Zamanian, Kazem

[["dc.bibliographiccitation.firstpage","1"],["dc.bibliographiccitation.journal","Earth-Science Reviews"],["dc.bibliographiccitation.lastpage","17"],["dc.bibliographiccitation.volume","157"],["dc.contributor.author","Zamanian, Kazem"],["dc.contributor.author","Pustovoytov, Konstantin"],["dc.contributor.author","Kuzyakov, Yakov"],["dc.date.accessioned","2018-11-07T10:13:16Z"],["dc.date.available","2018-11-07T10:13:16Z"],["dc.date.issued","2016"],["dc.description.abstract","Soils comprise the largest terrestrial carbon (C) pool, containing both organic and inorganic C. Soil inorganic carbon (SIC) was frequently disregarded because (1) it is partly heritage from soil parent material, (2) it undergoes slow formation processes and (3) has very slow exchange with atmospheric CO2. The global importance of SIC, however, is reflected by the fact that SIC links the long-term geological C cycle with the fast biotic C cycle, and this linkage is ongoing in soils. Furthermore, the importance of SIC is at least as high as that of soil organic carbon (SOC) especially in semiarid and arid climates, where SIC comprises the largest C pool. Considering the origin, formation processes and morphology, carbonates in soils are categorized into three groups: geogenic carbonates (GC), biogenic carbonates (BC) and pedogenic carbonates (PC). In this review we summarize the available data and theories on forms and formation processes of PC and relate them to environmental factors. After describing the general formation principles of PC, we present the specific forms and formation processes for PC features and the possibilities to use them-to reconstruct soil-forming factors and processes. The following PC are described in detail: earthworm biospheroliths, rhizoliths and calcified roots, hypocoatings, nodules, clast coatings, calcretes and laminar caps. The second part of the review focuses on the isotopic composition of PC: delta C-13, Delta C-14 and delta O-18, as well as clumped C-13 and O-18 isotopes known as Delta(47). The isotopic signature of PC enables reconstructing the formation environment: the dominating vegetation (delta C-13), temperature (delta O-18 and Delta(47)), and the age of PC formation (Delta C-14). The uncertainties in reconstructional and dating studies due to PC recrystallization after formation are discussed and simple approaches to consider recrystallization are summarized. Finally, we suggest the most important future research directions on PC, including the anthropogenic effects of fertilization and soil management. In conclusion, PC are an important part of SIC that reflect the time, periods and formation processes in soils. A mechanistic understanding of PC formation is a prerequisite to predict terrestrial C stocks and changes in the global C cycle, and to link the long-term geological with short-term biological C cycles. (C) 2016 Elsevier B.V. All rights reserved."],["dc.description.sponsorship","German Research Foundation (DFG) [KU 1184/34-1]"],["dc.identifier.doi","10.1016/j.earscirev.2016.03.003"],["dc.identifier.isi","000378368800001"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/40397"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Elsevier Science Bv"],["dc.relation.issn","1872-6828"],["dc.relation.issn","0012-8252"],["dc.title","Pedogenic carbonates: Forms and formation processes"],["dc.type","review"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","87"],["dc.bibliographiccitation.journal","Geoderma"],["dc.bibliographiccitation.lastpage","95"],["dc.bibliographiccitation.volume","282"],["dc.contributor.author","Zamanian, Kazem"],["dc.contributor.author","Pustovoytov, Konstantin"],["dc.contributor.author","Kuzyakov, Yakov"],["dc.date.accessioned","2018-11-07T10:05:48Z"],["dc.date.available","2018-11-07T10:05:48Z"],["dc.date.issued","2016"],["dc.description.abstract","Mollusk shells are commonly present in a broad array of geological and archaeological contexts. The shell carbonate can serve for numerical age determination (Delta C-14) and as a paleoenvironmental indicator (delta O-18, delta C-13). Shell carbonate recrystallization in soils, however, may re-equilibrate the carbon (C) isotopic signature with soil CO2. The equilibration dynamics remain poorly understood because of the absence of suitable experimental approaches. Here we used the artificial C-14-labeling technique to study the process of shell carbonate recrystallization as a function of time. Organic-free and organic-containing shell particles of Protothaca stamina were mixed with loess or a carbonate free loamy soil. The mixtures were placed in air-tight bottles, where the bottle air containing (CO2)-C-14 (pCO(2) = 2%). The C-14 activity of shells was measured over time and related to the recrystallization of shell carbonate. Recrystallization of shell carbonate already began after one day. The recrystallization rates were 10(-3)% day(-1) in organic-containing shell embedded in soil and 1.6 . 