The impact of climate on the biogeochemical functioning of volcanic soils

Chadwick, Oliver A.; Gavenda, Robert T.; Kelly, Eugene F.; Ziegler, K.; Olson, Carolyn; Elliott, W. Crawford; Hendricks, D. M.

doi:10.1016/j.chemgeo.2002.09.001

Cited by 358 publications

(387 citation statements)

References 48 publications

Supporting

Mentioning

356

Contrasting

Unclassified

Order By: Relevance

“…1). Local studies of climate gradients have shown that the relative importance of these two buffers is determined by leaching, which removes Ca 2+ from the soil 2,3,8,9 . In climates where evaporative demand exceeds precipitation, leaching rates are low, and dissolved Ca 2+ accumulates as CaCO 3 -buffering soil pH near 8.2 (ref.…”

mentioning

confidence: 99%

Water balance creates a threshold in soil pH at the global scale

Slessarev

Lin

Bingham

et al. 2016

Nature

417

255

View full text Add to dashboard Cite

Soil pH regulates the capacity of soils to store and supply nutrients, and thus contributes substantially to controlling productivity in terrestrial ecosystems 1 . However, soil pH is not an independent regulator of soil fertility-rather, it is ultimately controlled by environmental forcing. In particular, small changes in water balance cause a steep transition from alkaline to acid soils across natural climate gradients 2,3 . Although the processes governing this threshold in soil pH are well understood, the threshold has not been quantified at the global scale, where the influence of climate may be confounded by the effects of topography and mineralogy. Here we evaluate the global relationship between water balance and soil pH by extracting a spatially random sample (n = 20,000) from an extensive compilation of 60,291 soil pH measurements. We show that there is an abrupt transition from alkaline to acid soil pH that occurs at the point where mean annual precipitation begins to exceed mean annual potential evapotranspiration. We evaluate deviations from this global pattern, showing that they may result from seasonality, climate history, erosion and mineralogy. These results demonstrate that climate creates a nonlinear pattern in soil solution chemistry at the global scale; they also reveal conditions under which soils maintain pH out of equilibrium with modern climate.Climate controls many aspects of soil chemistry, affecting soil pH (ref. 4). Alkaline soils are known to be common in arid climates, while acid soils are known to be common in humid climates 1 . Surprisingly, however, the global-scale mechanisms governing this pattern remain broadly defined, and untested by direct observation. What are the dominant chemical equilibria that constrain soil pH? What aspect of climate defines the transition between alkaline and acid soils, and is the transition linear? The answers to these questions are fundamental to understanding soil development and surface geochemistry at the global scale. Furthermore, achieving this understanding may prove essential for representing soils in models of the terrestrial biosphere, given that soil pH controls many aspects of soil fertility 5,6 . Here we illustrate that simple geochemical and hydrological concepts can be used to build a mechanistic understanding of soil pH at the global scale.Interpretations of acid-titration experiments indicate that the soil pH is typically most strongly buffered by equilibrium with two secondary minerals: calcite (CaCO 3 ), or gibbsite (Al(OH) 3 ) 7,8 Fig. 1).Local studies of climate gradients have shown that the relative importance of these two buffers is determined by leaching, which removes Ca 2+ from the soil 2,3,8,9 . In climates where evaporative demand exceeds precipitation, leaching rates are low, and dissolved Ca 2+ accumulates as CaCO 3 -buffering soil pH near 8.2 (ref. 4). Conversely, in climates where precipitation exceeds evaporative demand, water leaches through the soil, removing Ca 2+ and allowing accumulation of relatively immobile...

show abstract

mentioning

confidence: 99%

Water balance creates a threshold in soil pH at the global scale

Slessarev

Lin

Bingham

et al. 2016

Nature

417

255

View full text Add to dashboard Cite

show abstract

“…Soil δ 34 S values that seem to decrease with increasing annual rainfall along the transects are notable (Fig. 4), because, other factors being equal, greater annual rainfall should drive more extensive depletion of rock-derived sulfur (Chadwick et al, 2003). That greater annual rainfall does not cause soil δ 34 S values to shift away from the basaltic parent material signature suggests that degree of weathering is not significant in determining ecosystem sulfur sources at these sites.…”

Section: Sulfur Sources In Terrestrial Ecosystemsmentioning

confidence: 98%

“…Alternatively, some aspect of the site's location along the leeward Kohala Coast might cause it to receive greater than expected deposition of volcanic emissions and the low δ 34 S values could still be atmospheric. Retention of parent material sulfur seems unlikely considering the measurable silicate weathering and losses of rock-derived elements from the site (Chadwick et al, 2003). Thus, only the 20 ka age gradient site (Fig.…”

Section: Sulfur Sources In Terrestrial Ecosystemsmentioning

confidence: 99%

“…From the Kohala Peninsula on the northern end of the island of Hawaii, 22 samples were analyzed from two transects on Hawi volcanics, assigned an age of approximately 150 ka . Supplementing those are samples from another three sites on the Hawi volcanics, assigned an age of 170 ka (Chadwick et al, 2003). Together, the transects span elevations from 160 to 1150 m, annual rainfall from 180 to 2500 mm, and distances from the coast of 1.7 to 9.4 km.…”

