Humans are creating significant global environmental change, including shifts in climate, increased nitrogen (N) deposition, and the facilitation of species invasions. A multi-factorial field experiment is being performed in an arid grassland within the Sevilleta National Wildlife Refuge (NWR) to simulate increased nighttime temperature, higher N deposition, and heightened El NiÃ±o frequency (which increases winter precipitation by an average of 50%). The purpose of the experiment is to better understand the potential effects of environmental drivers on grassland community composition, aboveground net primary production and soil respiration. The focus is on the response of two dominant grasses (Bouteloua gracilis and B eriopoda), in an ecotone near their range margins and thus these species may be particularly susceptible to global environmental change. It is hypothesized that warmer summer temperatures and increased evaporation will favor growth of black grama (Bouteloua eriopoda), a desert grass, but that increased winter precipitation and/or available nitrogen will favor the growth of blue grama (Bouteloua gracilis), a shortgrass prairie species. Treatment effects on limiting resources (soil moisture, nitrogen availability, species abundance, and net primary production (NPP) are all being measured to determine the interactive effects of key global change drivers on arid grassland plant community dynamics and ecosystem processes. On 4 August 2009 lightning ignited a ~3300 ha wildfire that burned through the experiment and its surroundings. Because desert grassland fires are patchy, not all of the replicate plots burned in the wildfire. Therefore, seven days after the wildfire was extinguished, the Sevilleta NWR Fire Crew thoroughly burned the remaining plots allowing us to assess experimentally the effects of interactions among multiple global change presses and a pulse disturbance on post-fire grassland dynamics. This data set provides soil N availability in each plot of the warming experiment for the monsoon season (also see SEV176).
Knowledge Network for Biocomplexity (KNB) Identifier
Data Policies: This dataset is released to the public and may be freely downloaded. Please keep the designated Contact person informed of any plans to use the dataset. Consultation or collaboration with the original investigators is strongly encouraged. Publications and data products that make use of the dataset must include proper acknowledgement of the Sevilleta LTER. Datasets must be cited as in the example provided. A copy of any publications using these data must be supplied to the Sevilleta LTER Information Manager. By downloading any data you implicitly acknowledge the LTER Data Policy (http://www.lternet.edu/data/netpolicy.html).
Sevilleta Long Term Ecological Research (LTER) Project
2006-01-01 - 2015-12-31
The Warming site is located just to the northeast of the Deep Well meteorological station. The site can best be accessed by parking on the main road next to signs for Deep Well and the mini-rhizotron study. Note that vehicles are not permitted on the road to the Deep Well meteorological station. Travel on foot towards Deep Well and look for a well-trod path to the northwest shortly before the meteorological station. For plot maps, see power point slides in the on-line Sevilleta LTER WIKI page. On August 4, 2009, a lightning-initiated fire began on the Sevilleta National Wildlife Refuge. By August 5, 2009, the fire had reached the Warming site, which was burned extensively though not entirely. Approximately 50% of plots burned on August 5 and those plots which did not burn were burned within three weeks by US Fish and Wildlife. Thus, the condition of all plots at the Warming site was comparable by early September 2009.
Collins, Scott; Pockman, William (2016-07-11): Warming-El Nino-Nitrogen Deposition Experiment (WENNDEx): Soil Nitrogen Data from the Sevilleta National Wildlife Refuge, New Mexico (2006 - present). Long Term Ecological Research Network. http://dx.doi.org/10.6073/pasta/4ea9b5c3d2a5231c33a72355b18f7700