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Papers by mario montesdeoca
AGU Fall Meeting Abstracts, Dec 1, 2018
Journal of Geophysical Research: Biogeosciences, 2021
Dissolved organic matter (DOM) can serve as an indicator of watershed carbon cycling, and links t... more Dissolved organic matter (DOM) can serve as an indicator of watershed carbon cycling, and links terrestrial to aquatic ecosystems. The extent DOM is microbially processed before it enters aquatic ecosystems is expected to change with soil depth and landscape position, and as some research suggests, in response to recovery from chronic acidification. Here we examined DOM within freely flowing soil pore water and stream water collected from reference and calcium silicate‐treated watersheds at the Hubbard Brook Experimental Forest, New Hampshire, USA. Dissolved organic carbon (DOC) and nitrogen (DON) concentrations as well as, absorption and fluorescence properties were analyzed to assess patterns in DOM quantity and quality. Parallel factor analysis was used to identify three predominant fluorescing DOM components (C1‐3). All three components were terrestrial in origin, however C3 exhibited spectral properties previously linked to the microbial processing of humic material. Distinct horizonal patterns emerged between genetic soil horizons. DOC quantity decreased with soil depth, so too did, the plant derived lignin‐like fraction (C2), while the C3 fraction increased. High‐elevation coniferous zones with shallow bedrock contributed to higher DOC concentrations in soil and stream water, while high and low‐elevation mineral soils exhibited greater C3 fractions and fluorescence indicators of microbially processed DOM. This pattern suggests these mineral soils are important organic carbon sinks, due to greater rates of microbial DOM processing. DOC in forest floor solutions, C3 fractions, and indicators of smaller molecular size (E2:E3) were all higher in the calcium silicate‐treated watershed, suggesting greater microbial processing of DOM.
Geochemical Perspectives Letters, 2020
Texts summarizing the quality control and quality assurance (QA/QC) procedures and the method of ... more Texts summarizing the quality control and quality assurance (QA/QC) procedures and the method of estimating atmospheric Hg deposition.
Ó The Author(s) 2011. This article is published with open access at Springerlink.com Abstract We ... more Ó The Author(s) 2011. This article is published with open access at Springerlink.com Abstract We studied the spatial distribution patterns of mercury (Hg) in lake water, littoral sediments, zooplankton, crayfish, fish, and common loons in 44 lakes of the Adirondacks of New York State, USA, a region that has been characterized as a ‘‘biological Hg hotspot’’. Our study confirmed this pattern, finding that a substantial fraction of the lakes studied had fish and loon samples exceeding established criteria for human and wildlife health. Factors accounting for the spatial variability of Hg in lake water and biota were lake chemistry (pH, acid neutralizing capacity (ANC), percent carbon in sediments), biology (taxa presence, trophic status) and landscape characteristics (land cover class, lake elevation). Hg concentrations in zooplankton, fish and common loons were negatively associated with the lake water acid-base status (pH, ANC). Bioaccumulation factors (BAF) for methyl Hg (MeHg) incr...
Hydrological Processes, 2008
FEMS Microbiology Ecology, 2010
Environmental Pollution, 2008
Canadian Journal of Fisheries and Aquatic Sciences, 2010
To study fish migration using otolith microchemistry, it is important to understand the relations... more To study fish migration using otolith microchemistry, it is important to understand the relationship between elements in the otoliths and in the surrounding water, including potential interactions with other elements. Selenium (Se) is a trace element with strong affinity for mercury (Hg). To test if Se is a reliable tracer for fish migration, the effects of dissolved Se and Hg concentrations on Se incorporation in fish otoliths were investigated experimentally. Brown bullheads ( Ameiurus nebulosus ) were reared in waters spiked with various concentrations of inorganic Se and Hg. Otolith Se:Ca increased nonlinearly with dissolved Se concentrations as there was no significant difference between fish reared in low and medium [Se] waters (Se:Ca for low [Se] waters, 7.64 × 10−6; medium, 6.59 × 10−6; high, 1.24 × 10−5). Our study also provided the first evidence of a negative effect of Hg on Se incorporation into otoliths (p = 0.01), a phenomenon most evident in high [Se] waters. Because ...
