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1. Warming-El Nino-Nitrogen Deposition Experiment (WENNDEx): Soil Nitrogen Data from the Sevilleta National Wildlife Refuge, New Mexico (2006 - 2020)

   https://doi.org/10.6073/pasta/2b7ab47e8e3bfab993e80cdae1c887f5  

   Collins, Scott; Pockman, William (January 2020, Environmental Data Initiative)

   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 Niño 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). 

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2. Warming-El Nino-Nitrogen Deposition Experiment (WENNDEx): Soil Temperature, Moisture, and Carbon Dioxide Data from the Sevilleta National Wildlife Refuge, New Mexico

   https://doi.org/10.6073/pasta/9e9f235128c82a46bb073589d91c6989  

   Collins, Scott (January 2021, Environmental Data Initiative)

   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 Nino 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. This dataset shows values of soil moisture, soil temperature, and the CO2 flux of the amount of CO2 that has moved from soil to air. 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. 

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3. Simulating the Potential for Invasive Grass Expansion to Alter Wildfire Behavior in Southern California With WRF‐Fire

   https://doi.org/10.1029/2024JG008574  

   Wang, Bowen; Madakumbura, Gavin D; Juliano, Timothy W; Williams, A Park (August 2025, Journal of Geophysical Research: Biogeosciences)

   Abstract Invasion by non‐native annual grasses poses a serious threat to native vegetation in California, facilitated through interaction with wildfires. Our work is the first attempt to use the coupled fire‐atmosphere model, WRF‐Fire, to investigate how shifts from native, shrub‐dominated vegetation to invasive grasses could have affected a known wildfire event in southern California. We simulate the Mountain Fire, which burned >11,000 ha in July 2013, under idealized fuel conditions representing varying extents of grass invasion. Expanding grass to double its observed coverage causes fire to spread faster due to the lower fuel load in grasses and increased wind speed. Beyond this, further grass expansion reduces the simulated spread rate because lower heat release partially offsets the positive effects. Our simulations suggest that grass expansion may generally promote larger faster‐spreading wildfires in southern California, motivating continued efforts to contain and reduce the spread of invasive annual grasses in this region. 

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4. Simulating Potential Impacts of Fuel Treatments on Fire Behavior and Evacuation Time of the 2018 Camp Fire in Northern California

   https://doi.org/10.3390/fire5020037  

   Seto, Daisuke; Jones, Charles; Trugman, Anna T.; Varga, Kevin; Plantinga, Andrew J.; Carvalho, Leila M.; Thompson, Callum; Gellman, Jacob; Daum, Kristofer (April 2022, Fire)

   Fuel break effectiveness in wildland-urban interface (WUI) is not well understood during downslope wind-driven fires even though various fuel treatments are conducted across the western United States. The aim of this paper is to examine the efficacy of WUI fuel breaks under the influence of strong winds and dry fuels, using the 2018 Camp Fire as a case study. The operational fire growth model Prometheus was used to show: (1) downstream impacts of 200 m and 400 m wide WUI fuel breaks on fire behavior and evacuation time gain; (2) how the downstream fire behavior was affected by the width and fuel conditions of the WUI fuel breaks; and (3) the impacts of background wind speeds on the efficacy of WUI fuel breaks. Our results indicate that WUI fuel breaks may slow wildfire spread rates by dispersing the primary advancing fire front into multiple fronts of lower intensity on the downstream edge of the fuel break. However, fuel break width mattered. We found that the lateral fire spread and burned area were reduced downstream of the 400 m wide WUI fuel break more effectively than the 200 m fuel break. Further sensitivity tests showed that wind speed at the time of ignition influenced fire behavior and efficacy of management interventions. 

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5. 2003 Prescribed Burn Effect on Chihuahuan Desert Grasses and Shrubs at the Sevilleta National Wildlife Refuge, New Mexico: Species Composition Study (2004-2018)

   https://doi.org/10.6073/pasta/51d4f3d0a91db1d68237e21b7bcafbcd  

   Muldavin, Esteban; Collins, Scott (January 2021, Environmental Data Initiative)

   Disturbance from fire can affect the abundance and distribution of shrubs and grasses in arid ecosystems. In particular, fire may increase grass and forb production while hindering shrub encroachment. Therefore, prescribed fires are a common management tool for maintaining grassland habitats in the southwest. However, Bouteloua eriopoda (black grama), a dominant species in Chihuahuan Desert grassland, is highly susceptible to fire resulting in death followed by slow recovery rates. A prescribed fire on the Sevilleta National Wildlife refuge in central New Mexico in 2003 provided the opportunity to study the effects of infrequent fires on vegetation in this region. This study was conducted along a transition zone where creosote bushes (Larrea tridentata) are encroaching on a black grama grassland. Before and after the fire, above ground plant productivity and composition were monitored from 2003 to present. Following the prescribed fire, there were fewer individual grass clumps and less above ground grass cover in burned areas compared to unburned areas. This decrease in productivity was primarily from a loss of B. eriopoda. Specifically, B. eriopoda density and cover were significantly lower following the fire with a slow recovery rate in the five years following the fire. Other grasses showed no such adverse response to burning. Data were collected from 2004-2013 and 2018. Data were not collected for 2014-2017. 

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