Matti Barthel's research while affiliated with Eawag: Das Wasserforschungs-Institut des ETH-Bereichs and other places

Publications (49)

Article
Freshwater aquaculture ponds constitute one of the important anthropogenic sources of atmospheric methane (CH4). Nevertheless, estimates of global CH4 emissions from freshwater aquaculture have large uncertainties due to a lack of data from different aquaculture types. Furthermore, despite that ebullition is a major pathway of CH4 in aquatic system...
Article
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Secondary forests constitute an increasingly important component of tropical forests worldwide. Although cycling of essential nutrients affects recovery trajectories of secondary forests, the effect of nutrient limitation on forest regrowth is poorly constrained. Here we use three lines of evidence from secondary forest succession sequences in cent...
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Efficient utilization of incident solar radiation and rainwater conservation in rain-fed smallholder cropping systems require the development and adoption of cropping systems with high resource use efficiency. Due to the popularity of cassava-maize intercropping and the food security and economic importance of both crops in Nigeria, we investigated...
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Aquatic losses of nutrients are important loss vectors in the nutrient budgets of tropical forests. Traditionally, research has focused mainly on losses of inorganic nutrient forms, whereas the potential contribution of organic and particulate losses to the total nutrient export budget is much less constrained. In this study, we quantified full aqu...
Article
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Background Across the tropics, the share of secondary versus primary forests is strongly increasing. The high rate of biomass accumulation during this secondary succession relies on the availability of essential nutrients, such as nitrogen (N). Nitrogen primarily limits many young secondary forests in the tropics. However, recent studies have shown...
Article
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Rivers act as a natural source of greenhouse gases (GHGs). However, anthropogenic activities can largely alter the chemical composition and microbial communities of rivers, consequently affecting their GHG production. To investigate these impacts, we assessed the accumulation of CO2, CH4, and N2O in an urban river system (Cuenca, Ecuador). High var...
Article
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Research in global change ecology relies heavily on global climatic grids derived from estimates of air temperature in open areas at around 2 m above the ground. These climatic grids do not reflect conditions below vegetation canopies and near the ground surface, where critical ecosystem functions occur and most terrestrial species reside. Here, we...
Preprint
Background Across the tropics, the share of secondary versus primary forests is strongly increasing. The high rate of biomass accumulation during this secondary succession relies on the availability of essential nutrients, such as nitrogen (N). Nitrogen primarily limits many young secondary forests in the tropics. However, recent studies have shown...
Article
Full-text available
Soil compaction caused by highly mechanized agriculture can constrain soil microbial diversity and functioning. Physical pressure on the soil decreases macropores and thereby limits oxygen diffusion. The associated shift from aerobic to anaerobic conditions can reduce nitrification and promote denitrification processes, leading to nitrogen (N) loss...
Article
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Globally, tropical forests are assumed to be an important source of atmospheric nitrous oxide (N 2 O) and sink for methane (CH 4). Yet, although the Congo Basin comprises the second largest tropical forest and is considered the most pristine large basin left on Earth, in situ N 2 O and CH 4 flux measurements are scarce. Here, we provide multi-year...
Preprint
Anthropogenic nitrogen inputs cause major negative environmental impacts, including emissions of the important greenhouse gas N2O. Despite their importance, changes in terrestrial N loss pathways driven by global change and spatial redistribution of N inputs are highly uncertain. We present a novel coupled soil-atmosphere isotope model (IsoTONE) to...
Article
Studies on sediment export from tropical forest watersheds are scarce. Of the assessments that do exist, most are of larger rivers or are model-based and lack validation with measured data. Understanding the mechanisms of sediment export dynamics in forested headwaters is important for assessing downstream effects and as a baseline for net impacts...
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Information on soil properties is crucial for soil preservation, the improvement of food security, and the provision of ecosystem services. In particular, for the African continent, spatially explicit information on soils and their ability to sustain these services is still scarce. To address data gaps, infrared spectroscopy has achieved great succ...