![Research paper thumbnail of Erratum to “Mercury dynamics of a northern hardwood canopy” [Atmos. Environ. 42 (29) (2008) 6905–6914]](https://attachments.academia-assets.com/84890618/thumbnails/1.jpg)
](Atmospheric Environment, 2009
Atmospheric Environment, 2008
Atmospheric emissions have led to widespread concern over mercury (Hg) contamination in aquatic a... more Atmospheric emissions have led to widespread concern over mercury (Hg) contamination in aquatic and terrestrial ecosystems. Plant litter is an important pathway of Hg inputs to forest ecosystems. We investigated the role of the canopy in Hg accumulation, transport and deposition in an upland forest ecosystem. The total Hg content of leaf tissue increased approximately 10-fold over the growing season across all species, from 4.4 AE 2.7 to 37.3 AE 12.4 ng g À1 , with estimated average linear Hg accumulation rates of 0.22, 0.23, and 0.35 ng g À1 day À1 for yellow birch (Betula alleghaniensis), sugar maple (Acer saccharum), and American beech (Fagus grandifolia), respectively. This linear concentration relationship suggests that the accumulation is regulated by mass transfer processes between the atmosphere and leaf tissue. Conversely, the methyl Hg content (0.17 AE 0.18 ng g À1) and accumulations were low. Concentrations of total Hg were also 42% higher in understory (w1 m), compared to overstory (w10 m), beech. Such disparities in leaf Hg content may result from within-canopy variation in environmental variables, a canopy Hg 0 (g) concentration gradient, or species-specific growth strategies. Annual Hg litterfall was 17.9 and 16.4 mg m À2 yr À1 for 2004 and 2005, respectively, representing the largest input of Hg to this forest ecosystem. Methyl Hg litter input was <0.12 mg m À2 yr À1 for 2005. Modeling estimates of transpiration uptake and Hg 0 (g) deposition suggest that Hg in leaf tissue is largely derived from atmospheric sources. Thus, litter Hg represents largely a new, rather than recycled, input to the forest ecosystem.
Soil Systems
Watershed recovery from long-term acidification in the northeastern U.S. has been characterized b... more Watershed recovery from long-term acidification in the northeastern U.S. has been characterized by an increase in the influx of dissolved organic matter (DOM) into surface waters. Increases in carbon quantity and shifts to more aromatic and “colored” OM has impacted downstream lakes by altering thermal stratification, nutrient cycling and food web dynamics. Here, we used fluorescence spectroscopy coupled with parallel factor analysis (PARAFAC) to model predominant carbon quality fractions and their seasonal changes within surface waters along landscape positions of Arbutus Lake watershed in the Adirondack region of NY, USA. All DOM components were terrestrial in origin, however their relative fractions varied throughout the watershed. DOM in headwater streams contained high fractions of recalcitrant (~43%) and microbial reprocessed humic-like OM (~33%), sourced from upland forest soils. Wetlands above the lake inlet contributed higher fractions of high molecular weight, plant-like o...
Sensors
In order to obtain a better perspective of the impacts of brownfields on the land–atmosphere exch... more In order to obtain a better perspective of the impacts of brownfields on the land–atmosphere exchange of mercury in urban areas, total gaseous mercury (TGM) was measured at two heights (1.8 m and 42.7 m) prior to 2011–2012 and after 2015–2016 for the remediation of a brownfield and installation of a parking lot adjacent to the Syracuse Center of Excellence in Syracuse, NY, USA. Prior to brownfield remediation, the annual average TGM concentrations were 1.6 ± 0.6 and 1.4 ± 0.4 ng · m − 3 at the ground and upper heights, respectively. After brownfield remediation, the annual average TGM concentrations decreased by 32% and 22% at the ground and the upper height, respectively. Mercury soil flux measurements during summer after remediation showed net TGM deposition of 1.7 ng · m − 2 · day − 1 suggesting that the site transitioned from a mercury source to a net mercury sink. Measurements from the Atmospheric Mercury Network (AMNet) indicate that there was no regional decrease in TGM conce...
