Airborne laser scanner-assisted estimation of aboveground biomass change in a temperate oak–pine forest

摘要: We estimated aboveground tree biomass and change in using repeated airborne laser scanner (ALS) acquisitions temporally coincident ground observations of forest biomass, for a relatively undisturbed period (2004-2007; ?07-04), contrasting disturbance (2007-2009; ?09-07), an integrated (2004-2009; ?09-04). A simple randomsampling (SRS) estimator was used to estimate means variances each measurement occasion interval. For year, linear regression models were predict mean total live, dead, components from ALS-derived variables. These predicted with R2 = 0.68, 0.59, 0.70 RMSEs 32.7, 30.5, 31.7 Mg ha-1 2004, 2007 2009, respectively. model assisted indirect estimatorwas then comparison the field-based SRS estimator. This approach decreased standard errors estimation relative estimator, but had larger estimation. Linear also directly field-estimated ALS ?-variables, calculated as difference between multi-temporal variables, study area. Integrated over 6 year period, these 0.81, 0.72, 0.68 2.0, 9.3, 1.0 yr-1 direct reduced estimates by 100-200% compared estimates. discuss several potential advantages limitations approaches. Our primary finding is that uncertainty both field