Magnesium and calcium isotope systematics in a headwater catchment underlain by amphibolite: Constraints on Mg–Ca biogeochemistry in an atmospherically polluted but well-buffered spruce ecosystem (Czech Republic, Central Europe)

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00025798%3A_____%2F20%3A00000048" target="_blank" >RIV/00025798:_____/20:00000048 - isvavai.cz</a>

Výsledek na webu

<a href="https://www.sciencedirect.com/science/article/pii/S0341816220301879" target="_blank" >https://www.sciencedirect.com/science/article/pii/S0341816220301879</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.catena.2020.104637" target="_blank" >10.1016/j.catena.2020.104637</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Magnesium and calcium isotope systematics in a headwater catchment underlain by amphibolite: Constraints on Mg–Ca biogeochemistry in an atmospherically polluted but well-buffered spruce ecosystem (Czech Republic, Central Europe)

Popis výsledku v původním jazyce

Lithogenic and biologically-fractionated magnesium (Mg) and calcium (Ca) are viewed as alternative controls of the &#61540;26Mg and &#61540;44Ca isotope signatures of streams and rivers. Understanding of Mg–Ca isotope systematics and of runoff generation in headwater catchments is crucial for upscaling riverine variability in &#61540;26Mg and &#61540;44Ca values to Mg–Ca isotope inputs into the oceans, and for global climate change considerations. Here we report Mg–Ca–Sr isotope systematics in a small, spruce-forested, high-elevation catchment in western Czech Republic, which has received high Mg and Ca inputs from dissolution of base-rich bedrock amphibolite and from industrial emissions. Our study site NAZ (Slavkov Forest) experienced a relatively long period of acid rain (ca. 1950-1995), accompanied by deposition of partly soluble dust from coal-burning power plants. Bedrock contained as much as 11 and 10 wt. percent of MgO and CaO, respectively. Input–output monitoring revealed a large net export of Mg, Ca, but also S, from the catchment via surface runoff. The &#61540;26Mg values increased in the order: open-area precipitation (-1.44 per mille) < soil water (-1.10 per mille) < spruce canopy throughfall (-1.00 per mille) < runoff (-0.96 per mille) < spruce bark (-0.59 per mille) < spruce needles (-0.46 per mille) < spruce xylem (-0.40 per mille) < bedrock (-0.32 per mille) < soil (-0.30 per mille) < spruce fine roots (-0.07 per mille). The &#61540;44Ca values increased in the order: spruce bark (-1.91 per mille) < spruce xylem (-0.86 per mille) < spruce fine roots (-0.83 per mille) < spruce needles (-0.43 per mille) < spruce canopy throughfall (0.31 per mille) < soil water (0.44 per mille) < soil (0.46 per mille) < open-area precipitation (0.69 per mille) < plagioclase (0.83 per mille) < bulk bedrock (0.86 per mille) < runoff (0.92 per mille) < amphibole (1.10 per mille). Our data indicated a relatively small Mg isotope fractionation toward higher &#61540;26Mg values in organic matter, and a large Ca isotope fractionation toward lower &#61540;44Ca values in all studied organic compartments. In contrast to Mg, most Ca isotope variability at NAZ was driven by biological fractionations. While excess Mg and Ca in NAZ export fluxes via catchment runoff are most easily explained by lithological control of runoff Mg–Ca, the Mg–Ca–Sr isotope systematics were also consistent with measurable atmospheric contribution to Mg and Ca in runoff.

Název v anglickém jazyce

Magnesium and calcium isotope systematics in a headwater catchment underlain by amphibolite: Constraints on Mg–Ca biogeochemistry in an atmospherically polluted but well-buffered spruce ecosystem (Czech Republic, Central Europe)

Popis výsledku anglicky

Lithogenic and biologically-fractionated magnesium (Mg) and calcium (Ca) are viewed as alternative controls of the &#61540;26Mg and &#61540;44Ca isotope signatures of streams and rivers. Understanding of Mg–Ca isotope systematics and of runoff generation in headwater catchments is crucial for upscaling riverine variability in &#61540;26Mg and &#61540;44Ca values to Mg–Ca isotope inputs into the oceans, and for global climate change considerations. Here we report Mg–Ca–Sr isotope systematics in a small, spruce-forested, high-elevation catchment in western Czech Republic, which has received high Mg and Ca inputs from dissolution of base-rich bedrock amphibolite and from industrial emissions. Our study site NAZ (Slavkov Forest) experienced a relatively long period of acid rain (ca. 1950-1995), accompanied by deposition of partly soluble dust from coal-burning power plants. Bedrock contained as much as 11 and 10 wt. percent of MgO and CaO, respectively. Input–output monitoring revealed a large net export of Mg, Ca, but also S, from the catchment via surface runoff. The &#61540;26Mg values increased in the order: open-area precipitation (-1.44 per mille) < soil water (-1.10 per mille) < spruce canopy throughfall (-1.00 per mille) < runoff (-0.96 per mille) < spruce bark (-0.59 per mille) < spruce needles (-0.46 per mille) < spruce xylem (-0.40 per mille) < bedrock (-0.32 per mille) < soil (-0.30 per mille) < spruce fine roots (-0.07 per mille). The &#61540;44Ca values increased in the order: spruce bark (-1.91 per mille) < spruce xylem (-0.86 per mille) < spruce fine roots (-0.83 per mille) < spruce needles (-0.43 per mille) < spruce canopy throughfall (0.31 per mille) < soil water (0.44 per mille) < soil (0.46 per mille) < open-area precipitation (0.69 per mille) < plagioclase (0.83 per mille) < bulk bedrock (0.86 per mille) < runoff (0.92 per mille) < amphibole (1.10 per mille). Our data indicated a relatively small Mg isotope fractionation toward higher &#61540;26Mg values in organic matter, and a large Ca isotope fractionation toward lower &#61540;44Ca values in all studied organic compartments. In contrast to Mg, most Ca isotope variability at NAZ was driven by biological fractionations. While excess Mg and Ca in NAZ export fluxes via catchment runoff are most easily explained by lithological control of runoff Mg–Ca, the Mg–Ca–Sr isotope systematics were also consistent with measurable atmospheric contribution to Mg and Ca in runoff.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10505 - Geology

Projekt

<a href="/cs/project/GA18-15498S" target="_blank" >GA18-15498S: Izotopové hmotové bilance vápníku a hořčíku v acidifikovaných malých povodích na horninovém podloží s kontrastním chemickým složením</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2020

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Catena

ISSN

0341-8162

e-ISSN

—

Svazek periodika

193

Číslo periodika v rámci svazku

October : 104637

Stát vydavatele periodika

DE - Spolková republika Německo

Počet stran výsledku

16

Strana od-do

nestránkováno

Kód UT WoS článku

000538770800031

EID výsledku v databázi Scopus

2-s2.0-85084677445