cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.25921/n3f6-a503
title: NOAA/WDS Paleoclimatology - Macal Chasm, Belize 5300 Year Stalagmite Isotope and Luminescence/Reflectance Data

description: The stalagmite MC01 was recovered from Macal Chasm cave on the Vaca Plateau of Belize in 1995, and an initial paleoclimate interpretation was published in 2007. Additional uranium-thorium ages have extended the paleoenvironmental record back from 3250 to 5250 cal yr BP, and the stable isotope (d18O and d13C) record is dramatically improved by 660 new values. A series of major dry events (MDEs) evident in stable isotopes, ultraviolet-stimulated luminescence, and petrography began ~ 3100 cal yr BP, and the initiation of these events coincides with an increase in El Nino dominance and southern shift in the Intertropical Convergence Zone. Three MDEs, centered at 1750 cal yr BP (200 CE), 1100 cal yr BP (850 CE), and 850 cal yr BP (1100 CE) and found in other regional climate records, coincide with Maya sociopolitical changes. Residuals from regression of d13C versus d18O are interpreted as a proxy for maize cultivation and land clearing, with residual values gradually increasing at the start of Preclassic Period settlement (3950 cal yr BP/2000 BCE), peaking after 2250 cal yr BP (300 BCE) during major Maya development in the Late Preclassic and Classic Periods, and dropping to pre-Preclassic values after regional land abandonment (~ 850 cal yr BP/1100 CE). Regional Maya population growth and cultural expansion may have been aided by abnormally low precipitation variability, as stable isotope variability suggests the Late Preclassic through the Late Classic was the most stable precipitation regime of the past 4000 years. This additional research on MC01 complements other regional paleoenvironmental records that suggest that MDEs coincided with disruptions in Maya society from the Preclassic through the Postclassic Periods. Although it is clear that not all significant sociopolitical changes can be attributed to the MDEs, these events likely played an antagonistic role in social stability.
description: Paleoenvironmental proxy data (oxygen isotope, carbon isotope, ultraviolet-stimulated luminescence, natural-light reflectance, petrography) from stalagmite MC01 from Macal Chasm, Vaca Plateau, Belize. Data given here are from the resampled and reanalyzed MC01-E record. Provided Keywords: speleothem, stalagmite, oxygen isotope, carbon isotope, luminescence, reflectance, petrography, Maya, Belize, Holocene.
 Type of petrographic boundary observed, Visual identification
 depth-cm	ageCalYrBP	petroType
 1.7	38	L-type
 5.1	365	L-type
 11.1	775	L-type
 15.0	1035	L-type
 18.3	1265	L-type
 22.8	1585	L-type
 28.7	2020	L-type
 29.1	2045	L-type
 33.0	2320	L-type
 36.0	2500	L-type
 42.3	2860	L-type
 45.7	3060	L-type
 54.8	3550	L-type
 74.1	4420	L-type
 80.9	4690	L-type
DOI: 10.25921/na8p-pt57
title: NOAA/WDS Paleoclimatology - Neodymium Isotope Data from the Western Flank of the Sicily Channel since the Last Deglaciation (13,900 BP)

description: Eastern Mediterranean deep-intermediate convection was highly sensitive to varying inputs of fresh water fluxes associated with increased rainfall during the African Humid period (15-6 kyr Before Present). Here we investigate changes in the water-outflow from the Eastern Mediterranean Sea since the last deglaciation using neodymium isotope ratios. Our results indicate enhanced outflow during the Younger Dryas, two times higher than present-day outflow and about three times higher than during the last Sapropel. We propose that the increased outflow into the western Mediterranean over the Younger Dryas was the result of the combined effect of 1) enhanced climate-driven convection in the Aegean Sea and 2) reduced convection of western deep water during this period. Our results provide solid evidence for an enhanced Younger Dryas westward flow of Eastern Mediterranean sourced waters in consonance with an intensification of Mediterranean water-outflow during a weakened state of the Atlantic circulation.
description: Neodymium records from planktic foraminifera coatings from NDT-6-2016 sediment core; Neodymium record from lithogenic <63 µm fraction from NDT-6-2016 sediment core; Eastern Mediterranean Source Waters (EMSW) estimations (EMSW_mix) with different mixing proportions between the eastern Mediterranean water masses contributing to the EMSW (LIW and EMDW) based on neodymium values from our record (NDT-6-2016) and SU92-33 (Balearic Sea), BC07 (Levantine Sea) and MS27PT (Nile slope). The first scenario is defined by the same relative contribution of LIW and EMDW (i.e. ??LIW =??EMDW), the second scenario the contribution of the LIW doubles that of the EMDW (i.e. ??LIW = 2*??EMDW) and the third scenario considers that the proportion of EMDW doubles that of the LIW (i.e. ??EMDW = 2*??LIW).
DOI: 10.25921/nqc0-gt08
title: NOAA/WDS Paleoclimatology - Farris fire data from Mica Mountain - IMPD US02_015

