Hello list,
I am doing a research for green-roofs analyzed with energyplus. Although I
have searched the internet for default or average values for LAI per plant
or per group of plants, I had no luck.
Can you please give me some guidance or some links about this value???
Thank you in advance
Sotiris Papantoniou
I've been wanting to find a resource/chart like you're describing for
some time...
This "guidebook" is pretty nice and something I'm keeping in my
reference files, but doesn't contain the specific info you're looking
for - you might find parts of it handy though:
http://ww2.cityofpasadena.net/waterandpower/cooltrees/Cool%20Trees%20Gui
debook.pdf
NICK CATON, E.I.T.
Hi Sotiris,
Well, it is very difficult to work out an averaged LAI for a rooftop garden,
especially for an intensive one. In general, it ranges from 1 to 6 or
7 depends on the species of plants. But for extensive rooftop, most likely
its LAI will be at low end (around 1 to 2, sometimes can be <1) due to
relatively sparse planting. It so happens that I've done my research in the
area. You may be interested in my PhD thesis at
http://scholarbank.nus.edu.sg/handle/10635/15511. We have done a field
measurement in an intensive rooftop garden and you are able to find some LAI
values at page 307 to 313.
Regards,
Cheney
Sotiris,
LAI values can range from 0(no plants) to 5 or higher. However, typical LAI values for extensive green roofs (substrate/soil thickness less than 6") are around 1-3. For my PhD Thesis at PennState I measured among other things the LAI of a healthy green roof sample with Delosperma nubigenum. The LAI was 2.7.
Hope this helps,
Paulo Cesar Tabares-Velasco, Ph.D.
Wow, you are doing exactly same research as I did before! ;)
Regards,
Cheney
Hi Cheney,
Happy to hear you also worked on this area. We were working on green roofs, but perhaps not same research methodology/ scope. I am not doing green roof at this time but I did it couple of years ago while I was doing my PhD at PennState working under supervision of Dr. Jelena Srebric and did all my experimental work inside an full-scale environmental chamber. In that way I was able to control environmental conditions such as radiation, air temp/RH/speed. Moreover, I measured simultaneously conduction, radiation (short and long wave), convection and evapotranspiration, as well as water content of substrate, LAI, plants and substrate temperature. It was a very detailed work probably beyond the scope of Sotiris' initial question and I had to design and built a new apparatus to measure all these heat fluxes. I would be glad to talk more in detail, but perhaps we are going little bit beyond the scope of this mail list.
So our studies might be similar but not precisely the same. We wanted to have a fully validated green roof model (based on physics principles), and back on those days we could not find the type/quality of experimental data to do this job so we produced this laboratory-grade data.
Greetings!
Paulo
Sotiris asked the same question in Eplus mailing list, and someone
posted this link. I'll just post it here as well to share it with the rest.
http://daac.ornl.gov/VEGETATION/LAI_support_images.html#table
Pedro.