Ronald Amundson
Biographic Data
| ID | 4495386 |
|---|---|
| NAME | Ronald Amundson |
| GIVEN NAMES | Ronald |
| FAMILY NAME | Amundson |
| SIGNATURE | AMUNDSON R |
| AFFILIATIONS | University of California, Berkeley |
| ORCID | 0000-0003-1510-7313 |
| VERIFIED | Yes |
| TOTAL WORKS | 18 |
| TOTAL CITATIONS | 56 |
| AUTHOR COUNT | 18 |
| EDITOR COUNT | 0 |
| FIRST PUBLICATION YEAR | 1988 |
| LATEST PUBLICATION YEAR | 2018 |
| H-INDEX | 3 |
A late Quaternary paleoenvironmental record in sand dunes of the northern Atacama Desert, Chile
This paper reports a previously unidentified paleoenvironmental record found in sand dunes of the Atacama Desert, Chile. Long-term aeolian deflation by prevailing onshore winds has resulted in the deposition of sand on the irregular surface of a Miocene-aged anhydrite outcrop. Two deposits ~25 km apart, along the prevailing wind trajectory, were hand excavated then analyzed for vertical (and temporal) changes in physical and chemical composition.…
Soil Development: Conceptual and Theoretical Models
Our view and definition of soil is derived through the lens of theory. In the nineteenth century, Vasily Dokuchaev articulated that soil is a natural body on the landscape, one whose properties are determined by a set of factors or variables. This concept essentially is the modern definition of soil and forms the underlying theory of soil science, or pedology. The establishment of this organizing framework has helped the field to grow and expand,…
Soil and human security in the 21st century
Global soil resources under stress The future of humanity is intertwined with the future of Earth's soil resources. Soil provides for agriculture, improves water quality, and buffers greenhouse gases in the atmosphere. Yet human activities, including agricultural soil erosion, are rapidly degrading soil faster than it is naturally replenished. At this rate, human security over the next century will be severely threatened by unsustainable soil man…
Methods of Separating Soil Carbon Pools Affect the Chemistry and Turnover Time of Isolated Fractions
A variety of physical and chemical techniques are used to fractionate soil organic matter, but detailed comparisons of the different approaches and tests of how separation methods influence the properties of isolated organic matter pools are lacking. In this case study based on A horizon samples of 2 California coniferous forests soils, we 1) evaluate the effects of root removal and ultrasonic dispersion on the properties of the -3 light fraction…
The implications for paleodietary and paleoclimatic reconstructions of intrapopulation variability in the oxygen and carbon isotopes of teeth from modern feral horses
We analyzed the isotopic patterns found in the tooth enamel of modern feral horses from Shackleford Banks, North Carolina (USA), which has a temperate climate and supports primarily C4 grasslands. Enamel δ13C values averaged −4.1‰ with a standard deviation (1σ) of 1.7‰, which corresponds to an average diet of 66 ± 12% C4 plants. Our results differ from dietary reconstructions from 1978 to 1981, which found that horses consumed 91% C4 plants. This…
Changing Role of the Embryo in Evolutionary Thought: Roots of Evo-Devo
In this book Ron Amundson examines 200 years of scientific views on the evolution-development relationship from the perspective of evolutionary developmental biology (evo-devo). This new perspective challenges several popular views about the history of evolutionary thought by claiming that many earlier authors made history come out right for the Evolutionary Synthesis." "This book will appeal to students and professionals in the philosophy of sci…
Tooth enamel biomineralization in extant horses: Implications for isotopic microsampling
Dating fluvial terraces by 230 Th/U on pedogenic carbonate, Wind River Basin, Wyoming
Reliable and precise ages of Quaternary pedogenic carbonate can be obtained with 230 Th/U dating by thermal ionization mass spectrometry applied to carefully selected milligram-size samples. Datable carbonate can form within a few thousand years of surface stabilization allowing ages of Quaternary deposits and surfaces to be closely estimated. Pedogenic carbonate clast-rinds from gravels of glacio-fluvial terraces in the Wind River Basin have med…
Global patterns of the isotopic composition of soil and plant nitrogen
We compiled new and published data on the natural abundance N isotope composition (δ 15 N values) of soil and plant organic matter from around the world. Across a broad range of climate and ecosystem types, we found that soil and plant δ 15 N values systematically decreased with increasing mean annual precipitation (MAP) and decreasing mean annual temperature (MAT). Because most undisturbed soils are near N steady state, the observations suggest …
