species, buffelgrass (Pennisetum ciliare), on diversity of native rangeland plant
communities in Sonora, Mexico.
1.6 Future Directions and Challenges
The remote sensing literature of the past 30 years attests to the enormous utility
and applications of VIs for landscape monitoring and vegetation health assessments. Nevertheless, new challenges and demands for robust remote sensing tools
exist in order to address upcoming ecological challenges that require more accurate and long term VI data records for climate studies, ecosystem sustainability,
and a more explicit understanding of the biophysical information contained in VI
measurements. Advancements in hyperspectral and combined optical-thermal
indices offer much potential in advancing remote sensing based landscape monitoring and applications.
Fig. 1.15 a Relationship
between tree species richness
and seasonal mid-point EVI
values derived from MODIS
using forest field survey
plots; and b map of predicted
tree richness delineated by
ecoregions into five classes
derived from mid-season
MODIS EVI values. Adapted
from Waring et al. (2006),
Copyright (2006), reprinted
with permission from
Elsevier
1 Indices of Vegetation Activity
27