All terrestrial ecosystems consist of aboveground and belowground components that interact to influence community- and ecosystem-level processes and properties. Here we show how these components are closely interlinked at the community level, reinforced by a greater degree of specificity between plants and soil organisms than has been previously supposed. As such, aboveground and belowground communities can be powerful mutual drivers, with both positive and negative feedbacks. A combined aboveground-belowground approach to community and ecosystem ecology is enhancing our understanding of the regulation and functional significance of biodiversity and of the environmental impacts of human-induced global change phenomena.

http://science.sciencemag.org/content/sci/304/5677/1629.full.pdf

Ecological linkages between aboveground and belowground biota.

Radiocarbon (14C) ages cannot provide absolutely dated chronologies for archaeological or paleoenvironmental studies directly but must be converted to calendar age equivalents using a calibration curve compensating for fluctuations in atmospheric 14C concentration. Although calibration curves are constructed from independently dated archives, they invariably require revision as new data become available and our understanding of the Earth system improves. In this volume the international 14C calibration curves for both the Northern and Southern Hemispheres, as well as for the ocean surface layer, have been updated to include a wealth of new data and extended to 55,000 cal BP. Based on tree rings, IntCal20 now extends as a fully atmospheric record to ca. 13,900 cal BP. For the older part of the timescale, IntCal20 comprises statistically integrated evidence from floating tree-ring chronologies, lacustrine and marine sediments, speleothems, and corals. We utilized improved evaluation of the timescales and location variable 14C offsets from the atmosphere (reservoir age, dead carbon fraction) for each dataset. New statistical methods have refined the structure of the calibration curves while maintaining a robust treatment of uncertainties in the 14C ages, the calendar ages and other corrections. The inclusion of modeled marine reservoir ages derived from a three-dimensional ocean circulation model has allowed us to apply more appropriate reservoir corrections to the marine 14C data rather than the previous use of constant regional offsets from the atmosphere. Here we provide an overview of the new and revised datasets and the associated methods used for the construction of the IntCal20 curve and explore potential regional offsets for tree-ring data. We discuss the main differences with respect to the previous calibration curve, IntCal13, and some of the implications for archaeology and geosciences ranging from the recent past to the time of the extinction of the Neanderthals.

https://dspace.stir.ac.uk/bitstream/1893/30981/1/intcal20_northern_hemisphere_radiocarbon_age_calibration_curve_055_cal_kbp.pdf

The IntCal20 Northern Hemisphere Radiocarbon Age Calibration Curve (0-55 cal kBP)

