Mycoforestry: decomposition of felled pine

Report on Monterey Pine Decomposition by Bay Area Applied Mycology on EBMUD Duffel Meadow

Part One

East Bay Municipal Utility District (EBMUD) in collaboration with Bay Area Applied Mycology (BAAM).

Scott Hill, Manager of Watershed and Recreation
Virginia Northrop, Senior Ranger

On November 13, 2012 three members of BAAM inoculated a freshly fallen Monterey Pine, Pinus radiata, with the spawn of Oyster Mushroom, Pleurotus pulmonarius, with the intention of enhancing the tree’s rate of decomposition. The fallen tree is located in a Monterey Pine grove on the property of the East Bay Municipal Utilities District (EBMUD) in Orinda, California.

On December 10, 2012 four members of BAAM inoculated a second fallen Monterey Pine with different species of mushroom mycelium. This procedure is discussed and pictures are displayed further into this report.

Amendments and observations are added to the end of the report.

The purpose of this project is to develop a new method for EBMUD to handle felled and fallen trees that will both A) eliminate the cost of removing fallen trees from EBMUD property, B) keep natural materials on site and C) reduce fire vulnerability.

EBMUD currently utilizes horses to haul fallen trees from their property. This current method reduces potential fuel for fires. However, hiring horses to haul fallen trees can be a fairly costly operation, and doing so also removes organic materials from the site.

By introducing mushroom spawn (also known as mycelium) into the freshly fallen tree, BAAM hopes to enhance the tree’s rate of decomposition. Once the spawn has been introduced to the tree, no further modifications will be made. Later stages of decomposition via bacteria and other fungi will occur naturally.

A secondary benefit of introducing mycelium to the fallen tree is a way of storing water inside the tree while the decomposition process occurs, thus potentially preventing the tree from becoming fodder for fires.

This project hopes to create new solutions and act as a source of observation for future projects.

This tree’s decomposition will be observed and documented over the next decade.

What is considered “successful decomposition” hasn’t been determined, however BAAM estimates the process will take five to ten years.

Notes and Observations
The Monterey Pines in the grove were planted in the 1940s. They are considered to be at the end of their life cycle. Because they were planted in a non-native habitat, they are beginning to weaken and fall.

This specific tree was chosen because it had fallen due to apparent natural causes and was still fresh. The tree was in a spacious and shaded grove of other Monterey Pines.

On Documentation
Periodic observation and documentation is necessary to track the results of this project. Checking and documenting changes to the site should occur once a season/four times a year. We don’t know for certain how long the tree will take to decompose. We theorize five to ten years. We don’t know for sure, and we haven’t decided what stage of decomposition is considered “successfully decomposed” enough to prevent it from fueling fires.

Materials and Labor
The on-site process took three hours, working comfortably, with three men sharing labor.

Two strains of Pleurotus pulmonarius mushroom spawn were used. The organic material used to inoculate the trees was spawned wooden dowels and spawned wheat straw. The first strain, which was grown on wooden dowels, was supplied by Fungi Perfecti. The second strain, which was initially grown on millet, then transferred and allowed to colonize on wheat straw, was purchased from Amycel.

Equipment: a chainsaw; some drills, drill bits, and batteries; nails; hammer; dowel spawn and straw spawn; rope; a crowbar; paraffin wax; a pot and stove in which to melt the wax; gloves to protect against heat of the wax; a brush to apply the melted wax; burlap bags; water

The Procedure
Six areas of the tree were modified. A large portion of the tree wasn’t modified. The following documentation includes photographs which may help to understand the procedures and materials used.


The freshly fallen Monterey Pine

Area 1:

Area 1 is closest to the base of the tree. Sean drilled about 150 holes into the tree with a 5/16” drill bit and plugged the holes with Pleurotus pulmonarius spawned dowels from Fungi Perfecti. By using a nail as a punch, we were able to hammer the dowels about an inch below the surface. I covered a few of those plugged spots with paraffin wax.


Sean drills holes into tree. Exposed dowels are shown before they were hammered into the tree

Area 2:

Mino scored the tree in a grid with a chainsaw. I stuffed it with Pleurotus pulmonarius straw spawn from one of Mino’s bags. The spawn originated from Amycel. The modified area was then covered with a soaked burlap sack and tied to the tree. The use of the burlap bag was intended to prevent direct sunlight from affecting the area, to trap in moisture, and to allow it to breathe.


Mino scores Area 2 of the tree


Gashes stuffed with straw spawn in Area 2


Scored and inoculated section covered with a burlap sack in Area

We originally intended to lift the bark off the fallen tree in sections so that we could apply the spawn directly to the exposed wood, then place the sections of bark back onto the tree as a protective covering. However, when we pulled at the bark, it chipped off. We instead decided to inoculate the tree by scoring the tree and stuffing the gashes with spawn, then covering the inoculated area with a burlap sack.


Instead of lifting off in sections, bark chipped off

Area 3:

Same as Area 2 and covered with burlap. The burlap sack was nailed to the tree in 6 points.


Sean stands over Area 3 before it was covered with a burlap sack

Area 4:

A sort of control group. Mino scored this area like he did with Areas 2 and 3, but we decided to leave the area uncovered and uninoculated in order to observe how this area of the fallen tree would rot over time in comparison to the inoculated areas.


Area 4, left scored but uninoculated and uncovered

Area 5:

Mino cut wedges into the tree with a chainsaw and I filled the exposed surface areas with Pleurotus pulmonarius spawn originally from Amycel. Straw was forced into the area around the wedge with a crowbar. We then covered the area with a soaked burlap sack and nailed it to the tree.


