cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.25921/af3c-7v69
title: NOAA/WDS Paleoclimatology - Margolis fire data from Rowe Mesa southcentral, northern New Mexico - IMPD USROW007

description: Pinon–juniper (PJ) fire regimes are generally characterised as infrequent high-severity. However, PJ ecosystems vary across a large geographic and bio-climatic range and little is known about one of the principal PJ functional types, PJ savannas. It is logical that (1) grass in PJ savannas could support frequent, low-severity fire and (2) exclusion of frequent fire could explain increased tree density in PJ savannas. To assess these hypotheses I used dendroecological methods to reconstruct fire history and forest structure in a PJ-dominated savanna. Evidence of high severity fire was not observed. From 112 fire-scarred trees I reconstructed 87 fire years (1547–1899). Mean fire interval was 7.8 years for fires recorded at >2 sites. Tree establishment was negatively correlated with fire frequency (r = -0.74) and peak PJ establishment was synchronous with dry (unfavourable) conditions and a regime shift (decline) in fire frequency in the late 1800s. The collapse of the grass-fuelled, frequent, surface fire regime in this PJ savanna was likely the primary driver of current high tree density (mean = 881 trees/ha) that is>600% of the historical estimate. Variability in bio-climatic conditions likely drive variability in fire regimes across the wide range of PJ ecosystems.
description: escription: This site was sampled as part of a project to reconstruct the fire history of the PJ dominated landscape of Rowe Mesa in northern New Mexico. 

Sample_storage_location: University of Arizona Laboratory of Tree-Ring Research, 1215 E Lowell St., Tucson, Arizona, 85721
Dating_method: crossdated
Area_sampled [hectares]: 1.3

FHX File Header: For additional information, see the header of this datasets FHX file, usrow007.fhx, located in the same folder as this file. 

Fire History Graphs: Fire History Graphs illustrate specific years when fires occurred and how many trees were scarred. They are available in both PDF and PNG formats. The graphs consist of 2 parts, both of which show the X axis (time line) at the bottom with the earliest year of information on the left and the latest on the right. The Fire Index Plot is the topmost plot, and shows two variables: sample depth (the number of recording trees in each year) as a blue line along the left Y axis, compared with the percent trees scarred shown as gray bars along the right Y axis. Below, the Fire Chronology Plot consists of horizontal lines representing injuries by year on individual sampled trees. Symbols are overlain that denote the years containing the dendrochronologically-dated fire scars or injuries. The sample ID of each tree is displayed to the right of each line. The Composite Axis below represents the composite information from all individual series. The symbols used to represent the fire scars or injuries, and the filters used to determine the composite information, are shown in the legend. These graphs were created using the Fire History Analysis and Exploration System (FHAES). See https://www.fhaes.org/ for more information.
DOI: 10.25921/ak9g-9b14
title: NOAA/WDS Paleoclimatology - White Moon Cave, California 8.2ka Calcium and Strontium Isotope Data

description: A multi-proxy record from a fast-growing stalagmite reveals variable hydroclimate on the California coast across the 8.2kyr event and a precursor event likely caused by initial drainage of proglacial Lake Agassiz. Using speleothem d44Ca, we develop the first semi-quantitative estimates of paleo-rainfall variability for California through calibration with measurements of the modern climate and cave environment. We find that the magnitude of rainfall variability during the 8.2kyr event approached the multi-year variability observable in the recent past (1950-2019) and the magnitude of variability during the precursor event likely exceeded this range. Additionally, we observe other instances of multi-decadal variability comparable in magnitude to the precursor event during the record. Our work suggests that speleothem calcium isotope ratios are a powerful semi-quantitative means to reconstruct paleo-rainfall, although numerous factors must be assessed in each cave system before applying this approach.
description: Calcium isotope (d44/40Ca) data from a stalagmite (WMC1), cave dripwater, modern calcite, and host rock samples, plus strontium isotope (87Sr/86Sr) data from WMC1, host rock, and soil samples collected from White Moon Cave, CA for the 8.2kyr climate event.
DOI: 10.25921/a6e6-sy60
title: NOAA/WDS Paleoclimatology - Hughes - Starvation Creek - SEGI - ITRDB CA724

