Increasing exports of Fe and DOC from soils, causing browning of freshwaters, have been reported in recent decades in many regions of the northern hemisphere. Afforestation, and in particular an increase of Norway spruce forest in certain regions, is suggested as a driver behind these trends in water chemistry. In this study, we tested the hypothesis that the gradual accumulation of organic soil layers

Direct measurement of methane emissions is cost-prohibitive for greenhouse gas offset projects, necessitating the development of alternative accounting methods such as proxies. Salinity is a useful proxy for tidal marsh CH4 emissions when comparing across a wide range of salinity regimes but does not adequately explain variation in brackish and freshwater regimes, where variation in emissions is large

The biogeochemistry of dissolved selenium (Se) was investigated over 3 years (2015–2017) in the subtropical, warm monomictic and meso-eutrophic Lake Kinneret (Sea of Galilee, Israel). We monitored seasonal variation and vertical distribution of dissolved total Se (T.Se), inorganic oxyanions (Se(IV) & Se(VI)), reduced Se fraction (Red.Se), organic (Org.Se) and volatile Se compounds. T.Se varied between ~ 100

Zooplankton communities are important components of aquatic food webs in part because they recycle nutrients and carbon. Lacking a complete understanding of the composition of organic material cycled by zooplankton, the breadth of their biogeochemical and ecological contributions to aquatic ecosystems is uncertain. Here, we show that large-bodied zooplankton communities from three diverse biomes across

The interaction of organic carbon (OC) with clay and metals stabilizes soil carbon (C), but the influence of specific clay-metal-OC assemblages (flocs) needs further evaluation. This study aimed to investigate the stability of flocs in soil as affected by external C inputs. Flocs representing OC-mineral soil fractions were synthesized using dissolved organic C (DOC) combined with kaolinite (1:1 layer

Carbon and nitrogen stable isotope ratios are increasingly used to study long-term change in food web structure and nutrient cycling. We retrospectively analyse elemental composition (C, N and P) and stable isotopes (δ13C, δ15N) in archived monitoring samples of two important taxa from the bottom of the food web; the filamentous ephemeral macroalgae Cladophora spp. and the blue mussel Mytilus edulis

The frequency and duration of lake ice cover is rapidly declining in the Northern Hemisphere. Limited research in oligotrophic and mesotrophic lakes suggests that extended periods of ice cover influence nitrogen (N) cycling by promoting nitrate (NO3−) accumulation. However, ice cover impacts on N cycling in shallow, high-nutrient, eutrophic lakes remains poorly understood. To understand drivers of

Soil organic matter (SOM) is the largest terrestrial pool of organic carbon, and potential carbon-climate feedbacks involving SOM decomposition could exacerbate anthropogenic climate change. However, our understanding of the controls on SOM mineralization is still incomplete, and as such, our ability to predict carbon-climate feedbacks is limited. To improve our understanding of controls on SOM decomposition

Coupled biogeochemical cycles drive ecosystem ecology by influencing individual-to-community scale behaviors; yet the development of process-based models that accurately capture these dynamics remains elusive. Soil organic matter (SOM) decomposition in particular is influenced by resource stoichiometry that dictates microbial nutrient acquisition (‘ecological stoichiometry’). Despite its basis in biogeochemical

As rock-derived primary minerals weather to form soil, they create reactive, poorly crystalline minerals that bind and store organic carbon. By implication, the abundance of primary minerals in soil might influence the abundance of poorly crystalline minerals, and hence soil organic carbon storage. However, the link between primary mineral weathering, poorly crystalline minerals, and soil carbon has

Salinization of freshwater ecosystems impacts carbon cycling, a particular concern for coastal wetlands, which are important agents of carbon sequestration. Previous experimental work using salt additions as a proxy for sea level rise, reveals widely divergent effects of salt on soil carbon processes. We performed a laboratory salt addition experiment on two different types of wetland soils (Ponzer