AGU Fall Meeting Abstracts, Dec 1, 2018
Journal of Geophysical Research: Biogeosciences, 2021
Dissolved organic matter (DOM) can serve as an indicator of watershed carbon cycling, and links t... more Dissolved organic matter (DOM) can serve as an indicator of watershed carbon cycling, and links terrestrial to aquatic ecosystems. The extent DOM is microbially processed before it enters aquatic ecosystems is expected to change with soil depth and landscape position, and as some research suggests, in response to recovery from chronic acidification. Here we examined DOM within freely flowing soil pore water and stream water collected from reference and calcium silicate‐treated watersheds at the Hubbard Brook Experimental Forest, New Hampshire, USA. Dissolved organic carbon (DOC) and nitrogen (DON) concentrations as well as, absorption and fluorescence properties were analyzed to assess patterns in DOM quantity and quality. Parallel factor analysis was used to identify three predominant fluorescing DOM components (C1‐3). All three components were terrestrial in origin, however C3 exhibited spectral properties previously linked to the microbial processing of humic material. Distinct horizonal patterns emerged between genetic soil horizons. DOC quantity decreased with soil depth, so too did, the plant derived lignin‐like fraction (C2), while the C3 fraction increased. High‐elevation coniferous zones with shallow bedrock contributed to higher DOC concentrations in soil and stream water, while high and low‐elevation mineral soils exhibited greater C3 fractions and fluorescence indicators of microbially processed DOM. This pattern suggests these mineral soils are important organic carbon sinks, due to greater rates of microbial DOM processing. DOC in forest floor solutions, C3 fractions, and indicators of smaller molecular size (E2:E3) were all higher in the calcium silicate‐treated watershed, suggesting greater microbial processing of DOM.
Geochemical Perspectives Letters, 2020
Texts summarizing the quality control and quality assurance (QA/QC) procedures and the method of ... more Texts summarizing the quality control and quality assurance (QA/QC) procedures and the method of estimating atmospheric Hg deposition.
Ó The Author(s) 2011. This article is published with open access at Springerlink.com Abstract We ... more Ó The Author(s) 2011. This article is published with open access at Springerlink.com Abstract We studied the spatial distribution patterns of mercury (Hg) in lake water, littoral sediments, zooplankton, crayfish, fish, and common loons in 44 lakes of the Adirondacks of New York State, USA, a region that has been characterized as a ‘‘biological Hg hotspot’’. Our study confirmed this pattern, finding that a substantial fraction of the lakes studied had fish and loon samples exceeding established criteria for human and wildlife health. Factors accounting for the spatial variability of Hg in lake water and biota were lake chemistry (pH, acid neutralizing capacity (ANC), percent carbon in sediments), biology (taxa presence, trophic status) and landscape characteristics (land cover class, lake elevation). Hg concentrations in zooplankton, fish and common loons were negatively associated with the lake water acid-base status (pH, ANC). Bioaccumulation factors (BAF) for methyl Hg (MeHg) incr...
Hydrological Processes, 2008
FEMS Microbiology Ecology, 2010
Environmental Pollution, 2008
Canadian Journal of Fisheries and Aquatic Sciences, 2010
To study fish migration using otolith microchemistry, it is important to understand the relations... more To study fish migration using otolith microchemistry, it is important to understand the relationship between elements in the otoliths and in the surrounding water, including potential interactions with other elements. Selenium (Se) is a trace element with strong affinity for mercury (Hg). To test if Se is a reliable tracer for fish migration, the effects of dissolved Se and Hg concentrations on Se incorporation in fish otoliths were investigated experimentally. Brown bullheads ( Ameiurus nebulosus ) were reared in waters spiked with various concentrations of inorganic Se and Hg. Otolith Se:Ca increased nonlinearly with dissolved Se concentrations as there was no significant difference between fish reared in low and medium [Se] waters (Se:Ca for low [Se] waters, 7.64 × 10−6; medium, 6.59 × 10−6; high, 1.24 × 10−5). Our study also provided the first evidence of a negative effect of Hg on Se incorporation into otoliths (p = 0.01), a phenomenon most evident in high [Se] waters. Because ...