Area 5 before burlap covering


Wedge sections of Area 5

Area 6:

Mino drilled holes into Area 6 and stuffed the holes with Fungi Perfecti’s Pleurotus pulmonarius spawned dowels just like Area 1. I covered nearly all the holes with melted paraffin wax. The wax is meant to both protect the mycelium from bugs and trap moisture in the holes.


Paraffin wax covering a hole inoculated by dowel spawn, Area 6



A Second Tree is Inoculated

On December 10, 2012, BAAM inoculated a second fallen tree in close proximity to the first with three different strains of mushroom, two of which were collected on EBMUD property.


It is with the goals and visions of BAAM to utilize local strains of mushrooms.


The three strains of mushrooms used includes a locally sampled strain of Pleurotus pulmonarius provided by Far West Fungi, and two strains of as-of-yet not identified species of wood-rotters. The wood-rotters in question were collected from wood chip piles in front of the EBMUD property. Myceliated wood chips, as well as mushroom fruit bodies of these strains were collected.


Currently, these strains are suspected of being a Pholiota sp. and a Gymnopilus sp. Identification still required. They were fruiting prodigiously from the wood chips, and digging through a shallow layer of the wood chips revealed the mycelium was “running” strong.


Local wood rotter with running mycelium


Mino collects mushrooms and wood chips covered with mycelium Monica snaps photos


Locally collected mushrooms and wood chips. Possibly “Psathyrella sp.”


As with the first tree, parts of this tree were scored in order to insert spawn. This method was designed to accelerate the decomposition of the tree. The four areas of the second tree are labeled Areas 7 through 10.

Area 7:

A section of the tree closest to its base was scored in wedges. Sawdust spawn colonized by Pleurotus pulmonarius provided by Far West Fungi was then packed into the open sections of the tree and the wedges were replaced. We covered the area with burlap. The burlap is intended to provide shade and to trap moisture.


Katie, Monica, and Canus mycophilicus Issa packspawn into the openings of the tree

Area 8:

Parallel cuts were scored into the tree, and the same spawn from Area 7 was applied to the opening of the tree. We covered the area with burlap.


Monica and Katie stuffing the tree with Pleurotus pulmonarius.

Area 9:

Wedges were scored into the tree. The fruit bodies and the wood chips with mycelium of a Psathyrella sp. [needs proper identification] were then placed onto the opening and covered with burlap. By using both myceliated wood chips and mushroom fruit bodies, we intend for both active cultures and potential new strains germinated from the spores of the mushroom to colonize and thrive within the wounds of the fallen tree.


Wedges were cut and filled with local myceliated wood chips and mushrooms

Area 10:

On a segment of the tree that was separated from its larger body, we applied myceliated wood chips and the fruit bodies of a mushroom we suspect to be a Gymnopilus sp. [identification needed] that was collected in front of the EBMUD office. We scored the area in stripes, removed the bark, applied the mushroom and wood chips, replaced the bark, and covered the area with a burlap bag.


The scored area of the tree is filled with myceliated wood chips and mushroom fruit bodies


Note-taker Joe sketches mushrooms next to Area 10



As an ongoing effort to track the progress of this project, we have taken periodic photographs.
Area 7, February 9, 2013


Photo by Mino de Angelis

This photo shows the health of the spawn of Area 7. Although we don’t know if the mushrooms are fruiting solely from the sawdust spawn provided by Far West Fungi or if it is decomposing and extracting any nutrients from the fallen tree, this fruiting shows that the spawn is at least active, and has enough moisture to produce mushrooms.
Area 8, February 9, 2013


Photo by Mino de Angelis

Area 8 is exhibiting the same traits as Area 7 as shown above.


As a continued update: In 2013 oyster mushrooms were found fruiting in areas of the log that were not directly inoculated. The mycelium appears to be running.
In 2015, three years into a devastating drought, the initial log that was inoculated was cut through close to our inoculation point. The exposed area shows decomposition has moved toward the core of the tree. As the lignin and cellulose decompose they reduce the threat of flammability of the log.


Decomposition starting from the perimeter toward center of log


Old Man Ridge Inoculation of Felled Pines with Mushroom Spawn

Part Two

Introduction: Based on the success of our earlier test on Pine in Duffel Meadow we thought it feasible to inoculate additional felled Pines that EBMUD, due to disease and age,  had taken down in an area known as Old Man Ridge. In November of 2012 BAAM inoculated about twenty-five of these trees with an assortment of myceliated spawn contributed to us by Far West Fungi.  We used one of the  original species, Pleurotus pulmonarius, but also experimented with Hericium erinaceus and at a later date added some locally harvested saprophytes: Gymnopilus junonius and Phaeolus schweinitzii.


The trees were felled by a team of professional loggers and laid in stacks about 6 to 8 logs 10 feet long. They were then notched according to our instructions. The notches were large enough to allow the crevices to be stuffed with spawn and the wedges to be reinstalled to mitigate moisture loss.  On our first outing a team of 15 volunteers stuffed the logs with spawn. Subsequent site visits were done with a team of four that tagged and noted GPS coordinates of the logs to allow follow-up studies.


We allowed for both inoculated logs and a control group of uninoculated logs.

In 2013 we noticed a high success rate amongst the Pleurotus pulmonarius inoculated logs.




View from Old Man Ridge


An example of the log grouping that we inoculated


The prepared notches


The team getting their first look at the method we will employ


Packing spawn into the notches


Oysters growing the next year from out of notch


Gymnopilus junonius fruiting from a pine stump


GPS Coordinates for follow-up study

To date 2015, despite Northern California’s three year drought, we have had enough favorable results to continue with the project on additional felled pine. For the 2014 season EBMUD personnel both notched and inoculated another 50 trees with Pleurotus pulmonarius provided by Far West Fungi. BAAM will continue to monitor all three of these sites.



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