Paleoclimatic Reconstruction Using the Correlation in δ 18 O of Hackberry Carbonate and Environmental Water, North America
Celtis sp. (commonly known as “hackberry”) fruits were collected from 101 North American sites located in 13 states and one Canadian province between the years of 1979–1994. The biomineralized carbonate endocarp of the hackberry, which is a common botanical fossil found throughout the Quaternary sediments of the Great Plains, was analyzed for its δ 18 O value and plotted against the δ 18 O value of site environmental water to demonstrate the pote…
Stable Isotope Dietary Analysis of Bison Bone Samples from the Hudson-Meng Bonebed: Effects of Paleotopography
Potential for 14 C Dating of Biogenic Carbonate in Hackberry ( Celtis ) Endocarps
Hackberry endocarp ( Celtis sp.) contains significant amounts (up to 70 wt%) of biogenic carbonate that is nearly pure aragonite (CaCO 3 ). Because of their high mineral content, hackberry endocarps are found abundantly in Tertiary and Quaternary sediments and are very common in many North American archaeological sites. We analyzed the 14 C content of different components of modern hackberries including the biogenic carbonate in hackberry endocar…
Determining Stone Tool Use: Chemical and Morphological Analyses of Residues on Experimentally Manufactured Stone Tools
Radiocarbon Dating of Soil Organic Matter
Radiocarbon ages of soil organic matter are evaluated with a model which incorporates the dynamics of the 14 C content of soil organic matter. Measured 14 C ages of soil organic matter or its fractions are always younger than the true ages of soils due to continuous input of organic matter into soils. Differences in soil C dynamics due to climate or soil depth will result in significantly different 14 C signatures of soil organic matter for soils…
Stable Isotope Ratios of Carbon in Phytoliths as a Quantitative Method of Monitoring Vegetation and Climate Change
The 13 C/ 12 C ratios of occluded carbon within opal phytoliths from the northern Great Plains show potential as a basis for paleoclimatic reconstruction. A significant correlation exists between the carbon isotopic composition of a host plant and that of the organic matter in its phytoliths. The 13 C/ 12 C ratios for phytoliths from surface layers of soils along climatic gradients reflect the current proportions of C 3 and C 4 plants. Variations…
Soil/landform relationships surrounding the Harappa archaeological site, Pakistan
A soil survey around the archaeological site of Harappa, Pakistan revealed alluvial deposits of five distinct ages based on relative position in the landscape and degree of soil profile development. the youngest deposit (age 1) is in the lowest landscape position and has received flood waters as recently as 1988. Soils there are in an incipient stage of development: only organic carbon and soluble salts have accumulated at the surface of the prof…
Knowledge or Certainty? A Reply to Cziko
In an Educational Researcher article, Cziko (April, 1989) questioned contemporary approaches toward the conduct of educational research, especially those involving experimentation. He justified the need for reform by appealing to the inherent unpredictability and indeterminacy of behavior and went on to suggest greater reliance on descriptive research. Cziko drew unwarranted conclusions about the feasibility of experimentation from his premises a…
Relationship Between Climate and Vegetation and the Stable Carbon Isotope Chemistry of Soils in the Eastern Mojave Desert, Nevada
The relationship between the stable C-isotope composition of the soil environment and modern climate and vegetation was determined empirically along a present-day climatic transect in the eastern Mojave Desert. The δ 13 C of the soil CO 2 and carbonates decreased with increasing elevation and plant density, even though plant assemblages at all elevations were isotopically similar. Several factors, including differences in the ratios of pedogenic …
Determining Stone Tool Use: Chemical and Morphological Analyses of Residues on Experimentally Manufactured Stone Tools
Knowledge or Certainty? A Reply to Cziko
In an Educational Researcher article, Cziko (April, 1989) questioned contemporary approaches toward the conduct of educational research, especially those involving experimentation. He justified the need for reform by appealing to the inherent unpredictability and indeterminacy of behavior and went on to suggest greater reliance on descriptive research. Cziko drew unwarranted conclusions about the feasibility of experimentation from his premises a…
