LIDAR Search Hits The Jackpot In Both Hemispheres
Save the Redwoods League, Ken Fisher and Redwood National & State Parks recently sponsored a total LIDAR scan flyover of the best remaining coast redwood habitat which includes Jedediah Smith, Del Norte, Prairie Creek & Humboldt Redwoods State Parks. Redwood National Park, Headwaters Forest and Montgomery State Reserve were also part of the search. Bill Kruse, retired LIDAR specialist, volunteered many hours of his time using supercomputers to process the LIDAR return data for creation of a "hit list" of all trees over 106m (348.7ft) for each park. The search area was narrowed to only process old growth forest that occurs in the elevation zone of sea level to 500m. Tall redwoods have never been documented growing above 400m (1300 ft) elevation, probably due to less frequent fog.
We anxiously waited for the return data from Bill Kruse. When the results finally poured in, Hyperion and Helios come in as #1 and #2 tallest in the entire data set at 114.85 m & 116.4 m respectively. The algorithm slightly overestimated the ground level for both trees, but the LIDAR was still surprisingly accurate considering the dense vegetation and irregular terrain of Redwood National Park. I could hardly believe Chris and I were lucky enough to find the 2 tallest trees in all of Redwood National Park. At that time, much of the area was unexplored. All those unknown gullies, high perched benches and north facing slopes along Redwood Creek could potentially have had something taller than Hyperion, but they did not according to the LIDAR "hit list". There were many tall unknown trees however, with some on the "hit list" coming back at well over 113m. Additionally, not a single tall redwood previously discovered by ground based surveyors was missed by the LIDAR (except a few that barely made 106m with whispy dead tops). Having investigated many of "hit list" trees myself, I believe that there are approximately 220 coast redwoods over 350 ft (106.7m). This would include about 140 found previously by ground based surveyors and another 80 found first by LIDAR. The vast majority of trees on the hit list grow in areas between 100m - 200m above sea level. A handfiul of trees are located between 200m and 300m elevation. A single 110m return comes from a tree growing high up on north facing bench at about 350m atlitude. While the precise height of this tree has not been verified by ground based surveyors, the tree is most likely the only example of a 350 ft + coast redwood with base & top both growing at over 1000 ft elevation...well above the fog belt. Perhaps this tree is a world record douglas fir ? This would be wishful thinking for sure.
The tallest LIDAR "hit list" tree verified by ground based surveyors to date is one called Orion. It was recently climbed by Steve Sillett and found to be 369.5'(112.63) tall. Below is a short list of tall LIDAR "hit list" trees that have been located and measured by ground based surveyors. Most of the LIDAR generated heights are accurate to within 1m, and are usually conservative due to the LIDAR hitting ferns and bushes etc... instead of acutal ground level. Some of the "hit list" trees were found to be leaning over ravines, with the LIDAR algorithm overestimating the height due to ground level being a point on a hill below the tree's actual base.
Below is a list of some tall redwoods found using LIDAR
Redwood - Redwood National Park.
Humboldt - Humboldt Redwoods State Park.
Prairie - Prairie Creek Redwoods State Park.
Grizzly - Grizzly Creek Redwoods StatePark.
Jedediah - Jedediah Smith State Park.
Montgomery - Montgomery Woods State Reserve.
Hendy - Hendy Woods State Park.
(~) - Handheld Laser - Preliminary Southern Hemisphere It should be noted that Centurion grows in a rather unexpected place for tall trees. The area is a steep, exposed hillside of mostly 2nd growth and dead standing timber. It is unlikely any tall tree hunter would
have found Centurion, were it not for LIDAR.
Redwood - Redwood National Park. Humboldt - Humboldt Redwoods State Park. Prairie - Prairie Creek Redwoods State Park. Grizzly - Grizzly Creek Redwoods StatePark. Jedediah - Jedediah Smith State Park. Montgomery - Montgomery Woods State Reserve. Hendy - Hendy Woods State Park. (~) - Handheld Laser - Preliminary
Southern HemisphereUsing LIDAR, Forestry Tasmania recently found the tallest known hardwood on Earth, a eucalyptus regans standing nearly 100m. The tree was climbed and directly measured in 2009 by both Tom Greenwood and Steve Sillett. They both got the same measurement of 99.6m tall above average ground level. This discovery is every bit as significant as the discovery of Hyperion in that a new height record was shattered by about 2.6m or 8', essentialy shattering the previous record. Forestry Tasmania's 101m estimate may have been based on the low side of ground level. Interestingly, this tree is not very well protected and grows on a steep hillside near Arve Rd, Tasmania. This area was nearly destroyed by fire in 1961. Centurion, unlike the others, re-sprouted. The orignal height of the tree was at least 103m based on the size of the broken top. This new champion beats out the previous tallest known eucalytpus, 97m dead top Icarus Dream in Andromeda Reserve. The 3rd tallest known is Mount Tree, also in Andromeda Reserve, at 96.6m. This makes eucalyptus, a hardwood, the 2nd tallest known species of tree on Earth. It surpasses even the mighty douglas fir, a softwood, with the tallest known specimen today being the 99.4m Brummett Fir.
It should be noted that Centurion grows in a rather unexpected place for tall trees. The area is a steep, exposed hillside of mostly 2nd growth and dead standing timber. It is unlikely any tall tree hunter would have found Centurion, were it not for LIDAR.
LIDAR profile for a redwood forest. The tallest crown is in the center of the image.
LIDAR coverage map for Redwood National Park. (Click Image To See Entire Map Set)
Left: LIDAR grid search using a small aircraft. Illustration from Wyoming Dept. of Interior Right: Centurion, tallest hardwood on Earth, found with LIDAR technology
LIDAR profile (Forestry Tasmania) for Centurion showing multiple leaders above 96m. (Click image for a larger view)