Maintained (Wet) Tree: Ignition occurs at 0 seconds; fire at ignition point on tree continues to burn but does not spread at 30 seconds; fire at ignition point on tree continues to burn but does not spread at 1 minute; fire at ignition point on tree did not spread, flames self-extinguish, and tree (trunk, branches, and needles) is fully intact at 1 minute and 30 seconds (end of video).
Dry Tree: Ignition occurs at 0 seconds; other tree branches become involved at 5 seconds; most of the tree is burning at 15 seconds; tree is fully engulfed in flames at 30 seconds; only the tree trunk and portions of some of the larger branches are intact after all the needles have burned away at 1 minute and 30 seconds (end of video).
Courtesy of http://www.usfa.fema.gov/citizens/home_fire_prev/holiday-seasonal/holiday.shtm.