description: The first dendroclimatic reconstruction of May 1 snow water equivalent (SWE) was developed from a Sequoiadendron giganteum regional tree-ring chronology network of 23 sites in central California for the period 90-2012 CE. The reconstruction is based on a significant relationship between May 1 SWE and tree-ring growth and shows climate variability from interannual to intercentennial time scales. A regression-based reconstruction equation explains up to 55% of the variance of SWE for 1940-2012. Split-sample validation supports our use of a reconstruction model based on the full period of reliable observational data (1940-2012). Thresholds for May 1 SWE low (15 percentile) and high (80 percentile) years were selected based on the exploratory scatterplots relationship between observed and reconstructed data for the period 1940-2012. The longest period of consecutive low-SWE years in the reconstruction is 2 years and the frequency of the lowest SWE years is highest during the period 710-809 CE. The longest high-SWE period, defined by consecutive wet years, is 3 years (558-560 CE). SWE and its reconstruction positively correlate with northeastern Pacific sea surface temperatures, the low-frequency variability of which may provide some predictive ability. Ultimately, the instrumental record and reconstruction suggest that unlike other sites in the region, twentieth century SWE variability in these Sequoia groves has remained within historical boundaries and relatively buffered from extremes and severe declines, though this is likely to change in coming decades with potentially negative effects on water availability for these trees.
description: NOAA Template Raw Measurements file added 2021-02-22.
DOI: 10.15468/dl.dbe3py
title: Occurrence Download

description: A dataset containing 0 species occurrences available in GBIF matching the query:
{
 "and" : [
 "TaxonKey is Pandanus utilis",
 "Country is Libya",
 "HasCoordinate is true"
 ]
}

 The dataset includes 0 records from 0 constituent datasets; see https://api.gbif.org/v1/occurrence/download/0006123-251009101135966/datasets/export for details.
DOI: 10.25921/agtr-3t27
title: NOAA/WDS Paleoclimatology - Thapa - Hattisude - PIRO - ITRDB NEPA057

description: Pine forests provide goods and services crucial to more than ten million people living in the middle-mountains (600-4000m) of Nepal. These critically important forests are already often overexploited and could be at risk from future climate change. In order to investigate the combined effects of climate and human disturbances on the growth of pine forests, we established a new network of tree-ring sites in six Pinus wallichiana and four P. roxburghii forests across the dry inner valleys of eastern Nepal's Koshi River watershed. We produced measurements of total annual ring widths, and detrended individual tree-ring series with 67% cubic splines to produce site-level chronologies. The Koshi tree-ring chronologies were compared against local records of mean monthly temperature and total monthly rainfall to identify the main climatic factor(s) limiting pine growth. We also employed a relative growth change method to estimate growth releases and suppressions in ring-width series as indicators of disturbances. At all sites, trees are relatively young (median age was 102 years) and variations in ring-width provide estimates of tree growth over only the past century. Ring-width chronologies from the Koshi have a weak common signal strength in comparison to trees from the same species obtained from sites in the central Himalaya, and the climate-growth response of Koshi pines appears to be governed primarily by moisture balance during winter. Disturbance events evident in pine ring-width data are largely asynchronous, which suggests these forest have been historically perturbed by human influences rather than large-scale climatic or ecological influences. The sacred forest at Sikri contained the oldest living trees (118 years), had the lowest number of disturbance events, and preserved a stronger common signal, which provided additional evidence of the effects of humans on other pine forests in the Koshi basin. Based on our findings, we suggest that modeling the future growth and distribution of pine trees in eastern Nepal should consider winter moisture. Furthermore, management strategies to better conserve pine forests in eastern Nepal should incorporate the two competing influences of climate and human activities on tree growth.
description: Koshi River basin, Nepal NOAA Template Raw Measurements file added 2020-11-18.
DOI: 10.25921/aa5w-hp28
title: NOAA/WDS Paleoclimatology - Easter Island 2000 Year Lake Sediment Elemental and Organic Carbon Data

description: The small and remote Easter Island (Rapa Nui) has a complex and still partially unknown history of human colonization and interactions with the environment. Previous research from sedimentary archives collected in the three freshwater bodies of Rapa Nui document dramatic environmental changes over the last two millennia. Yet, the characteristics of sediments and paleoenvironmental records are challenging to interpret, mainly due to poor temporal resolution, hiatuses and sediment mixing.

