New! Big Basin Park Nature Trail Guide Now Available: Impacts of Climate Change Fires on an Old-Growth Coast Redwood Forest

NEW! Printable Interpretive Brochure for the Redwood Trail in Big Basin Redwoods State Park. Print it out and bring it with you to the Park.

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• Not a repeat or re-hash of what you’ve heard in the media or elsewhere

• Written by scientists and environmental specialists and based on observations of recovery in the park and the latest scientific findings

• Makes known ecosystem impacts of the 2020 fire that are not fully understood by all

Click here for the link to the Redwood Trail interpretive guide.

Warning — There is no internet connectivity in Big Basin State Park. Print out this trail guide at home, take it with you to the park, and walk the Redwood Trail with it in hand to learn a lot.

And, in case you missed them… Our 2023 and 2022 Scientific Research Virtual Symposia on Post-fire Recovery in Big Basin State Park Can be Accessed HERE

Stream Impacts of the 2020 CZU Fire

Recovery of Gazos and Waddell Creeks is Slow and Variable

Fisheries Biologist Jerry Smith provides the the full story from 2021 to today. The lower main stem, but not the west fork, of Waddell Creek showed some improvement of stream channel conditions in 2024 with improved pool depth. Also a positive event was the recovery of ground cover vegetation on many streamside areas and some slopes. However, the west slope of the West Fork is still bare of ground cover and erosion will likely continue there for years. Also discouraging is that the deep and complex woody pools that are critical habitat areas for California red-legged frogs, western pond turtles, coho and yearling steelhead are presently extremely scarce. As in 2023, steelhead were very scarce, and no coho were captured. For the full story illustrated with maps and 81 color photos, click here.

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In Gazos Creek, habitat quality showed modest improvement in 2024 from that of previous post-fire years. In those years debris flows and bank erosion had filled many pools with sediment. Large amounts of wood (both conifers and alders) were added to the channel in 2021-22 and 2022-23. This is usually a very good thing as in-channel wood is an important component of stream habitat for fish, frogs, and salamanders. However much of the wood added to the channel and flood plains has not yet added to in-channel habitat formation, with wood accumulated in several large log jams that potentially affect fish passage. In 2023 the mean abundance of juvenile steelhead was extremely low compared to most pre-fire years and no cojo salmon were present. Despite the apparent modest habitat improvement in 2024, steelhead abundance was almost tripled compared to 2023. For a detailed account of stream changes since the fire including maps and 87 color photos, click here.

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August 2024 — Two Myths About Coast Redwood Bark

Introducing a new occasional series to address both popular misconceptions about redwood ecology and under-reported but significant properties of coast redwoods.

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There are two prominent myths about the nature of coast redwood bark. The first is that it is the tannic acid in the bark that makes it fire resistant. Presentations on many respected Internet sites will tell you so. But is it true? Redwood expert, Dr. Rudolf Becking, in the Introduction to his book, Pocket Flora of the Redwood Forest, discusses tannins and says their real role is to protect the tree from attack by insects or fungus. He later talks about fire resistance, and the role of bark, but makes no mention of tannins. Yet one need not consult an expert to answer this question. It is well known that the bark of Tanoak trees has a high concentration of tannin. Yet all one needs to do is to put a tanoak log in the fireplace and watch it burn. It burns quite readily — bark and all. However this observation might be misleading. See the Update below.

The second myth is that redwood bark does not burn. In the book, Fire in California's Ecosystems by Neil Sugihara et al., he says, "Redwood bark serves as either a resister or enabler of fire damage to the cambium layer depending on its thickness and the water content of it loosely packed, sponge-like fibers."

Bark thickness increases with age, so young redwoods have no bark protection and burn easily. Almost all redwood mortality in the 2020 Big Basin fire was in small diameter trees with thin bark Water content of bark varies with the weather. When the bark is dry, such as after a drought, bark burns well, since the water it collects comes directly from rain impacting the tree. Consequently, climate change, by promoting more intense or prolonged droughts, will make redwoods more flammable. On a positive note, many references also mention that the heartwood of redwoods is less flammable than that of many other forest trees since it lacks the flammable oils and resins that they contain. This is known to be true but it doesn’t provide protection all the time.

