Solute geochemical mass-balances and mineral weathering rates in small watersheds II: Biomass nutrient uptake, more equations in more unknowns, and land use/land cover effects

Price, James E.; Hardy, Christopher R.; Tefend, Karen S.; Szymanski, David W.

doi:10.1016/j.apgeochem.2012.01.020

Cited by 16 publications

(24 citation statements)

References 82 publications

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“…To add equations to the mass‐balance matrix, the mole fraction of each base cation released by each mineral ( F j , c ) involved in chemical weathering must be known and is calculated as follows (formalized from Price et al ., ):

F_{j, c} = \frac{(β_{c, j} S G_{j} P_{j}) / m m_{j}}{\sum_{j = 1}^{δ} ((), β_{c, j} S G_{j} P_{j}) / m m_{j}}

where F j , c is the mole fraction of element c released to the system by phase j (dimensionless); β c , j is the stoichiometric coefficient of species c in phase j (moles); SG j is the specific gravity of phase j (dimensionless); P j is the percentage of the total bedrock volume loss attributable to the dissolution of phase j (%); mm j is the molar mass of phase j (grams mole –1 ); δ is the number of minerals j involved in weathering and containing element c .…”

Section: Methodsmentioning

confidence: 99%

“…Dormant (D) and growing (G) seasons are indicated. Horizontal dashed lines represent volume‐weighted mean dormant season (steady‐state) concentrations (after Price et al ., ).…”

Section: Methodsmentioning

confidence: 99%

“…Previous mass‐balance studies of the Hauver Branch watershed had more unknowns (individual primary minerals and/or secondary minerals) than equations (the number of elements for which stream solute data are available) (Velbel and Price, , and references cited therein). This study improves on earlier work by using solid‐phase data to add more equations to the mass‐balance matrix, allowing the calculation of weathering rates for all minerals known to be weathering (Price et al ., ). These minerals include both silicates and carbonates, the latter of which have been well studied in granitic terrains (e.g.…”

Section: Introductionmentioning

confidence: 99%

“…Recently, Price et al . () calculated a deciduous macronutrient uptake stoichiometry of K 1·0 Mg 1·0 Ca 1·4 using paired watersheds located in Pennsylvania, USA, which differed appreciably only in percentage of forest cover.…”

Section: Introductionmentioning

confidence: 99%

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Mass‐balance modeling of mineral weathering rates and CO₂ consumption in the forested, metabasaltic Hauver Branch watershed, Catoctin Mountain, Maryland, USA

Price

Rice

Szymanski

2013

Earth Surf Processes Landf

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Mineral weathering rates and a forest macronutrient uptake stoichiometry were determined for the forested, metabasaltic Hauver Branch watershed in north‐central Maryland, USA. Previous studies of Hauver Branch have had an insufficient number of analytes to permit determination of rates of all the minerals involved in chemical weathering, including biomass. More equations in the mass‐balance matrix were added using existing mineralogic information. The stoichiometry of a deciduous biomass term was determined using multi‐year weekly to biweekly stream‐water chemistry for a nearby watershed, which drains relatively unreactive quartzite bedrock. At Hauver Branch, calcite hosts ~38 mol% of the calcium ion (Ca2+) contained in weathering minerals, but its weathering provides ~90% of the stream water Ca2+. This occurs in a landscape with a regolith residence time of more than several Ka (kiloannum). Previous studies indicate that such old regolith does not typically contain dissolving calcite that affects stream Ca2+/Na+ ratios. The relatively high calcite dissolution rate likely reflects dissolution of calcite in fractures of the deep critical zone. Of the carbon dioxide (CO2) consumed by mineral weathering, calcite is responsible for approximately 27%, with the silicate weathering consumption rate far exceeding that of the global average. The chemical weathering of mafic terrains in decaying orogens thus may be capable of influencing global geochemical cycles, and therefore, climate, on geological timescales. Based on carbon‐balance calculations, atmospheric‐derived sulfuric acid is responsible for approximately 22% of the mineral weathering occurring in the watershed. Our results suggest that rising air temperatures, driven by global warming and resulting in higher precipitation, will cause the rate of chemical weathering in the Hauver Branch watershed to increase until a threshold temperature is reached. Beyond the threshold temperature, increased recharge would produce a shallower groundwater table and reduced chemical weathering rates. Copyright © 2013 John Wiley & Sons, Ltd.

