Oak Wilt in Texas

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Oak Wilt in Texas
and the
Texas Oak Wilt Suppression Project
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Oak Wilt
Veinal necrosis on live oak

• Caused by the fungal pathogen Ceratocystis
  fagacearum.
• This native pathogen affects oaks in some 20
  eastern and mid-western states (worst outbreak
  is in Texas).
• Fungal spores vectored by insects, primarily
  nitidulid beetles.
• Red oaks and live oaks are most susceptible.
• Veinal necrosis is a diagnostic symptom on live
  oak leaves.

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Oak Wilt in Texas

• First identified in Texas in Dallas in 1961.
• Live oaks and red (Spanish) oaks are most
  severely affected.
• Only red oaks produce fungal mats.
• Most tree losses occur from pathogen spread
  through connected root systems (common in
  live oaks).

Fungal mat on red oak
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Distribution of Oak Wilt in Texas

• 55 counties in Central Texas
• 6 counties in West Texas

Fort Worth
Dallas
College Station
Austin
San Antonio
Houston
Counties in Texas with oak wilt cover an area
larger than VT, NH, MA, CT, NJ, RI and MD
combined.
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Impact of Oak Wilt in Texas
Rural Areas
Thousands of acres of live oaks have become
victims of oak wilt in rural areas of Central
Texas.
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Impact of Oak Wilt in Texas
Rural Residential Areas
Loss of live oaks to oak wilt has greater
economic impact around ranch houses.
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Impact of Oak Wilt in Texas
Suburban Areas (1-10 acres)
The many new ranchettes (lt10 ac) in Central
Texas have increased incidence and impact of oak
wilt.
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Impact of Oak Wilt in Texas
Urban Areas (lt 1 acre)
Oak wilt may reduce urban property values by
15-20.
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Texas Oak Wilt Suppression Project
1988 - 2001
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Cooperators

• USDA Forest Service/ Forest Health Protection
• Texas Forest Service
• Cities, neighborhoods, private landowners
• Texas Cooperative Extension
• Texas Agricultural Experiment Station
• Lower Colorado River Authority

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TFS Oak Wilt Staff

• Project director (10) support staff
• Administrative coordinator (30) support
  staff
• Oak wilt technical coordinator (100)
• Oak wilt field coordinator (35)
• 6 staff foresters (45 - 80)
• 5 urban foresters (10 - 15) percent of
  time devoted to Oak Wilt Project

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Oak Wilt Technical Advisory Board

• Dr. Dave Appel, TAMU
• Dr. Brad Barber, TFS
• Dr. Ron Billings, TFS
• Carrie Burns, City of Lakeway
• Kim Camilli, TFS
• Jay Culver, City of Austin
• Eugene Gehring, Arborist
• Jordy Hagen, Bartlett Tree Services

• Emsud Horosovic, City of Round Rock
• Billy Kniffen, Hays County Extension
• Jon Long, Oak Wilt Specialists of Texas
• Dr. Forrest Oliveria, USDA Forest Service
• Curt Randa, City of Cedar Park
• Dale Starkey, USDA Forest Service
• Damon Waitt, Johnson Wildflower Center
• Dr. Dan Wilson, USDA Forest Service
• New Members in 2001

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Project Objectives

• Public awareness
• Detection and evaluation
• Technical assistance to landowners
• Cost shares for oak wilt control
• Special projects
• Implement long-range management of oak wilt

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Increase Public Awarenessof Oak Wilt
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Public Awareness

• Circulars and publications
• Internet web pages, public fairs
• Training sessions, tours and demonstrations
• Responding to phone calls, e-mail inquiries
• News articles, videos, posters, displays, etc.
• One-on-one site visits

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Oak Wilt Training in Boerne August 17, 2001
150 Participants
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Oak Wilt Hot Line
For answers to most often asked questions
Call 512 - 473 - 3517
Courtesy of Lower Colorado River Authority
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Cost Share Procedures

• Initial contact
• Field inspection
• Cultural resource survey
• Treatment plan
• Landowner agreement

• Treatment installation
• Completion report
• Reimbursement (50)
• Post-suppression evaluation

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Barrier Treatments

• Trenching (at least 4 feet deep) to halt oak
  wilt spread through connected root systems
• Roguing (removal of diseased trees within
  trenched area)

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Most Common Trenching Equipment in Texas
Ripper Bar
Back Hoe
Rock Saw
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52-Inch Rock SawUsed in Recent Years
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Trenching Accomplishments1988 - 2001

• To date, the Project has installed a total of
  2,655,900 feet (503 miles) of trenches in 35
  counties since 1988 to halt the spread of 1,903
  oak wilt centers.
• Equivalent to a trench extending from Houston
  to Lubbock.
• Of this total, ca. 8 have been installed in
  urban sites, 14 in suburban sites, 35 in rural
  residential sites, and 43 in rural
  non-residential sites.
• Two of every 3 trenches have held without
  breakouts.