In this study, we reconstruct past changes in lithogenic inputs, weathering processes, redox conditions, productivity and water levels in the Rano Aroi wetland over the last 2000 years through the determination of major, trace and rare earth elements in a new peat core collected in 2017. The chronology is based on 8 14C AMS dates for the upper 1.5 m and provides decadal to multi-decadal resolution which is unprecedented for the island of Rapa Nui. The multielemental proxies depict seven distinct chronological phases marked by well-defined geochemical transitions. With only a few minor fluctuations, climate conditions were dry and the mire was mildly anoxic during the first millennium (0-1000 CE) to the arrival of the first Polynesians in Rapa Nui (800-1300 CE) and until ~1400 CE, followed by wetter conditions afterwards. The record documents with unprecedented accuracy and resolution intense droughts occurring during the middle Little Ice Age between 1520 and 1710 CE, which may have been exacerbated by human activities and triggered dramatic cultural shifts. During the interval of first contact between the Rapanuis and Europeans, the climate changed to wetter conditions, followed by intense precipitations between 1790 and 1900 CE.
description: Rano Aroi, Rapa Nui (Easter Island), 2000 year lake sediment elemental and OC% data.
DOI: 10.25921/aqfp-g886
title: NOAA/WDS Paleoclimatology - Stefanuk - Frontenac Arch FR02 - ACSH - ITRDB CANA625

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
description: Sample plots were circular with a radius of 75m, located within sugar maple dominated stands in protected areas within each region including Algonquin Provincial Park, Frontenac Provincial Park, Charleston Lake Provincial Park and the Queen's University Biological Station. NOAA Template Raw Measurements file added 2021-02-22.
DOI: 10.25921/atpf-6m43
title: NOAA/WDS Paleoclimatology - Larson - Yellow River State Forest Update - QUAL - ITRDB IA038

description: New and updated multi-century tree-ring chronologies from living oak trees, remnants, and archeological beams from across the Driftless Area of southwest Wisconsin and northeast Iowa, USA, were developed to fill a spatial gap in the network of available tree-ring chronologies. We produced a robust 303-year summer drought reconstruction (June-August Palmer's Modified Drought Index (PMDI): r2 = 0.45) that identified clusters of extreme droughts and pluvials (PMDI <= -4.0 or >= 4.0) in the early 1700s and more even distributions of drought conditions, with the exception of the post 1930s period when drought became relatively infrequent. Compared to the Living Blended Drought Atlas (LBDA) and the North American Drought Atlas (NADA), our reconstruction more accurately represented moderate moisture conditions across the Driftless Area, the NADA and LBDA more closely represented extreme pluvials, and our reconstruction and the LBDA better represented extreme drought years. The three reconstructions largely captured the same high-frequency variability in drought conditions and differed most at low frequencies. Significant correlations were identified between our reconstruction and corn (r = 0.30, n = 91, p = 0.002) and soybean (r = 0.25, n  = 81, p = 0.012) yields, with the strength of the correlations increasing over recent decades suggesting a tighter coupling of interannual climate variability and crop productivity in the region. Superposed epoch analyses indicated significantly wetter conditions in the Driftless Area two years after major volcanic eruptions. In the context of long-term climatic variability, the Driftless Oaks drought reconstruction demonstrated that drought and pluvial conditions more extreme than those experienced during the instrumental record have occurred in the past.
description: Oak ring width data from the Driftless Area of southwest Wisconsin and northeast Iowa, USA, sampled from living oak trees, remnants, and archeological beams.
DOI: 10.25921/a1v7-t684
title: NOAA/WDS Paleoclimatology - Harley - Hoot Woods - QURU - ITRDB IN014