Article
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Soil macronutrient availability is one of the abiotic controls that alters the exchange of greenhouse gases (GHGs) between the soil and the atmosphere in tropical forests. However, evidence on the macronutrient regulation of soil GHG fluxes from central African tropical forests is still lacking, limiting our understanding of how these biomes could...
Conference Paper
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The exchange of the climate-relevant greenhouse gases (GHGs) at the soil-atmospheric interface is regulated by both abiotic and biotic controls. However, evidence on nutrient limitations of soil GHG fluxes from African tropical forest ecosystems is still rare. Therefore, an ecosystem-scale nutrient manipulation experiment (NME) consisting of nitrog...
Article
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Primary tropical forests generally exhibit large gaseous nitrogen (N) losses, occurring as nitric oxide (NO), nitrous oxide (N2O) or elemental nitrogen (N2). The release of N2O is of particular concern due to its high global warming potential and destruction of stratospheric ozone. Tropical forest soils are predicted to be among the largest natural...
Article
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Nitrogen (N) availability can be highly variable in tropical forests on regional and local scales. While environmental gradients influence N cycling on a regional scale, topography is known to affect N availability on a local scale. We compared natural abundance of 15N isotopes of soil profiles in tropical lowland forest, tropical montane forest, a...
Preprint
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Research in environmental science relies heavily on global climatic grids derived from estimates of air temperature at around 2 meter above ground1-3. These climatic grids however fail to reflect conditions near and below the soil surface, where critical ecosystem functions such as soil carbon storage are controlled and most biodiversity resides4-8...
Article
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Due to regular influx of organic matter and nutrients, waste stabilization ponds (WSPs) can release considerable quantities of greenhouse gases (GHGs). To investigate the spatiotemporal variations of GHG emissions from WSPs with a focus on the effects of sludge accumulation and distribution, we conducted a bathymetry survey and two sampling campaig...
Article
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Tropical forest soils are an important source and sink of greenhouse gases (GHGs), with tropical montane forests, in particular, having been poorly studied. The understanding of this ecosystem function is of vital importance for future climate change research. In this study, we explored soil fluxes of carbon dioxide (CO2), methane (CH4), and nitrou...
Preprint
Full-text available
Information on soil properties is crucial for soil preservation, improving food security, and the provision of ecosystem services. Especially, for the African continent, spatially explicit information on soils and their ability to sustain these services is still scarce. To address data gaps, infrared spectroscopy has gained great success as a cost-...
Preprint
Full-text available
Tropical forests contribute significantly to the emission and uptake of carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O). However, studies on the soil environmental controls of greenhouse gases (GHGs) from African tropical forest ecosystems are still rare. The aim of this study was to disentangle the regulation effect of soil nutrients...
Article
Full-text available
Soil respiration is an important carbon flux and key process determining the net ecosystem production of terrestrial ecosystems. To address the lack of quantification and understanding of seasonality in soil respiration of tropical forests in the Congo Basin, soil CO2 fluxes and potential controlling factors were measured annually in two dominant f...
Preprint
Full-text available
Nitrogen (N) availability can be highly variable in tropical forests on a regional and on a local scale. While environmental gradients influence N cycling on a regional scale, topography is known to affect N availability on a local scale. We compared stable isotope signatures (δ15N) of soil profiles in tropical lowland forest, tropical montane fore...
Article
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Sub-Saharan Africa (SSA) is home to approximately ¼ of the global livestock population, which in the last 60 years has increased by factors of 2.5-4 times for cattle, goats and sheep. An important resource for pastoralists, most livestock live in semi-arid and arid environments , where they roam during the day and are kept in enclosures (or bomas)...
Preprint
Full-text available
Rivers act as a natural source of greenhouse gases (GHGs) that can be released from the metabolisms of aquatic organisms. Anthropogenic activities can largely alter the chemical composition and microbial communities of rivers, consequently affecting their GHG emissions. To investigate these impacts, we assessed the emissions of CO2, CH4, and N2O fr...