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Cost/foot and number of trenches vary with land
use category

• Rural Non-residential More than 10 acre ranch
  without a residence in vicinity of trench
• Rural Residential Home site on ranch of
  more than 10 acres
• Suburban 1-10 acre home sites in transition
  area between rural and urban areas
• Urban Urban residential setting (lt 1 acre)

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Percent of Total Trenches by Land Use
Percent
U Urban S Suburban R. R. Rural
Residential R. N. Rural Non-residential
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Cost of Oak Wilt Trenching by Land Use
Total Cost/Foot
U Urban S Suburban R. R. Rural
Residential R. N. Rural Non-residential
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What are Economic Benefits of 500 miles of
trenches?

• The 500 miles of trenches effectively protect a
  total of 15,000 acres from oak wilt spread over
  5 years.
• These 15,000 acres include 20,000 urban trees,
  valued at 70 million, 150,000 suburban trees
  (47 million), 110,000 trees (78 million) on
  rural residential sites, and 210,000 trees (5
  million) on rural non-residential sites.
• The total value saved is ca. 200 million for an
  investment of 10 million.

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Prevention
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Prevention of Oak Wilt

• Avoid pruning between January and June
• Paint wounds and pruning cuts
• Remove and dispose of diseased trees
• Treat threatened oaks with fungicide Alamo
• Proper management of oak firewood
• Plant resistant trees, diversify landscapes

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Other Special Projects

• Aerial sketch mapping and ground verification
  of oak wilt centers
• Development of computerized data management
  system
• Economic analysis of Project activities
• Partnerships with cities of Austin and Lakeway
• National Oak Wilt Symposium
  North American Forest Insect
  Work Conference

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Aerial Detection Surveys

• Sketch map surveys conducted over 13 million
  acres (319 USGS quadrangles or 19 counties).
• Total of 8,002 mortality centers detected on 13
  million acres of 5,714 centers (71) ground
  checked to date, 4,989 (87) are oak wilt.
• An estimated 6,962 oak wilt centers occur on
  the 13 million acres of land surveyed to date.
• Assuming 20 of land in oaks, this represents
  2.7 oak wilt centers/1000 acres of host type.

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Economic Analysis
FY 1990 - 1996
Objective To determine the economic efficiency
of the Texas Oak Wilt Suppression Project.
Benefits Infected tree removal and tree
replanting costs avoided by cooperators due to
Project- installed trenches to halt oak wilt
spread for 5 years (although many additional
benefits are involved).
Costs Total Project costs, including cost
shares and administrative costs (5,491,468 for
FY 1990-1996).
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Results of Benefit Cost Analysis
Urban 6 1 Suburban 14 1 Rural
Residential 8 1 Rural Non-residential
4 1
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Project Accomplishments

• Network of TFS foresters established throughout
  Central Texas to provide technical assistance.
  
• Aerial detection surveys conducted over 13
  million acres (ca. 19 counties) ca.
  8,000 oak wilt centers detected and 5,000
  confirmed on ground to date.
• Public awareness of oak wilt greatly increased
  and 1.6 million of cost shares distributed
  in 35 counties.
• More than 2.6 million feet (503 miles) of
  trenches installed to control 1,900 oak wilt
  centers.
• Several thousand infected red oaks removed and
  live oaks injected with fungicide.

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Highlights in FY 2000-2001

• Oak wilt technical coordinator position filled
  (Kim Camilli) 10 new members added to Technical
  Advisory Board.
• New office opened in Johnson City (Robert
  Edmonson) Lampasas position filled (Jay
  Hein).
• City of Lakeway adopted as newest city partner
  and oak wilt forester hired by city (Carrie
  Burns).
• Oak wilt how to brochure translated into
  Spanish.
• Computerized Operations Information System
  revamped.
• Office facilities in Austin expanded to better
  serve public.

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The Texas Oak Wilt Program is integrated with
other federal programs.
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Coordination with other Programs
Oak Wilt Program
Stewardship Program
Urban Forestry Program
Fire Prevention Program
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What is the Impact of the Suppression Project on
a Landscape Scale?

• Assume 8,000 - 10,000 oak wilt centers in Texas
• Only 150 - 200 centers controlled per year with
  Project assistance
• New centers develop each year as Texas
  population expands

• Without additional federal and state support,
  the Project is unlikely to substantially reduce
  the incidence of oak wilt on a landscape scale.

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Does this mean that suppression efforts are
futile?
Oak wilt in Texas
Suppression Project
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Are Suppression Efforts Futile?
Definitely Not !
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Oak wilt is analogous to auto accidents

• Both will increase as the human population in
  Central Texas increases.
• Frequency and severity can be reduced through
  public education ( defensive driving class).
• With oak wilt, trenching reduces potential
  losses, as do seat belts and air bags in autos.
• Prevention is preferred and most effective
  approach.

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Long-range Strategic Plan

• Apply integrated approach to pest management
• Identify priority areas for education,
  prevention suppression
• Empower communities to address oak wilt
• Increase state funding technical assistance
  staff
• Seek federal funds from federal Cooperative
  Forest Health Program
• Plant resistant trees diversify landscapes

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When it comes to oak wilt, Texans are learning to
Make the best of a bad situation
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Thank youfor your attention!