Tag Archives: Tall Trees Grove

Groves of Tall Redwoods – Changes over Decades, Centuries, and Millennia

1       Tall Redwood Groves – Recent Changes in Height

Redwood tree height measurement came into its own in the 1990’s.  Skilled researchers and naturalists combined laser rangefinder technology, LiDAR height estimation, hiking and climbing skill, and direct tape drop from the canopy to create a nearly complete inventory of tall redwood trees throughout their range (with the exceptions of Six Rivers National Forest and Headwaters Reserve, which have not been thoroughly assessed). From this it was determined redwoods over 100 meters (328 feet) in height were uncommon, totaling about 2,000 trees.  And redwoods over 350 feet (106.7 meters) in height were very uncommon, totaling about 230 trees.  Each tall tree is remeasured every five years or so, with the tallest trees having more frequent measurements.

 I don’t have direct access to the 15-25 years of longitudinal height data for tall redwoods but through research I was able to find height information for the tallest known trees in the year 2000 as well as their remeasured heights as of 2015.  There were 129 trees over 350 feet on the 2000 list, indicating many more 350-foot redwoods were yet to be identified, particularly in Redwood National Park.  Here are the height changes for these 129 trees in inches growth per year (parks with smaller tree counts are excluded) on the left axis and 2015 height on the right axis (line).

On the chart the trees are grouped by Bull Creek (Humboldt Redwoods along Bull Creek), Eel River (Humboldt Redwoods along Eel River including Rockefeller Loop), Montgomery (Montgomery Woods State Natural Reserve) and Redwood (Redwood National Park).

Height Change (left axis and bars) and 2015 Height (right axis and line)

It is evident in all four areas most trees had height increases over fifteen years.  Nine trees lost height, a few in each area.  Median height growth was about three inches per year.  Over the past few years two of the trees in the data have fallen.

The chart also includes tree height in 2015.  Correlation between 2015 height and height change is 0.53, correlation between 2000 height and height change is 0.02.  So height change was not related to initial starting height.

Here is summary data related to the chart.

Height Changes Summary

This data indicates the canopy of very tall redwood trees increased three feet from 2000 to 2015.   The canopy in 2000 was the result of several thousand years of forest development. Then why did the tallest existing redwood trees increase on average another three feet in height from 2000 to 2015?  Some potential contributing factors:

  • More sun reaching the leaves of edge habitat trees due to cutting of nearby trees from 1860-1979.
  • Fire suppression
  • Increased atmospheric CO2 providing more energy for photosynthesis

2       The Future of These Tall Trees

Based on plot information, 350-foot tall redwoods are between 700 and 2000 years old, with the median age 1180 years.  It is very likely almost all of the current 350-foot tall redwoods will fall over the next 1000 years, being replaced by grow in from trees currently under 350 feet and trees yet to sprout.

Let’s test this against the known 350-foot trees to fall in the last 30 years in Humboldt Redwoods State Park.

Humboldt Redwoods Fallen Trees

It can be expected about ten percent of the tallest redwoods will fall every 100 years, with 3-4 trees falling each decade.

Before falling many trees will lose and regain height over time.  About two thirds of the 350-foot redwoods in study plots have reiterated tops.

3       What is the Maximum Height for Redwoods

The current tallest tree is about 381 feet tall.  There are four trees around 375 feet tall or taller, and all four are gaining height.  Then the data shows the canopy for very tall trees in general is increasing by about one foot every five years.

So will there be 385-foot redwoods in 20 years?  Could be.

Will there be 390-foot redwoods in 50 years, and 400-foot redwoods in 100 years?  Maybe.  The theoretical maximum height based on tree structure and physics has been calculated to be 425 feet.  There is no reliable historic record for a redwood tree over 400 feet in height.  One was measured right at 400 feet about fifty years ago along Wilson Creek by an expert timber cruiser.

Will some second growth Douglas Fir beat all the redwoods and get to 400 feet first?  Maybe, but then again the reliable historic maximum height for Douglas Fir is 393 feet.

Thanks for reading.

Tall Trees Grove in Redwood National Park

1       Formation of Tall Trees Grove

There is not much published research on the age of the northern California redwood forests.  Redwood trees have been on Earth for millions of years in various forms.  The coast redwoods that grow along a narrow belt from Big Sur to extreme southern Oregon are a remnant of the ancient redwood populations.  It is thought they were almost wiped out at the peak of the latest ice age, with only a few groves surviving in canyons around Big Sur.  But then as the glaciers retreated, the jet stream and Pacific inflow moisture shifted northward 400 miles.  The redwoods followed, establishing their present range.

