Tallest, Largest Redwoods: Measuring

This page is an off-shoot of Coast Redwoods which has photos and a book list, one of which is Forest Giants of the Pacific Coast: suggested redwood books

Circle Solver - Standard Units Area Diameter Circumference

From this page here, you can download an October 2008 tallest redwoods update from Michael Taylor. This page has old and new redwoods data for comparison. See how some redwoods changed over time. The information toward the end is oldest.

The info represents years invested by explorers like Atkins and Taylor. The photo below is Michael Taylor doing a preliminary measurement near Lost Man Creek, November of 2008. Michael has a knack for navigating through forest, like a "Gazel of the Redwoods". Atkins and Sillett are in a photo near page end, preparing for a laser measurement. Few people know the redwood forest like these people. Here is a feet & meter converter below. And a circle dimension calculator is to the right:

Input Number Here

2008 Tallest Redwoods List

Tallest Trees List / October 2008 Update / MS Word .doc < Download Document
2008 download is a rather extensive list

2009

Next, a few names of tallest redwoods 2009 in meters. Source was Gymnosperm Database:

Name, park, height in meters
Hyperion - Redwood 115.61
Helios - Redwood 114.58
Icarus - Redwood 113.14
Stratosphere Giant - Humboldt 113.05
National Geographic - Redwood 112.71
Orion - Redwood 112.63
Federation Giant Humboldt 112.62
Paradox Tree - - Humboldt 112.51
Mendocino Tree - Montgomery 112.32
Mellenium - Humboldt 111.92
Apex - Humboldt 111.83
Pipe Dream - Humboldt 111.71
Harry Cole Tree - Humboldt 111.65
Rockefeller - Humbolt 111.59
Minaret - Humboldt 111.56
Alice Rhodes - Humboldt 111.53
Mother & Daughter - Humboldt 111.50
Lone Fern - Humboldt 111.47

Pre-dating 2000

Below, are redwood sizes pre-dating 2000: another snap shot in time. Abbreviations are parks: PCRST = Prairie Creek Redwoods State Park, JSRSP = Jedediah Smith Redwoods State Park, RNP = Redwood National Park, H = Humboldt or M = Montgomery, etc.

The table will provide the height, the diameter at breast height / DBH, and the volume of the trunk and main stems in cubic feet. These trees have been discovered and measured by several people. Chris Atkins and Michael Taylor found the bulk of the tallest redwoods. Data below was the result of work by Chris Atkins, Michael Taylor, Robert Van Pelt, Steve Sillett and Ron Hildebrant.

Measuring redwood trunks

A few common measurements for redwoods are diameter, height and trunk volume. This section is mainly about measuring diameter of huge redwood trees. Basically, redwood diameter is measured at DBH or diameter breast high: 4 feet & 6 inches above soil grade.

Image to the right: Chris Atkins and Professor Steve Sillett setting a tripod to measure redwood height with a laser rangefinder in Redwood National Park. Equipment like this allows researchers to measure several redwoods per day, or more. A DBH measurement is included also.

The way redwoods are measured for research can differ from how trees are measured for nomination as national champions.

If a redwood is on a slope, find the elevation where the trunk enters the soil on the downhill side of the redwood. Not where it enters the composting needles or leaves, but the soil. Next find the elevation where the trunk enters the soil on the uphill side. Unless the area is level grade. Then estimate the mid-point of the trunk between those, go up the trunk 4 feet and 6" and measure diameter there, extending a tape horizontally around the bole. Include hollows or indented areas of the trunk. In other words, don't press the tape inward against the bark at every recessed spot.

In part, diameter is a matter of opinon because a judgement has to be made about where soil grade is. Twigs and leaves do not count as soil, but humous and finely composted needles can.

Some experts who are adept with instuments can measure irregular trunk bases rather meticulously to determine wood volume and shape, sometimes referred to as the footprint on the forest floor.

To keep things simple, because some trunks are eliptical, measure circumference and do the math. Stick with the average. Example for redwood with 70' circumference: is 70' / π, or 70' divided by 3.14 = 22.29' diameter.

Many giant redwoods have lower trunks like volcanoes. In some cases it appears like soil grade should be near the trunk. But in if all needles and twigs could be removed, it becomes apparent that soil grade is feet farther down. It helps to stand back from the redwoods and take a look from a distance. Stand 20 or 30 feet away and look around for the average soil level.

Diameter measuring can be more complicated, but those basics are adquate for most people. If a redwood or conifer trunk branches into multiple stems below the DBH height, then only the largest stem may be measured: a failure to know true size. That's one rule of one system. If there is a burl, some experts move the tape above it.

Beginners ... use the KISS principle. Estimate 4.5' above the average soil grade, measure circumference, and divide by 3.14. For convenience, use the automatic conversion table on this page to convert diameter, circumference and area. Fill out one field, and the others should be generated for you. Enter numbers whole or as decimals like 5.6 if you wish.