Economic and social effects Equivalent water thickness Forecasting Hieracium umbellatum Intraspecific trait variation Leaf dry matter Leaf dry matter content Leaf mass per area Leaf water content Least squares approximations PROSPECT Partial least square regression Partial least squares regression (PLSR) Partial least squares regression models Plants (botany) Radiative transfer Reflection Rosa rugosa Rubus caesius Species specifics accuracy assessment correlation dry matter functional role herb prediction radiative transfer sampling shrub surface reflectance