description: Fire scars are used widely to reconstruct historical fire regime parameters in forests around the world. Because fire scars provide incomplete records of past fire occurrence at discrete points in space, inferences must be made to reconstruct fire frequency and extent across landscapes using spatial networks of fire-scar samples. Assessing the relative accuracy of fire-scar fire history reconstructions has been hampered due to a lack of empirical comparisons with independent fire history data sources. We carried out such a comparison in a 2780-ha ponderosa pine forest on Mica Mountain in southern Arizona (USA) for the time period 1937–2000. Using documentary records of fire perimeter maps and ignition locations, we compared reconstructions of key spatial and temporal fire regime parameters developed from documentary fire maps and independently collected fire-scar data (n = 60 plots). We found that fire-scar data provided spatially representative and complete inventories of all major fire years (>100 ha) in the study area but failed to detect most small fires. There was a strong linear relationship between the percentage of samples recording fire scars in a given year (i.e., fire-scar synchrony) and total area burned for that year (y = 0.0003x + 0.0087, r2 = 0.96). There was also strong spatial coherence between cumulative fire frequency maps interpolated from fire-scar data and ground-mapped fire perimeters. Widely reported fire frequency summary statistics varied little between fire history data sets: fire-scar natural fire rotations (NFR) differed by <3 yr from documentary records (29.6 yr); mean fire return intervals (MFI) for large-fire years (i.e., ≥25% of study area burned) were identical between data sets (25.5 yr); fire-scar MFIs for all fire years differed by 1.2 yr from documentary records. The known seasonal timing of past fires based on documentary records was furthermore reconstructed accurately by observing intra-annual ring position of fire scars and using knowledge of tree-ring growth phenology in the Southwest. Our results demonstrate clearly that representative landscape-scale fire histories can be reconstructed accurately from spatially distributed fire-scar samples.
description: 
This dataset was contributed as part of the North American Tree-ring Fire Scar Synthesis (NAFSS) project (https://www.ncei.noaa.gov/access/paleo-search/study/34853). Data were contributed to the project from the original data generators.

Sample Storage Location: Laboratory of Tree-Ring, University of Arizona
Dating Method: Dated
Related ITRDB_Chronology: Not Applicable

Fire scar data from this site are available in FHX2 format at:
  https://www.ncei.noaa.gov/pub/data/paleo/firehistory/firescar/northamerica/us02_015.fhx
along with associated metadata at:
  https://www.ncei.noaa.gov/pub/data/paleo/firehistory/firescar/northamerica/us02_015-noaa.txt
DOI: 10.25921/nfqt-sv32
title: NOAA/WDS Paleoclimatology - Buchwal - Kurungnakh Island, Lena River Delta - LAGM - ITRDB RUS394

