Valley oak health improved with fire mimicry care

1 10 2018

Slide1

Two years ago I treated a number of valley oaks in Alamo, CA using a fire mimicry protocol. Here are photos of the oaks showing their response over the past 2 years. As you can see, there has been a notable improvement in the density and size of the leaf canopies both in 2017 and 2018. However, the photos in 2018 were taken a bit earlier than the original photos, which could explain some of the difference in canopy density.

Or maybe I’m just a Photoshop magician! There is a way to find out . . .

Slide2 Read the rest of this entry »

Advertisements




Fire mimicry reverses decline in coast redwoods

30 09 2018

Slide12

As I’ve discussed  previously (here), coast redwoods in many areas are showing symptoms of dieback, typically beginning towards the top and progressing downward. Drought and disease have been implicated in the redwood decline, but the true cause remains elusive. I suspect the decline is ultimately related to the altered fire ecology.

In October 2016 I applied fire mimicry treatments to a grove of coast redwoods in Alamo, CA that were in decline. Here are the results after two years.

Slide11 Read the rest of this entry »





Sudden Oak Life talk and discussion on October 13, 2018

21 09 2018

For those of you interested in learning more about an ecological vs. pathological approach to Sudden Oak Death, please attend my talk and discussion on Saturday, October 13, 2018, 10 – 12 noon at Lyngso Garden Materials, San Carlos, CA. The talk is free but you must register at:

https://www.eventbrite.com/e/sudden-oak-life-registration-50423488010

Slide3





More results from oaks in Fairfax, CA

30 07 2018

Slide01

More results of fire mimicry treatments of coast live oaks in Fairfax, CA after nearly two years. Several of these oaks have stem canker infections, probably Sudden Oak Death. Still . . .

Slide02 Read the rest of this entry »





Four-year results of fire mimicry treatments of oaks in Fairfax, CA

30 07 2018

Slide1

Four years ago I began fire mimicry treatments on a grove of coast live oaks in Fairfax, CA. Several of these oaks are infected with stem canker disease, probably Sudden Oak Death. As you can see most of the oaks, as indicated by the size and fullness of their canopies, have responded nicely to the treatments.

Slide2 Read the rest of this entry »





Fire mimicry/canker surgery results with oaks in Fairfax, CA

23 07 2018

Slide2

In July of 2016 I began fire mimicry treatments on several coast live oaks in Fairfax, CA. Here are photos showing the response of the oaks after two years. As you can see most of the oaks are showing noticeable improvement in canopy greenness and density.

One of the oaks (Case No. 20160722.4 – see below) had two stem canker infections, probably Sudden Oak Death, that were surgically removed and cauterized in 2016. The last two photos below show the healing of the wounds, both on the same tree. There appears to be no sign of a lingering infection. It’s still too soon to say for sure if the procedure has worked, but the healing results so far are better than expected.

Read the rest of this entry »





Do lichens play a role in oak decline?

20 07 2018
Lichens in tree

(image downloaded from web June 2013)

Any careful observer of oaks in California cannot help but notice a dense covering of lichens growing on the trunks and branches of many of the trees. In some cases, the biomass of lichens in the canopy rivals and even exceeds the biomass of the oak foliage. Under extreme conditions of lichen cover, the oaks appear sickly and in decline.

Lichens in oak

Coast live oaks covered in epiphytic Usnea and Ramalina lichens. (February 2018, Aptos, CA)

There is a popular meme in naturalist and conservation circles that lichens do not harm trees and merely use them for support. Adherents to this ‘harmless lichen’ meme point out that lichens are photosynthetic and, thus, do not draw any resources from the trees. Some note that lichens support nitrogen-fixing bacteria, which can add to the nutrient pool and benefit the trees. Furthermore, lichens are known to be highly sensitive to air pollution, so the presence of abundant lichens in a tree is a sign of good local air quality.

I have long been doubtful about the science behind this meme. As an experienced researcher of forest decline I have frequently noted that sick and dying trees often have a dense growth of lichens in their canopies. Defenders of the ‘harmless lichen’ meme describe this as the opportunistic growth of lichens on sick trees, as the reduced foliage allows for additional light for the lichens to grow. It is certainly true that lichens benefit from sick trees in this way, but I believe that lichens are not merely innocent bystanders or benefactors in the demise of a tree. Read the rest of this entry »