description: Understanding the historic variability in the hydroclimate provides important information on possible extreme dry or wet periods that in turn inform water management plans. Tree rings have long provided historical context of hydroclimate variability of the U.S. However, the tree-ring network used to create these countrywide gridded reconstructions is sparse in certain locations, such as the Midwest. Here, we increase (n = 20) the spatial resolution of the tree-ring network in southern Indiana and compare a summer (June-August) Palmer Drought Severity Index (PDSI) reconstruction to existing gridded reconstructions of PDSI for this region. We find both droughts and pluvials that were previously unknown that rival the most intense PDSI values during the instrumental period. Additionally, historical drought occurred in Indiana that eclipsed instrumental conditions with regard to severity and duration. During the period 1962-2004 CE, we find that teleconnections of drought conditions through the Atlantic Meridional Overturning Circulation have a strong influence (r = -0.60, p < 0.01) on secondary tree growth in this region for the late spring-early summer season. These findings highlight the importance of continuing to increase the spatial resolution of the tree-ring network used to infer past climate dynamics to capture the sub-regional spatial variability. Increasing the spatial resolution of the tree-ring network for a given region can better identify sub-regional variability, improve the accuracy of regional tree-ring PDSI reconstructions, and provide better information for climatic teleconnections.
description: Eastern Deciduous Forest, Climate response, Palmer Drought Severity Index NOAA Template Raw Measurements file added 2020-09-03.
DOI: 10.25921/avv8-fw56
title: NOAA/WDS Paleoclimatology - Maxwell - Lilly-Dickey Woods - LITU - ITRDB IN018

description: Understanding the historic variability in the hydroclimate provides important information on possible extreme dry or wet periods that in turn inform water management plans. Tree rings have long provided historical context of hydroclimate variability of the U.S. However, the tree-ring network used to create these countrywide gridded reconstructions is sparse in certain locations, such as the Midwest. Here, we increase (n = 20) the spatial resolution of the tree-ring network in southern Indiana and compare a summer (June-August) Palmer Drought Severity Index (PDSI) reconstruction to existing gridded reconstructions of PDSI for this region. We find both droughts and pluvials that were previously unknown that rival the most intense PDSI values during the instrumental period. Additionally, historical drought occurred in Indiana that eclipsed instrumental conditions with regard to severity and duration. During the period 1962-2004 CE, we find that teleconnections of drought conditions through the Atlantic Meridional Overturning Circulation have a strong influence (r = -0.60, p < 0.01) on secondary tree growth in this region for the late spring-early summer season. These findings highlight the importance of continuing to increase the spatial resolution of the tree-ring network used to infer past climate dynamics to capture the sub-regional spatial variability. Increasing the spatial resolution of the tree-ring network for a given region can better identify sub-regional variability, improve the accuracy of regional tree-ring PDSI reconstructions, and provide better information for climatic teleconnections.
description: Eastern Deciduous Forest, Climate response, Palmer Drought Severity Index NOAA Template Raw Measurements file added 2020-09-03.
DOI: 10.25921/ae7h-q269
title: NOAA/WDS Paleoclimatology - Peltier - Southwest Ecological Memory Project Site P3 - PIED - ITRDB AZ615

