Premium
Relationship between sagebrush species and structural characteristics and L andsat T hematic M apper data
Author(s) -
Sivanpillai Ramesh,
Ewers Brent E.
Publication year - 2013
Publication title -
applied vegetation science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.096
H-Index - 64
eISSN - 1654-109X
pISSN - 1402-2001
DOI - 10.1111/j.1654-109x.2012.01207.x
Subject(s) - canopy , vegetation (pathology) , explained variation , elevation (ballistics) , regression analysis , variance (accounting) , regression , environmental science , atmospheric sciences , geography , ecology , mathematics , statistics , biology , physics , medicine , geometry , pathology , accounting , business
Questions Do the spectral patterns recorded by L andsat T hematic M apper ( TM ) for various sagebrush species differ from each other? Could ancillary data derived from topographic variables (elevation, slope and aspect) strengthen the relationship between sagebrush and spectral characteristics? Location R awlins, W yoming, USA . Methods Field data on sagebrush species and structural characteristics collected in 2005 were regressed against spectral values and transformed indices derived from L andsat TM data. Step‐wise regression methods were used to build (1) a combined model that ignored species and physical differences in sagebrush, and (2) four different models that took those differences in account. Parsimonious models were selected with significant independent variables that accounted for the largest amount of the ground‐measured variation in cover. Results In the combined model, a subset of L andsat bands and topographic values accounted for 65% ( P < 0.001) of variance in sagebrush canopy cover. However, when separate regression models were fitted based on species type (big and low sagebrush) and height (for big sagebrush only), L andsat data accounted for 71–85% ( P < 0.001) of the ground measured variance. Conclusions Spectral patterns of sagebrush species and their physical characteristics were distinguishable with L andsat TM data. Transformed indices derived from L andsat data accounted for more variance than the original spectral bands. Future research should focus on testing the relationship between L andsat TM data and sites where sagebrush is present with other vegetation to facilitate landscape and regional mapping of changing sagebrush ecosystems.