title: Extracting Plant Phenology Metrics in a Great Basin Watershed: Methods and Considerations for Quantifying Phenophases in a Cold Desert.
abstract: Plant phenology is recognized as important for ecological dynamics. There has been a recent advent of phenology and camera networks worldwide. The established PhenoCam Network has sites in the United States, including the western states. However, there is a paucity of published research from semi-arid regions. In this study, we demonstrate the utility of camera-based repeat digital imagery and use of R statisticalphenopixpackage to quantify plant phenology and phenophases in four plant communities in the semi-arid cold desert region of the Great Basin. We developed an automated variable snow/night filter for removing ephemeral snow events, which allowed fitting of phenophases with a double logistic algorithm. We were able to detect low amplitude seasonal variation in pinyon and juniper canopies and sagebrush steppe, and characterize wet and mesic meadows in area-averaged analyses. We used individual pixel-based spatial analyses to separate sagebrush shrub canopy pixels from interspace by determining differences in phenophases of sagebrush relative to interspace. The ability to monitor plant phenology with camera-based images fills spatial and temporal gaps in remotely sensed data and field based surveys, allowing species level relationships between environmental variables and phenology to be developed on a fine time scale thus providing powerful new tools for land management.
authors.affiliation: USDA-ARS, Great Basin Rangelands Research Unit, Reno, NV 89512, USA. keirith.snyder@ars.usda.gov.
authors.forename: Keirith A
authors.initials: KA
authors.lastname: Snyder
authors.affiliation: USDA-ARS, Great Basin Rangelands Research Unit, Reno, NV 89512, USA. b.wehan@gmail.com.
authors.forename: Bryce L
authors.initials: BL
authors.lastname: Wehan
authors.affiliation: Environmental Protection Agency of Aosta Valley, ARPA Valle d'Aosta, Climate Change Unit, Saint-christophe 11020, Italy. g.filippa@arpa.vda.it.
authors.forename: Gianluca
authors.initials: G
authors.lastname: Filippa
authors.affiliation: Western Regional Climate Center, Desert Research Institute, Reno, NV 89512, USA. justin.huntington@dri.edu.
authors.forename: Justin L
authors.initials: JL
authors.lastname: Huntington
authors.affiliation: Department of Agriculture, Nutrition and Veterinary Science, University of Nevada, Reno, NV 89557, USA. tstringham@cabnr.unr.edu.
authors.forename: Tamzen K
authors.initials: TK
authors.lastname: Stringham
authors.affiliation: Department of Agriculture, Nutrition and Veterinary Science, University of Nevada, Reno, NV 89557, USA. devonsnyder@cabnr.unr.edu.
authors.forename: Devon K
authors.initials: DK
authors.lastname: Snyder
mesh_terms: D000465:Algorithms; D003247:Conservation of Natural Resources / Q000379:methods; D003889:Desert Climate; D017753:Ecosystem; D010781:Photography / Q000379:methods*; D012621:Seasons
keywords: PhenoCam network; StarDot cameras; camera-based repeat digital photography; pinyon and juniper; sagebrush steppe; semi-arid meadows