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Pitch Canker

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A Decade of Differences in Pitch Canker Infestation of Monterey Pines in Asilomar Forest Project


Pitch canker and other plant diseases, such as sudden oak death, have the potential to change the vegetative cover and that in turn affects the watershed. Plant cover can affect water infiltration, soil erosion, solar radiation, wildlife, just about everything. Monterey County is one of the three remaining native ranges of Monterey pine, Pinus radiata.

Pitch canker, Fusarium circinatum, is a fungal disease. Three Monterey pines in Asilomar State Beach were first infested by pitch canker in 1992. In 1996, the initial survey made by the Parks Department discovered that 1,800 pines (33% of total) were infested by pitch canker. By 1999, pitch canker infestation has spread throughout the entire Monterey Peninsula region.

In 1999, Monterey County Agricultural Commissioner’s Office (MCACO) and the CSUMB’s (then) Spatial-Information Visualization & Analysis (SIVA) Center jointly developed a pitch canker monitoring, education and outreach project, under agreement with the California Department of Forestry (CDF) under a grant pursuant to SB 1712. The “Pitch Canker Infestation Conference” (2001) on CSUMB campus, and an online report on “Pitch Canker Infestation: A Case Study of Asilomar Forest” were produced, among many other activities.

Pitch Canker Study in Asilomar Forest

Asilomar forest is located at the Asilomar State Beach and Ground in Pacific Grove, Monterey County, CA. Monterey pines are dominant in Asilomar forest. In 2000 when a survey was about to begin, many Monterey pines in the Asilomar Park were overwhelmed by the disease. Special training sessions on the identification of the disease were launched in 2000. A dozen volunteers collected the disease severity data in 2001, and the CSUMB-SIVA staff and students geo-located over 3,000 locations of Monterey pines and tree stumps using a GPS device with a laser rangefinder. A GIS analysis identified the severity level of pitch canker infestation in the Asilomar forest: 16% dead; 46% severe; 25% moderate; and 12% initial. Only less that 2% were un-infested. To see the final report of this study, click here.

Achievement of Pitch Canker Infestation Data Collection and Study

The data collected in 1999 – 2001 by the joint efforts of the Monterey County Agricultural Commissioner and the CSUMB – SIVA Center have been useful for the California State Park Natural Resources Managers to track Pitch Canker infected trees throughout Asilomar State Beach and Conference Grounds. Having all trees tagged and graphically mapped has made management of this Monterey Pine Forest more efficient and productive. It is hoped that this effort can be replicated in the near future.

A Decade Later

Pitch canker did not kill all the pines as was feared by some, so what happened? There have been anecdotal reports of recovery of infected trees. How many trees recovered and is there any correlation to the level of infestation at the time of the initial survey? Is there new recruitment? What is the current impact? Are there indications of resistance development in the population? As far as we know, nobody is systematically looking at this yet.

Presently, the Monterey County Agricultural Commissioner's Office and Asilomar State Beach and Conference Ground (Asilomar State Park) have been jointly sponsoring a project, Changes and Future for Pitch Canker Infested Monterey Pines at Asilomar Forest Watershed.

Current activities can be viewed at

The Pitch Canker Task Force web site, which includes management guidelines, can be seen here.

DRAFT: A Decade of Differences in Pitch Canker Infestation of Monterey Pines in Asilomar Forest

  1. Pitch Canker Data Processing: So far, pitch canker GIS datasets processed in early 2000’s have been partially recovered. The following datasets will be re-established.
    1. To recover archived pitch canker dataset for Asilomar forest.
    2. To setup the report on Pitch Canker Infestation: A Case Study of Asilomar Forest, on the MCACO website.
    3. Develop a BLOG for detail information about pitch canker infestation studies.
  2. Recruiting data collectors by:
    1. MCACO staff CSUMB intern
    2. One professional arborist (supervisor)
  3. Input to pitch canker datasheet by local foresters
    1. Hold a meeting of invited local foresters
    2. Input to add pitch canker data variables
    3. Update 2012/13 pitch canker datasheet for survey
  4. Training Data Collection Process (by Asilomar State Environmental Scientist (ASES), survey supervisor, CSUMB student intern and MCACO)
    1. Understanding existing data collection format on each Monterey pine
      1. Locating a tree tag and tag number corresponding to (existing) data collection and maps
      2. Pitch Canker Severity Index
      3. GIS map with location of Monterey pines with tag numbers
    2. Data Collection Sheets (an existing data sheet as well as the 2012/13 data sheet with similar format so that comparison between 2002 and 2012 will be made.)
    3. Monterey pines (pitch canker) restoration requirements
  5. 2012/2013 Data collection
    1. Locate the tag and tag number.
    2. Evaluate the status of pitch canker severity, and note it on the data sheet.
    3. Add fields relevant to Monterey pines (pitch canker) restoration requirements (to define specifics)
    4. Collected data sheet will be maintained at the Parks Office until MCACO picks them up.
  6. Urban Forest Water Management data collection
    1. Identification of urban forest water factors (field) -- drains, erosion, storm shelters, PG urban water runoff, etc.
    2. Understanding urban-forest water system at Asilomar (soil, drainage, runoff, management)
    3. Developing (urban forest) watershed management plan
    4. (Urban-forest) watershed management and plan for Asilomar B&CG - Report with maps (for Student and Asilomar SBCG)
  7. Data Analysis (GIS)
    1. 2010 status of pitch canker infestation (Initial expectation was that all Monterey Pines will be killed.)
    2. Differences between 2002 and 2012 pitch canker infestation in Asilomar forest (Some may have died and removed. Some may still be standing with same severity. Some might have recovered. Some non-infested trees may or may not have infested.)
    3. Tree Restoration Plan at Asilomar SBCG (Monterey pines and others)
    4. What’s anticipated for the future of the Monterey pines in Asilomar?
  8. Report Preparation
    1. Developing (urban forest) watershed management plan at Asilomar SBCG
    2. Tree Restoration Plan at Asilomar SBCG (Monterey pines and others)
    3. A Decade of Differences in Pitch Canker Infestation of Monterey Pines in Asilomar Forest (2002-2012)