Author
Hulet, April | |
ROUNDY, BRUCE - Brigham Young University | |
PETERSEN, STEVE - Brigham Young University | |
BUNTING, STEPHEN - University Of Idaho |
Submitted to: Society for Range Management Meeting Abstracts
Publication Type: Abstract Only Publication Acceptance Date: 9/25/2012 Publication Date: 2/25/2013 Citation: Hulet, A., Roundy, B., Petersen, S., Bunting, S. 2013. Utilizing NAIP imagery to estimate tree cover and biomass in pinyon and juniper woodlands [abstract]. 66th Annual Meeting of the Society for Range Management, February 3-7, 2013, Oklahoma City, Oklahoma. Paper No. 272. Interpretive Summary: Technical Abstract: Land managers need to be able to rapidly assess and monitor fuels in pinyon and juniper (PJ) woodlands. Geospatial technologies, particularly remote sensing, could potentially be used in these ecosystems to better understand the spatial distribution of fuels and monitor PJ expansion at a scale necessary to make management decisions. This research utilized the National Agriculture Imagery Program (NAIP) aerial imagery to assess the relationship between remotely sensed tree cover and ground based cover and biomass measurements collected as part of the Sagebrush Steppe Treatment Evaluation Project (SageSTEP). eCognition Developer software was used to extract tree cover from imagery using object-based image analysis (OBIA) techniques. Ground measurements were collected during the summer of 2006 in 30x33-m subplots using the crown diameter method; biomass was estimated using structurally based analytic models. Averaged across all sites, OBIA cover estimates were approximately 2.5% less than ground-measured cover. Cover estimates from the two methods were highly correlated (r = 0.91) suggesting that NAIP imagery and OBIA techniques are a good method to rapidly identify areas threatened by PJ expansion. Preliminary correlation results between OBIA cover estimates and ground-measured biomass are highly correlated for Utah juniper trees (r = 0.87). However, for western juniper trees the correlation is less (r = 0.57), which may be due to structural differences between juniper species which impacts both our OBIA cover estimates and ground-measured biomass |