Atmospheric Environment, 2009
Atmospheric Environment, 2008
Atmospheric emissions have led to widespread concern over mercury (Hg) contamination in aquatic a... more Atmospheric emissions have led to widespread concern over mercury (Hg) contamination in aquatic and terrestrial ecosystems. Plant litter is an important pathway of Hg inputs to forest ecosystems. We investigated the role of the canopy in Hg accumulation, transport and deposition in an upland forest ecosystem. The total Hg content of leaf tissue increased approximately 10-fold over the growing season across all species, from 4.4 AE 2.7 to 37.3 AE 12.4 ng g À1 , with estimated average linear Hg accumulation rates of 0.22, 0.23, and 0.35 ng g À1 day À1 for yellow birch (Betula alleghaniensis), sugar maple (Acer saccharum), and American beech (Fagus grandifolia), respectively. This linear concentration relationship suggests that the accumulation is regulated by mass transfer processes between the atmosphere and leaf tissue. Conversely, the methyl Hg content (0.17 AE 0.18 ng g À1) and accumulations were low. Concentrations of total Hg were also 42% higher in understory (w1 m), compared to overstory (w10 m), beech. Such disparities in leaf Hg content may result from within-canopy variation in environmental variables, a canopy Hg 0 (g) concentration gradient, or species-specific growth strategies. Annual Hg litterfall was 17.9 and 16.4 mg m À2 yr À1 for 2004 and 2005, respectively, representing the largest input of Hg to this forest ecosystem. Methyl Hg litter input was <0.12 mg m À2 yr À1 for 2005. Modeling estimates of transpiration uptake and Hg 0 (g) deposition suggest that Hg in leaf tissue is largely derived from atmospheric sources. Thus, litter Hg represents largely a new, rather than recycled, input to the forest ecosystem.
Soil Systems
Watershed recovery from long-term acidification in the northeastern U.S. has been characterized b... more Watershed recovery from long-term acidification in the northeastern U.S. has been characterized by an increase in the influx of dissolved organic matter (DOM) into surface waters. Increases in carbon quantity and shifts to more aromatic and “colored” OM has impacted downstream lakes by altering thermal stratification, nutrient cycling and food web dynamics. Here, we used fluorescence spectroscopy coupled with parallel factor analysis (PARAFAC) to model predominant carbon quality fractions and their seasonal changes within surface waters along landscape positions of Arbutus Lake watershed in the Adirondack region of NY, USA. All DOM components were terrestrial in origin, however their relative fractions varied throughout the watershed. DOM in headwater streams contained high fractions of recalcitrant (~43%) and microbial reprocessed humic-like OM (~33%), sourced from upland forest soils. Wetlands above the lake inlet contributed higher fractions of high molecular weight, plant-like o...
Sensors
In order to obtain a better perspective of the impacts of brownfields on the land–atmosphere exch... more In order to obtain a better perspective of the impacts of brownfields on the land–atmosphere exchange of mercury in urban areas, total gaseous mercury (TGM) was measured at two heights (1.8 m and 42.7 m) prior to 2011–2012 and after 2015–2016 for the remediation of a brownfield and installation of a parking lot adjacent to the Syracuse Center of Excellence in Syracuse, NY, USA. Prior to brownfield remediation, the annual average TGM concentrations were 1.6 ± 0.6 and 1.4 ± 0.4 ng · m − 3 at the ground and upper heights, respectively. After brownfield remediation, the annual average TGM concentrations decreased by 32% and 22% at the ground and the upper height, respectively. Mercury soil flux measurements during summer after remediation showed net TGM deposition of 1.7 ng · m − 2 · day − 1 suggesting that the site transitioned from a mercury source to a net mercury sink. Measurements from the Atmospheric Mercury Network (AMNet) indicate that there was no regional decrease in TGM conce...