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Sudden Oak Death….Not So Sudden.

By Ralph J. Zingaro-Consulting Arborist

Before we can begin to evaluate a tree decline complex, we must all begin to agree on one fact- that trees worldwide are dying at an unprecedented rate.  1

Fact:  Almost 90% of the native dogwood trees on the East Coast are dead.  The reason is acidic precipitation which causes an accumulation of aluminum in the soils that eventually kill tree roots.  This complex also involves a secondary fungus that is associated with the real cause of tree decline. In addition, sugar maples,red spruce and many other tree species are declining and dying due to decades of air pollution.   2

Fact:  The largest documented case of tree death due to air pollution took place right here in California in San Bernadino California on Ponderosa Pines.3

Fact:  Over the last several decades, atmospheric nitrogen is being deposited at alarming rates due to automobile emissions, industrial air pollution, and agricultural industry.  This excess input of nitrogen is changing the microbial community and activity associated with Quercus agrifolia- Coastal Live Oaks.4

Fact:  It is universally recognized that biotic andabiotic factors concur to predispose oaks and other trees to decline and eventual death.  5

Fact:  All of the qualified forest pathologists  in California have retired and their vacancies have not been filled.   6

For the past 5 years , while public agencies have been lobbying for millions of dollars in funding, Bioscape Inc. has been studying the soils and foliage of declining anddying trees on a 500 acre research site in Marin County.  What our studies  have revealed is not unlike what others have found in other parts of the country and the world where trees are dying.  Soils are becoming more acid, which causes leaching of bases like calcium to be rapidly leached from the soil, which causes toxic aluminum to become available, which kills tree roots and mycorrhizae, which are directly responsible for the absorption of essential water and nutrients like phosphorous,calcium and potassium.  Trees exhibit drought-like symptoms, but drought is not what is affecting trees, it is the toxic aluminum that kills the roots.  Trees become weak and are invaded by secondary fungi and insects.  Our trees are literally being strangled to death by decades of acidic deposition or acid rain.

Common Sense-Not So Common:

Common sense dictates that if trees are dying from a clear nutritional deficiency of phosphorous, calcium and potassium , we need to stabilize these trees with an immediate injection of phosphorous to help trees function again.  What we recommend is an injection of a University of California patented phosphite nutrient directly into the tree.  This injection gets the tree to grow again in the short term.  Secondarily, since the soils are deficient in the various minerals as well, we need to remineralize the soils to help trees to grow and function again in the long term.Phosphite fertilizers also help mycorrhizae to grow again on roots of oaks.  

For more information contact visit www.treatsuddenoakdeath.com . Or call 707-338-1420.

1 The Dying of the Trees by Charles Little

2 US Forest Service Asheville NC  Dr. Bob Anderson

3 The Dying of the Trees by Charles Little

4 Nitrogen Cycling and Microbial Structure Under Oaks: Effects of Nitrogen Deposition and Elevated CO2 ,Cara Hinkson-Cario

5 Status of Oak Decline Studies in Italy and some Views of the European situation, A. Ragazzi & S. Moricca & I Dellavalle

6 Personal Communication from Dr. Wayne Sinclair Prof. Emeritus  Cornell University Dept. of Plant Pathology