NPP Study: Annual aboveground net primary production, summary by site

Summarizes mean aboveground net primary production, in g/m2/yr, by year for each of 15 sites. Annual totals derived by summing seasonal production values for winter (October - February), spring (February - May), and fall (May - October) increments for a single calendar year. Please refer to these publications to evaluate the appropriateness of these data for your intended use prior to contacting Debra Peters, Responsible Investigator, with a data request. Peters, Debra P. C., Jin Yao, Osvaldo E. Sala, and John P. Anderson. 2012. Directional climate change and potential reversal of desertification in arid and semiarid ecosystems. Global Change Biology 18, no. 1 151-63. doi 10.1111/j.1365-2486.2011.02498.x. Peters, Debra P. C., Jin Yao, Dawn Browning, and Albert Rango. 2014. Mechanisms of grass response in grasslands and shrublands during dry or wet periods. Oecologia 174 1323-34. Attention: These data are not appropriate for estimates of percentage cover. NPP-associated percent cover measurements were developed for and are used solely to provide the best estimate of biomass production. Becuase the methodology results in measurements of overlapping subcanopy systems and canopies of adjacent individuals, NPP percent cover measurements are not an appropriate measure of actual aerial plant cover. Doing so will result in inflated numbers for the "actual" vegetative cover. Attention: Data through 2003 was replaced online per below on 9/22/2011. Analyses and results for ANPP differ from previous uses of the data from 1989-1998 (Huenneke et al., 2002) in three ways: (1) Yucca elata was removed prior to analysis because its growth form results in large errors in biomass estimates from year-to-year, (2) regressions between biomass and plant volume used an intercept equal to 0 to be consistent with a recent study in a similar system (Muldavin et al., 2008), and (3) reference harvests obtained in extreme years resulted in adjusted regression coefficents through time that reflect year-to-year variation in ANPP. These changes result in ANPP values that are smaller compared (Peters et al. submitted) with previous studies (Huenneke et al., 2002).