Presentation Title

Spatial variations in N deposition: Differences in NH4+ and NO3- deposition between sites and vegetation types in southern California Chaparral

Faculty Mentor

Dr. Vourlitis

Start Date

18-11-2017 12:30 PM

End Date

18-11-2017 1:30 PM

Location

BSC-Ursa Minor 86

Session

Poster 2

Type of Presentation

Poster

Subject Area

biological_agricultural_sciences

Abstract

Nitrogen (N) deposition describes the input of reactive nitrogen from the atmosphere to the biosphere due in part to fossil fuel emissions. This experiment analyzed and compared the dry deposition of ammonium (NH4+) and nitrate (NO3-) captured in through-fall over a period of 1 year. Measurements were conducted at three different sites comparing two different vegetation types: shrubs and forests. The deposition data was collected using ion exchange resin (IER) collectors and chemical extraction methods were used to measure the N collected in throughfall. Every 3 months IER collectors were swapped out and replaced and leaf area index was measured. Meteorological data was collected and used from San Pasqual Valley, which is located approximately 25 km east of the study area. Our null hypothesis was that N deposition would not vary between sites or vegetation types. Our results indicate that there were significant differences in NH4+ and NO3- deposition between sites and vegetation types. Higher elevation sites experienced significantly more NH4+ and NO3- than lower elevation sites, even though differences in elevation were only 45 m, and trees captured 2.5-times more NH4+ that shrubs. These large differences were unexpected and suggest that spatial variations in N deposition are large in Southern California. This is an ongoing experiment and more time is needed in order to understand these patterns. Monitoring and understanding these patterns is crucial for ongoing research monitoring of N deposition as well as understanding potential environmental effects of increased N deposition locally and globally.

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Nov 18th, 12:30 PM Nov 18th, 1:30 PM

Spatial variations in N deposition: Differences in NH4+ and NO3- deposition between sites and vegetation types in southern California Chaparral

BSC-Ursa Minor 86

Nitrogen (N) deposition describes the input of reactive nitrogen from the atmosphere to the biosphere due in part to fossil fuel emissions. This experiment analyzed and compared the dry deposition of ammonium (NH4+) and nitrate (NO3-) captured in through-fall over a period of 1 year. Measurements were conducted at three different sites comparing two different vegetation types: shrubs and forests. The deposition data was collected using ion exchange resin (IER) collectors and chemical extraction methods were used to measure the N collected in throughfall. Every 3 months IER collectors were swapped out and replaced and leaf area index was measured. Meteorological data was collected and used from San Pasqual Valley, which is located approximately 25 km east of the study area. Our null hypothesis was that N deposition would not vary between sites or vegetation types. Our results indicate that there were significant differences in NH4+ and NO3- deposition between sites and vegetation types. Higher elevation sites experienced significantly more NH4+ and NO3- than lower elevation sites, even though differences in elevation were only 45 m, and trees captured 2.5-times more NH4+ that shrubs. These large differences were unexpected and suggest that spatial variations in N deposition are large in Southern California. This is an ongoing experiment and more time is needed in order to understand these patterns. Monitoring and understanding these patterns is crucial for ongoing research monitoring of N deposition as well as understanding potential environmental effects of increased N deposition locally and globally.