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GEOCARB III: a revised model of atmospheric CO 2 over Phanerozoic time
- Am. J. Sci
, 2001
"... of atmospheric CO 2, has been made with emphasis on factors affecting CO 2 uptake by continental weathering. This includes: (1) new GCM (general circulation model) results for the dependence of global mean surface temperature and runoff on CO 2, for both glaciated and non-glaciated periods, coupled ..."
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Cited by 135 (6 self)
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of atmospheric CO 2, has been made with emphasis on factors affecting CO 2 uptake by continental weathering. This includes: (1) new GCM (general circulation model) results for the dependence of global mean surface temperature and runoff on CO 2, for both glaciated and non-glaciated periods, coupled with new results for the temperature response to changes in solar radiation; (2) demonstration that values for the weathering-uplift factor f R(t) based on Sr isotopes as was done in GEOCARB II are in general agreement with independent values calculated from the abundance of terrigenous sediments as a measure of global physical erosion rate over Phanerozoic time; (3) more accurate estimates of the timing and the quantitative effects on Ca-Mg silicate weathering of the rise of large vascular plants on the continents during the Devonian; (4) inclusion of the effects of changes in paleogeography alone (constant CO 2 and solar radiation) on global mean land surface temperature as it affects the rate of weathering; (5) consideration of the effects of volcanic weathering, both in subduction zones and on the seafloor; (6) use of new data on the � 13 C values for Phanerozoic limestones and organic matter; (7) consideration of the relative weathering
Tracing the origin of dissolved silicon transferred from various
, 2010
"... soil-plant systems towards rivers: a review ..."
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Biotic feedback extends the life span of the biosphere
"... The Sun is becoming more luminous with time and will eventually overheat the biosphere. However, life cools the Earth by amplifying the rate of silicate rock weathering and maintaining a low level of atmospheric CO2. Recent studies indicate a much stronger biotic weathering effect than in models use ..."
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The Sun is becoming more luminous with time and will eventually overheat the biosphere. However, life cools the Earth by amplifying the rate of silicate rock weathering and maintaining a low level of atmospheric CO2. Recent studies indicate a much stronger biotic weathering effect than in models used to estimate the life span of the biosphere. Here we show that the resulting feedback lengthens the survival of complex life by delaying the loss of CO2 from the atmosphere. The weathering biota can potentially maintain the Earth in a habitable state when otherwise it would be too hot for them. If so, catastrophic warming rather than gradual CO2 starvation will terminate complex life. Despite the possibility of an irreversible collapse, the current biosphere should remain resilient to carbon cycle perturbation or mass extinction events for at least 0:8 Gyr and may survive for up to 1:2 Gyr. 1
Export of chloride after clear-cutting in the Hubbard Brook sandbox experiment. Biogeochemistry 63
, 2003
"... Abstract. The objective of this study was to discern the source of higher than usual concentrations of chloride in drainage water collected from experimental forest plots after clear-cutting. When the sand-box experiments were initiated at the Hubbard Brook Experimental Forest Station three vegetati ..."
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Abstract. The objective of this study was to discern the source of higher than usual concentrations of chloride in drainage water collected from experimental forest plots after clear-cutting. When the sand-box experiments were initiated at the Hubbard Brook Experimental Forest Station three vegetation types were established: red pine, grass, and minimally vegetated (scattered lichens and bryophytes) as the “bare ” control plot. After 15 years of growth the trees were cut down and above-ground biomass re-moved from the red pine sandbox. For several years prior to the cut, high concentrations ( 75 M) of dissolved Cl − in drainage waters occurred in November/December. This is attributed to the buildup of rainfall-derived Cl − due to evapotranspiration that depletes soil moisture to low levels resulting in a lack of drainage during this period. The excess Cl − is quickly flushed out by subsequent drainage over a few weeks and Cl − concentrations return to values characteristic of rainfall and throughfall. After the trees were removed in May, 1998, Cl − continued to be leached from the system. The concentration of Cl − peaked (175 M) in Sept. 1998 and did not return back to base level concentration until Dec. 1999. The Cl − release pattern is distinctly different from that of dissolved NO3−, which peaked about one year later than Cl−. An excess (over that of the control sandbox) of 78 g Cl − was released in the 1.5 year period after clear-cut, showing that a large amount of leachable chloride is stored in the bulk soil/root/
Tripartite association in alder: effects of Frankia and Alpova piplophloes on the growth, nitrogen fixation, and mineral acquisition of Alnus tenuifolia. Plant and Soil
, 2003
"... Abstract The role of tripartite associations among Frankia, Alpova diplophloeus (an ectomycorrhizal fungus) and Alnus tenuifoliain growth, nitrogen fixation, ectomycorrhizal formation, and mineral acquisition of A. tenuifolia was investigated. Seedlings of A. tenuifolia were planted in pots contain ..."
