By Dale Williams
Torrey Pines State Natural Reserve just north of San Diego is a majestic wilderness with views to the ocean, scenic sandstone cliffs and is home to one of the world’s rarest pine trees, the Torrey Pine. Anyone who has visited Torrey Pines Reserve in the past two years will have seen the large numbers of trees that died. You see them along both sides of the main road to the visitor center, along Guy Fleming Trail, and several other locations. As I watched them die, I wondered why nobody was testing the soil, analyzing tree samples, or doing anything that might help determine the cause. I wanted to do something but didn’t know what.
The media reported that the die-off was due to drought and beetles, but Torrey Pine trees were dying on the irrigated Torrey Pines Golf Course too, which is right next to the Reserve. Drought couldn’t be the cause of their deaths.
I started doing my own investigation and found the aluminum level in tree bark was high. The analysis showed 418 parts per million (ppm) of aluminum. My understanding is that farmers start to worry about their crops when their aluminum count reaches 200 ppm. I also found that rainwater contained a high amount of aluminum. The reading was 1.03 ppm which is five times higher than California’s drinking water limit of 0.2 ppm. And I found that fog was acidic, around Ph 4. Ph is a measurement of how acidic or alkaline a substance is. The Environmental Protection Agency says this combination of aluminum and acidity can mobilize the aluminum into a form that is toxic to trees.
We also know that the aluminum in the tree is not coming from the soil because a lab test called “Calcium/Aluminum Molar Ratio Stress Test” was done and determined that no aluminum stress was coming from the soil. So we have this situation where there’s a high level of aluminum in the tree, we know it’s toxic and we know it’s not coming from the soil.
And on top of that, we know Torrey Pine Trees are adapted to absorb moisture from fog through their needles as a survival mechanism. Most of the other plants in the Reserve have adapted other ways to survive in times of drought such as small, thick and/or hairy leaves that prevent moisture loss and they are doing fine. To me, the cause of Torrey Pine Tree death is obvious. The Torrey Pine Tree absorbs the poison created by the acid fog and dies, while the rest of the Reserve doesn’t (at least the majority of it) and lives.
Although this theory is not 100% proven, it’s getting close. I think we still need to analyze and compare needles versus roots. If the aluminum reading in the needles is higher than the roots, the poison is coming from the fog. If roots have a higher aluminum reading, it’s coming from the soil. (Although a test mentioned above has already shown no aluminum stress from the soil.) In addition, I think we should analyze the condensed fog that drips off the needles because so far, I have only been talking about aluminum but there are probably other bad things in there that we should know about.
Neither California State Parks nor the Torrey Pines Docent Society wants to be involved in testing these trees. I am looking for a few local people to help me take this issue to community leaders that might be supportive. If anyone is interested, please email me.
I have started a petition asking California State Parks to test the trees. It started amazingly well with over 200 supporters in the first week. Please sign it here PETITION. I am posting updates of this effort on the petition site if anyone wishes to follow. You don’t need to sign the petition to read the updates.
A detailed analysis is included in the video below. It includes all the lab tests, details on how the combination of aluminum and acidity is toxic, links to studies that determined coastal pine trees absorb moisture through their needles, and an evaluation of how high the 418 ppm in tree bark actually is. Please sign the petition. Our rare and endangered Torrey Pine Trees are much too important than to let California State Parks avoid this issue.
Dale Williams is a retired landscape architect and was a volunteer at Torrey Pines Reserve for 2 years.