Environmental Engineering Reference
In-Depth Information
Fig. 10.4
Map of
above
ground
biomass in grassland
area of Viote Monte Bondone
(pasture,
blue area
; intensive
managed meadow
green
area
; extensive managed
meadow
red area
)
mineral fertilization and cut once a year in mid-July. Some areas are not fertilized
and biomass is commonly harvested as hay. Pastures are located on the southern
parts of this area and grazed between June and September by cattle. There are
some areas that have been abandoned and have been invaded by shrubs. A peat
bog is located in the central part of the plateau.
Remote and proximal sensing tools were used to upscale plot measurements to
ecosystem level. Grassland biophysical parameters, linked to carbon stock, such
as LAI, biomass, phytomass, and Green herbage ratio (GR) were measured using
both ground-truth and satellite data. The performances of the most common Near
Infrared Radiometer (NIR) and red/green-based vegetation indices were compared
with ones that also make use of the Microwave Imaging Radiometer (MIR) band,
in relation to their ability to predict grassland biophysical parameters. From satel-
lite platforms, an IRS-1C-LISS III image (25 m resolution in the visible-NIR and
70 m resolution in the MIR) and a SPOT 5 image (10 m resolution in the visible-
NIR and MIR) were used. MIR-based indices performed better than NIR and red/
green-based ones in estimating biophysical variables, with no saturation effect
(Vescovo and Gianelle
2008
). Biomass showed a linear regression with Canopy
Index (MIR/green ratio) and with the Normalised Canopy Index (NCI) calculated
as a normalised difference between MIR and green bands (IRS: R2
=
0.91 and
0.90, respectively; SPOT: R2
=
0.63 and 0.64). The use of satellite images, in
particular IRS ones, permitted to reconstruct the grassland biomass of the Monte
Bondone plateau, and to analyze the effect of the different management practices
and intensity. The pasture and the extensive managed grassland produced the same
