Hirsikangas and Rovaniemi coniferous sites: VALERI in Finland

1
Hirsikangas and Rovaniemi coniferous sites
VALERI in Finland

• Pauline Stenberg Miina Rautiainen, University
  of Helsinki
• Pekka Voipio, Finnish Forest Research Institute
• Terhikki Manninen, Finnish Meteorological
  Institute

2
Location of the sites
Arctic circle
3

• Rovaniemi (est. 2004)

• Hirsikangas (est. 2003)

Norway spruce dominated 3 x 3 km 24 ESUs
Scots pine dominated 3 x 3 km 34 ESUs
4
LAI measurements

• LAI-2000 measurements at each ESU
• Hemispherical photos from Rovaniemi
• Understory LAI measurements from Hirsikangas

5
LAI distributions(LAI as obtained with the
LAI-2000 instrument)
6
Canopy and understory LAI at Hirsikangas
7
Measurements at Hirsikangas-characterizing the
forests for RT modelling-

• stand structure
• (density, dbh, height, crown length, etc)
• LAI
• shoot structure
• crown shape
• canopy cover
• understory BRDF with goniometry

8
Use of data from the VALERI sitesanalyses and
modelling

• Related to ground truth
• modelling of crown shape and shoot structure
• testing methods for measuring canopy cover
• improving the LAI sampling design
• Related to remote sensing
• inversion of the Kuusk-Nilson forest reflectance
  model
• simulations with the PARAS model
• relationships of LAI and spectral vegetation
  indices
• combined microwave and optical LAI algorithms

9
Identified problems

• combinations of red and NIR not sensitive enough
  
• separating overstory and understory LAI
• spectral signal of mixed understory
• quantifying canopy cover
• fragmented forest stands (small scale variation
  in LAI)
• shoot scattering phase function

10
Future plans

• Plans for summer 2005
• Understory BRDF measurements
• LAI measurements
• VALERI LAI measurement design optimization for
  boreal conditions
• Needle optical properties measurements
• Estimating canopy cover
• Using hemispherical photos from coniferous stands
  for estimating LAI
• Combined microwave and optical algorithm for LAI
  retrieval
• And later on
• empirical testing of spectral invariants (p, pt)
• shoot scattering phase function measurements

11
Thank you.