Stable Isotope Dietary Analysis of Bison Bone Samples from the Hudson-Meng Bonebed: Effects of Paleotopography
Soil/landform relationships surrounding the Harappa archaeological site, Pakistan
A soil survey around the archaeological site of Harappa, Pakistan revealed alluvial deposits of five distinct ages based on relative position in the landscape and degree of soil profile development. the youngest deposit (age 1) is in the lowest landscape position and has received flood waters as recently as 1988. Soils there are in an incipient stage of development: only organic carbon and soluble salts have accumulated at the surface of the prof…
Relationship Between Climate and Vegetation and the Stable Carbon Isotope Chemistry of Soils in the Eastern Mojave Desert, Nevada
The relationship between the stable C-isotope composition of the soil environment and modern climate and vegetation was determined empirically along a present-day climatic transect in the eastern Mojave Desert. The δ 13 C of the soil CO 2 and carbonates decreased with increasing elevation and plant density, even though plant assemblages at all elevations were isotopically similar. Several factors, including differences in the ratios of pedogenic …
Soil/landform relationships surrounding the Harappa archaeological site, Pakistan
A soil survey around the archaeological site of Harappa, Pakistan revealed alluvial deposits of five distinct ages based on relative position in the landscape and degree of soil profile development. the youngest deposit (age 1) is in the lowest landscape position and has received flood waters as recently as 1988. Soils there are in an incipient stage of development: only organic carbon and soluble salts have accumulated at the surface of the prof…
Knowledge or Certainty? A Reply to Cziko
In an Educational Researcher article, Cziko (April, 1989) questioned contemporary approaches toward the conduct of educational research, especially those involving experimentation. He justified the need for reform by appealing to the inherent unpredictability and indeterminacy of behavior and went on to suggest greater reliance on descriptive research. Cziko drew unwarranted conclusions about the feasibility of experimentation from his premises a…
Stable Isotope Ratios of Carbon in Phytoliths as a Quantitative Method of Monitoring Vegetation and Climate Change
The 13 C/ 12 C ratios of occluded carbon within opal phytoliths from the northern Great Plains show potential as a basis for paleoclimatic reconstruction. A significant correlation exists between the carbon isotopic composition of a host plant and that of the organic matter in its phytoliths. The 13 C/ 12 C ratios for phytoliths from surface layers of soils along climatic gradients reflect the current proportions of C 3 and C 4 plants. Variations…
Radiocarbon Dating of Soil Organic Matter
Radiocarbon ages of soil organic matter are evaluated with a model which incorporates the dynamics of the 14 C content of soil organic matter. Measured 14 C ages of soil organic matter or its fractions are always younger than the true ages of soils due to continuous input of organic matter into soils. Differences in soil C dynamics due to climate or soil depth will result in significantly different 14 C signatures of soil organic matter for soils…
Potential for 14 C Dating of Biogenic Carbonate in Hackberry ( Celtis ) Endocarps
Hackberry endocarp ( Celtis sp.) contains significant amounts (up to 70 wt%) of biogenic carbonate that is nearly pure aragonite (CaCO 3 ). Because of their high mineral content, hackberry endocarps are found abundantly in Tertiary and Quaternary sediments and are very common in many North American archaeological sites. We analyzed the 14 C content of different components of modern hackberries including the biogenic carbonate in hackberry endocar…
Determining Stone Tool Use: Chemical and Morphological Analyses of Residues on Experimentally Manufactured Stone Tools
Stable Isotope Dietary Analysis of Bison Bone Samples from the Hudson-Meng Bonebed: Effects of Paleotopography
Paleoclimatic Reconstruction Using the Correlation in δ 18 O of Hackberry Carbonate and Environmental Water, North America
Celtis sp. (commonly known as “hackberry”) fruits were collected from 101 North American sites located in 13 states and one Canadian province between the years of 1979–1994. The biomineralized carbonate endocarp of the hackberry, which is a common botanical fossil found throughout the Quaternary sediments of the Great Plains, was analyzed for its δ 18 O value and plotted against the δ 18 O value of site environmental water to demonstrate the pote…
