003). Although we neglect the lateral transport of POC, we simulate decomposition of submerged litter in floodplains and rivers as an important source of DOC and CO 2 to the water column.…”

Section: Introductionmentioning

confidence: 99%

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ORCHILEAK (revision 3875): a new model branch to simulate carbon transfers along the terrestrial–aquatic continuum of the Amazon basin

et al. 2017

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Abstract. Lateral transfer of carbon (C) from terrestrial ecosystems into the inland water network is an important component of the global C cycle, which sustains a large aquatic CO 2 evasion flux fuelled by the decomposition of allochthonous C inputs. Globally, estimates of the total C exports through the terrestrial-aquatic interface range from 1.5 to 2.7 Pg C yr −1 (Cole et al., 2007;Battin et al., 2009;Tranvik et al., 2009), i.e. of the order of 2-5 % of the terrestrial NPP. Earth system models (ESMs) of the climate system ignore these lateral transfers of C, and thus likely overestimate the terrestrial C sink.In this study, we present the implementation of fluvial transport of dissolved organic carbon (DOC) and CO 2 into ORCHIDEE (Organising Carbon and Hydrology in Dynamic Ecosystems), the land surface scheme of the Institut PierreSimon Laplace ESM. This new model branch, called OR-CHILEAK, represents DOC production from canopy and soils, DOC and CO 2 leaching from soils to streams, DOC decomposition, and CO 2 evasion to the atmosphere during its lateral transport in rivers, as well as exchange with the soil carbon and litter stocks on floodplains and in swamps. We parameterized and validated ORCHILEAK for the Amazon basin, the world's largest river system with regard to discharge and one of the most productive ecosystems in the world.With ORCHILEAK, we are able to reproduce observed terrestrial and aquatic fluxes of DOC and CO 2 in the Amazon basin, both in terms of mean values and seasonality. In addition, we are able to resolve the spatio-temporal variability in C fluxes along the canopy-soil-water continuum at high resolution (1 • , daily) and to quantify the different terrestrial contributions to the aquatic C fluxes. We simulate that more than two-thirds of the Amazon's fluvial DOC export are contributed by the decomposition of submerged litter. Throughfall DOC fluxes from canopy to ground are about as high as the total DOC inputs to inland waters. The latter, however, are mainly sustained by litter decomposition. Decomposition of DOC and submerged plant litter contributes slightly more than half of the CO 2 evasion from the water surface, while the remainder is contributed by soil respiration. Total CO 2 evasion from the water surface equals about 5 % of the terrestrial NPP. Our results highlight that ORCHILEAK is well suited to simulate carbon transfers along the terrestrialaquatic continuum of tropical forests. It also opens the perspective that provided parameterization, calibration and validation is performed for other biomes, the new model branch could improve the quantification of the global terrestrial C sink and help better constrain carbon cycle-climate feedbacks in future projections.

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Section: Doc In Precipitation and Throughfallmentioning

confidence: 91%

Section: S Riverh2o90th [Mm]mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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ORCHILEAK (revision 3875): a new model branch to simulate carbon transfers along the terrestrial–aquatic continuum of the Amazon basin

et al. 2017

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“…riod are similarly large, thus pointing to a negligible effect of forest disturbance on DOC leaching. Numerous studies have identified the forest floor as a DOC source (Borken et al, 2011;Michalzik et al, 2001). Windthrow generally causes a (short-term) pulse of above-and belowground litter (Harmon et al, 2011).…”

Section: Impact Of Stormsmentioning

confidence: 99%

Model-aided quantification of dissolved carbon and nitrogen release after windthrow disturbance in an Austrian karst system

et al. 2016

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Abstract. Karst systems are important for drinking water supply. Future climate projections indicate increasing temperature and a higher frequency of strong weather events. Both will influence the availability and quality of water provided from karst regions. Forest disturbances such as windthrow can disrupt ecosystem cycles and cause pronounced nutrient losses from the ecosystems. In this study, we consider the time period before and after the wind disturbance period (2007/08) to identify impacts on DIN (dissolved inorganic nitrogen) and DOC (dissolved organic carbon) with a process-based flow and solute transport simulation model. When calibrated and validated before the disturbance, the model disregards the forest disturbance and its consequences on DIN and DOC production and leaching. It can therefore be used as a baseline for the undisturbed system and as a tool for the quantification of additional nutrient production. Our results indicate that the forest disturbance by windthrow results in a significant increase of DIN production lasting ∼ 3.7 years and exceeding the pre-disturbance average by 2.7 kg ha −1 a −1 corresponding to an increase of 53 %. There were no significant changes in DOC concentrations. With simulated transit time distributions we show that the impact on DIN travels through the hydrological system within some months. However, a small fraction of the system outflow (< 5 %) exceeds mean transit times of > 1 year.

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The nitrogen cycle of tropical montane forest in Ecuador turns inorganic under environmental change

Wilcke

Leimer

Peters

et al. 2013

Global Biogeochemical Cycles

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[1] Water-bound nitrogen (N) cycling in temperate terrestrial ecosystems of the Northern Hemisphere is today mainly inorganic because of anthropogenic release of reactive N to the environment. In little-industrialized and remote areas, in contrast, a larger part of N cycling occurs as dissolved organic N (DON). In a north Andean tropical montane forest in Ecuador, the N cycle changed markedly during 1998-2010 along with increasing N deposition and reduced soil moisture. The DON concentrations and the fractional contribution of DON to total N significantly decreased in rainfall, throughfall, and soil solutions. This inorganic turn of the N cycle was most pronounced in rainfall and became weaker along the flow path of water through the system until it disappeared in stream water. Decreasing organic contributions to N cycling were caused not only by increasing inorganic N input but also by reduced DON production and/or enhanced DON decomposition. Accelerated DON decomposition might be attributable to less waterlogging and higher nutrient availability. Significantly increasing NO 3 -N concentrations and NO 3 -N/NH 4 -N concentration ratios in throughfall and litter leachate below the thick organic layers indicated increasing nitrification. In mineral soil solutions, in contrast, NH 4 -N concentrations increased and NO 3 -N/NH 4 -N concentration ratios decreased significantly, suggesting increasing net ammonification. Our results demonstrate that the remote tropical montane forests on the rim of the Amazon basin experienced a pronounced change of the N cycle in only one decade. This change likely parallels a similar change which followed industrialization in the temperate zone of the Northern Hemisphere more than a century ago.

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Untitled

Cited by 525 publications

References 59 publications

ORCHILEAK (revision 3875): a new model branch to simulate carbon transfers along the terrestrial–aquatic continuum of the Amazon basin

ORCHILEAK (revision 3875): a new model branch to simulate carbon transfers along the terrestrial–aquatic continuum of the Amazon basin

Model-aided quantification of dissolved carbon and nitrogen release after windthrow disturbance in an Austrian karst system

The nitrogen cycle of tropical montane forest in Ecuador turns inorganic under environmental change

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