USA — According to plant pathologist and forest ecologist Lee Klinger, two ancient remedies for Sudden Oak Death and other symptoms of forest decline exist and are readily available.
One of the remedies is controlled fire, a practice used by Native Americans for thousands of years.
The other involves treating forest soils with a pulverized soil nutrient called Azomite, which can be used in conjunction with applications of lime wash on individual affected trees.
Azomite is a trace mineral hydrogen bomb, a white powder mined, manufactured and shipped out of Utah. According to a scientific paper written about Klingers work, it contains 19 minerals and some 60elements, almost two thirds of the naturally occurring elements on the periodic table.
Daniel Brooke, who sells Azomite and other tree care products from his business in San Rafael, said that Azomite is manufactured according to a recipe designed by Klinger.
Klinger said that he sprinkles Azomite on his breakfast cereal in the morning.
Klinger and Brooke said that forest soils can be treated with Azomite for between $1,000 and $1,500 an acre. This sum will buy the customer one ton of Azomite (which runs about $800 a ton, delivered) and will also provide money to pay for the labor in applying it. Brooke said that smaller amounts of Azomite can be purchased for $25 per bag.
During his presentation, which took place at the home of Anne Crowder and Doug Prado in the hills southwest of Willits, Klinger said that Sudden Oak Death, and most other diseases that affect trees and forests, are caused by acidification of the soil.
The problem of forest decline is global, Klinger said. In every location, it is linked to acidification.
The process of forest decline is a natural process, which results from a more acidic environment in the soil, which in turn leads to a population transition from trees to lower organisms, such as mosses and lichens. The end phase of this cycle is, essentially, peat, Klinger said.
He pointed out that after a forest has devolved into a peat bog, a period of rejuvenation occurs, in which the soil de-acidifies, allowing another cycle of forest life to begin.
He noted that a culprit in this cycle are bryophytic plants, or bryophytes: non-vascular plants such as mosses and liverworts.
Where you have mosses you have not a lot of live roots and a lot of dead roots, Klinger said. Where you dont have a lot of mosses, in a forest, you tend to have a lot of live roots and not a lot of dead roots. There is a negative correlation between mosses and vascular plants.
Klinger stated that ten thousand year old pollen samples preserved in oceanic sediment off the coast of California indicate that in oak woodlands in North America, this natural cycle of forest life apparently was arrested in the early oak phase and held there in a kind of temporal limbo for thousands of years.
Klinger said that this was accomplished by human intervention. Native Americans, he said, used regular applications of controlled fire to preserve the oak woodlands in health and to keep soil acidification from setting in. He said that they did this in order to maintain a stable supply of acorns, which was a staple of their diet.
But he added that in situations where forests have already declined due to acidification, fire alone may not be enough to return the forest to health. Fire will help immenselydont get me wrong, he said. But it may not be enough without more mineralization.
Later in his presentation, Klinger took the audience outside the Prado and Crowder home, to a tan oak tree that, while still vigorous and green, had a lot of splitting bark around its trunk. He applied a coating of lime wash to the tree and spread one 44 pound bag of Azomite around its base. He said later that had the tree been really sick he would have used two bags.
When asked why the oaks were getting Sudden Oak Death, Klinger pointed out that in a sense they were an indicator species for the forests as a whole.
The oaks are showing signs of decline, Sudden Oak Death, and other diseases, first, because they are more sensitive to acidification than are redwoods and firs, Klinger said. They are in that senses an indicator species. Their decline now presages conditions in the forest that will be more general in the future.
Although prescribed burning is the second treatment method recommended by Klinger to prevent soil acidification, at the state level, the trend at CDF is to move away from fire as a means of vegetation management. Jeff Stevens, a manager with the Vegetation Management Program at the Department of Forestry in Sacramento, said that acres treated under the controlled burn method dipped from 23,279 acres in 2000-2001 to just 4,322 acres this year, statewide.
It is becoming increasingly difficult to burn, he said. We have to work with air quality districts and they have to meet their mandates. In most cases air quality is trying hard to work with us, but on some occasions they simply say air quality is too poor and you cant burn, and when they do that, we simply have to respect their authority.
Stevens said that in most cases prescribed burning is used to reduce wildfire hazard in what are called WUI areaswildland/urban interface areas. he said that because of public concern and air quality mandates, most CDF vegetation managers are moving away from broad landscape treatments, such as fire, and moving toward mechanical treatment.
Some communities are more tolerant of prescribed burning, and some arent, he said.
According to Tony Linegar of the countys Department of Agriculture, Sudden Oak Death has infected four locations in Mendocino County, all along the Highway 128 corridor between Yorkville and Philo. He said that he doesnt know how many acres of forest are involved, but estimates that the total area involved is probably less than one hundred acres. He said that there have been no new infestations in the last three years.
We are now thinking that Sudden Oak Death is tied to very moist conditions, and that it takes about two years for symptoms to show up, Linegar said. After the extremely wet and cool spring we had this past spring, a lot of people are thinking that a fresh outbreak of the disease may not be far off. I have read reports of what people think is a new outbreak in Marin County that is already happening.