description: Trees are long-lived organisms that integrate climate conditions across years or decades to produce secondary growth. This integration process is sometimes referred to as 'climatic memory.' While widely perceived, the physiological processes underlying this temporal integration, such as the storage and remobilization of non-structural carbohydrates (NSC), are rarely explicitly studied. This is perhaps most apparent when considering drought legacies (perturbed post-drought growth responses to climate), and the physiological mechanisms underlying these lagged responses to climatic extremes. Yet, drought legacies are likely to become more common if warming climate brings more frequent drought. To quantify the linkages between drought legacies, climate memory and NSC, we measured tree growth (via tree ring widths) and NSC concentrations in three dominant species across the southwestern USA. We analyzed these data with a hierarchical mixed effects model to evaluate the time-scales of influence of past climate (memory) on tree growth. We then evaluated the role of climate memory and the degree to which variation in NSC concentrations were related to forward-predicted growth during the hot 2011-2012 drought and subsequent 4-year recovery period. Populus tremuloides exhibited longer climatic memory compared to either Pinus edulis or Juniperus osteosperma, but following the 2011-2012 drought, P. tremuloides trees with relatively longer memory of temperature conditions showed larger (more negative) drought legacies. Conversely, Pinus edulis trees with longer temperature memory had smaller (less negative) drought legacies. For both species, higher NSC concentrations followed more negative (larger) drought legacies, though the relevant NSC fraction differed between P. tremuloides and P. edulis. Our results suggest that differences in tree NSC are also imprinted upon tree growth responses to climate across long time scales, which also underlie tree resilience to increasingly frequent drought events under climate change.
description: These tree ring data were collected to assess the climate memory of tree growth around the southwestern US in "ecologically sampled" trees. Trees were from a range of size classes and vigors, but were all dominant or co-dominant. NOAA Template Raw Measurements file added 2022-04-04.
DOI: 10.25921/a3b7-6j98
title: NOAA/WDS Paleoclimatology - Margolis fire data from Rowe Mesa east, northern New Mexico - IMPD USROW002

description: Pinon–juniper (PJ) fire regimes are generally characterised as infrequent high-severity. However, PJ ecosystems vary across a large geographic and bio-climatic range and little is known about one of the principal PJ functional types, PJ savannas. It is logical that (1) grass in PJ savannas could support frequent, low-severity fire and (2) exclusion of frequent fire could explain increased tree density in PJ savannas. To assess these hypotheses I used dendroecological methods to reconstruct fire history and forest structure in a PJ-dominated savanna. Evidence of high severity fire was not observed. From 112 fire-scarred trees I reconstructed 87 fire years (1547–1899). Mean fire interval was 7.8 years for fires recorded at >2 sites. Tree establishment was negatively correlated with fire frequency (r = -0.74) and peak PJ establishment was synchronous with dry (unfavourable) conditions and a regime shift (decline) in fire frequency in the late 1800s. The collapse of the grass-fuelled, frequent, surface fire regime in this PJ savanna was likely the primary driver of current high tree density (mean = 881 trees/ha) that is>600% of the historical estimate. Variability in bio-climatic conditions likely drive variability in fire regimes across the wide range of PJ ecosystems.
description: Description: This site was sampled as part of a project to reconstruct the fire history of the PJ dominated landscape of Rowe Mesa in northern New Mexico.\r\nSample_storage_location: University of Arizona Laboratory of Tree-Ring Research, 1215 E Lowell St., Tucson, Arizona, 85721\r\nDating_method: crossdated\r\nArea_sampled [hectares]: 4\r\nFHX File Header: For additional information, see the header of this datasets FHX file, usrow002.fhx, located in the same folder as this file.\r\nFire History Graphs: Fire History Graphs illustrate specific years when fires occurred and how many trees were scarred. They are available in both PDF and PNG formats. The graphs consist of 2 parts, both of which show the X axis (time line) at the bottom with the earliest year of information on the left and the latest on the right. The Fire Index Plot is the topmost plot, and shows two variables: sample depth (the number of recording trees in each year) as a blue line along the left Y axis, compared with the percent trees scarred shown as gray bars along the right Y axis. Below, the Fire Chronology Plot consists of horizontal lines representing injuries by year on individual sampled trees. Symbols are overlain that denote the years containing the dendrochronologically-dated fire scars or injuries. The sample ID of each tree is displayed to the right of each line. The Composite Axis below represents the composite information from all individual series. The symbols used to represent the fire scars or injuries, and the filters used to determine the composite information, are shown in the legend. These graphs were created using the Fire History Analysis and Exploration System (FHAES). See https://www.fhaes.org/ for more information.