description: Tundra is primarily a habitat for shrub growth, not trees, but growth of prostrate forms of trees has been reported occasionally from the subarctic tundra region. In the light of on-going climate change, climate sensitivity studies of these unique trees are essential to predict vegetation dynamics and potential northward expansion of boreal forest tree species into tundra. Here we studied one of the northernmost Larix Mill. trees and Betula nana L. shrubs (72°N) from the Siberian tundra for the common period 1980-2017. We took advantage of the discovery of a single cohort of prostrate Larix trees within a tundra ecosystem, i.e., ca. 60 km northwards from the northern treeline, and compared climate-growth relationships of the two species. Both woody plants were sensitive to the July temperature, however this relationship was stable across the entire study period (1980-2017) only for Betulanana chronology. Additionally, radial growth of Larix trees became negatively correlated to temperatures during the previous summer. In recent period moisture sensitivity between Larix trees and Betula nana shrubs was contrasting, with generally wetter soil conditions favoring Larix trees growth and dryer conditions promoting Betula nana growth. Our study indicates that Larix trees radial growth in recent years is more sensitive to moisture than to summer air temperatures, whereas temperature sensitivity of Betulanana shrub is stable over time. We provide first detailed insight into the annual resolution on Larix tree growth sensitivity to climate in the heart of the tundra. The potentially higher Betulanana shrub resistance to warmer and drier climate versus Larix trees on a tundra revealed in our study needs to be further examined across habitats of various soil, moisture and permafrost status.
DOI: 10.25921/nmhw-7s58
title: NOAA/WDS Paleoclimatology - Iniguez fire data from Rincon Peak RP04 - IMPD USRPK_04

description: Spatial and temporal patterns of fire history are affected by factors such as topography, vegetation, and climate. It is unclear, however, how these factors influenced fire history patterns in small isolated forests, such as that found on Rincon Peak, a “sky island” mountain range in southern Arizona, USA. We reconstructed the fire history of Rincon Peak to evaluate the influences of broad-scale (i.e., climate) versus local-scale (i.e., topographic) factors on fire occurrence and extent. We evaluated both fire scars and tree demography (natality and mortality) to investigate surface fire and crown fire events. The fire history of a 310 ha study area surrounding the top of Rincon Peak was reconstructed by tree-ring sampling in 21 plots. Between 1648 and 1763, spreading fires on Rincon Peak were controlled primarily by regional climate. Widespread surface fires occurred during drought years, and were generally synchronized with regional fire events known from an extensive network of other fire history studies. After 1763, fire extent was apparently limited by local factors (i.e., fuels) as frequent fires continued to burn, but were limited to the southern part of the study area until a widespread fire occurred in 1819. Landscape fires (i.e., fires that scarred ≥2 plots) were absent from the entire study area between 1819 and 1867 despite continued burning in adjacent mountain ranges. Multiple lines of evidence indicate that the 1867 fire was both a surface and a stand-replacing event that killed most trees within a 60 ha patch. Our findings suggest that past climatic variations had important effects on fire regimes and age structures of small, fragmented ponderosa pine (Pinus ponderosa) landscapes like Rincon Peak. Given anticipated climate changes, the rich biodiversity harbored in these steep, isolated landscapes will be critical habitat in the migration of species and should therefore be considered high conservation priority.
description: 
This dataset was contributed as part of the North American Tree-ring Fire Scar Synthesis (NAFSS) project (https://www.ncei.noaa.gov/access/paleo-search/study/34853). Data were contributed to the project from the original data generators.

Sample Storage Location: Laboratory of Tree-Ring, University of Arizona
Dating Method: Dated
Related ITRDB_Chronology: Not Applicable

Fire scar data from this site are available in FHX2 format at:
  https://www.ncei.noaa.gov/pub/data/paleo/firehistory/firescar/northamerica/usrpk_04.fhx
along with associated metadata at:
  https://www.ncei.noaa.gov/pub/data/paleo/firehistory/firescar/northamerica/usrpk_04-noaa.txt
DOI: 10.15468/dl.rnvwzt
title: Occurrence Download

description: A dataset containing 4 species occurrences available in GBIF matching the query:
{
 "and" : [
 "TaxonKey is Cenchrus geniculatus",
 "Country is Spain",
 "HasCoordinate is true"
 ]
}

 The dataset includes 4 records from 1 constituent datasets; see https://api.gbif.org/v1/occurrence/download/0021191-251009101135966/datasets/export for details.
 