Update November 18, 2024 — Tannins Deserve More Credit

Recently coming to our attention was an article in a journal on the physical and chemical properties of construction materials. It reported on the test result of a lab test on the fire-resistant properties of giant sequoia wood. The giant sequoia is a tree in the same genus as coast redwood and with bark that is similar. In the article presented, test results showing that high levels of tannin in the bark did confer a significant degree of fire resistance to the tree (1). So how can this be true if other tree species containing high tannin levels do not show resistance to fire?

The answer is that the term “tannin” does not refer to one specific chemical compound but rather to a group of related compounds — not all of which have fire-retardant properties.

So, to correct the above article we must say that the type of tannins found in coast redwood do provide some fire resistance to the tree — so it is not a myth. However, it is also true that not all trees with high tannin levels are fire resistant.

Inside the trunk of coast redwoods, the greatest concentration of tannins is likely located in the sapwood and the newer heartwood. One theoretical role of tannins would be to slow the progression of fire once the fire gets inside the tree, such as through a basal cavity, and protect the outer perimeter from burning. Many old-growth redwoods have these cavities where the fire burned for a while inside then stopped. If the fire was especially severe, the fire might continue to burn away the inside of the tree, leading to a hollow tree. The sequence of three photos below show one possible scenario, not yet fully proven, of how hollow trees could be formed due to the fire-resistant effects of tannin.

(1) Tributsch, H. and S. Fiechter. 2008. The Material Strategy of Fire-resistant Tree Barks. WIT Transactions of the Built Environment, vol. 97, pages 43-52.

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April 2024 — New Information about the 2020 Big Basin Fire

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Bioregional Council board member and forest biologist Steve Singer prepared a new presentation that reveals some of the effects of the fire on the park ecosystem that have not been widely reported in the media. Called “The 2020 Big Basin Fire – The Untold Story” it discusses the underlying cause of the fire and actions that we can take to reduce the likelihood of future fires of this extreme severity. It can be seen here.

About the Bioregional Council

The Santa Cruz Mountains Bioregional Council is a public benefit non-profit corporation administered by biologists and natural resource professionals on a voluntary basis. We are the only organization in the Santa Cruz Mountains whose sole purpose is to protect native biodiversity throughout the entire Bioregion and to promote the science-based, sustainable use of our natural resources.

Most recently we have been focusing our attention on the 2020 CZU Lightning Complex Fire and human-induced climate change. That fire burned 97% of Big Basin State Park and was a fire of unprecedented severity. We present post-fire park research findings below. Elsewhere on this website are recommendations for management of Big Basin after the fire, progress reports on forest recovery, and many photos showing fire damage done to the park.

The 2020 fire was the first climate-change megafire to burn an old-growth coast redwood forest, but we fear it might not be the last. Some simple but important steps you can take to fight climate change are provided further down this home page.

We join with other local scientists in sounding the alarm about the looming world-wide catastrophe if humankind doesn’t take stronger steps to slow and then reverse the levels of greenhouse gases in our atmosphere. Dr. Gary Griggs, Distinguished Professor of Earth Sciences at the University of California – Santa Cruz, and an expert on climate change, presents some alarming facts about the worldwide impacts of global warming and urges us all to take prompt action. Read about it here.

Post-fire Research Findings in Big Basin State Park

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Two Symposia are now Available To View on YouTube:

2022 — 1st Symposium on Post-fire Research https://www.youtube.com/watch?v=Pe2c8TDSgK0

2023— 2nd Symposium on Post-fire Research https://www.youtube.com/watch?v=DtdmH3KCU8s

2022 Program Agenda:

(1:50) Introduction – Jen Michelsen, President, SCMBC

(5:10) Prescribed Burning Effects on Fire Severity – Sky Biblin, SJSU

(23:17) Post-fire Response of Redwood Flora – Mojgan Mahdizadeh, SJSU

(36:58) Fire & Fungi in the Santa Cruz Mountains – Christian Schwarz

(56:53) Fire & Soil Microbial Communities – Caroline Daws, Stanford Univ.