National Science Education Standards

https://cyberleninka.org/article/n/352063.pdf

87Sr/86Sr, δ13C and δ18O evolution of Phanerozoic seawater

CHAPTER 1. INTRODUCTION TO KARST. 1.1 Definitions. 1.2 The Relationship Between Karst And General Geomorphology And Hydrogeology. 1.3 The Global Distribution Of Karst. 1.4 The Growth Of Ideas. 1.5 Aims Of The Book. 1.6 Karst Terminology. CHAPTER 2. THE KARST ROCKS. 2.1 Carbonate Rocks And Minerals. 2.2 Limestone Compositions And Depositional Facies. 2.3 Limestone Diagenesis And The Formation Of Dolomite. 2.4 The Evaporite Rocks. 2.5. Quartzites And Siliceous Sandstones. 2.6 Effects Of Lithologic Properties Upon Karst Development. 2.7 Interbedded Clastic Rocks. 2.8 Bedding Planes, Joints, Faults And Fracture Traces. 2.9 Fold Topography. 2.10 Paleokarst Unconformities. CHAPTER 3. DISSOLUTION: CHEMICAL AND KINETIC BEHAVIOUR OF THE KARST ROCKS. 3.1 Introduction. 3.2 Aqueous Solutions And Chemical Equilibria. 3.3 The Dissolution Of Anhydrite, Gypsum And Salt. 3.4 The Dissolution Of Silica. 3.5 Bicarbonate Equilibria And The Dissolution Of Carbonate Rocks In Normal Meteoric Waters. 3.6 The S-O-H System And The Dissolution Of Carbonate Rocks. 3.7 Chemical Complications In Carbonate Dissolution. 3.8 Biokarst Processes. 3.9 Measurements In The Field And Lab Computer Programs. 3.10 Dissolution And Precipitation Kinetics Of Karst Rocks. CHAPTER 4. DISTRIBUTION AND RATE OF KARST DENUDATION. 4.1 Global Variations In The Solutional Denudation Of Carbonate Terrains. 4.2 Measurement And Calculation Of Solutional Denudation Rates. 4.3 Solution Rates In Gypsum, Salt And Other Non-Carbonate Rocks. 4.4 Interpretation Of Measurements. CHAPTER 5. KARST HYDROLOGY. 5.1 Basic Hydrological Concepts, Terms And Definitions. 5.2 Controls On The Development Of Karst Hydrologic Systems. 5.3 Energy Supply And Flow Network Development. 5.4 Development Of The Water Table And Phreatic Zones. 5.5 Development Of The Vadose Zone. 5.6 Classification And Characteristics Of Karst Aquifers. 5.7 Applicability Of Darcy's Law To Karst. 5.8 The Fresh Water/Salt Water Interface. CHAPTER 6. ANALYSIS OF KARST DRAINAGE SYSTEMS. 6.1 The 'Grey Box' Nature Of Karst. 6.2 Surface Exploration And Survey Techniques. 6.3 Investigating Recharge And Percolation In The Vadose Zone. 6.4 Borehole Analysis. 6.5 Spring Hydrograph Analysis. 6.6 Polje Hydrograph Analysis. 6.7 Spring Chemograph Interpretation. 6.8 Storage Volumes And Flow Routing Under Different States Of The Hydrograph. 6.9 Interpreting The Organisation Of A Karst Aquifer. 6.10 Water Tracing Techniques. 6.11 Computer Modelling Of Karst Aquifers. CHAPTER 7. SPELEOGENESIS: THE DEVELOPMENT OF CAVE SYSTEMS. 7.1 Classifying Cave Systems. 7.2 Building The Plan Patterns Of Unconfined Caves. 7.3 Unconfined Cave Development In Length And Depth. 7.4 System Modifications Occurring Within A Single Phase. 7.5 Multi-Phase Cave Systems. 7.6 Meteoric Water Caves Developed Where There Is Confined Circulation Or Basal Injection Of Water. 7.7 Hypogene Caves: (A) Hydrothermal Caves Associated Chiefly With Co2. 7.8 Hypogene Caves: (B) Caves Formed By Waters Containing H2s. 7.9 Sea Coast Eogenetic Caves. 7.10 Passage Cross-Sections And Smaller Features Of Erosional Morphology. 7.11 Condensation, Condensation Corrosion, And Weathering In Caves. 7.12 Breakdown In Caves. CHAPTER 8. CAVE INTERIOR DEPOSITS. 8.1 Introduction. 8.2 Clastic Sediments. 8.3 Calcite, Aragonite And Other Carbonate Precipitates. 8.4 Other Cave Minerals. 8.5 Ice In Caves. 8.6 Dating Of Calcite Speleothems And Other Cave Deposits. 8.7 Paleo-Environmental Analysis Of Calcite Speleothems. 8.8 Mass Flux Through A Cave System: The Example Of Friar's Hole, W.Va. CHAPTER 9. KARST LANDFORM DEVELOPMENT IN HUMID REGIONS. 9.1 Coupled Hydrological And Geochemical Systems. 9.2 Small Scale Solution Sculpture - Microkarren And Karren. 9.3 Dolines - The 'Diagnostic' Karst Landform? 9.4 The Origin And Development Of Solution Dolines. 9.5 The Origin Of Collapse And Subsidence Depressions. 9.6 Polygonal Karst. 9.7 Morphometric Analysis Of Solution Dolines. 9.8 Landforms Associated With Allogenic Inputs. 9.9 Karst Poljes. 9.10 Corrosional Plains And Shifts In Baselevel. 9.11 Residual Hills On Karst Plains. 9.12 Depositional And Constructional Karst Features. 9.13 Special Features Of Evaporite Terrains. 9.14 Karstic Features Of Quartzose And Other Rocks. 9.15 Sequences Of Carbonate Karst Evolution In Humid Terrains. CHAPTER 10.THE INFLUENCE OF CLIMATE, CLIMATIC CHANGE AND OTHER ENVIRONMENTAL FACTORS ON KARST DEVELOPMENT. 10.1 The Precepts Of Climatic Geomorphology. 10.2 The Hot Arid Extreme. 10.3 The Cold Extreme: 1 Karst Development In Glaciated Terrains. 10.4 The Cold Extreme: 2 Karst Development In Permafrozen Terrains. 10.5 Sea Level Changes, Tectonic Movement And Implications For Coastal Karst Development. 10.6 Polycyclic, Polygenetic And Exhumed Karsts. CHAPTER 11. KARST WATER RESOURCES MANAGEMENT. 11.1 Water Resources And Sustainable Yields. 11.2 Determination Of Available Water Resources. 11.3 Karst Hydrogeological Mapping. 11.4 Human Impacts On Karst Water. 11.5 Groundwater Vulnerability, Protection, And Risk Mapping. 11.6 Dam Building, Leakages, Failures And Impacts. CHAPTER 12. HUMAN IMPACTS AND ENVIRONMENTAL REHABILITATION. 12.1 The Inherent Vulnerability Of Karst Systems. 12.2 Deforestation, Agricultural Impacts And Rocky Desertification. 12.3 Sinkholes Induced By De-Watering, Surcharging, Solution Mining And Other Practices On Karst. 12.4 Problems Of Construction On And In The Karst Rocks - Expect The Unexpected! 12.5 Industrial Exploitation Of Karst Rocks And Minerals. 12.6 Restoration Of Karstlands And Rehabilitation Of Limestone Quarries. 12.7 Sustainable Management Of Karst. 12.8 Scientific, Cultural And Recreational Values Of Karstlands.

