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On the continental scale, climate is an important determinant of the distributions of plant taxa and ecoregions. To quantify and depict the relations between specific climate variables and these distributions, we placed modern climate and plant taxa distribution data on an approximately 25-kilometer (km) equal-area grid with 27,984 points that cover Canada and the continental United States (Thompson and others, 2015). The gridded climatic data include annual and monthly temperature and precipitation, as well as bioclimatic variables (growing degree days, mean temperatures of the coldest and warmest months, and a moisture index) based on 1961-1990 30-year mean values from the University of East Anglia (UK) Climatic...
Effective monitoring and prediction of flood and drought events requires an improved understanding of how and why surface-water expansion and contraction in response to climate varies across space. This paper sought to (1) quantify how interannual patterns of surface-water expansion and contraction vary spatially across the Prairie Pothole Region (PPR) and adjacent Northern Prairie (NP) in the United States, and (2) explore how landscape characteristics influence the relationship between climate inputs and surface-water dynamics. Due to differences in glacial history, the PPR and NP show distinct patterns in regards to drainage development and wetland density, together providing a diversity of conditions to examine...
In areas of low uplift rate on the Pacific Coast of North America, reoccupation of emergent marine terraces by later high-sea stands has been hypothesized to explain the existence of thermally anomalous faunas (mixtures of warm and cool species) of last interglacial age. If uplift rates have been low for much of the Quaternary, it follows that higher (older) terraces should also show evidence of reoccupation. Strontium isotope analyses of fossils from a high-elevation marine terrace on Anacapa Island, California yield a suite of ages ranging from ~2.4-2.3 Ma to ~1.4-1.5 Ma. These results indicate that terrace reoccupation and fossil mixing on Anacapa Island could have taken place over several interglacial periods...
Categories: Data;
Tags: Anacapa Island,
California,
Channel Islands National Park,
Climatology,
Geochemistry,
This data release contains the data tables for the USGS North American Packrat Midden Database (version 5.0). This version of the Midden Database contains data for 3,331 packrat midden samples obtained from published sources (journal articles, book chapters, theses, dissertations, government and private industry reports, conference proceedings) as well as unpublished data contributed by researchers. Compared to the previous version of the Midden Database (i.e., ver. 4), this version of the database (ver. 5.0) has been expanded to include more precise midden-sample site location data, calibrated midden-sample age data, and plant functional type (PFT) assignments for the taxa in each midden sample. In addition,...
This data release provides a digital inventory of the Robert S. Thompson packrat midden collection consisting of 1,740 midden samples and subsamples primarily collected in the Great Basin region of Nevada, as well as in Arizona, California, Colorado, Oklahoma, Utah, and Washington, USA, by Robert S. Thompson (USGS scientist emeritus) and others between 1977 and 2006. Middens are waste piles composed of the urine and feces of packrats (Neotoma spp.) also containing plant materials, bones, and insects. Radiocarbon dating of middens indicates they can be preserved for as long as 50,000 years, and their fossil plant assemblages document changes in plant community composition through time, providing important records...
Categories: Data,
Data Release - In Progress;
Tags: Botany,
Climatology,
Ecology,
USGS Science Data Catalog (SDC)
Post-fire shifts in vegetation composition will have broad ecological impacts. However, information characterizing post-fire recovery patterns and their drivers are lacking over large spatial extents. In this analysis we used Landsat imagery collected when snow cover (SCS) was present, in combination with growing season (GS) imagery, to distinguish evergreen vegetation from deciduous vegetation. We sought to (1) characterize patterns in the rate of post-fire, dual season Normalized Difference Vegetation Index (NDVI) across the region, (2) relate remotely sensed patterns to field-measured patterns of re-vegetation, and (3) identify seasonally-specific drivers of post-fire rates of NDVI recovery. Rates of post-fire...
The Mammoth Springs (MS) fossil site at Hot Springs, South Dakota, provides a unique opportunity to reconstruct paleoenvironmental conditions. We used luminescence dating on fine sand sized potassium feldspars to establish a chronological framework for the site. In addition, we dated a late Pleistocene paludal proxy site using luminescence and incorporated those results with previous radiocarbon dating. Radiocarbon dating of the MS sinkhole organics suggested that the ages of the sediments that hosted the fossils was ~22-26 ka, while luminescence dating on feldspar grains suggested substantially older ages of ~130-255 ka. Analysis of the equivalent dose dispersion of the luminescence samples showed that the sediments...
Categories: Data;
Types: Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Black Hills,
Climatology,
Fall River,
Geochemistry,
Geomorphology,
High-frequency observations of surface water at fine spatial scales are critical to effectively manage aquatic habitat, flood risk and water quality. We developed inundation algorithms for Sentinel-1 and Sentinel-2 across 12 sites within the conterminous United States (CONUS) covering >536,000 km2 and representing diverse hydrologic and vegetation landscapes. These algorithms were trained on data from 13,412 points spread throughout the 12 sites. Each scene in the 5-year (2017-2021) time series was classified into open water, vegetated water, and non-water at 20 m resolution using variables not only from Sentinel-1 and Sentinel-2, but also variables derived from topographic and weather datasets. The Sentinel-1 model...
Geochronologic and isotopic data for Paleohydrologic history of Pluvial Lake San Agustin, New Mexico
This dataset includes tables of radiocarbon, uranium thorium series, and luminescence geochronologic ages and stable carbon and oxygen isotope compositions for sedimentary and organic samples.
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