DOI: 10.1007/s10533-017-0383-0
Scopus记录号: 2-s2.0-85030312162
论文题名: Iron reduction: a mechanism for dynamic cycling of occluded cations in tropical forest soils?
作者: Hall S.J. ; Huang W.
刊名: Biogeochemistry
ISSN: 0168-2563
EISSN: 1573-515X
出版年: 2017
卷: 136, 期: 1 起始页码: 91
结束页码: 102
语种: 英语
英文关键词: Cation
; Iron
; Luquillo Experimental Forest
; Occluded
; Redox
; Walker-Syers model
Scopus关键词: calcium
; cation
; dissolution
; forest soil
; groundwater
; ion exchange
; iron
; leaching
; magnesium
; numerical model
; nutrient availability
; potassium
; redox conditions
; reduction
; soil organic matter
; soil type
; tropical forest
; Luquillo Experimental Forest
; Puerto Rico
英文摘要: Nutrient cations can limit plant productivity in highly weathered soils, but have received much less attention than phosphorus and nitrogen. The reduction of iron (Fe) in anaerobic microsites of surface soils can solubilize organic matter and P sorbed or occluded with short-range-ordered (SRO) Fe phases. This mechanism might also release occluded cations. In the Luquillo Experimental Forest, Puerto Rico, we measured cation release during anaerobic laboratory incubations, and assessed patterns of cation availability in surface soils spanning ridge-slope-valley catenas. During anaerobic incubations, potassium (K), calcium (Ca) and magnesium (Mg) significantly increased with reduced Fe (Fe(II)) in both water and 0.5 M HCl extractions, but did not change during aerobic incubations. In the field, 0.5 M HCl-extractable Fe(II) and Fe(III) were the strongest predictors of K, Mg, and Ca on ridges (R2 0.57–0.75). Here, both Ca and Mg decreased with Fe(III), while K, Ca, and Mg increased with Fe(II), consistent with release of Fe-occluded cations following Fe reduction. Manganese in ridge soils was extremely low, consistent with leaching following reductive dissolution of Mn(IV). On slopes, soil C was the strongest cation predictor, consistent with the importance of organic matter for cation exchange in these highly weathered Oxisols. In riparian valleys, cation concentrations were up to 16-fold greater than in other topographic positions but were weakly or unrelated to measured predictors, potentially reflecting cation-rich groundwater. Predictors of cation availability varied with topography, but were consistent with the potential importance of microsite Fe reduction in liberating occluded cations, particularly in the highly productive ridges. This mechanism may explain discrepancies among indices of “available” soil cations and plant cation uptake observed in other tropical forests. © 2017, Springer International Publishing AG. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/83222
Appears in Collections: 气候减缓与适应 气候变化事实与影响
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作者单位: Department of Ecology, Evolution, and Organismal Biology, Iowa State University, 251 Bessey Hall, Ames, IA, United States
Recommended Citation:
Hall S.J.,Huang W.. Iron reduction: a mechanism for dynamic cycling of occluded cations in tropical forest soils?[J]. Biogeochemistry,2017-01-01,136(1)