(1:14:56) Fire Impacts on Breeding Hermit Thrush – Allison Nelson, Gold Country Avian Studies

(1:36:02) Mammal Recovery After the Fire – Kristy Doerr, SJSU

(1:46:22) Fire Impacts to Coastal Gazos and Waddell Creeks – Jerry Smith, SJSU

A complete program agenda with full titles and speaker affiliations can be found here.

2023 Program Agenda:

(3:00) Introduction – Jen Michelsen, President, SCMBC

(6:30) Status of Fish, Frogs, & Habitat on Coastal Waddell Creek – Jerry Smith, SJSU

(35:43) Old Carbon Stores Fuel Redwood Sprouts – Drew Peltier, Univ. Nev.- LV

(57:27) Post-fire Ceanothus Invasion of Redwoods & Threats to Knobcone Pines – Jon Keeley, USGS, UCLA

(1:18:42) Fire: Initial Impacts on Breeding Birds – Alex Rinkert, consulting biologist

(1:37:21) The Future Park – Reimagining Big Basin – Will Fourt, Calif. State Parks

A complete program agenda with full titles and speaker affiliations can be found here.

Five Things That You Didn’t Know About the 2020 Big Basin Fire… And Need to Know

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The mature and old-growth redwood trees have mostly survived the fire and that is a very good thing. However, other plants and animals are not doing so well.

1. It was the hottest and most damaging fire to occur in Big Basin in all of recorded history. It was the first mega-fire to hit an old-growth coast redwood forest. By mega-fire, we mean a fire of such exceptional intensity that it would not likely have occurred if the variables that determine fire severity had not been altered by climate change. It is unlikely that the park will look the same in our lifetime.

2. Of the more than 3000 acres of old-growth redwoods in the park, only 9 small areas, totaling less than 100 acres, escaped the fire (1). Many hundreds of animals were killed by the fire. The lack of fire refuge areas means that re-population of the park by most smaller terrestrial wildlife species will be a very slow process.

3. An estimated 83% of the potentially suitable marbled murrelet nest trees in the park were destroyed by the fire, placing the future of this species in Big Basin in doubt (2). Eighty-five percent of Douglas-firs greater than 4 cm in diameter were killed by the fire (3). Although almost all old-growth redwoods survived by sprouting new branches, if only a few, the fire destroyed almost all the large branches in the canopy which provided nest sites for murrelets. Since the fire murrelet nesting behavior has only been observed in the few small green spots that did not burn.

4.  There is now a dense growth of grasses, weeds, and shrubs on the forest floor that is not a normal part of the redwood forest plant community.  The lack of tree canopy cover has allowed sunlight to penetrate to the forest floor changing the microclimate.  What was once a shady, cool, and damp environment is now sunny, warm, and dry (4).

5.  Douglas-firs are now very scarce in the park and will likely remain so.  The dense plant cover on the forest floor has made it impossible for seedlings of redwood and Douglas-fir to establish themselves and grow in all but the few areas of the park where the tree canopy cover still exists and there is open ground below (5). 

When native and non-native invasive species take over the forest floor they take away the space needed by native redwood forest species like these:

Considering the severe impacts listed above, it should be clear that we, as a society, and including our elected representatives, our government agencies, our land conservancies, and our private business enterprises, need to do all we can to reduce carbon emissions and thereby prevent future mega-fires from occurring. The cost of doing nothing is too high. A simple list of eight things you can do to help save the planet is provided below. 

Sources: (1) Potter, C. 2023. Impacts of the CZU Lightning Complex Fire of August 2020 on the Forests of Big Basin Redwoods State Park, California Fish and Wildlife Scientific Journal 109:c1 (see October 2021 satellite imagery), (2) Singer, S.W. and A. Rinkert, in prep., Impacts of the CZU Lightning Complex Fire on Marbled Suitable Nest Trees in Big Basin State Park. Unpublished report for the Santa Cruz District, California State Parks. (3) Mahdizadeh, M. and W. Russell 2021. Initial Floristic Response to High Severity Wildfire in an Old-Growth Coast Redwood (Sequoia sempervirens) Forest, Forests 12, 1135, https://doi.org/10.3390/f10281135; (4) S.W. Singer, pers. comm.; and (5) M. Mahdizadeh, pers. comm. 