Data from some individual datasets included in this download may be licensed under less restrictive terms.
DOI: 10.25921/nm7t-4p42
title: NOAA/WDS Paleoclimatology - Baringo-Tugen Hills-Barsemoi, Kenya 3.29-2.58 Ma Leaf Wax Biomarker, Hydrogen and Carbon Isotope, Magnetic Susceptibility, and Si/Ti Data

description: Terrestrial-marine dust fluxes, pedogenic carbonate δ13C values, and various paleovegetation proxies suggest that Africa experienced gradual cooling and drying across the Pliocene-Pleistocene (Plio-Pleistocene) boundary (2.58 million years ago [Ma]). However, the timing, magnitude, resolution, and relative influences of orbitally-driven changes in high latitude glaciations and low latitude insolation differ by region and proxy. To disentangle these forcings and investigate equatorial eastern African climate across the Plio-Pleistocene boundary, we generated a high-resolution (~3,000-year) data set of compound-specific n-alkane leaf wax δ2H values—a robust proxy for atmospheric circulation and precipitation amount—from the HSPDP-BTB13-1A core, which spans a ~3.3–2.6 Ma sequence in the Baringo-Tugen Hills-Barsemoi Basin of central Kenya. In combination with the physical sedimentology, our data indicate that precipitation varied strongly with orbital obliquity, not precession, during the late Pliocene, perhaps imparted by variations in the cross-equatorial insolation gradient. We also observe a marked shift toward wetter conditions beginning ~3 Ma that corresponds with global cooling, drying in western Australia, and a steepening of the west-east zonal Indian Ocean (IO) sea surface temperature (SST) gradient. We propose that northward migration of the Subtropical Front reduced Agulhas current leakage, warming the western IO and causing changes in the IO zonal SST gradient at 3 Ma, a process that has been observed in the latest Pleistocene-Holocene but not over longer timescales. Thus, the late Cenozoic moisture history of eastern Africa is driven by a complex mixture of low-latitude insolation, the IO SST gradient, and teleconnections to distal high-latitude cooling.
description: For chronology, please see https://doi.org/10.1016/j.palaeo.2019.109519. Age model comes from a combination of 40Ar/39Ar dates and magneto- and sequence stratigraphy
DOI: 10.15468/dl.y7ctg7
title: Occurrence Download

description: A dataset containing 55 species occurrences available in GBIF matching the query:
{
 "and" : [
 "TaxonKey is one of (Schaefferia frutescens)",
 "StateProvince is one of (Bahamas, Cayman Is., Colombia, Costa Rica, Cuba, Dominican Republic, Guatemala, Haiti, Jamaica, Leeward Is., Mexico Gulf, Mexico Northeast, Mexico Southeast, Mexico Southwest, Puerto Rico, Trinidad-Tobago, Turks-Caicos Is., Venezuela, Windward Is.)",
 "BasisOfRecord is Specimen"
 ]
}

 The dataset includes 55 records from 3 constituent datasets; see https://api.gbif.org/v1/occurrence/download/0021192-251009101135966/datasets/export for details.
 
Data from some individual datasets included in this download may be licensed under less restrictive terms.
DOI: 10.25921/n25g-b108
title: NOAA/WDS Paleoclimatology - Touchan - Kamouaa - CDLI - ITRDB LBN010

description: The first large-scale network of 79 tree-ring chronologies in the Eastern Mediterranean and Near East (EMNE; 33°N–42°N, 21°E–43°E) is described and analyzed to identify the seasonal climatic signal in indices of annual ring width. Correlation analysis and cluster analysis are applied to tree-ring data and gridded climate data to assess the climate signal embedded in the network in preparation for climate field reconstructions and formal proxy/model intercomparison experiments. The lengths of the 79 combined chronologies range from 89 to 990 years. The monthly correlations and partial correlations reveal a pervasive positive association with May, June, and sometimes July precipitation, positive correlations with winter and spring (December through April) temperatures, and negative relationships with May through July temperature, although as expected, there are site-to-site exceptions to these general patterns. Cluster analysis suggests three groups of sites based on their association with climate. The chronologies for the EMNE have coherent seasonal precipitation and temperature signals across a fairly broad geographical domain. The predominant signal is a positive growth response to May–June precipitation. Collectively, the findings suggest that the network can be exploited to develop season-specific field reconstructions of precipitation and drought history in the EMNE.
DOI: 10.25921/ns1e-bv12
title: NOAA/WDS Paleoclimatology - Black - Hamma Hamma - PSME - ITRDB WA157