Article
The isotopic composition of nitrous oxide (N2O) provides useful information for evaluating N2O sources and budgets. Due to the co‐occurrence of multiple N2O transformation pathways, it is, however, challenging to use isotopic information to quantify the contribution of distinct processes across variable spatiotemporal scales. Here, we present an ov...
Article
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Isotopic composition of soil‐emitted nitrous oxide (N2O), especially the intramolecular distribution of 15N in N2O known as site preference (SP), can be used to track the two major N2O emitting soil‐processes nitrification and denitrification. Online analysis of SP in ambient air has been achieved recently, yet those approaches only allowed address...
Article
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For the past two decades, the measurement of nitrous oxide (N 2 O) isotopocules-isotopically substituted molecules 14 N 15 N 16 O, 15 N 14 N 16 O and 14 N 14 N 18 O of the main isotopic species 14 N 14 N 16 O-has been a promising technique for understanding N 2 O production and consumption pathways. The coupling of non-cryogenic and tuneable light...
Article
Forests exhibit leaf and ecosystem level responses to environmental changes. Specifically, rising carbon dioxide (CO2) levels over the past century are expected to have increased the intrinsic water‐use efficiency (iWUE) of tropical trees while the ecosystem is gradually pushed into progressive nutrient limitation. Due to the long‐term character of...
Preprint
Full-text available
Abstract. Soil respiration is an important carbon flux and key process determining the net ecosystem production of terrestrial ecosystems. To address the enormous lack of quantification and understanding of seasonality in soil respiration of tropical forests in the Congo Basin, soil CO<sub>2</sub> fluxes and potential controlling factors were measu...
Preprint
Full-text available
Abstract. Tropical forest soils are an important contributor to the global greenhouse (GHG) budget and understanding this ecosystem function is of vital importance for future global change and climate research. In this study, we quantified soil fluxes of carbon dioxide (CO<sub>2</sub>), methane (CH<sub>4</sub>) and nitrous oxide (N<sub>2</sub>O) of...
Preprint
Full-text available
Abstract. For the past two decades, the measurement of N<sub>2</sub>O isotopocules – isotopically substituted molecules <sup>14</sup>N<sup>15</sup>N<sup>16</sup>O, <sup>15</sup>N<sup>14</sup>N<sup>16</sup>O and <sup>14</sup>N<sup>14</sup>N<sup>18</sup>O of the main isotopic species <sup>14</sup>N<sup>14</sup>N<sup>16</sup>O – has been a promising t...
Article
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In the mostly pristine Congo Basin, agricultural land-use change has intensified in recent years. One potential and understudied consequence of this deforestation and conversion to agriculture is the mobilization and loss of organic matter from soils to rivers as dissolved organic matter. Here, we quantify and characterize dissolved organic matter...
Article
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Soil moisture strongly affects the balance between nitrification, denitrification and N2O reduction and therefore the nitrogen (N) efficiency and N losses in agricultural systems. In rice systems, there is a need to improve alternative water management practices, which are designed to save water and reduce methane emissions but may increase N2O and...
Article
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Soil moisture strongly affects the balance between nitrification, denitrification and N2O reduction and therefore the nitrogen (N) efficiency and N losses in agricultural systems. In rice systems, there is a need to improve alternative water management practices, which are designed to save water and reduce methane emissions, but may increase N2O an...
Article
There is increasing pressure to reduce water use in irrigated rice production to save water, reduce methane emissions and reduce grain arsenic uptake arising from anaerobic conditions. However, under such practices emissions of nitrous oxide (N2O) often increase. Rice systems generally exhibit strong stratification of environmental conditions that...
Article
Central European grasslands are characterized by a wide range of different management practices in close geographical proximity. Site-specific management strategies strongly affect the biosphere-atmosphere exchange of the three greenhouse gases (GHG) carbon dioxide (CO2), nitrous oxide (N2O) and methane (CH4). The evaluation of environmental impact...