NEW—2023 CZU Post-fire Survey of Waddell Creek by Jerry Smith

Jerry Smith re-surveyed fish and stream conditions in Waddell Creek in August of 2023 and found significant deterioration since 2022. Heavy winter rains falling on fire-denuded slopes caused significant sediment input to the channel that severely damaged fish habitat. Instead of showing recovery from the fire, channel conditions have actually gotten worse in this area. For more information, read his cumulative 2020 to 2023 report, well-illustrated with photos, that can be found at this link. The photos below provide a preview of what can be found in his new report.

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Summary of CZU Fire Impacts Through 2022 on Waddell, Gazos, and Scott Creeks with Many Photos

Since 1992, Jerry Smith has annually sampled juvenile coho salmon and steelhead at the same index sites, including the same individual habitats when possible, in Waddell, Gazos, and Scott creeks. The 2020 CZU Fire blocked fish sampling that fall, but allowed him to assess the impacts of the fire on upslope, streamside, and channel conditions on Gazos and Waddell creeks in 2021 and 2022, and Scott Creek in 2022, and to also resume fish sampling on Gazos Creek in 2021 and on Waddell and Scott creeks in 2022.

On Waddell the fire impacts increased upstream of mile 2.6, and the streamside/riparian fire damage to Gazos and Scott creeks was less severe than on Waddell Creek. Erosion and sedimentation in the first winter after the fire were minimized by the mild winter, but the drought conditions delayed the recovery of shrub and herb ground cover until 2022. In October and December 2021 heavy rain on the unprotected slopes resulted in massive erosion, and heavy flood flows moved sediment throughout the watershed, filling pools even in downstream sites with little direct fire damage. October and December floods also moved channel wood and fire-toppled trees, producing potential fish passage log jams in narrow, entrenched channels on Waddell Creek and especially on Gazos Creek.

The 2022 slide show (with text), ‘Impact of the CZU Fire on Stream Habitat in the Coastal Portions of Gazos and Waddell Creeks’ can be found here. This presentation was part of our November symposium but had to be cut short, so the full information is presented here.

The combined October 2022 and 2021 Waddell Creek report can be found here.

The combined 2022 and 2021 Gazos Creek reports can be found here.

The 2022 channel assessment of Scott Creek can be found here.

The comprehensive report on juvenile coho salmon and steelhead in these 3 creeks from 2007 to 2022 can be found here. The findings have major implications for the long-term survival of coho and steelhead in the Bioregion.

Recommendations for Re-Imagining Big Basin

TO: Mr. Barney Matsumota, Chair, Big Basin Reimagining Planning Team

SUBJECT: Santa Cruz Mountains Bioregional Council (SCMBC) Comments on the Reimagining Big Basin Plan

The Santa Cruz Mountains Bioregional Council is pleased to endorse the recommendations on restoring, managing, and operating Big Basin State Park after the fire that have been prepared by the California State Park Rangers Association (CSPRA). Their April 17, 2022 letter containing the recommendations, all of which we support, is attached.

Below we have condensed and paraphrased the recommendations to make it easy for you to review them. See their letter for the full recommendations.

Recommendations for the Reimagining Big Basin Planning Effort

1. The Big Basin Redwoods General Plan should be used as a guide for management, including the provision to keep major use areas outside of the prime redwood areas.

2. New interpretive messaging is needed to indicate causes of mega-fires, how redwoods react to them, and how park managers can best respond.

3. The fire and subsequent hazardous tree removal work has created a much more open forest canopy which has allowed sunlight to reach the forest floor. This, in turn, has created a dense growth of grasses, herbs, and shrubs that pose a new weed spread and fire hazard problem that needs to be addressed.

4. Revegetation will be needed in some areas of the park. Those areas should be mapped and a native plant nursery created to provide suitable plant materials for use.

5. Remaining areas of suitable marbled murrelet nesting habitat should be mapped out and protected from disturbance.

6. The historic park headquarters building should be rebuilt in its original style but in a different location. It should be used for interpretation purposes and not as an operational headquarters.

7. Archeological surveys should be conducted throughout the park to expand our knowledge of indigenous people’s use of what has become the park.

8. The park infrastructure should be rebuilt and operated so as to minimize the carbon footprint and provide an example of how we as a society can reduce global warming.