From this we know the Tall Trees Grove cannot be more than 12,000 or so years old.  Whether it is 4,000, 8,000, or 10,000 years old, I don’t know and have never seen anything speculating on the age of the forests in Redwood National Park.   Given redwood trees live to 1,000 to 2,000 years of age it can be estimated there have been at most eight generations of redwoods in this grove.

2       Human History of Tall Trees Grove

Native Americans have lived in the Redwood National Park area for several thousand years.  Again, I have not read anything more precise, so from that will go with 10,000 years.  In the most recent times, just before European settlement, about five hundred Native Americans identified as the Chilula tribe lived on the northeast side of redwood creek near the inflow to the Pacific Ocean.  Some of the open berry fields on the first part of Redwood Creek trail going south were probably maintained by the Chilula through controlled fires.  In the summer the Chilula hiked south along Redwood Creek and then through Tall Trees Grove and up a trail to the Bald Hills.  This indicates the trail from the Tall Trees Grove parking area to the Tall Trees Grove is substantially an improved Chilula foot path.

3       Identification of Tall Tree and Establishment of Redwood National Park

In 1963 Paul Zahl and his family spent the summer around Prairie Creek Redwoods State Park.  Zahl was employed by National Geographic Society and tasked to document the redwood parks and to look for new areas with very tall redwoods.  At some point in 1963, Zahl was sitting on a hill across from the south part of Tall Trees Grove, and noted a very tall tree in the grove.  Surveyors were hired and the tree was measured at 368 feet.  It was on Arcata Redwood Company land.  The president of that company, Howard Libbey, pledged not to cut the grove while plans were being made for the establishment of Redwood National Park.  There was a lot of back and forth as to the location of the park but eventually the Redwood Creek watershed won out and the park was established five years later. 

There is a little bit of intrigue associated with the actual tallest tree in the 1960’s.  Correspondence exits between Paul Zinke (Humboldt Redwoods area researcher) and Rudolf Becking (Redwood National Park area researcher) regarding possibly taller trees at the confluence of Bull Creek and Eel River in Humboldt Redwoods State Park.  But it was decided to keep the issue low key to help get Redwood National Park established.  Google “letter from Paul Zinke to Rudolf Becking” and follow the results to see a copy of this 1966 letter.

4       Tall Trees Grove Logistics

It is well documented on the park web sites a certain procedure needs to be followed to access Tall Trees Grove.  The visitor center just south of Orick or the one in Crescent City provide permits to use the Tall Trees Grove access road along with the combination for the locked gate that sits at the entrance of the access road. The access road is a maintained old logging road and heads south from Bald Hills Road just past the Redwood Creek overlook to the Tall Trees Grove parking lot on the hill above Redwood Creek.  Be sure to shut and lock the gate after pulling through and drive the six or so winding miles on the unpaved road at a moderate pace to keep the dust down and the stones out of your wheels. The trail from the hillside parking area down to Tall Trees Grove is not difficult but it is steep coming back up, about 700 feet elevation gain in a little over a mile.  There are five or so rest benches along the trail.

Some people camp along Redwood Creek a short distance from Tall Trees Grove.  If you are doing this let the ranger know when getting your Tall Trees Grove permit, you will then receive a bear proof cannister for your food.  There are a lot of black bears in the Tall Trees Grove area that eat fish, frogs, crustaceans and the bark of young redwoods.  Then there are also mountain lions which follow the deer down to the creek.

5       Tall Trees Grove Itself

Tall Trees Grove itself it not large. The flat with the tallest trees is about 30 acres then there are another 100 or so acres of mixed old growth forest on the hillside. However there is a high density of very tall redwoods. The grove has four of the fifty tallest trees in the world (National Geographic (Nugget), Paul Zahl, Howard Libbey (Tall Tree), and the Redwood Creek Giant.

The grove also has a nice Big Leaf Maple forest right by the creek.  It is possible these maples are in a part of the grove that is subject to flood inundation.

In the summer when the water is low the gravel bars along Redwood Creek can be accessed to provide views of Tall Trees Grove and the surrounding area.  This is the most special and scenic part of seeing Tall Trees Grove.

On the hike up take time to appreciate the hillside forest, noting the large redwoods all along the trail as well as tall Douglas firs higher up.  There is a nice rhododendron bloom on this trail in June. Thanks for reading.

Rhododendron on hill along Tall Trees Grove trail
Hillside Douglas fir fallen over Tall Trees Grove trail
Redwood NP Tall Trees Grove north side from Redwood creek
National Geographic Redwood, a trail side tree in Tall Trees Grove