Article
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Drought down-regulates above- and belowground carbon fluxes, however, the resilience of trees to drought will also depend on the speed and magnitude of recovery of these above- and belowground fluxes after re-wetting. Carbon isotope composition of above- and belowground carbon fluxes at natural abundance provides a methodological approach to study...
Article
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Intensification of pastoral agriculture is occurring rapidly across New Zealand, including increasing use of irrigation and fertiliser application in some regions. While this enables greater gross primary production (GPP) and livestock grazing intensity, the consequences for the net ecosystem carbon budget (NECB) of the pastures are poorly known. H...
Article
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Intensification of pastoral agriculture is occurring rapidly across New Zealand, including increasing use of irrigation and fertiliser application in some regions. While this enables greater gross primary production (GPP) and livestock grazing intensity, the consequences for the net ecosystem carbon budget (NECB) of the pastures are poorly known. H...
Article
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New Zealand's largest industrial sector is pastoral agriculture, giving rise to a large fraction of the country's emissions of methane (CH4) and nitrous oxide (N2O). We designed a system to continuously measure CH4 and N2O fluxes at the field scale on two adjacent pastures that differed with respect to management. At the core of this system was a c...
Article
Branch or shoot chamber measurements integrate over both foliar and woody tissue carbon dioxide (CO2) fluxes and their associated influences on the carbon isotopic composition of atmospheric/headspace CO2. Here, we quantified the bias introduced by woody tissue carbon isotope fluxes on apparent leaf (13)C discrimination (Δ(13)Capparent) estimates,...
Article
Pulse labelling experiments provide a common tool to study short-term processes in the plant-soil system and investigate below-ground carbon allocation as well as the coupling of soil CO2 efflux to photosynthesis. During the first hours after pulse labelling, the measured isotopic signal of soil CO2 efflux is a combination of both physical tracer d...
Article
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Above- and belowground processes in plants are tightly coupled via carbon and water fluxes through the soil–plant–atmosphere system. The oxygen isotopic composition of atmospheric CO2 and water vapour (H2Ov) provides a valuable tool for investigating the transport and cycling of carbon and water within this system. However, detailed studies on the...
Article
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On-line measurements of photosynthetic carbon isotope discrimination (13Δ) under field conditions are sparse. Hence, experimental verification of the natural variability of instantaneous 13Δ is scarce, although 13Δ is, explicitly and implicitly, used from leaf to global scales for inferring photosynthetic characteristics. This work presents the fir...
Article
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Since substrates for respiration are supplied mainly by recent photo-assimilates, there is a strong but time-lagged link between short-term above- and belowground carbon (C) cycling. However, regulation of this coupling by environmental variables is poorly understood. Whereas recent studies focussed on the effect of drought and shading on the link...

Citations

... LRS located in the open water of lakes and reservoirs would have more water movement leading to a higher DO (Fig. S1c). In contrast, the more enclosed and stagnant nature of CWRS, IPS, and FRS would allow the accumulation of DOC and nutrients ( Fig. S1e-i) and depletion of DO (Fig. S1c), which would favor methanogenesis (Fang et al., 2022;Holgerson et al., 2016;Zhu et al., 2016). Consequently, CH 4 fluxes in CWRS, IPS and FRS were all an order of magnitude higher than LRS (Fig. 2e-h). ...
... While urban land areas increased by 58,000 km 2 worldwide from 1970 to 2000, an average increase of 1,527,000 km 2 is predicted by 2030 (Seto et al., 2011). High population density challenges freshwater hygiene and consequently human health (Benassi et al., 2021;Ho et al., 2022;McLellan et al., 2015;Vörösmarty et al., 2000;Walters et al., 2011). Anthropogenic activities, such as the introduction of sewage water, and with that faecal bacteria, into natural water systems, cause eutrophication and other forms of pollution that may alter the natural microbial community composition in aquatic systems. ...
