Description:
Dates: 09-15-2020 - 03-31-2021
Agency: National Park Service
Location: Glen Canyon National Recreation Area
Overview:
The primary focus of this internship will be to complete additional GIS analysis of the NASA DEVELOP park maps for Glen Canyon National Recreation Area prepared in 2018 and 2019, which show sequential vegetation changes over the past 24 years and which include an initial assessment of plant cover and productivity (Spence and Cushing 2019). GLCA staff will ground truth both the NASA DEVELOP maps and GLCA 2017 parkwide vegetation map by completing additional long-term vegetation plots in areas of the park that are not currently covered. Quantitative methods will focus on new plots in vegetation types not covered in previous monitoring, in particular pinyon-juniper woodlands. Currently, there are 87 permanent long-term monitoring plots in the park (methods are outlined in Spence 2017). Data derived from these plots include current plant community composition, biological soil crusts, and soil conditions. Using these data, it will be possible to identify the loss of key plant components such as Indian ricegrass (Achnatherum hymenoides) and that show a shift to a different future vegetation composition. These will describe key indicators of aridification and the resultant increase in bare and eroding soils (NRCS 2010). Spring-summer NDVI data will be available for the period of 1995 to 2019 for the entire park. Using GIS analyses, these data will be overlaid with soils and vegetation data from the 2017 GLCA vegetation classification. The principal focus will be on those vegetation types that are shown to have experienced the greatest declines in productivity based on plot and NDVI data. Preliminary data suggest that the NRCS ecological sites Desert Sand, Semidesert Sand, Semidesert Sandy Loam, and Semidesert Shallow Sandy Loam have experienced the largest changes over the last 25 years. Some of these ecological sites show significant declines in vegetation and biological soil crust cover and productivity. The vegetation composition on these sites include desert grasslands, blackbrush shrublands, and pinyon-juniper woodlands. Species distribution models (SDM’s) are currently available from the USGS for two critical plant species, pinyon pine (Pinus edulis) and Utah juniper (Juniperus osteosperma; Copeland et al. 2018). SDM’s are not available for blackbrush or grass species. The USGS will be consulted on whether there is a potential to model some of these species for the study. These SDM’s will be used in combination with the most current downscaled GCM’s for climate projections to model changes over time based on predicted future climates in GLCA. Weather station data from the region will also be consulted.
Field work may include visiting additional relict sites in the park that have not been grazed, although most of these sites are very difficult to access. This project will provide critical information on the impacts of climate change and livestock grazing in the largest unit of the NPS where grazing occurs.
Responsibilities:
The primary focus of this internship will be to complete additional GIS analysis of the NASA DEVELOP park maps for Glen Canyon National Recreation Area prepared in 2018 and 2019, which show sequential vegetation changes over the past 24 years and which include an initial assessment of plant cover and productivity (Spence and Cushing 2019).
- Documentation of changes in plant community composition indicating that, either in specific areas or parkwide, GLCA is transitioning from grassland or mixed grass/shrub communities to desert shrub and annual plant communities.
- Indications that aridification/desertification is occurring parkwide and further impacting both natural and cultural resources through loss of plant cover and biological soil crusts, increasing soil erosion.
- Identification of specific areas that show significant changes in vegetative composition over the past 24 years and/or that are experiencing loss of vegetation cover due to climate change and aridification/desertification.
- Identifying specific soil-vegetation community combinations that seem to be most at-risk from the impacts of ongoing climate change.
- Determining specific resource indicators that show that climate change is impacting terrestrial landscapes (livestock/human accessible areas, relict areas or both) and that grazing livestock is and may further accelerate those impacts.
- Maps, compiled range data and GIS layers showing results of the project. These layers will include extrapolated rangeland health conditions for specific allotments based on a variety of data sources, including NDVI-based change layers to help prioritize management actions.
Qualifications:
Advanced GIS skills and abilities; landscape ecology and landform interpretation; soils knowledge. Experience utilizing Esri products such as ArcGIS Desktop, ArcGIS Online, and Collector. Previous experience with remote sensing, raster reclassification, model builder, and researching GIS methodologies and establishing workflows needed. Strong data management skills also required. Cartographic and presentation skills preferred. The applicant must be a U.S. citizen or U.S. permanent legal resident (“green-card-holder”) between the ages of 18 and 30 years old, inclusive, or veteran up to age 35. Prior to starting this position, a government security background clearance will be required.