Peatlands of the Madre de Dios River of Peru: Distribution, Geomorphology, and Habitat Diversity

Householder, John Ethan; Janovec, John P.; Tobler, Mathias W.; Page, Susan; Lähteenoja, Outi

doi:10.1007/s13157-012-0271-2

Cited by 69 publications

(70 citation statements)

References 28 publications

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“…Peak discharge from the wet season flood pulse occurs between April and May, as recorded at the Tamshiyacu River gauging station (Espinoza Villar et al, 2009b). Householder et al (2012) and Lahteenoja et al (2009a, b). Histosols form the dominant soil type for peatlands in this region (Andriesse, 1988;Lahteenoja and Page, 2011).…”

Section: Study Site and Sampling Designmentioning

confidence: 78%

“…Unlike their Southeast Asian counterparts, most peatlands in the Amazon basin are unaffected by human activity at the current time (Lahteenoja et al, 2009a, b;Lahteenoja and Page, 2011), except for ecosystems in the Madre de Dios region in southeastern Peru, which are impacted by gold mining (Householder et al, 2012). Because we have little or no data on ecosystem-level land-atmosphere fluxes from Amazonian peatlands (Lahteenoja et al, 2009b(Lahteenoja et al, , 2012Kirschke et al, 2013;Nisbet et al, 2014), it is difficult to ascertain if rates of GHG flux from these ecosystems are similar to or different from mineral soil wetlands (e.g., varzea).…”

Section: Introductionmentioning

confidence: 99%

“…Since the identification of extensive peat forming wetlands in the north (Lahteenoja et al, 2009a, b;Lahteenoja and Page 2011) and south (Householder et al, 2012) of the Peruvian Amazon, several studies have been undertaken to better characterize these habitats, investigating vegetation composition and habitat diversity (Draper et al, 2014;Kelly et al, 2014;Householder et al, 2012;Lahteenoja and Page, 2011), vegetation history (Lähteenoja and Roucoux, 2010), C stocks (Lahteenoja et al, 2012;Draper et al, 2014), hydrology (Kelly et al, 2014), and peat chemistry (Lahteenoja et al, 2009a, b). Most of the studies have focused on the PastazaMarañón foreland basin (PMFB), where one of the largest stretches of contiguous peatlands has been found (Lahteenoja et al 2009a;Lahteenoja and Page, 2011;Kelly et al, 2014), covering an estimated area of 35 600 ± 2133 km 2 (Draper et al, 2014).…”

Section: Introductionmentioning

confidence: 99%

“…Most of the studies have focused on the PastazaMarañón foreland basin (PMFB), where one of the largest stretches of contiguous peatlands has been found (Lahteenoja et al 2009a;Lahteenoja and Page, 2011;Kelly et al, 2014), covering an estimated area of 35 600 ± 2133 km 2 (Draper et al, 2014). Up to 90 % of the peatlands in the PMFB lie in flooded backwater river margins on floodplains and are influenced by large, annual fluctuations in water table caused by the Amazonian flood pulse (Householder et al, 2012;Lahteenoja et al, 2009a). These floodplain systems are dominated by peat deposits that range in depth from ∼ 3.9 m (Lahteenoja et al, 2009a) to ∼ 12.9 m (Householder et al, 2012).…”

Section: Introductionmentioning

confidence: 99%

“…Up to 90 % of the peatlands in the PMFB lie in flooded backwater river margins on floodplains and are influenced by large, annual fluctuations in water table caused by the Amazonian flood pulse (Householder et al, 2012;Lahteenoja et al, 2009a). These floodplain systems are dominated by peat deposits that range in depth from ∼ 3.9 m (Lahteenoja et al, 2009a) to ∼ 12.9 m (Householder et al, 2012). The remaining 10 % of these peatlands are not directly influenced by river flow and form domed (i.e., raised) nutrient-poor bogs that likely only receive water and nutrients from rainfall (Lahteenoja et al, 2009b).…”

Section: Introductionmentioning

confidence: 99%

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

et al. 2017

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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...

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Section: Study Site and Sampling Designmentioning

confidence: 78%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

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

et al. 2017

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Evaluating approaches for estimating peat depth

Parry

West

Holden

et al. 2014

J. Geophys. Res. Biogeosci.

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Estimates of peat depth are required to inform understanding of peatland development, functioning, and ecosystem services such as carbon storage. However, there is a considerable lack of peat depth data at local, national, and global scales. Recent studies have attempted to address this knowledge deficit by using manual probing and ground-penetrating radar (GPR) to estimate depth. Despite increasing application, little consideration has been given to the accuracy of either of these techniques. This study examines the accuracy of probing and GPR for measuring peat depth. Corresponding GPR and probing surveys were carried out at a catchment scale in a blanket peatland. GPR depth estimations, calibrated using common midpoint (CMP) surveys, were found to be on average 35% greater than probe measurements. The source of disagreement was found to be predominantly caused by depth probes becoming obstructed by artifacts within the peat body, although occasionally probing rods also penetrated sediments underlying the peat. Using the Complex Refractive Index Model, it was found that applying a single velocity of 0.036 m ns À1 across a single site may also result in À8 to +17% error in estimation of peat depth due to spatial variability in water content and porosity. It is suggested that GPR calibrated at each site using CMP surveys may provide a more accurate method for measuring peat depth.

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Source to sink: Evolution of lignin composition in the Madre de Dios River system with connection to the Amazon basin and offshore

et al. 2016

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While lignin geochemistry has been extensively investigated in the Amazon River, little is known about lignin distribution and dynamics within deep, stratified river channels or its transformations within soils prior to delivery to rivers. We characterized lignin phenols in soils, river particulate organic matter (POM), and dissolved organic matter (DOM) across a 4 km elevation gradient in the Madre de Dios River system, Peru, as well as in marine sediments to investigate the source‐to‐sink evolution of lignin. In soils, we found more oxidized lignin in organic horizons relative to mineral horizons. The oxidized lignin signature was maintained during transfer into rivers, and lignin was a relatively constant fraction of bulk organic carbon in soils and riverine POM. Lignin in DOM became increasingly oxidized downstream, indicating active transformation of dissolved lignin during transport, especially in the dry season. In contrast, POM accumulated undegraded lignin downstream during the wet season, suggesting that terrestrial input exceeded in‐river degradation. We discovered high concentrations of relatively undegraded lignin in POM at depth in the lower Madre de Dios River in both seasons, revealing a woody undercurrent for its transfer within these deep rivers. Our study of lignin evolution in the soil‐river‐ocean continuum highlights important seasonal and depth variations of river carbon components and their connection to soil carbon pools, providing new insights into fluvial carbon dynamics associated with the transfer of lignin biomarkers from source to sink.

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Peatlands of the Madre de Dios River of Peru: Distribution, Geomorphology, and Habitat Diversity

Cited by 69 publications

References 28 publications

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

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

Evaluating approaches for estimating peat depth

Source to sink: Evolution of lignin composition in the Madre de Dios River system with connection to the Amazon basin and offshore

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