... Forests account for 33% of the land surface, which are the most widely distributed terrestrial ecosystems on the earth, and release approximately 2. 4-5.7 Tg of N 2 O-N into the atmosphere each year (IPCC 2014;Tian et al. 2019). Globally, (sub)tropical forests are considered to be the largest source of N 2 O after cropland (Lashof and Ahuja 1990;Zhang et al. 2011), while recent studies have also shown that warming reduced soil N 2 O emissions from Congolese tropical forests (Barthel et al. 2022). Therefore, tropical and subtropical forest ecosystems might play a critical role in the changes of atmospheric N 2 O concentration and/or still with larger uncertainties. ...
... Third, solitary bees that nest above-ground may be more responsive to changing climate than those that nest below-ground, presumably because environmental conditions are less variable below-ground (Forrest, 2015;Lembrechts et al., 2021). In a previous 9-year study, Stemkovski et al. (2020) found that nest location was the strongest trait predicting wild bee emergence times in montane habitats, with above-ground species emerging on average about 10 days before below-ground nesting species. ...
... We also added the Lab samples to the Global_Cal and implemented the SBL and LOCAL as described previously to determine whether this would improve the prediction accuracy of these algorithms. This differs from Summerauer et al. (2021) where the spiking samples were forced into the neighbourhoods thereby ensuring that they are used. ...
... The forest site characteristics as well as further details about the NME were reported in Manu et al. (2022). The present study builds on an earlier study conducted within the framework of the NME (Tamale et al., 2021) with the aim to disentangle the effect of deforestation for fertilized sugarcane on soil GHG fluxes. In the present study, we compare the soil GHG fluxes measured from the untreated forest plots of the Tamale et al. (2021) study, here after referred to as reference forest plots, to the soil GHG fluxes measured from 12 replicate plots of a completely randomized design (CRD) experiment established in the neighboring sugarcane plantation (1 • 41'37.9" ...
... then in the short term (months). Micro hybrid composites are excellent materials for long-term dental restorations, rivalling and often excelling amalgams 101 . ...
... The foliar enrichment factor (δ 15 N mineral soil À δ 15 N plant foliage ) did not differ among the sites, suggesting it may not be an integrated proxy to reflect the status of N cycling across forest ecosystems over broad spatial scales. However, the sharper increase in δ 15 N from topsoil to subsoil at DAX-51, MES-45, and QY-42 than at DHS-23 ( Figure 5) confirmed that the pattern of soil δ 15 N in the soil profile is closely related to N availability (N saturation stages) of the sites with steeper increase indicating less N availability as reported by other studies (Baumgartner et al., 2021;Hobbie & Ouimette, 2009). However, our results suggest that strong dependence of plants on mycorrhizal fungi (particularly ECM) may not be the main reason for a steep increase in soil δ 15 N with depth as previously suggested (Hobbie & Ouimette, 2009) because the sharp increase in soil δ 15 N from the Oi layer to mineral soil at DAX-51, MES-45, and QY-42 did not accompany 15 N depletion of either ECM or AM plant foliage (Appendix S1: Table S1). ...
... The current predictive distribution modelling study was conducted with the finer resolution of climatic data currently available (i.e., 30 arc sec-approx. 1 km at the equator) considering the fact that the climatic conditions of the Himalaya, vary significantly with shortest distances because of the topographically diverse habitats. Secondly, the near-surface climate is as essential as the aerial climatic factors in determining a species' range 108,109 . However, due to the non-availability of the former for future climatic scenarios, the current study relied heavily on aerial climatic data. ...
... These results highlight the indirect impacts of land-use change on increasing GHG production from rivers and streams which are currently being omitted in land-use planning and resource management. The high-dissolved GHG concentrations from sites close to urban, road, and agricultural areas were highly likely caused by the pollutants from the point discharges of combined sewer overflows and Ucubamba WWTP in the Tomebamba and Cuenca tributaries as well as the non-point surface runoff from roads and arable areas Ho et al. (2021b). For example, being the second-largest GHG contributor, Tarqui tributary had high nutrient and organic matter load as its surrounded landscapes mainly occupied by agricultural irrigation and livestock production (Jerves-Cobo et al. 2018b). ...