Karst Hydrogeology and Geomorphology

The Edwards aquifer of central Texas is an extensive, karstified flow system developed in rocks deposited on a Cretaceous limestone platform. Development of the aquifer was controlled by changes in sea level, large-scale hydrodynamic and tectonic processes in the Gulf of Mexico, and local climatic and geomorphic processes. The aquifer is a vital water resource and provides a diverse set of habitats, including those for several endangered species that live in its major spring systems. Because of its unique stratigraphic, hydraulic, and hydrochemical properties, the Edwards aquifer is a natural laboratory that is well suited for hydrogeologic studies. Because of numerous economic, social, and political interests in the use of the water and because of the rapid rate of population growth (and urbanization) of its watersheds, the aquifer is also a source of political conflict. Competing interests for its waters have stimulated an ongoing debate over how the aquifer would best be utilized. Historical water-balance analysis demonstrates that major water shortages will develop with the recurrence of historic decadal droughts. Future decisions regarding the aquifer’s use will therefore have significant socioeconomic and environmental ramifications. These decisions should be based upon accurate hydrogeological data. The general nature of how the aquifer functions is understood, but more detailed interpretations are needed. Application of ground-water flow models based on field data and natural geochemical tracers have the potential to reduce uncertainties in the details of how the aquifer functions now and will function in response to potential future developments. Edwards Aquifer continued on p. 2

The Edwards aquifer: A resource in conflict

https://www.jsg.utexas.edu/banner/files/Wong-et.-al.-2015.pdf

Holocene climate variability in Texas, USA: An integration of existing paleoclimate data and modeling with a new, high-resolution speleothem record

https://www.jsg.utexas.edu/banner/files/Casteel-Banner-2014-Temperature-driven-calcite-growth-and-trace-element-variations.pdf

Temperature-driven seasonal calcite growth and drip water trace element variations in a well-ventilated Texas cave: Implications for speleothem paleoclimate studies

The growth rate and composition of cave calcite deposits (speleothems) are often used as proxies for past environmental change. There is, however, the potential for bias in the speleothem record due to seasonal fluctuations in calcite growth and dripwater chemistry. It has been proposed that the growth rate of speleothem calcite in Texas caves varies seasonally in response to density-driven fluctuations in cave-air CO2, with lower growth rates in the warmer months when cave-air CO2 is highest. We monitored CO2 in three undeveloped caves and three tourist caves spread over 130 km in central Texas to determine whether seasonal CO2 fluctuations are confined to tourist caves, which have been modified from their natural states, and the extent to which cave-air CO2 is controlled by variations in cave geometry, host rocks, cave volume, and soils. Nearly 150 lateral transects into six caves over three years show that CO2 concentrations vary seasonally in five of the caves monitored, with peak concentrations in the warmer months and lower concentrations in the cooler months. The caves occur in six stratigraphic units of lower Cretaceous marine platform carbonate rocks and vary in volume (from 100 to .100,000 m) and geometry. Seasonal CO2 fluctuations are regional in extent and unlikely due to human activity. Seasonal fluctuations are independent of cave geometry, volume, depth, soil thickness, and the hosting stratigraphic unit. Our findings indicate that seasonal variations in calcite deposition may introduce bias in the speleothem record, and should be considered when reconstructing paleoclimate using speleothem proxies.

/pdf/temporal-variability-of-cave-air-co2-in-central-texas-4jmj7lkb4z.pdf

Temporal variability of cave-air CO2 in central Texas

http://www.geo.utexas.edu/faculty/banner/Publications/Uranium%20series%20evidence-Earth_Planetary%201991.pdf

Jay L. Banner

Papers

The Edwards aquifer: A resource in conflict

Holocene climate variability in Texas, USA: An integration of existing paleoclimate data and modeling with a new, high-resolution speleothem record

Temperature-driven seasonal calcite growth and drip water trace element variations in a well-ventilated Texas cave: Implications for speleothem paleoclimate studies

Temporal variability of cave-air CO2 in central Texas

Uranium-series evidence on diagenesis and hydrology in Pleistocene carbonates of Barbados, West Indies