Net primary production (NPP) and climate data from Sevilleta LTER core and control sites in desert grassland and shrubland ecosystems, 1999 - 2017

This dataset and R code were used to create the figures, tables and statistical
analyses for the following publication: Rudgers, JA et al. 2018. Climate sensitivity
functions and net primary production: A framework for incorporating climate mean and
variability. Ecology. Data were collected by the Sevilleta LTER program, which is located in
the Sevilleta National Wildlife Refuge (SNWR), New Mexico. These are long-term, continuing
data sets. Data collection started in 1999 at the black grama grassland and creosote
shrubland, and in 2002 for blue grama grassland. Meteorological stations started recording
data as early as 1989. The study abstract from Rudgers et al. 2018 is: Understanding controls on net primary production (NPP) has been a long-standing goal in
ecology. Climate is a well-known control on NPP, although the temporal differences among
years within a site are often weaker than the spatial pattern of differences across sites.
Climate sensitivity functions describe the relationship between an ecological response
(e.g., NPP) and both the mean and variance of its climate driver (e.g., aridity index),
providing a novel framework for understanding how climate trends in both mean and variance
vary with NPP over time. Nonlinearities in these functions predict whether an increase in
climate variance will have a positive effect (convex nonlinearity) or negative effect
(concave nonlinearity) on NPP. The influence of climate variance may be particularly intense
at ecosystem transition zones, if species reach physiological thresholds that create
nonlinearities at these ecotones. Long-term data collected at the confluence of three
dryland ecosystems in central New Mexico revealed that each ecosystem exhibited a unique
climate sensitivity function that was consistent with long-term vegetation change occurring
at their ecotones. Our analysis suggests that rising temperatures in drylands could alter
the nonlinearities that determine the relative costs and benefits of variance in
precipitation for primary production.