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Abstract The role of tripartite associations among Frankia, Alpova diplophloeus (an ectomycorrhizal fungus) and Alnus tenuifoliain growth, nitrogen fixation, ectomycorrhizal formation, and mineral acquisition of A. tenuifolia was investigated. Seedlings of A. tenuifolia were planted in pots containing a mixture of ground basalt-perlite, or perlite alone, which served as the control. The seedlings were inoculated with Frankia isolated from root nodules of alder, followed by spores of A. diplophloeus and grown for 5 months in a greenhouse. The seedlings grown in the pots with a mixture of ground basalt-perlite after dual inoculation with Frankia and A. diplophLoeus had the heaviest shoots and root nodules in dry weight, and showed the greatest nitrogen-fixing ability measured by acetylene reduction. Ectomycorrhizas formed with A. diplophloeus increased when this fungus was inoculated together with Frankia. The mineral composition (P, K, Ca, Fe, Mg, Mn, Na, Si and Al) in the seedlings was also determined. The results of these experiments showed that the tripartite association could improve the growth, nitrogen fixation and mineral acquisition (rock solubilization) of A. tenuifolia.
Plant responses to soil heterogeneity and global environmental change
"... 1. Recent evidence suggests that soil nutrient heterogeneity, a ubiquitous feature of terrestrial ecosystems, modulates plant responses to ongoing global change (GC). However, we know little about the overall trends of such responses, the GC drivers involved and the plant attributes affected. 2. We ..."
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1. Recent evidence suggests that soil nutrient heterogeneity, a ubiquitous feature of terrestrial ecosystems, modulates plant responses to ongoing global change (GC). However, we know little about the overall trends of such responses, the GC drivers involved and the plant attributes affected. 2. We synthesized literature to answer the question: Does soil heterogeneity significantly affect plant responses to main GC drivers, such as elevated atmospheric carbon dioxide concentration (CO2), nitrogen (N) enrichment and changes in rainfall regime? 3. Overall, most studies have addressed short-term effects of N enrichment on the performance of model plant communities using experiments conducted under controlled conditions. The role of soil heterogeneity as a modulator of plant responses to elevated CO 2 may depend on the plasticity in nutrient uptake patterns. Soil heterogeneity does interact with N enrichment to determine plant growth and nutrient status, but the outcome of this interaction has been found to be both synergistic and inhibitory. The very few studies published on interactive effects of soil heterogeneity and changes in rainfall regime prevented us from identifying any general pattern. 4. We identify the long-term consequences of soil heterogeneity on plant community dynamics in the field, and the ecosystem-level responses of the soil heterogeneity 9 GC driver interaction, as the
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, 2013
"... Pathways of volcanic glass alteration in laboratory experiments through inorganic ..."
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Pathways of volcanic glass alteration in laboratory experiments through inorganic
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, 2013
"... Mechanisms of nutrient limitation and nutrient acquisition in managed and unmanaged forest ecosystems ..."
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Mechanisms of nutrient limitation and nutrient acquisition in managed and unmanaged forest ecosystems
Nutrient Removals in Woody Biomass: Preliminary Estimates from the Sub-Boreal Spruce Long- Term Soil Productivity Study
, 2000
"... The Long-Term Soil Productivity (LTSP) Study (Ministry of Forests E.P. 1148) seeks to understand the longterm impacts of organic matter removals and soil ..."
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The Long-Term Soil Productivity (LTSP) Study (Ministry of Forests E.P. 1148) seeks to understand the longterm impacts of organic matter removals and soil