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F_{j, c} = \frac{(β_{c, j} S G_{j} P_{j}) / m m_{j}}{\sum_{j = 1}^{δ} ((), β_{c, j} S G_{j} P_{j}) / m m_{j}}

Section: Methodsmentioning

confidence: 99%

“…Dormant (D) and growing (G) seasons are indicated. Horizontal dashed lines represent volume‐weighted mean dormant season (steady‐state) concentrations (after Price et al ., ).…”

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Mass‐balance modeling of mineral weathering rates and CO₂ consumption in the forested, metabasaltic Hauver Branch watershed, Catoctin Mountain, Maryland, USA

Price

Rice

Szymanski

2013

Earth Surf Processes Landf

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“…Research on the impact of different land use patterns on soil has mostly focused on physical and chemical properties, such as analyses of microbial biomass carbon and nitrogen (Wang et al 2006;Xu et al 2009;Price et al 2012;Fliessbach et al 2013). Comparatively little research has been performed on how land use variations affect the functional diversity of soil microbes.…”

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confidence: 99%

Comparative study on microbial community structure across orchard soil, cropland soil, and unused soil

Cui¹,

Zhao²,

Lv³

et al. 2017

Soil & Water Res.

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We examined the effects of three different soil conditions (orchard soil, cropland soil, unused soil) on the functional diversity of soil microbial communities. The results first showed that orchard and cropland land use significantly changed the distribution and diversity of soil microbes, particularly at surface soil layers. The richness index (S) and Shannon diversity index (H) of orchard soil microbes were significantly higher than the indices of the cropland and unused soil treatments in the 0–10 cm soil layer, while the S and H indices of cropland soil microbes were the highest in 10–20 cm soil layers. Additionally, the Simpson dominance index of cropland soil microbial communities was the highest across all soil layers. Next, we found that carbon source differences in soil layers under the three land use conditions can mainly be attributed to their carbohydrate and polymer composition, indicating that they are the primary cause of the functional differences in microbial communities under different land uses. In conclusion, orchard and cropland soil probably affected microbial distribution and functional diversity due to differences in vegetation cover, cultivation, and management measures.

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Hydraulic redistribution by plants and nutrient stoichiometry: Shifts under global change

Sardans

Peñuelas²

2014

Ecohydrology

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Hydraulic lift, water movement from deep to upper soil layers by roots, is a widespread process in temperate and semi-arid environments. It can contribute 17-81% of total water transpired and favour the uptake of nutrients available mainly from soil organic matter decomposition (e.g. N). Downward siphoning, water movement from upper to deep soil layers, can represent 10-60% of total transpired water, favouring the uptake of nutrients supplied mainly from the leaching of bedrock minerals (e.g. P and K). These vertical water movements also can affect the N : P ratio of runoff waters when, in the case of hydraulic lift, they open the possibility for a given pulse of water to circulate multiple times across the N-rich upper soil layers. Plants, thus, affect the stoichiometry of nutrients in soils and groundwater not only through the physical protection of the soil and through the water uptake but also through water redistribution. Soil water redistribution can also play an outstanding role in the ecosystem responses to global change drivers. The increase in soil patchiness in current and future arid lands modifies runoff fluxes, hydraulic lift and downward siphoning, allowing plants to dispose of higher water and nutrient availabilities. The higher use of hydraulic lift and/or downward siphoning by alien species is a possible cause of alien plant success. Further mechanistic and quantitative research is thus warranted to discern the plant role in water and nutrient cycling and in the responses to global change.

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Solute geochemical mass-balances and mineral weathering rates in small watersheds II: Biomass nutrient uptake, more equations in more unknowns, and land use/land cover effects

Cited by 16 publications

References 82 publications

Mass‐balance modeling of mineral weathering rates and CO₂ consumption in the forested, metabasaltic Hauver Branch watershed, Catoctin Mountain, Maryland, USA

Mass‐balance modeling of mineral weathering rates and CO₂ consumption in the forested, metabasaltic Hauver Branch watershed, Catoctin Mountain, Maryland, USA

Comparative study on microbial community structure across orchard soil, cropland soil, and unused soil

Hydraulic redistribution by plants and nutrient stoichiometry: Shifts under global change

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Solute geochemical mass-balances and mineral weathering rates in small watersheds II: Biomass nutrient uptake, more equations in more unknowns, and land use/land cover effects

Cited by 16 publications

References 82 publications

Mass‐balance modeling of mineral weathering rates and CO2 consumption in the forested, metabasaltic Hauver Branch watershed, Catoctin Mountain, Maryland, USA

Mass‐balance modeling of mineral weathering rates and CO2 consumption in the forested, metabasaltic Hauver Branch watershed, Catoctin Mountain, Maryland, USA

Comparative study on microbial community structure across orchard soil, cropland soil, and unused soil

Hydraulic redistribution by plants and nutrient stoichiometry: Shifts under global change

Contact Info

Product

Resources

About

Mass‐balance modeling of mineral weathering rates and CO₂ consumption in the forested, metabasaltic Hauver Branch watershed, Catoctin Mountain, Maryland, USA

Mass‐balance modeling of mineral weathering rates and CO₂ consumption in the forested, metabasaltic Hauver Branch watershed, Catoctin Mountain, Maryland, USA