description: Tree ring data from the International Tree Ring Data Bank and World Data Center for Paleoclimatology archives.  Most data sets include raw treering measurements (most are annual ring width, with some collections of earlywood or latewood width or wood density), plus chronologies (standardized growth indices for a site compiled from multiple treering samples). Reconstructions of climate variables are included with some of these data sets.  Each data type is stored in a separate data file; the data type is coded into the file name. For details please see: http://www.ncdc.noaa.gov/paleo/treeinfo.htmll
DOI: 10.25921/npee-v283
title: NOAA/WDS Paleoclimatology - Patterson - Lower Truckee River Site MRE - PPFR - ITRDB NV524

description: Tree ring data from the International Tree Ring Data Bank and World Data Center for Paleoclimatology archives.  Most data sets include raw treering measurements (most are annual ring width, with some collections of earlywood or latewood width or wood density), plus chronologies (standardized growth indices for a site compiled from multiple treering samples). Reconstructions of climate variables are included with some of these data sets.  Each data type is stored in a separate data file; the data type is coded into the file name. For details please see: http://www.ncdc.noaa.gov/paleo/treeinfo.htmll
DOI: 10.25921/n443-0561
title: NOAA/WDS Paleoclimatology - Brazil Margin Stable Isotope Data for the Last Glacial Cycle

description: Vertical profiles of benthic foraminiferal oxygen and carbon isotopes (δ18O and δ13C) imply the volume of southern source water (SSW) in the Atlantic basin expanded during the Last Glacial Maximum. Shoaling of the boundary between SSW and northern source water (NSW) may reduce mixing between the two watermasses, thereby isolating SSW and enhancing its ability to store carbon during glacial intervals. Here we test this hypothesis using profiles of δ18O and δ13C from the Brazil Margin spanning the last glacial cycle (0–150 ka). Shoaling of the SSW-NSW boundary occurred during Marine Isotope Stage (MIS) 2, 4, and 6, consistent with expansion of SSW and greater carbon sequestration in the abyss. But the watermass boundary also shoaled during MIS 5e, when atmospheric CO2 levels were comparable to MIS 1. Additionally, we find there was little change in watermass structure across the MIS 5e-d transition, the first major decline in CO2 of the last glacial cycle. Thus, the overall pattern in glacial-interglacial geometry is inconsistent with watermass mixing acting as a primary control on atmospheric pCO2. We also find that δ13C values for MIS 5e are systematically lower than MIS 1, with the largest difference (~1‰) occurring in the upper water column. Low δ13C during MIS 5e was most likely due to a long-term imbalance in weathering and deposition of calcium carbonate or input of 13C-depleted carbon from a reservoir external to the ocean-atmosphere system.
DOI: 10.25921/ngb0-6051
title: NOAA/WDS Paleoclimatology - Griffin - Tejon Valley Transect Mid Riparian - QULO - ITRDB CA732

description: Tree ring data from the International Tree Ring Data Bank and World Data Center for Paleoclimatology archives.  Most data sets include raw treering measurements (most are annual ring width, with some collections of earlywood or latewood width or wood density), plus chronologies (standardized growth indices for a site compiled from multiple treering samples). Reconstructions of climate variables are included with some of these data sets.  Each data type is stored in a separate data file; the data type is coded into the file name. For details please see: http://www.ncdc.noaa.gov/paleo/treeinfo.htmll
DOI: 10.25921/ndng-3w03
title: NOAA/WDS Paleoclimatology - Woodruff - Squirrel Creek PSME - PSME - ITRDB ID034

description: Tree ring data from the International Tree Ring Data Bank and World Data Center for Paleoclimatology archives.  Most data sets include raw treering measurements (most are annual ring width, with some collections of earlywood or latewood width or wood density), plus chronologies (standardized growth indices for a site compiled from multiple treering samples). Reconstructions of climate variables are included with some of these data sets.  Each data type is stored in a separate data file; the data type is coded into the file name. For details please see: http://www.ncdc.noaa.gov/paleo/treeinfo.htmll