Ohia trees are dying rapidly, Why?

[Tink]

I am led to believe the whitish powder was baking soda, as it acts as a desiccant (drying agent) on their skin, so therefore somewhat effective. Don't know the organic breakdown of baking soda other than it acts as an acid neutralizer as well but would think pretty inert in most instances at the dosage applied.

Community begins with Aloha

[MarkP]

"Biological Control
Strawberry Guava
Psidium cattleianum
In 2012 Hawai‘i Department of Agriculture and USDA
Forest Service released the scale insect Tectococcus
ovatus for the control of strawberry guava (Psidium
cattleianum), one of Hawaii’s worst forest weeds, at
demonstration sites on the island of Hawai‘i. The scale is
being monitored by the Forest Service Institute of Pacific
Islands Forestry. Establishment of the scale has occurred
slowly but reproduction has been observed at the field
sites. Outreach activities scheduled for 2013 will precede
additional releases on Hawai‘i and other islands where
this invasive tree continues to invade and degrade native
forests."

That's from the link below. I now own some property on the edge of the Ola'a Forest Preserve, one of the areas where Tectococcus Ovatus was released I believe. I have yet to see any evidence of it though. We are trying to clear that property. You would not believe how utterly corrupted the environment is by strawberry guava in that area. Probably 90 percent of the biomass is guava. There are areas where there are multiple layers of blown down guava laying down like a giant game of pick-up sticks. Such areas are impenetrable to walk through and almost impenetrable to light. Our neighbor who has been there decades says that you used to be able to walk through there easily 25 years ago. It was in fact pastureland then.

In case anybody was wondering, Sydney Singer is not a reliable source of information on anything.

http://www.fs.usda.gov/Internet/FSE_DOCU...415099.pdf

[Opihikaobob]

quote:

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Originally posted by rainyjim

"So it does appear that it is indeed a fungus - even though it only had affected sweet potatoes , so as yet an undermined variation of the original sweet potatoe virus."

Its not a virus its a fungus. These are not interchangeable.

"And then their is the vectoring factor, or ideas on how the disease started ."

The vector is as of yet unknown.

"Honestly I have not read all of the posts on this topic , but it appears that the trees
start dying from the top down - is this correct?"I

The researchers at CTAHR / USDA have aready confirmed this.

"If so then the vectoring leads to the virus being airborn in some fashion - right or wrong?"

Incorrect, there is no reason to think that this fungus is 'airborne'.

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The vector is as yet unknown. - that means as "unknown " so the possibility of an airborne "fungus" is still a possibility.
Dying from top down. Confirmed.

[Midnight Rambler]

quote:

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Originally posted by Opihikaobob

Thank you Justin, "lose the ability to pump water up" meaning the problem starts at say the root level ,but the visible effects of the tree dying, start at the crown? Or is it that the dying of the crown results in the the loss of the ability to pump up water?

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The fungus grows in the vascular tissue of the wood, which is like a tree's arteries. Wood is like a bundle of tubes filled with water and nutrients, with the roots taking in water from the ground and delivering it to the leaves so that they can produce energy. When the fungus grows in there, it blocks the tubes and the flow of water and food, leading to the leaves drying up first, then the rest of the tree quickly dying as it gets strangled. It's just like if someone pinched off the carotid artery in your neck.

[Opihikaobob]

quote:

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Originally posted by Midnight Rambler

quote:

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Originally posted by Opihikaobob

Thank you Justin, "lose the ability to pump water up" meaning the problem starts at say the root level ,but the visible effects of the tree dying, start at the crown? Or is it that the dying of the crown results in the the loss of the ability to pump up water?

---

The fungus grows in the vascular tissue of the wood, which is like a tree's arteries. Wood is like a bundle of tubes filled with water and nutrients, with the roots taking in water from the ground and delivering it to the leaves so that they can produce energy. When the fungus grows in there, it blocks the tubes and the flow of water and food, leading to the leaves drying up first, then the rest of the tree quickly dying as it gets strangled. It's just like if someone pinched off the carotid artery in your neck.

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Thanks for the info ,but still doesn't negate the airborn vector possibility.

[terracore]

I recently attended a presentation by Kent Dumlao of the Hawaii Dept of Agriculture on the subject of Ohia Wilt (Rapid Ohia Death). He said that the fungus responsible, Ceratocystis fimbriata is a common fungus that comes in many variants, and the variant that is attacking and killing the Ohia in Hawaii has never been recorded before, and they do not know why it is only effecting Ohias.

He also said that the only effective measure in place to control it is quarantine. Their researchers are exploring a number of anti-fungal products and at least one of them is potentially promising.

For those of you who haven't been following the quarantine, you cannot ship Ohia products from the BI to any other island and starting in January 2016 you also cannot ship soil or products containing soil from the BI without a permit. The permits seem difficult and costly to obtain.

The fungus is basically spread by everything: Insects, wind, shoes, animals, car tires, etc. It is one of their top priorities because the Ohia forests protect watershed areas and when the Ohias die invasives replace them, erosion patterns are changed, basically the entire ecosystem is at risk. They do not know how this fungus variant got here because it's never been seen before. While they continue to research ways to stop the fungus the next best thing they can do is try and contain it. My favorite quote he said was "the quarantine is ahead of the science"... on other words, there isn't enough science data to say DO NOT EXPORT SOIL but they don't want another repeat of science lagging reality causing yet another ecological disaster. And kudos to them for that.

ETA: italics

Also need to add, he also said that while this disease kills trees quickly, it is not particularly fast in being visible. Parts of the tree die as it is unable to take in water and that the leaves stay intact on the dying portions. Eventually the tree starts to appear unhealthy (at this point the tree is already a goner) and as it dies its potentially infecting surrounding trees. Surrounding trees that may appear healthy may actually be infected and are not only dying, but also contagious themselves.

[Guest]

Thanks for the update terracore. Not sure if a swifter response to the initial diseased areas would have helped? It unfortunately took years to get someone out here to take a real look at the dying Ohia. Previously studied die offs that costed millions back in the 50's and 70's somewhat slowed the county, jmo though.

[kalakoa]

they don't want another repeat of science lagging reality causing yet another ecological disaster

That's why the quarantine doesn't start until 2016?

[terracore]

The Ohia quarantine is already in effect. The quarantine against transporting soil begins in 2016. Sounds reasonable to me. If you REALLY wanted to get the quarantine ahead of the science, everything including humans would be quarantined on the BI and they would just drop care packages from the air.

[geochem]

quote:

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Originally posted by terracore

The Ohia quarantine is already in effect. The quarantine against transporting soil begins in 2016. Sounds reasonable to me. If you REALLY wanted to get the quarantine ahead of the science, everything including humans would be quarantined on the BI and they would just drop care packages from the air.

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Great idea, let's see if we can get it on the ballot.... and see how long the care packages last... or maybe we could start with Puna?