Nitrogen (N) fertilization has enhanced the forest land carbon (C) sink by increasing the amount of C stored in soils, possibly through reductions in decomposition. Established differences in nutrient acquisition strategies between trees that associate with arbuscular mycorrhizal (AM) and ectomycorrhizal (ECM) fungi have been shown to influence the magnitude of this N effect on decomposition and soil

Urea can degrade water quality and stimulate toxic phytoplankton in P-rich lakes, yet little is known of its sources, abundance, or transportation in lotic systems, particularly within the Northern Great Plains. We measured physico-chemical parameters biweekly during May–September 2010–2012 at 16 stations along a 250 km lotic continuum to quantify spatial and temporal variation in urea concentrations

Wildfire is a major driver of nitrogen (N) cycling and export from terrestrial to aquatic systems. While fire is a natural process in many watersheds, it can still degrade water quality by rapidly flushing N to streams. This can be particularly problematic in watersheds that experience high levels of N deposition or where climate change is promoting larger and more severe fires. The extent and duration

The biogeochemical model, PnET-BGC, was modified and parameterized using field data from an experimental whole-tree harvest of watershed (W5) in 1983–1984 at the Hubbard Brook Experimental Forest (HBEF), New Hampshire, USA. The model simulated the hydrology, biomass accumulation, and soil solution and stream water chemistry responses to forest cutting. The parameterized model was then applied to other

Understanding N budgets of tundra ecosystems is crucial for projecting future changes in plant community composition, greenhouse gas balances and soil N stocks. Winter warming can lead to higher tundra winter nitrogen (N) mineralization rates, while summer warming may increase both growing season N mineralization and plant N demand. The undulating tundra landscape is inter-connected through water and

The northern slope water of the South China Sea (SCS) is oligotrophic. The regenerated nitrogen from dissolved organic nitrogen (DON) has been suggested to play a pivotal role in sustaining primary productivity; however, DON cycling has not been investigated there. Dissolved free amino acids (DFAAs) and polyamines (DFPAs) are two major groups of labile DON that are used rapidly by heterotrophic bacteria

Stream restoration, such as channel reconfiguration and riparian zone revegetation, is increasing in response to aquatic impairment in agroecosystems. Though riparian zones effectively remove nitrogen (N), conditions that foster nitrate (NO3−) removal (e.g., soil saturation, low oxygen, available carbon) may facilitate the release of soluble reactive phosphorus (SRP) and greenhouse gases (GHGs—carbon

The effects of single macrofauna taxa on benthic nitrogen (N) cycling have been extensively studied, whereas how macrofaunal communities affect N-related processes remains poorly explored. In this study, we characterized benthic N-cycling in bioturbated sediments of the oligotrophic Öre Estuary (northern Baltic Sea). Solute fluxes and N transformations (N2 fixation, denitrification and dissimilative

Iron is one of the most abundant elements on the planet and a micronutrient for most organisms. In many coastal regions worldwide, mangrove forests affect the dynamics and mobility of different elements to the oceans especially through their soils. The biogeochemistry of mangrove soils responds to numerous factors that vary within different spatial and time scales. In this sense, seasonality can be

Landcover changes have altered the natural carbon cycle; however, most landcover studies focus on either forest conversion to agriculture or urban, rarely both. We present differences in dissolved organic carbon (DOC) concentrations and dissolved organic matter (DOM) molecular composition within Upper Mississippi River Basin low order streams and rivers draining one of three dominant landcovers (forest

Eutrophication has been identified as the primary cause of water quality deterioration in inland waters worldwide, often associated with algal blooms or fish kills. Eutrophication can be controlled through watershed management and in-lake measures. An extreme heatwave event, through its impact on mineralization rates and internal nutrient loading (phosphorus—P, and nitrogen—N), could counteract eutrophication

Correlations between organic carbon (OC) and fine mineral particles corroborate the important role of the abundance of soil minerals with reactive surfaces to bind and increase the persistence of organic matter (OM). The storage of OM broadly consists of particulate and mineral-associated forms. Correlative studies on the impact of fine mineral soil particles on OM storage mostly combined data from