10(-2)% day(-1) in organic-free shells in loess. Removal of organic compounds increased shell porosity, and so, increased the contact surface for exchange with soil solution. Organic-free shells recrystallized much faster in loess (0.56% in 56 days) than in other treatments. Recrystallization was 2 to 7 times higher in loess (in the presence and absence of organic compounds, respectively) than in carbonate-free soil. Loess carbonate itself can recrystallize and accumulate on shells, leading to overestimation of shell carbonate recrystallization. A model for shell carbonate recrystallization as a function of time was developed. The model considers the presence or absence of organic compounds in shell structure and geogenic carbonates in the embedding matrix. The model enabled all results to be fitted with R-2 = 0.98. The modelled time necessary for nearlyfull recrystallization (95% of shell carbonate) was 88 years for organic free shells in loess and up to 770 years for organic-containing shells in carbonate-free soil. After this period, the original isotopic signature will vanish completely and will be replaced by a new delta C-13 and Delta C-14 signature in the shell structure. Thus, shell carbonate recrystallization may proceed relatively rapidly in terms of geologic time. This is necessary to consider in the interpretation of dating results and paleoenvironmental reconstructions. (C) 2016 Elsevier B.V. All rights reserved."],["dc.description.sponsorship","German Research Foundation (DFG) [KU 1184/34-1]"],["dc.identifier.doi","10.1016/j.geoderma.2016.07.013"],["dc.identifier.isi","000381837100010"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/38970"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Elsevier Science Bv"],["dc.relation.issn","1872-6259"],["dc.relation.issn","0016-7061"],["dc.title","Recrystallization of shell carbonate in soil: C-14 labeling, modeling and relevance for dating and paleo-reconstructions"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","141"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Radiocarbon"],["dc.bibliographiccitation.lastpage","150"],["dc.bibliographiccitation.volume","59"],["dc.contributor.author","Zamanian, Kazem"],["dc.contributor.author","Pustovoytov, Konstantin"],["dc.contributor.author","Kuzyakov, Yakov"],["dc.date.accessioned","2020-12-10T15:22:11Z"],["dc.date.available","2020-12-10T15:22:11Z"],["dc.date.issued","2017"],["dc.description.abstract","Fruit carbonate of Buglossoides arvensis (syn. Lithospermum arvense) is a valuable dating and paleoenvironmental proxy for late Quaternary deposits and cultural layers because CaCO3 in fruit is assumed to be accumulated from photosynthetic carbon (C). However, considering the uptake of HCO3-by roots from soil solution, the estimated age could be too old depending on the source of HCO3-allocated in fruit carbonate. Until now, no studies have assessed the contributions of photosynthetic and soil C to the fruit carbonate. To evaluate this, the allocation of photo-assimilated carbon and root uptake of HCO3-was examined by radiocarbon (C-14) labeling and tracing. B. arvensis was grown in carbonate-free and carbonate-containing soils (sand and loess, respectively), where 14C was provided as (1) (CO2)-C-14 in the atmosphere (5 times shoot pulse labeling), or (2) (Na2CO3)-C-14 in soil solution (root-labeling; 5 times by injecting labeled solution into the soil) during one month of fruit development. Distinctly different patterns of 14C distribution in plant organs after root-and shoot labeling showed the ability of B. arvensis to take up HCO3-from soil solution. The highest C-14 activity from root labeling was recovered in roots, followed by shoots, fruit organics, and fruit carbonate. In contrast, C-14 activity after shoot labeling was the highest in shoots, followed by fruit organics, roots and fruit carbonate. Total photo-assimilated C incorporated via shoot labeling in loess-grown plants was 1.51mg lower than in sand, reflecting the presence of dissolved carbonate (i.e. CaCO3) in loess. Loess