Net Primary Productivity (NPP) Weight Data at the Sevilleta National Wildlife Refuge, New Mexico

Several long-term studies at the Sevilleta LTER measure net primary
production (NPP) across ecosystems and treatments. 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 (ANPP) is the change
in plant biomass, including loss to death and decomposition, over a
given period of time. To measure this change, vegetation variables,
including species composition and the cover and height of
individuals, are sampled up to three times yearly (winter, spring,
and fall) at permanent plots within a study site. The weight data
presented here is obtained by harvesting a series of covers for
species observed during plot sampling. These species are always
harvested from habitat comparable to the plots in which they were
recorded. This data is then used to make volumetric measurements of
species and build regressions correlating biomass and volume. From
these calculations, seasonal biomass and seasonal and annual NPP are
determined.