Lake-rich Arctic deltas differ biogeochemically from tundra lakes, and their role as sources and sinks of greenhouse gases remains poorly understood. Under-ice and open-water changes in methane (CH4) storage (43 lakes, 2014), floating chamber measurements of total and diffusive CH4 evasion to the atmosphere (6 lakes, 2014–2015), and water-column CH4 oxidation (MOX) (6 lakes, 2014–2015) permitted evaluation

This study presents a conceptual framework of buffering through storage and recycling of elements in terrestrial ecosystems and reviews the current knowledge about storage and recycling of elements in plants and ecosystems. Terrestrial ecosystems, defined here as plant-soil systems, buffer inputs from the atmosphere and bedrock through storage and recycling of elements, i.e., they dampen and delay

Here we use a top-down and bottom-up approach in landscape ecology to analyze the active microbes processing methane fluxes (FCH4) in seasonally flooded-forest (FOR) and -traditional farming systems (TFS) in Amazonian floodplains flooded with black, white, and clear water. Our results revealed higher CH4 emissions from water-atmosphere interface in clear water floodplain, followed by black and white

Recent studies demonstrate a strong influence of soil age on long-term silicon (Si) dynamics in terrestrial ecosystems, but how variation in ecosystem water balance and soil parent material impact this trajectory is unknown. We addressed this by studying a 2-million-year dune chronosequence in southwestern Australia characterized by a positive water balance (+ 50 mm year−1) and a lower carbonate concentration

Agriculturally-driven land use change and hydrologic modifications have influenced solute transport in midwestern U.S. streams. A clear understanding of the mechanisms driving nutrient export from agricultural watersheds will be critical in mitigating diffuse nutrient pollution, given anticipated shifts in hydrology associated with a changing climate. Specifically, more frequent, intense precipitation

The diel dynamic of the CO2 concentration in soils in relation to temperature is not yet fully understood. Air temperature might control the soil CO2 concentration due to thermal convective venting at sites experiencing large temperature differences between the atmosphere and the soil. Therefore, the objective of this study was to determine the soil CO2 concentration and its temporal dynamic in a deep

Managed grasslands have the potential to store carbon (C) and partially mitigate climate change. However, it remains difficult to predict potential C storage under a given soil or management practice. To study C storage dynamics due to long-term (1952–2009) phosphorus (P) fertilizer and irrigation treatments in New Zealand grasslands, we measured radiocarbon (14C) in archived soil along with observed

Nitrogen (N) removal from stormwater runoff prior to its export to sensitive downstream water bodies is a common goal for urban stormwater ponds (SWPs). Denitrification removes nitrate (NO3−) from stormwater runoff by conversion to di-nitrogen gas (N2), permanently removing reactive N from the ecosystem. Typically, N removal in SWPs is quantified via mass balance approaches, but the internal biogeochemical

Methane (CH4) emission from tree stems (stem CH4 emission) is a previously overlooked emission pathway in forested wetlands. Despite growing evidence of its significance to both regional and global CH4 budgets, the drivers and mechanisms of stem CH4 emission in wetlands are not fully understood. To clarify the environmental drivers of stem CH4 emission, we conducted chamber-based flux measurements

The carbonate chemistry was investigated in the semiarid eutrophic Araruama Lagoon (Brazil), one of the largest hypersaline coastal lagoons in the world. Spatial surveys during winter and summer periods were performed, in addition to a diurnal sampling in summer. The hypersaline waters have higher concentrations of total alkalinity (TA) and dissolved inorganic carbon (DIC) than the seawater that feed

Manganese (Mn) has been identified as a regulatory bottleneck in carbon (C) turnover because of its role as an enzymatic co-factor in the oxidative decomposition of C by Mn-peroxidase (MnP). We tested this limit on decay using forest soils from coastal British Columbia with contrasting Mn concentrations. Moderately weathered soils (Brunisols) had an average 3.6-fold increase in MnP activity within