carbonate dissolution and root-respired CO2 in soil solution are both sources of HCO3-for root uptake. Considering this dilution effect by carbonates, the total incorporated HCO3-comprised 0.15% of C in fruit carbonate after 10 hr of shoot labeling. However, if the incorporated HCO3-during 10 hr of shoot labeling is extrapolated for the whole month of fruit development (i.e. 420-hr photoperiod), fruit carbonate in loess-grown plants incorporated approximately 6.3% more HCO3-than in sand. Therefore, fruit carbonates from plants grown on calcareous soils may yield overestimated C-14 ages around 500 yr because of a few percentage uptake of HCO3-by roots. However, the age overestimation because of HCO3-uptake becomes insignificant in fruits older than approximately 11,000 yr due to increasing uncertainties in age determination."],["dc.identifier.doi","10.1017/RDC.2016.123"],["dc.identifier.eissn","1945-5755"],["dc.identifier.isi","000398544900010"],["dc.identifier.issn","0033-8222"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/73303"],["dc.language.iso","en"],["dc.notes.intern","DOI Import GROB-354"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","PUB_WoS_Import"],["dc.publisher","Univ Arizona Dept Geosciences"],["dc.relation.issn","1945-5755"],["dc.relation.issn","0033-8222"],["dc.title","Carbon Sources in Fruit Carbonate of Buglossoides arvensis and Consequences for 14 C Dating"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","134"],["dc.bibliographiccitation.journal","CATENA"],["dc.bibliographiccitation.lastpage","138"],["dc.bibliographiccitation.volume","142"],["dc.contributor.author","Zamanian, Kazem"],["dc.contributor.author","Pustovoytov, Konstantin"],["dc.contributor.author","Kuzyakov, Yakov"],["dc.date.accessioned","2018-11-07T10:12:31Z"],["dc.date.available","2018-11-07T10:12:31Z"],["dc.date.issued","2016"],["dc.description.abstract","The radiocarbon method has been frequently used to date mollusk shell carbonate. The accuracy of estimated ages, however, depends on the degree and completeness of shell carbonate recrystallization. Although the effect of contamination of the shell CaCO3 with environmental carbon (C) is well known, the role of Ca2+ in diagenetic processes remains unclear. Addition of young C to shells during diagenesis occurs in soil solution, where the Ca2+ concentration is in equilibrium with exchangeable Ca2+ and/or weathering of Ca-bearing minerals. While the exchange process takes place within seconds, the dissolution equilibrium requires longer timescales (on the order of months). It has therefore been hypothesized that the dissolution and recrystallization of shell carbonate in soils with higher cation exchange capacity (CEC) should proceed slower compared to those with low CEC. The objective was to determine the effects of soil CEC and exchangeable cations on shell carbonate recrystallization using the C-14 labeling approach. Shell particles of the bivalve Protothaca staminea were mixed with carbonate-free sand (CEC = 0.37 cmol(+) kg(-1)) (Sand), a loamy soil (CEC = 16 cmol(+) kg(-1)) (Loam) or the same loamy soil saturated with KCl, where exchangeable cations were replaced with K+ (Exchanged). The high-sensitivity C-14 labeling/tracing approach was used to determine carbonate recrystallization rates. Shell carbonate recrystallization after 120 days in Loam and Exchanged (0.016 and 0.024 mg CaCO3, respectively) showed one order of magnitude lower recrystallization than in Sand (0.13 mg CaCO3). A high level of soil exchangeable Ca2+ decreased the solubility of shell carbonate and consequently its recrystallization because the exchange is faster than dissolution. Therefore, soil CEC and cation composition are determinant factors of shell carbonate recrystallization. Shells in soils with low CEC may undergo more intensive recrystallization; hence they may need further pretreatments before the dating procedure. (C) 2016 Elsevier B.V. All rights reserved."],["dc.description.sponsorship","German Research Foundation (DFG) [KU 1184/34-1]"],["dc.identifier.doi","10.1016/j.catena.2016.03.012"],["dc.identifier.isi","000376714200012"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/40254"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Elsevier Science Bv"],["dc.relation.issn","1872-6887"],["dc.relation.issn","0341-8162"],["dc.title","Cation exchange retards shell carbonate recrystallization: consequences for dating and paleoenvironmental reconstructions"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]