More Like this

1. Point-Quarter Distance and Dimension Measurements to Calculate Shrub Density and Estimate Shrub ANPP in a Chihuahuan Desert Creosote Shrubland at the Sevilleta National Wildlife Refuge, New Mexico

   https://doi.org/10.6073/pasta/079019c988152e8ece0d38ee45684943  

   Moore, Douglas I; Collins, Scott L (January 2021, Environmental Data Initiative)

   In an effort to better quantify NPP of Creosotebush in the Five-Points region, it was decided to test the Point-Quarter method against the standard 1-m2 quadrat method that has been in use since 1998. Transects were laid out across the 5 mammal trapping webs as well as across burned and unburned plots of the Mixed Shrub site (MS). Repeated measures of the same bushes are performed seasonally. Whole shrubs of various size classes are collected, sorted, and weighed to develop regressions for biomass. Purpose: Data was collected initially to determine density and dimensions of creosote bush in the Five points area on core rodent webs and on burned and unburned plots following the 2003 prescribed burn. It was decided to expand the project by continuing measurements through time to quantify the change in shrub size and with simultaneous harvest of shrubs to measure NPP. 

   more » « less
2. Perennial Bioenergy Crop Yield and Quality Response to Nitrogen Fertilization

   https://doi.org/10.1007/s12155-019-10072-z  

   Wang, Sichao; Sanford, Gregg R.; Robertson, G. Philip; Jackson, Randall D.; Thelen, Kurt D. (November 2019, BioEnergy Research)

   At two sites in the North Central USA (Michigan (KBS) and Wisconsin (ARL)), we evaluated the effect of N fertilization on the yield and quality of five perennial bioenergy feedstock cropping systems: (1) switchgrass (Panicum virgatum L.), (2) giant miscanthus (Miscanthus × giganteus), (3) a native grass mixture (5 species), (4) an early successional field (volunteer herbaceous species), and (5) a restored prairie (18 species). In a randomized complete block design with 5 replicates and 2 split plots, N was applied at 0 and 56 kg ha−1 to split plots for each cropping system from 2010 to 2016. No yield response to N was detected in switchgrass at either location in any year. Giant miscanthus exhibited a positive yield response to N at both sites (11% at KBS and 83% at ARL). Nitrogen fertilizer addition significantly reduced glucose (KBS 12.9 and 13.8 g kg−1 year−1, ARL 11.2 and 9.7 g kg−1 year−1) in the native grass mix and restored prairie systems respectively. Nitrogen fertilizer also reduced xylose at KBS in the switchgrasss, native grass mix, and restored prairie (4.9, 7.5, and 5.0 g kg−1 year−1). At ARL, N fertilization reduced xylose levels in switchgrass, giant miscanthus, and restored prairie (7.4, 6.8, and 6.2 g kg−1 year−1) and increased xylose levels in the early successional system (5.0 g kg−1 year−1). 

   more » « less
3. Carbon dioxide and methane chamber flux data from temperate S. alterniflora salt-marsh

   https://doi.org/10.6084/m9.figshare.20099321.v1  

   Hill, Andrew; Vargas, Rodrigo (January 2022, figshare)

   A collection of carbon dioxide (CO2), methane (CH4) gas flux and leaf area index (LAI) datasets from a temperate salt-marsh with S. alternifloria vegetation cover (39.09 ˚N, 75.44 ˚W). Measurements were collected from May 2020 through December of 2020 with 2 separate collection times per month for a total of 16 field sampling campaigns. Measurements were performed on 5 plots located within the footprint of an eddy covariance tower which collects ecosystem scale CO2 and CH4 fluxes (Ameriflux Site ID: StJ). Supporting measurements were also performed for leaf-level photosynthesis rates and plot LAI during each chamber campaign. </p> </p> The dark and light flux chambers each occupied 1.0 m2 ground area and the vegetation stand was fully enclosed by the chambers. The sediment chambers each occupied 0.025 m2 ground area and the vegetation stand was excluded from the chambers. CO2 and CH4 fluxes from all chambers were measured with a portable greenhouse gas analyzer (LGR  Los Gatos Research, Model 915-0011, San Jose, CA) for approximately 2-3 min after chamber closure. The dark and soil chambers were 100% opaque while the light chamber allowed for 90% transmission of photosynthetically active radiation. Sediment fluxes and leaf-level photosynthesis was measured from 2 points within each of the larger chamber plots. Leaf-level photosynthesis was measured with a  portable photosynthesis meter (Li-6400, Licor, Lincoln, NE) and LAI was measured with a ceptometer (Accupar LP80, Meter Inc, Pullman, WA, USA). All measurements were made consecutively over the span of 2-3 hours with leaf-level measurements preformed first, followed by light chambers, dark chambers, sediment chambers and plot LAI.  </p> </p> </p> 

   more » « less
4. Tracegas fluxes in forests and old fields under enhanced nitrogen regimes at the Kellogg Biological Station, Hickory Corners, MI (2001 to 2020)

   https://doi.org/10.6073/pasta/e3f0df0d5fe656817ab207aa52704866  

   Ambus, Per; McSwiney, Claire; Robertson, G. (January 2020, Environmental Data Initiative)

   Dataset Abstract 10 m2 plots in the old field and forest ecosystems were fertilized with 2 rates of nitrogen. N2O, CO2 and CH4 measurements were made with a static chamber method original data source http://lter.kbs.msu.edu/datasets/53 

   more » « less
5. Plant Removal Study: Recovery of Vegetation Following Disturbance at the Sevilleta National Wildlife Refuge, New Mexico

   https://doi.org/10.6073/pasta/2fb515b5379db855862b0247d517b478  

   Peters, Debra (January 2021, Environmental Data Initiative)

   In 1995, a removal study was initiated at the Sevilleta LTER to examine the response of vegetation following the removal of dominant species. Five sites were selected that were dominated by either blue grama (site 1), blue and black grama (site 2), black grama (site 3), black grama and creosote (site 4), or creosote (site 5). A sixth site was later added in the blue grama community along the foothills of the Los Pinos Mountains (site 6). At sites 1, 3, 5, and 6, five 3m x 4m plots had all plants of the dominant species removed; five 3m x 4m plots were controls. At site 2, 5 plots had blue grama removed, 5 plots had black grama removed, and 5 plots were controls. At site 4, 5 plots had black grama removed, 5 plots had creosote removed, and 5 plots were controls. Initial cover prior to removal was estimated by species for each plot. Grass was removed using a shovel to collect above-ground biomass and crowns just below the soil surface. Shrubs were removed using large clippers to collect above-ground biomass to the soil surface. All biomass removed was bagged, dried, and weighed. Plot maintenance or removal of the target dominant species is performed annually or as needed. Rain gauges were installed at each site and the corners of the areas containing each set of plots GPS'd. Plot corners are marked by nails and are flagged periodically to aid identification and minimize foot traffic in the plots. Each northeast nail has a metal tag with site and plot number on it. Erosion bridges (1 m long) were installed in plots 1, 3 and 5 (removals and controls) at sites 1-5. Initial measurements were made in 1996. 

   more » « less