Upbuilding pedogenesis under active loess deposition in a super-humid, temperate climate — quantification of deposition rates, soil chemistry and pedogenic thresholds

Eger, André; Almond, Peter C.; Condron, Leo M.

doi:10.1016/j.geoderma.2012.06.019

Cited by 34 publications

(27 citation statements)

References 58 publications

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“…The dune complex contains two gradients: a chrono‐sequence of dune ridges of increasing age with increasing distance from the coast (~170–6500 years B.P.) [ Eger et al ., ; Wells and Goff , , ] and a dust flux gradient originating from the braided river bed of the Haast with a maximum dust deposition rate of 28.4 g m −2 yr −1 at the site closest to the river declining with river distance [ Eger et al ., ].…”

Section: Methodsmentioning

confidence: 99%

Phosphorus fertilization by active dust deposition in a super‐humid, temperate environment—Soil phosphorus fractionation and accession processes

Eger

Almond

Condron

2013

Global Biogeochemical Cycles

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[1] The inventory of soil phosphorus (P) is subject to significant changes over time. The main primary form, bedrock-derived apatite P, becomes progressively lost through leaching, or transformed into more immobile and less plant-accessible, secondary organic and mineral forms. Here we studied the rejuvenating effect of dust deposition on soil P along an active dust flux gradient downwind of a braided river. Along the gradient, we measured soil P fractions to 50 cm depth of six Spodosols and one Inceptisol, supplemented by tree foliage P concentrations. While an increasing dust flux correlates with a twofold increase of foliar P and soil organic P along the gradient, apatite P declines from~50 to 3 g m À2 and total P shows no response. Compared to dust-unaffected Spodosols, depth distribution of total P becomes increasingly uniform and organic P propagates deeper into the soil under dust flux. Further, the effect of topsoil P eluviation attenuates due to higher organic P content and the zone of high apatite P concentrations associated with un-weathered subsoil becomes progressively removed from the upper 50 cm. We interpret these patterns as being consistent with upbuilding pedogenesi and conclude that dust-derived mineral P is assimilated in the organic surface horizon and does not reach the mineral soil. Dust-derived mineral P is temporarily stored in the living biomass and returns to the soil with plant and microbial detritus as organic P, which is subsequently buried by further dust increments. We further conclude that (1) the efficiency of P fertilization of the ecosystem by dust accession is higher than through P advection in dust-unaffected Spodosols and (2) organic P may serve as an important source of labile P in a high-leaching environment.Citation: Eger, A., P. C. Almond, and L. M. Condron (2013), Phosphorus fertilization by active dust deposition in a super-humid, temperate environment-Soil phosphorus fractionation and accession processes, Global Biogeochem.

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Section: Methodsmentioning

confidence: 99%

Phosphorus fertilization by active dust deposition in a super‐humid, temperate environment—Soil phosphorus fractionation and accession processes

Eger

Almond

Condron

2013

Global Biogeochemical Cycles

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“…On the country's South Island, the floodplains of extensive braided river systems are well established as a supply of fine sediment that is prone to deflation [ McGowan , ; Eden and Hammond , ]. Exposed bars and inactive channels in these alluvial systems commonly act as emissive surfaces, and several field studies have quantified rates of dust deposition downwind of braided floodplains [e.g., Cox et al , cited by Marx and McGowan , ; McGowan et al , ; Eger et al , ]. In the semiarid rain shadow region east of the Southern Alps, degraded tussock grasslands are also recognized as a prominent source area for dust, with land erodibility within the intermontane basins of such high‐country rangelands (e.g., Mackenzie Basin) having been exacerbated by anthropogenic activity [ McGowan and Ledgard , ].…”

Section: Regional High‐latitude Dust Sourcesmentioning

confidence: 99%

“…While the rain shadow effect of the Southern Alps range promotes dust emission in drier conditions on its leeside, the uplift of dust from alluvial floodplains and its subsequent local deposition have also been reported in superhumid areas on the South Island west coast, where the process is linked to active loess formation [ Eden and Hammond , ; Marx and McGowan , ; Eger et al , ]. Approximately 19% of the South Island has been assessed as affected by wind erosion to some degree [ Salter , 1984].…”

Section: Regional High‐latitude Dust Sourcesmentioning

confidence: 99%

High‐latitude dust in the Earth system

et al. 2016

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Natural dust is often associated with hot, subtropical deserts, but significant dust events have been reported from cold, high latitudes. This review synthesizes current understanding of high‐latitude (≥50°N and ≥40°S) dust source geography and dynamics and provides a prospectus for future research on the topic. Although the fundamental processes controlling aeolian dust emissions in high latitudes are essentially the same as in temperate regions, there are additional processes specific to or enhanced in cold regions. These include low temperatures, humidity, strong winds, permafrost and niveo‐aeolian processes all of which can affect the efficiency of dust emission and distribution of sediments. Dust deposition at high latitudes can provide nutrients to the marine system, specifically by contributing iron to high‐nutrient, low‐chlorophyll oceans; it also affects ice albedo and melt rates. There have been no attempts to quantify systematically the expanse, characteristics, or dynamics of high‐latitude dust sources. To address this, we identify and compare the main sources and drivers of dust emissions in the Northern (Alaska, Canada, Greenland, and Iceland) and Southern (Antarctica, New Zealand, and Patagonia) Hemispheres. The scarcity of year‐round observations and limitations of satellite remote sensing data at high latitudes are discussed. It is estimated that under contemporary conditions high‐latitude sources cover >500,000 km2 and contribute at least 80–100 Tg yr−1 of dust to the Earth system (~5% of the global dust budget); both are projected to increase under future climate change scenarios.

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“…However, in other cases they are humid or even super humid. For example, southern Icelandic dust sources experience rainfall >1,500 mm/yr (Bullard, 2017), while on the west coast of the South Island of New Zealand, average local dust deposition rates of 10-143 g/m 2 /yr (Eger et al, 2012;Marx and McGowan, 2005) were recorded where rainfall of >5,000 mm/yr occurs, resulting in loess formation (Almond and Tonkin, 1999;Eger et al, 2012). Therefore, at least in some environments, dust emissions may not be limited by aridity.…”

Section: Climate Controlsmentioning

confidence: 99%