The InternationaI Archives oj the Photogrammetry, Remote Sensing andSpatial Information Sciences. Vol. XXXVII. Part B7. Beijing 2008 
33 
i.Ai 
Figure 2. Wavelet analysis results on LAI (top) and NDVI 
(bottom) along the transect in July. Dark warm color represents 
higher variation and solid lines are the positive results of 
significant tests. 
Ground measured LAI showed matching trend with NDVI 
derived from space. Both indicated that the maximum growing 
season is July with maximum LAI and NDVI values (Figure 4). 
Figure 4 also showed that tamed grassland (smooth brome) has 
higher NDVI values and the maximum NDVI appeared later 
comparing to native prairies. 
4. CONCLUSIONS 
This study indicated the dynamic spatial and temporal 
variations of LAI and NDVI in a Canadian Prairie. Spatially, 
LAI has several levels of variations from small scale to large 
scale, which can be controlled by different factors. NDVI from 
remote sensing data can be used to represent the LAI variation 
at several scales. The maximum growing season for the study 
area is July for native prairies, but it is delayed to August for 
tamed grassland. 
Figure 3. Temporal change of the study area from both 
ground and satellite views. 
— Native—Tame • LAI 
Figure 4. Quantitative measurements of LAI from ground for 
native prairies (red dots) and NDVI for two grassland types 
from SPOT satellite imagery for native prairie (red line) and 
tamed grassland (green line). 
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