Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Values of high frequency power when viewing the four rooftop images. Control: no vegetation with concrete floor; type G: grass vegetation; type GS: grass-shrubs vegetation; type GST: grass-shrubs-trees vegetation; n = 15, mean ± SE; *, p < 0.05.
