1. Oak Wilt in Texas
and the
Texas Oak Wilt
Suppression Project

2. 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.

3. 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

4. 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.

5. 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.

6. Impact of Oak Wilt in Texas
Rural
Residential
Areas
Loss of live oaks to oak wilt
has greater economic impact
around ranch houses.

7. Impact of Oak Wilt in Texas
Suburban
Areas
(1-10 acres)
The many new “ranchettes”
(<10 ac) in Central Texas have increased incidence and impact of oak wilt.

8. Impact of Oak Wilt in Texas
Urban Areas
(< 1 acre)
Oak wilt may reduce urban
property values by 15-20%.

9. Texas
Oak Wilt
Suppression Project

10. 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

11. 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 ( %)
5 urban foresters ( %) * percent of time devoted to Oak Wilt Project

12. 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

13. 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

14. Increase Public Awareness of Oak Wilt

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

16. Oak Wilt Training in Boerne
August 17, 2001
150 Participants

17. Oak Wilt Hot Line Call 512 - 473 - 3517
For answers to most often asked questions
Call
Courtesy of Lower Colorado River Authority

18. Cost Share Procedures Initial contact Field inspection
Cultural resource survey
Treatment plan
Landowner agreement
Treatment installation
Completion report
Reimbursement (50%)
Post-suppression evaluation

19. 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)

20. Trenching Equipment in Texas
Most Common
Trenching Equipment in Texas
Ripper Bar
Back Hoe
Rock Saw

21. 52-Inch Rock Saw Used in Recent Years

22. Trenching Accomplishments 1988 - 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.

23. 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 (< 1 acre)

24. Percent of Total Trenches by Land Use
U = Urban
S = Suburban
R. R. = Rural
Residential
R. N. = Rural
Non-residential

25. Cost of Oak Wilt Trenching by Land Use
Total Cost/Foot
U = Urban
S = Suburban
R. R. = Rural
Residential
R. N. = Rural
Non-residential

26. 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.

27. Prevention

28. 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

29. 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

30. 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 oak wilt centers/1000 acres of host type.

31. Economic Analysis FY
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 ).

32. Results of Benefit : Cost Analysis
Urban : 1
Suburban : 1
Rural Residential : 1
Rural Non-residential 4 : 1

33. 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.

34. Highlights in FY
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.

35. The Texas Oak Wilt Program is integrated with other federal programs.

36. Coordination with other Programs
Oak Wilt Program
Stewardship
Program
Urban Forestry
Program
Fire Prevention
Program

37. What is the Impact of the Suppression Project on a Landscape Scale?
Assume 8, ,000 oak wilt centers in Texas
Only 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.

38. Does this mean that suppression efforts are futile?
Oak wilt
in Texas
Does this mean that suppression efforts are futile?
Suppression Project

39. Are Suppression Efforts Futile?
Definitely
Not !

40. 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.

41. 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

42. When it comes to oak wilt, Texans are learning to:
Make the best
of a bad situation

43. Thank you for your attention!