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. While measures of both below- and above-ground biomass are important in estimating total NPP, this study focuses on above-ground net primary production (ANPP). Above-ground net primary production is the change in plant biomass, including loss to death and decomposition, over a given period of time. Volumetric measurements are made using vegetation data from permanent plots collected in SEV297, "Extreme Drought in Grassland Ecosystems (EDGE) Net Primary Production Quadrat Data" and regressions correlating biomass and volume constructed using seasonal harvest weights from SEV157, "Net Primary Productivity (NPP) Weight Data."
Derivation of Biomass and Net primary Production:
Data from SEV297 and SEV157 are used to calculate the seasonal and annual production (i.e., biomass) of each species in each quadrat for a given year. Allometric equations derived from harvested samples of each species for each season are applied to the measured cover, height, and count of each species in each quadrat. This provides seasonal biomass for winter, spring, and fall.
Seasonal net primary production (NPP) is derived by subtracting the previous season's biomass from the biomass for the current season. For example, spring NPP is calculated by subtracting the winter weight from the spring weight for each species in a given quadrat. Negative differences are considered to be 0. Likewise, fall production is computed by subtracting spring biomass from fall biomass. Annual biomass is taken as the sum of spring and fall NPP.
The bounding box coordinates for the corners of the polygon which encompasses the full EDGE black site are:NW: -106.729227 34.337913 Decimal DegreesNE: -106.728434 34.337937 Decimal DegreesSW: -106.729144 34.337298 Decimal DegreesSE: -106.728392 34.337310 Decimal DegreesEDGE blue:NW: -106.622610 34.342141 Decimal DegreesNE: -106.621689 34.342079 Decimal DegreesSW: -106.623365 34.341518 Decimal DegreesSE: -106.622711 34.341015 Decimal Degrees