Search for: All records

Creators/Authors contains: "Shaver, Gus"

Note: When clicking on a Digital Object Identifier (DOI) number, you will be taken to an external site maintained by the publisher. Some full text articles may not yet be available without a charge during the embargo (administrative interval).
What is a DOI Number?

Some links on this page may take you to non-federal websites. Their policies may differ from this site.

  1. Vegetation indices calculated from reflectance spectra collected at Arctic LTER experimental plots at Toolik Lake, Alaska during the 2007-2025 growing seasons. Long term experimental plots span several different vegetation types: Heath (DHT89), Moist Acidic Tussock (MAT81, MAT89, and MAT06), Moist Non-Acidic Tussock (MNT97), Non-Acidic Non-Tussock (MNN97), Shrub (SHB89), and Wet Sedge (WSG89). Plots are differentiated by their experimental treatment and are located in replicate blocks. Canopy reflectance is measured by hand-held spectrophotometer and NDVI is calculated. 
    more » « less
  2. Above ground plant biomass and leaf area were measured in a tussock tundra experimental site. The plots were set up in 1981 and have been harvested in previous years (See Shaver and Chapin Ecological Monographs, 61, 1991 pp.1-31). 
    more » « less
  3. Whole plant biomass totals and root biomass (partitioned by percent of total leaf area) for species, tissue type, and functional group for the Arctic LTER experimental 1981 mesic acidic tussock tundra (MAT81) for the 2000 and 2015 harvests. Because most of the root biomass could not be identified to species in either 2000 or 2015, the calculation of root biomass and element content for roots not identified to species was estimated by the proportion of those species’ contributions to total leaf area. Specific Leaf Area (SLA = leaf area per gram leaf, centimeter squared per gram) values were available from several previous harvests of this experiment; in the present study, we used measurements from the 1995 harvest (Shaver et al. 2001). 
    more » « less
  4. Plant and root biomass, nitrogen, carbon, and phosphorus were measured in 2015 in the Arctic LTER tussock tundra experimental site (MAT81). This site was established in 1981 and has been harvested in previous years (see Shaver and Chapin Ecological Monographs, 61(1), 1991, pp.1-31, https://doi.org/10.2307/1942997). Data tables include the biomass for each harvested quadrat and block summaries for percent carbon, nitrogen, and phosphorus for control and fertilized plots from the original 4-block design. New control plots, established in 2015, are in a separate data table and include biomass, percent carbon, nitrogen, and phosphorus for each quadrat. 
    more » « less
  5. A complete accounting of biomass, C, N, and P allocation both among tissue types (leaves, stems, rhizomes, roots) and among species and plant functional types from Arctic LTER 1981 Moist Acidic Tussock (MAT81) long-term experiment’s untreated control plots and plots that were fertilized annually, harvested after 20 and 35 years, near Toolik Lake Field Station, Alaska. Data are gram per meter squared summarized by block. 
    more » « less
  6. Late season thaw depth was measured in the Arctic Long Term Ecological Research (ARC LTER) experimental plots (1981 Moist Acidic Tussock, 1989 Moist Acidic Tussock, 2006 Low Fertilization Moist Acidic Tussock, 1989 Moist Non-acidic Tussock, 1989 Moist Non-acidic Non-tussock and 1989 Wet Sedge tundra) at Toolik Lake, Alaska using a steel thaw probe. Note: for 2017-2018 only 1989 Moist Non-Acidic Tussock Tundra and 2006 Low fertilization Moist Acidic Tussock Tundra were measured. For other sites it has become difficult to distinguish rocks from frozen soil with a steel thaw probe. Starting in 2023 weekly thaw depth measurements were made throughout the growing season in the 2006 Low fertilization Moist Acidic Tussock Tundra experiment. 
    more » « less
  7. Above and below-ground plant biomass, including plant roots, was measured in Arctic LTER's moist acidic tussock tundra experimental site (MAT81). The plots were set up in 1981 and have been harvested in previous years (See Shaver and Chapin Ecological Monographs, 61(1), 1991 pp.1-31). This file contains the 2000 harvested biomass and percent carbon and nitrogen summaries for control and fertilized plots. Leaf area data for select species are available in Shaver, G. 2016. https://doi.org/10.6073/pasta/13915ef410067ef23bad0faff678319c 
    more » « less
  8. Air temperature and relative humidity at 3 meters, soil temperatures at 2 depths, 5 and 10 cm, canopy temperatures and soil moisture at 10 cm were measured in an Arctic Long Term Experimental Research (ARC-LTER) heath tundra site (DHT89) at Toolik Lake Field Station, North slope, Alaska. Only control and nutrient addition (nitrogen plus phosphorus ) treatments plots soils were measured. Note: In version 1 the moisture columns were mixed up. The fractional volumetric water columns were actually the period frequency of the wave of the sensor (Campbell Scientific CS616). Version 3 adds calculated percent moisture corrected for organic soil. 
    more » « less