Dating fluvial terraces by 230 Th/U on pedogenic carbonate, Wind River Basin, Wyoming
Reliable and precise ages of Quaternary pedogenic carbonate can be obtained with 230 Th/U dating by thermal ionization mass spectrometry applied to carefully selected milligram-size samples. Datable carbonate can form within a few thousand years of surface stabilization allowing ages of Quaternary deposits and surfaces to be closely estimated. Pedogenic carbonate clast-rinds from gravels of glacio-fluvial terraces in the Wind River Basin have med…
Global patterns of the isotopic composition of soil and plant nitrogen
We compiled new and published data on the natural abundance N isotope composition (δ 15 N values) of soil and plant organic matter from around the world. Across a broad range of climate and ecosystem types, we found that soil and plant δ 15 N values systematically decreased with increasing mean annual precipitation (MAP) and decreasing mean annual temperature (MAT). Because most undisturbed soils are near N steady state, the observations suggest …
Tooth enamel biomineralization in extant horses: Implications for isotopic microsampling
The implications for paleodietary and paleoclimatic reconstructions of intrapopulation variability in the oxygen and carbon isotopes of teeth from modern feral horses
We analyzed the isotopic patterns found in the tooth enamel of modern feral horses from Shackleford Banks, North Carolina (USA), which has a temperate climate and supports primarily C4 grasslands. Enamel δ13C values averaged −4.1‰ with a standard deviation (1σ) of 1.7‰, which corresponds to an average diet of 66 ± 12% C4 plants. Our results differ from dietary reconstructions from 1978 to 1981, which found that horses consumed 91% C4 plants. This…
Changing Role of the Embryo in Evolutionary Thought: Roots of Evo-Devo
In this book Ron Amundson examines 200 years of scientific views on the evolution-development relationship from the perspective of evolutionary developmental biology (evo-devo). This new perspective challenges several popular views about the history of evolutionary thought by claiming that many earlier authors made history come out right for the Evolutionary Synthesis." "This book will appeal to students and professionals in the philosophy of sci…
Methods of Separating Soil Carbon Pools Affect the Chemistry and Turnover Time of Isolated Fractions
A variety of physical and chemical techniques are used to fractionate soil organic matter, but detailed comparisons of the different approaches and tests of how separation methods influence the properties of isolated organic matter pools are lacking. In this case study based on A horizon samples of 2 California coniferous forests soils, we 1) evaluate the effects of root removal and ultrasonic dispersion on the properties of the -3 light fraction…
Soil and human security in the 21st century
Global soil resources under stress The future of humanity is intertwined with the future of Earth's soil resources. Soil provides for agriculture, improves water quality, and buffers greenhouse gases in the atmosphere. Yet human activities, including agricultural soil erosion, are rapidly degrading soil faster than it is naturally replenished. At this rate, human security over the next century will be severely threatened by unsustainable soil man…
Soil Development: Conceptual and Theoretical Models
Our view and definition of soil is derived through the lens of theory. In the nineteenth century, Vasily Dokuchaev articulated that soil is a natural body on the landscape, one whose properties are determined by a set of factors or variables. This concept essentially is the modern definition of soil and forms the underlying theory of soil science, or pedology. The establishment of this organizing framework has helped the field to grow and expand,…
A late Quaternary paleoenvironmental record in sand dunes of the northern Atacama Desert, Chile
This paper reports a previously unidentified paleoenvironmental record found in sand dunes of the Atacama Desert, Chile. Long-term aeolian deflation by prevailing onshore winds has resulted in the deposition of sand on the irregular surface of a Miocene-aged anhydrite outcrop. Two deposits ~25 km apart, along the prevailing wind trajectory, were hand excavated then analyzed for vertical (and temporal) changes in physical and chemical composition.…
Geology (11 works) · Chemistry (10 works) · Geography (8 works) · Paleontology (8 works) · Soil water (8 works) · Archaeology and ancient environmental studies (7 works) · Geology and Paleoclimatology Research (7 works) · Soil Science (7 works) · Biology (6 works) · Ecology (6 works)