Core Site Grid Quadrat Data for the Net Primary Production Study at the Sevilleta National Wildlife Refuge, New Mexico

Begun in spring 2013, this project is part of a long-term study at
the Sevilleta LTER measuring net primary production (NPP) across
three distinct ecosystems: creosote-dominant shrubland (Site C),
black grama-dominant grassland (Site G), and blue grama-dominant
grassland (Site B). Net primary production is a fundamental
ecological variable that quantifies rates of carbon consumption and
fixation. Estimates of NPP are important in understanding energy
flow at a community level as well as spatial and temporal responses
to a range of ecological processes. Above-ground net primary
production is the change in plant biomass, represented by stems,
flowers, fruit and foliage, over time and incorporates growth as
well as loss to death and decomposition. To measure this change the
vegetation variables in this dataset, including species composition
and the cover and height of individuals, are sampled twice yearly
(spring and fall) at permanent 1m x 1m plots within each site. A
third sampling at Site C is performed in the winter. The data from
these plots is used to build regressions correlating biomass and
volume via weights of select harvested species obtained in SEV999,
"Net Primary Productivity (NPP) Weight Data." This biomass
data is included in SEV999, "Seasonal Biomass and Seasonal and
Annual NPP for Core Grid Research Sites."