Wind disturbance in northern hardwood forests of the US North Central Great Lakes region creates heterogeneously distributed structural attributes such as downed woody debris (DWD) and canopy openings across temporal and spatial scales. The decomposition of DWD contributes to greenhouse gas (GHG) fluxes, provides habitat, and potentially influences soil biogeochemistry. We assessed the effects of DWD

Forest soils are an important carbon (C) sink and critical component of the global C cycle. Warmer temperatures and increased atmospheric nitrogen (N) deposition are altering the biogeochemistry in forest soils and disrupting the intricate balance between C storage and C respired across the globe. The molecular biogeochemistry of soil organic matter (SOM) with warming, N-addition, and simultaneous

Tropical forests contain some of the largest soil carbon (C) stocks on Earth, making them broadly relevant to terrestrial-climate feedbacks, yet our understanding of how their soil organic C (SOC) fractions vary over space and time is limited. We studied effects of season, fertility, and mean annual precipitation (MAP) on the C contents of soil fractions across 14 lowland forests in Panama. We measured

Manganese (Mn) is an essential plant micronutrient that influences photosynthesis, ecosystem productivity, and soil carbon storage. Our objective was to quantify how Mn uptake by forest vegetation relates to Mn release into soil solution through mineral dissolution. A greenhouse pot experiment was conducted to quantify Mn uptake by red maple saplings as a function of mineral solubility to test whether

Recent observations and numerical simulations have profoundly established that the C:N:P ratios in the ocean deviate from the canonical Redfield Ratio (106:16:1). Physical and biogeochemical processes have been hypothesized to be responsible for this deviation. However, a paucity of concurrent observations on biogeochemical and physical parameters have barred us to understand their exact role on the

Droughts are recognized to impact global biogeochemical cycles. However, the implication of desiccation on in-stream carbon (C) cycling is not well understood yet. We subjected sediments from a lowland, organic rich intermittent stream to experimental desiccation over a 9-week-period to investigate temporal changes in microbial functional traits in relation to their redox requirements, carbon dioxide

In the original version the name of the second author was misspelled. The correct name is Ayumi Hyodo.

The interface between lotic and lentic ecosystems is often a zone of intense metabolic activity, as primary production in streams and rivers can be light limited whereas nutrients often limit primary production in lake ecosystems. Our objective was to model the influence that rivermouths (the lotic-lentic interface) could have on the loads of soluble reactive phosphorus (SRP) and dissolved inorganic

The storage and cycling of soil organic carbon (SOC) are governed by multiple co-varying factors, including climate, plant productivity, edaphic properties, and disturbance history. Yet, it remains unclear which of these factors are the dominant predictors of observed SOC stocks, globally and within biomes, and how the role of these predictors varies between observations and process-based models. Here

Atmospheric nitrogen (N) deposition rates affect soil N dynamics, influencing soil respiration (RS) rates. However, for the Mediterranean region, the effect of changes in atmospheric N deposition on RS are not well constrained yet. We investigated the interplay between increased N deposition and tree species composition on RS at a Scots pine—Pyrenean oak ecotone in Central Spain, and whether the observed

Riparian zones of headwater streams have valuable ecosystem functions and are prevalent across many landscapes. Nevertheless, studies of greenhouse gas (GHG; CO2, CH4, N2O) fluxes from these unique ecosystems, with fluctuating water tables and high soil organic matter, remain limited. Our objectives were to (1) to quantify the effects of local riparian groundwater conditions on soil GHG flux rates

There is little knowledge about microbial functional community structures and the relationships between microbial communities and nitrogen transformation processes. Here, we investigated the relationships between soil microbial communities and nitrogen mineralisation potentials in a cool temperate forest throughout the growing season. Microbial communities were assessed by quantification of the total

Water tables in high-latitude peatlands are expected to fall because of climate change, with significant consequences for carbon cycling in these ecosystems. At present, the understanding of how climate-induced changes will affect soil microbial communities and functions in peatlands still remains controversial. In this study, we compared the potential activities of soil oxidase and hydrolytic enzymes

