The use of time-integrated NOAA NDVI data and rainfall to assess landscape degradation in the arid shrubland of Western Australia

Ground-based data on total phytomass were collected in 1998 and 1999 from four sampling domains, each nearly 1000 kin, within the and shrubland of Western Australia. These data were used in models relating rainfall and landscape characteristics to total phytomass to provide landscape-scale estimates of total phytomass and rainfall-use efficiency for 1992-1999 (referred to as RUEp). These modelled estimates were compared with remotely sensed estimates of total phytomass (I-NDVI) and rainfall-use efficiency (I-NDVI/annual rainfall; referred to as RUEN) using data from NOAA satellites. There was good agreement between ground-based and remotely sensed estimates of total phytomass but less agreement between estimates of rainfall-use efficiency. Partitioning the landscape on the basis of landscape resilience did not improve the amount of variance accounted for in RUEp or RUEN and there were conflicting relationships between landscape-scale indicators of landscape function and RUEN. There was, however, evidence to suggest that temporal change in RUEN may provide a useful broad-scale indicator of landscape degradation or recovery over decadal time intervals. Recommendations are made for broad-scale application of this indicator based on temporal trends in RUEN. (C) 2003 Elsevier Science Inc. All rights reserved.