Herbivores override climate control of grassland production in Yellowstone National Park

Understanding the factors regulating temporal variation in grassland annual aboveground net primary production (ANPP) is dominated by studying the effects of climate, particularly water, in ungrazed grassland. However, the overwhelming majority of the Earth’s grasslands are grazed by large herbivores, which have large effects on ANPP and interact with climate in unknown ways. Here we analyzed an eight-year data set of ANPP across a 26-year period that included widely variable climatic conditions and consumption rates by herds of elk (Cervus elaphus), bison (Bison bison), and pronghorn (Antilocapra americana) at 25 grassland sites in Yellowstone National Park (YNP). We found that ANPP was primarily a positive function of consumption rate and secondarily affected by a nonlinear temperature effect, with ANPP declining in hot years. Water balance (WB, a measure of soil moisture available to plants) did not affect ANPP. Examining the difference between grazed minus ungrazed (fenced) ANPP (i...., , # Herbivores override climate control of grassland production in Yellowstone National Park

Dataset DOI: [10.5061/dryad.7m0cfxq71](10.5061/dryad.7m0cfxq71)

## Description of the data and file structure

The data file incudes eight years of plant aboveground biomass data spanning three decades (1988-1989, 1999-2001, 2012-2014) to examine how variation in local climate, soil chemistry, and grazing intensity affect aboveground production in grasslands of YNP that are grazed by large migratory herds of wild ungulates.  In each of the eight years, aboveground production (g m-2), consumption (g m-2 removed) and climatic conditions for sequential sampling intervals during the April to September growing season were determined at 25 grazed grasslands.  In addition, ANPP was calculated for fenced (ungrazed) grassland at 13 of the sites.

### Files and variables

#### File: YNP\_data\_abridged.csv

**Description:** Here we synthesize eight years of data spanning three decades (1988-1989, 1999-200...,