Globally widespread woody encroachment into grass-dominated ecosystems has substantial consequences for carbon (C), nitrogen (N), and phosphorus (P) cycles. Despite its significance as an essential macronutrient, however, little is known regarding potential changes in the sulfur (S) cycle. We quantified S concentrations, stoichiometric relationships, and δ34S values in the plant-soil environment to

Organic tracers (bulk δ13C and δ15N) are being increasingly used in sediment/particulate organic carbon source apportionment studies at the catchment scale to support sustainable land management decisions. Here, the use of these isotopic tracers in sediment fingerprinting depends on the critical assumption that δ13C and δ15N values remain conservative during the sediment delivery continuum. Such assumption

Phosphorus (P) is considered an indispensable and finite resource that limits crop yields, and soil P is distributed heterogeneously in space. However, a systematic analysis of previous studies indicates that there are large gaps in our knowledge regarding the spatial patterns of soil P due to the lack of sufficient field observations, especially at larger scales. Thus, we explored the spatial patterns

Leaf stoichiometry and its biogeography play vital roles in nutrient cycling of plant communities. To understand the potential drivers of leaf stoichiometry in karst ecosystems, we measured leaf morphological traits (dry mass content (DM), specific leaf area (SLA)), and biochemical traits (C, N, P, K and Ca stoichiometry) of 53 species of different functional groups, as well as soil properties, across

Water pollution disrupts the ecological integrity of urbanized river systems, but its impacts on riverine metabolic processes and carbon fluxes are poorly studied in developing countries. Three seasonal field surveys were combined with two high-resolution measurements and an in situ incubation experiment to investigate the effects of untreated wastewater on organic matter biodegradation and the partial

Estuaries are productive ecosystems that provide important ecosystem functions such as the storage and cycling of dissolved organic matter (DOM) and nutrients. Intermittently closed/open lakes and lagoons (ICOLLs) can significantly impact biogeochemical processing and release of terrestrial nitrogen and carbon into the coastal environment due to longer residence times that can extend nutrient processing

To test the effect of electrolysis and microbial remediation technology in polluted river sediment, we explored the possibility of using electrolysis method to remove ammoniacal nitrogen–nitrogen (NH3–N), nitrate-nitrogen (NO3––N) and phosphate ions-phosphorous (PO43−–P). The electrolysis was carried out by double electrolysis reaction system with a pair of a titanium (Ti) mesh cathode, a Ti/Ti dioxide

Global environmental change alters the production, terrestrial export, and photodegradation of organic carbon in northern lakes. Sedimentary biogeochemical records can provide a unique means to understand the nature of these changes over long time scales, where observational data fall short. We deployed in situ experiments on two shallow subarctic lakes with contrasting light regimes; a clear tundra

We investigated soil organic carbon (SOC) storage and the quantitative relationship between SOC and geochemical properties in tropical surface and subsurface soils, where information on various soil geochemical properties remains limited. We used soil samples from 178 sites in Indonesia, Thailand, Cameroon, and Tanzania as tropical soils and 34 sites in Japan as a comparison. The tropical soils were

We investigate the "macronutrient-access hypothesis", which states that the balance between stoichiometric macronutrient demand and accessible macronutrients controls nutrient assimilation by aquatic heterotrophs. Within this hypothesis, we consider bioavailable dissolved organic carbon (bDOC), reactive nitrogen (N) and reactive phosphorus (P) to be the macronutrients accessible to heterotrophic assimilation

Despite multiple pieces of evidence that root-derived carbon (C) can profoundly regulate mineral nitrogen (N) cycling, it is still not elucidated whether tree roots differentially modulate the production and retention of ammonium (NH4+) versus nitrate (NO3−) through the rhizosphere effect (RE). Using the 15N isotope labeling technique, we investigated how plant roots regulated the production and retention

Freeze–thaw (FT) events exert a great physiological stress on the soil microbial community and thus significantly impact soil biogeochemical processes. Studies often show ambiguous and contradicting results, because a multitude of environmental factors affect biogeochemical responses to FT. Thus, a better understanding of the factors driving and regulating microbial responses to FT events is required