low deciduous LAI values?

[david_simpson@chalmers_se]

I started looking at the LAI values from the rawdata directory of CLM3.5. Over most of England and Northern France the LAI values for deciduous forest (broadleaf_deciduous_temperate_tree) look very low, around 2 m2/m2 or less. Values in Ireland are larger, ca. 3.

Even the needleleaf_evergreen_temperate_tree values are low, < 3 m2/m2

LAI of forests in these regions should be higher I though, ca. 4-5 m2/m2 (projected area), so I wonder if the low value reflect something about the density of forests or similar problems?

or should the rawdata LAI be divided by the PFT area to get the vegetation LAI?

Thanks

 

[slevis]

The LAI values in clm's raw datasets and surface datasets already represent LAI within a pft's area rather than grid cell average values. Low values are the outcome of assumptions made in the conversion of satellite data to LAI values by pft.

Sam Levis
CLM Science Community Liaison

 

[david_simpson@chalmers_se]

Thanks Sam,

OK, now I know. Just a follow-up: if I were to try to estimate the most realistic LAI for all of Europe, would it be a reasonable rule-of-thumb to trust those grid squares where the relevant PFT was dominant or had some high percentage? Or is there any other indicator of robustness I could look for? My basic aim is to get a best-estimate of LAI across Europe first, then the world, for each PFT. I don't need pixel-level detail, but rather the right spatial patterns.

Thanks,

Dave

 

[slevis]

Sounds reasonable to me. Good luck with your work.

Sam