9. Messaging should not understate the threat posed by megafires. The character and impacts of the 2020 fire went beyond “nature’s way of renewing the forest.” Understanding the limitations of even a robust prescribed burning program, under the altered conditions of global climate change, should be part of the interpretive message to visitors.

The Santa Cruz Mountains Bioregional Council (www.scmbc.org) is a public benefit non-profit corporation comprised of biologists and natural resource professionals. We are the only organization in the Santa Cruz Mountains Bioregion whose sole purpose is to support the science-based use and conservation of our natural resources.

Thank you for your consideration of our recommendations.

Jen Michelsen, President SCMBC

Big Basin Fire Recovery: Spring 2022

Big Basin’s second Spring after the fire reveals major changes to the forest landscape — Observations and photos by Steve Singer, Biologist, in this update.

SUCCESSFUL MURRELET NEST IN BIG BASIN — VIDEO of bird fledging from nest and article by alex rinkert — see below

On July 9 at 8:55pm a nestling marbled murrelet hopped off a nest in Big Basin State Park and began its very first flight, which would take it seven miles to the Pacific Ocean.

The nest tree, an old-growth Douglas-fir, was in a tiny 9-acre stand that did not burn. It’s estimated that at least 50% of the suitable nest trees in the remaining 4,400 acres of old-growth forest habitat which did burn, were lost. What’s more, the old-growth Douglas — firs that murrelets prefer over redwoods for nesting — were preferentially killed by the fire.

Watch the murrelet fledging video produced by Frans Lanting for California State Parks (link here). Avian biologist Alex Rinkert discovered this nest and his account of the find and subsequent fledging of the young can be found here.

Read more about the status of Marbled Murrelets in the Santa Cruz Mountains (link here).

EARLIER REPORTS ON FIRE RECOVERY AT BIG BASIN

Follow this link to see the July 2021 report and park photos.

Follow this link to see the Spring 2021 park photos.

Follow this link to see the Fall 2020 park photos and to read “The Emptiness of a Devastated Landscape,” an essay by Steve Singer who was stunned by his first visit to Big Basin, two months after the fire.

POWER POINT SHOW ON COAST REDWOODS AND FIRE

Associate Director Zane Moore, a UC Davis graduate student working on redwood genomics, prepared an excellent presentation on Coast Redwoods and Fire. He also focused on the fire’s impact on Big Basin State Park. It was prepared for the Santa Cruz City Museum of Natural History and is a little over one hour in length. Watch it here.

REDWOOD FOREST IMPACTS OF THE CZU LIGHTNING FIRE COMPLEX: Climate Change Hits Home with Catastrophic Results

The CZU Lightning Complex fire was an unprecedented fire event throughout all of recorded history for the Santa Cruz Mountains. Here we will report what happened, why it happened, and what it means. Although the fire burned many vegetation types, we will focus here on the redwood forest which comprised the bulk of the burn area. Read more here…

In March, the California Fish and Wildlife Commission listed the Foothill Yellow-legged Frog (Rana boylii) as endangered in the Central Coast Region, which includes the Santa Cruz Mountains Bioregion. This is the rarest frog that occurs in the Bioregion. Read more about the Foothill Yellow-legged Frog here.

The Western Pond Turtle (Emys marmorata) is currently under review for possible listing under the federal Endangered Species Act. For 25+ years Dr. Jerry Smith has studied a population at the mouth of Waddell Creek and has documented a dramatic decline in turtle numbers in the last 15 years, apparently due to a loss of nesting habitat; only older turtles are now present. This habitat is limited because they don’t nest on the damp or vegetated edge of a pond or stream. Instead the adults will travel ¼ mile or more to find an open sparsely vegetated area or fallow or unirrigated agricultural field in which to lay their eggs, and the soil must remain undisturbed until the following spring when the young emerge from the ground. Agricultural practices, such as plowing and planting a winter cover crop, will kill the young turtles while they are still in the ground. Few land owners, land managers, or county environmental officials are aware of these nesting requirements. Read more about the Western Pond Turtle here.

The Bioregional Council is dedicated to the preservation and enhancement of regional biodiversity over time through education, the dissemination of accurate scientific information and assistance in the planning, coordination and implementation of conservation efforts.