A comparison of soil climate and biological activity along an elevation gradient in the eastern Mojave Desert

Amundson, Ronald; Chadwick, Oliver A.; Sowers, Janet M.

doi:10.1007/bf00379042

Cited by 69 publications

(43 citation statements)

References 18 publications

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“…Therefore, average crop production was 2.7 Mg grain/ha/year for the humid subregion and 2.1 Mg grain/ha/year in the semiarid. This pattern agrees with the observation that precipitation constrains plant production in arid to subhumid ecosystems (Sala et al 1988;Amundson et al 1989;Jobbagy & Jackson 2000). As a result, the estimated C input rate was greater in the humid subregion than in the semiarid subregion: 0.9 Mg C/ha/year and 0.75 Mg C/ha/year, correspondingly.…”

Section: Resultssupporting

confidence: 89%

Estimation of carbon inputs to soils from wheat in the Pampas Region, Argentina

Civeira¹

2011

CZECH J GENET PLANT

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Abstract:Recently soils have gained more attention within the global change debate as the largest terrestrial carbon (C) pool. Different soils and vegetation types have substantial impacts on many of the processes that take place in the ecosystem functioning and thus in soil organic C stocks. An accurate estimation of vegetation C inputs to soils may aid in more precise estimation of the future release or sequestration of soil organic C. Wheat production affects C inputs and thus soil C sequestration in soils. The objective of this research was to evaluate C inputs by wheat, from 1993 to 2002 in the Pampas Region. The estimated C input rate by wheat was greater in the humid subregion than in the semiarid subregion: 0.9 and 0.75 Mg C/ha/year, correspondingly. This pattern agrees with the observation that precipitation constrains plant production in arid to subhumid ecosystems. The average organic C input by wheat into the soils throughout the period was 8.1 Mg C/ha in the humid subregion and, 6.75 Mg C/ha in the semiarid subregion.

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Section: Resultssupporting

confidence: 89%

Estimation of carbon inputs to soils from wheat in the Pampas Region, Argentina

Civeira¹

2011

CZECH J GENET PLANT

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“…The difference between soil textures diminishes in humid sites, and the effects on water retention and C and N pools are dampened The difference in potential N mineralization between coarse-and fine-textured soils would be greatest in arid ecosystems due to the relative difference in soil water holding capacity. However, more important than the direct effect of water availability on microbial activity would be the change in the overall size of the C and N pools due to increased NPP inputs (Amundson et al 1989;Austin and Sala 2002). Thus, along a gradient of water availability, the realized changes in N mineralization under very arid conditions would be small due to small soil C and N pools, in spite of the importance of soil textural differences (Fig.…”

Section: Water Pulses In Arid and Semiarid Ecosystemsmentioning

confidence: 98%

Water pulses and biogeochemical cycles in arid and semiarid ecosystems

et al. 2004

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The episodic nature of water availability in arid and semiarid ecosystems has significant consequences on belowground carbon and nutrient cycling. Pulsed water events directly control belowground processes through soil wet-dry cycles. Rapid soil microbial response to incident moisture availability often results in almost instantaneous C and N mineralization, followed by shifts in C/N of microbially available substrate, and an offset in the balance between nutrient immobilization and mineralization. Nitrogen inputs from biological soil crusts are also highly sensitive to pulsed rain events, and nitrogen losses, particularly gaseous losses due to denitrification and nitrate leaching, are tightly linked to pulses of water availability. The magnitude of the effect of water pulses on carbon and nutrient pools, however, depends on the distribution of resource availability and soil organisms, both of which are strongly affected by the spatial and temporal heterogeneity of vegetation cover, topographic position and soil texture. The 'inverse texture hypothesis' for net primary production in water-limited ecosystems suggests that coarse-textured soils have higher NPP than fine-textured soils in very arid zones due to reduced evaporative losses, while NPP is greater in fine-textured soils in higher rainfall ecosystems due to increased water-holding capacity. With respect to belowground processes, fine-textured soils tend to have higher water-holding capacity and labile C and N pools than coarse-textured soils, and often show a much greater flush of N mineralization. The result of the interaction of texture and pulsed rainfall events suggests a corollary hypothesis for nutrient turnover in arid and semiarid ecosystems with a linear increase of N mineralization in coarse-textured soils, but a saturating response for fine-textured soils due to the importance of soil C and N pools. Seasonal distribution of water pulses can lead to the accumulation of mineral N in the dry season, decoupling resource supply and microbial and plant demand, and resulting in increased losses via other pathways and reduction in overall soil nutrient pools. The asynchrony of resource availability, particularly nitrogen versus water due to pulsed water events, may be central to understanding the consequences for ecosystem nutrient retention and long-term effects on carbon and nutrient pools. Finally, global change effects due to changes in the nature and size of pulsed water events and increased asynchrony of water availability and growing season will likely have impacts on biogeochemical cycling in water-limited ecosystems.

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“…Studies of variation in soil properties in dierent precipitation regimes generally show that concentrations of extractable/exchangeable nutrients are relatively high in semiarid sites and decrease with increasing precipitation (HoÈ gberg 1989;Schulze et al 1991). Soil organic carbon follows the opposite pattern, increasing with increasing annual rainfall (Amundson et al 1989;Burke et al 1991;Quilchano et al 1995a). While total soil nutrient contents may also increase, C:N and C:P ratios in soils widen with increasing mean annual precipitation (MAP) (Roberts et al 1989), suggesting that with increasing rainfall, the rate of carbon accretion in soil exceeds that of total nutrient accumulation.…”

Section: Introductionmentioning

confidence: 93%

Nutrient dynamics on a precipitation gradient in Hawai'i

1998

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We evaluated soil and foliar nutrients in five native forests in Hawai'i with annual rainfall ranging from 500 mm to 5500 mm. All of the sites were at the same elevation and of the same substrate age; all were native-dominated forests containing Metrosiderospolymorpha Gaud. Soil concentrations of extractable NO-N and PO-P, as well as major cations (Ca, Mg, and K), decreased with increasing annual precipitation, and δN values became more depleted in both soils and vegetation. For M.polymorpha leaves, leaf mass per area (LMA) and lignin concentrations increased significantly, while δC values became more depleted with increasing precipitation. Foliar phosphorus, and major cation (Ca, Mg, and K) concentrations for M.polymorpha all decreased significantly with increasing precipitation. For other native forest species, patterns of LMA, δC, and δN generally mirrored the pattern observed for M. polymorpha. Decreasing concentrations of available rock-derived nutrients in soil suggest that the effect of increased rainfall on leaching outweighs the effect of increasing precipitation on weathering. The pattern of decreased foliar nutrient concentrations per unit leaf area and of increased lignin indicates a shift from relatively high nutrient availability to relatively high carbon gain by producers as annual precipitation increases. For nitrogen cycling, the pattern of higher inorganic soil nitrogen concentrations in the drier sites, together with the progressively depleted δN signature in both soils and vegetation, suggests that nitrogen cycling is more open at the drier sites, with smaller losses relative to turnover as annual precipitation increases.

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A comparison of soil climate and biological activity along an elevation gradient in the eastern Mojave Desert

Cited by 69 publications

References 18 publications

Estimation of carbon inputs to soils from wheat in the Pampas Region, Argentina

Estimation of carbon inputs to soils from wheat in the Pampas Region, Argentina

Water pulses and biogeochemical cycles in arid and semiarid ecosystems

Nutrient dynamics on a precipitation gradient in Hawai'i

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