Section: Soil and Vegetation Samplingmentioning

confidence: 99%

See 1 more Smart Citation

Steep spatial gradients of volcanic and marine sulfur in Hawaiian rainfall and ecosystems

Bern

Chadwick

Kendall

et al. 2015

Science of The Total Environment

View full text Add to dashboard Cite

• Sources of sulfur in Hawaiian ecosystems were investigated via sulfur isotopes.• Basalt, sea-salt, volcanic and marine biogenic emissions have distinct isotope ratios.• Atmospheric deposition sources of sulfur dominated all but one site investigated.• Steep gradients of marine vs. volcanic atmospheric deposition were found.• Gradients occurred with distance to the coast and elevation. a b s t r a c t a r t i c l e i n f o Sulfur, a nutrient required by terrestrial ecosystems, is likely to be regulated by atmospheric processes in welldrained, upland settings because of its low concentration in most bedrock and generally poor retention by inorganic reactions within soils. Environmental controls on sulfur sources in unpolluted ecosystems have seldom been investigated in detail, even though the possibility of sulfur limiting primary production is much greater where atmospheric deposition of anthropogenic sulfur is low. Here we measure sulfur isotopic compositions of soils, vegetation and bulk atmospheric deposition from the Hawaiian Islands for the purpose of tracing sources of ecosystem sulfur. Hawaiian lava has a mantle-derived sulfur isotopic composition (δ 34 S VCDT) of − 0.8‰. Bulk deposition on the island of Maui had a δ 34 S VCDT that varied temporally, spanned a range from +8.2 to + 19.7‰, and reflected isotopic mixing from three sources: sea-salt (+ 21.1‰), marine biogenic emissions (+ 15.6‰), and volcanic emissions from active vents on Kilauea Volcano (+ 0.8‰). A straightforward, weathering-driven transition in ecosystem sulfur sources could be interpreted in the shift from relatively low (0.0 to +2.7‰) to relatively high (+17.8 to +19.3‰) soil δ 34 S values along a 0.3 to 4100 ka soil age-gradient, and similar patterns in associated vegetation. However, sub-kilometer scale spatial variation in soil sulfur isotopic composition was found along soil transects assumed by age and mass balance to be dominated by atmospheric sulfur inputs. Soil sulfur isotopic compositions ranged from +8.1 to +20.3‰ and generally decreased with increasing elevation (0-2000 m), distance from the coast (0-12 km), and annual rainfall (180-5000 mm). Such trends reflect the spatial variation in marine versus volcanic inputs from atmospheric deposition. Broadly, these results illustrate how the sources and magnitude of atmospheric deposition can exert controls over ecosystem sulfur biogeochemistry across relatively small spatial scales.Published by Elsevier B.V.

show abstract

“…This sequestration is limited by basalt quality (Ca þMg concentration and degree of previous weathering) [4,10] and weathering conditions, such as low temperatures in Siberia or dry conditions in Ethiopia [16], which slow the rate of chemical reactions. Weathering is enhanced by increasing the reactive surface area and by increasing temperature and moisture: EW will proceed most rapidly in warm, wet environments [15,26,31]. Rates of CO 2 capture by EW are uncertain, but the most Ca-and Mg-rich silicate rocks have the capacity to sequester .1t CO 2 t 21 rock, while basic rocks, including basalts, range from 200 -800 kg CO 2 t 21 rock [4,10,15].…”

Section: Basalt Weathering For C Sequestrationmentioning

confidence: 99%

Potential of global croplands and bioenergy crops for climate change mitigation through deployment for enhanced weathering

et al. 2017

View full text Add to dashboard Cite

Conventional row crop agriculture for both food and fuel is a source of carbon dioxide (CO 2 ) and nitrous oxide (N 2 O) to the atmosphere, and intensifying production on agricultural land increases the potential for soil C loss and soil acidification due to fertilizer use. Enhanced weathering (EW) in agricultural soils-applying crushed silicate rock as a soil amendment-is a method for combating global climate change while increasing nutrient availability to plants. EW uses land that is already producing food and fuel to sequester carbon (C), and reduces N 2 O loss through pH buffering. As biofuel use increases, EW in bioenergy crops offers the opportunity to sequester CO 2 while reducing fossil fuel combustion. Uncertainties remain in the long-term effects and global implications of large-scale efforts to directly manipulate Earth's atmospheric CO 2 composition, but EW in agricultural lands is an opportunity to employ these soils to sequester atmospheric C while benefitting crop production and the global climate.

show abstract

The impact of climate on the biogeochemical functioning of volcanic soils

Cited by 358 publications

References 48 publications

Water balance creates a threshold in soil pH at the global scale

Water balance creates a threshold in soil pH at the global scale

Steep spatial gradients of volcanic and marine sulfur in Hawaiian rainfall and ecosystems

Potential of global croplands and bioenergy crops for climate change mitigation through deployment for enhanced weathering

Contact Info

Product

Resources

About