1. Invasive Species 101:
Primer for Green Industry Professionals
Robert Emanuel, Ph.D.
Water Resources and Community Development Faculty,
Tillamook and Clatsop counties

2. Introduction
What are invasive species?
Why should we care?
Biology & management
Some invaders to watch
What can professionals do?
Resources for more information.

3. Invasive species means an alien species
whose introduction does or is likely to
cause economic or environmental harm
or harm to human health.

7. Biological invaders destroy habitats or
out‐compete native plants and
animals.
Why should we care?
Invasive species costs Americans about
$143 billion/year!
At least 30 new potential biological
invaders enter the US every day…

9. Understanding Biological Invasions

10. Definitions: Invasive Plants
“Weed”
Exotics A plant
(non‐native) growing
where you do
Lots of beneficial
not want it.
species: Crops,
pasture, forestry “Noxious”
& ornamentals.
A regulatory
designation.
“Invasive”
Spreads
Natives outside of
cultivation, and
Co‐evolution causes
with other environmental
species, our & economic
natural heritage harm.

11. What makes a plant invasive?
Lack normal environmental constraints
Fast growth and reproduction
Highly adaptable a wide range of conditions
Often can transform their environment
Promoted by new or existing disturbances
Less biodiversity in the native ecosystem
Sometimes work with other invasive species

12. Key Stages in Plant Invasions
Escape
Lag Time Invasion
Introduction
Area Infested
Cost
Time

13. What does this mean for management?
People notice them here
Prevention or
Eradication Local control and
(Inexpensive) management only
(Expensive)
Control Costs
Area Infested
Introduction
Detection: focus resources here
Time

14. The Wildfire Model

16. How do we manage invasive plants?
Prevention *
Quarantine before introduction
Monitoring & mapping
Chemical treatment (herbicides)
Biological controls (biocontrol)
Cultural treatment (hand pulling, cutting, etc.)

17. Some Invasive Species
High Desert Oregon & Environs

19. Flowering Rush: Butomus umbellatus

20. Photo – butterfly bush infestation in
Lane Co.
Butterfly Bush: Buddleja davidii

21. Photo ‐ butterfly bush infestation in
Lane Co.
Butterfly Bush (Buddleia davidii) Photo: OSU

22. Butterfly bush (Buddleja davidii and B. variants)

23. Purple Loosestrife: Lythrum salicaria

24. Purple loosestrife (Lythrum salicaria)

25. Photos: King County , WA
Garden Loosestrife: Lysimarchia vulgaris

26. Desert Indigobush: Amorpha fruticosa

27. Photo ‐ knotweed
Japanese Knotweed: Fallopia cuspidatum

28. Glenn Miller, ODA
Giant Knotweed: Fallopia sachalinese

29. Photo ‐ knotweed
Knotweed: Fallopia x bohemicum

30. Japanese knotweed (Fallopia cuspidatum) & giant knotweed (Fallopia sachalinense)

31. Photo: OSU
Yellow Flag Iris: Iris pseudacorus

33. Yellow flag iris (Iris psuedacoris)

34. Photo: Paul Wray, Iowa State University
Russian Olive: Elaeagnus angustifolia

35. Photo: USFS
Tree of Heaven: Ailanthus altissima

36. Jan Samanek, State Phytosanitary Administration, Czenia

37. Tamarix ramosissima

40. Tamarix parviflora Leslie
Gulch, OR, 2007

41. T. parviflora
invading the
Lower Owyhee
River, OR, 2007

43. Eric Coombs, ODA
Eric Coombs, ODA
Mediterranean sage: Salvia aethiopis

44. Eric Coombs, ODA

45. Mediterranean Sage (Salvia aethiopis )

46. Clary Sage: Salvia sclarea

47. Patterson’s Curse: Echium plantagineum

50. Patterson’s Curse (Echium plantagineum)

51. Leafy Spurge: Euphorbia esula

52. Leafy Spurge (Euphorbia esula)

53. BS Thurner Hof
Myrtle spurge: Euphorbia myrsintes

54. BS Thurner Hof

55. Myrtle spurge (Euphobia myrsintes)

56. Yellow Star Thistle: Centaurea solistialis

57. Yellow Star Thistle (Centaurea solistialis)

59. Wendy VanDyk Evans, Bugwood,org

60. Dave Powell, USFS
Yellow Toadflax: Linaria vulgaris

61. John Cardina, Ohio State
University, Bugwood,org

62. John Cardina, Ohio State University, Bugwood,org

63. Steve Dewey, Utah State University, Bugwood,org

64. Elizabeth Bella, USFS

66. Dalmatian toadflax: Linaria dalmatica

68. Michael Shephard, USDA Forest Service
Orange Hawkweed: Hieracium aurantiacum

69. Orange Hawkweed: Hieracium aurantiacum

70. Michael Shephard, USDA Forest Service
Orange Hawkweed: Hieracium aurantiacum

71. Orange Hawkweed (Hieracium aurantiacum)

73. Photos: Michael L. Charters
Spanish Broom: Spartium junceum

74. Scotch Broom: Cytisus scoparius

75. French Broom: Genista monspessulana

76. But wait! There’s MORE!

77. Photo: University of Georgia
Herb Robert: Geranium robertianum

78. Fennel: Foeniculum vulgare

79. Photo: Johnathan J. Stegeman
Bachelor’s button: Centaurea cyanus

80. Richard Old
Camelthorn: Alhagi maurorum

82. Only you can prevent the invasion!

83. What can Green Industry Professionals Do?
Know the enemy & teach others about them
Research new stock before you order it
Grow, sell or design for native & non‐invasive
plants wherever possible
Help the public with information on treatment

84. What can Green Industry Professionals Do?
Get involved in landscape management
ordinances where appropriate
Get involved in weed management boards
Help support local weed identification and
education efforts
Help support research focused on invasives,
control and alternatives

85. What can industry professionals do?
Watch for hitchhikers in nursery stock
Use weed‐free soil and mulch
Watch introductions for aggressive behavior
Discourage use of commercial wildflower or
other mixes.
Check clothes, vehicles, equipment, & pets

86. Commercial Wildflower or Plant Border
Mixes (AKA “Meadow in a Can”)

87. If you have a known invasive
(but a client can’t part with it)
Deadhead faithfully
Use root barriers
Dispose of plant material properly—bagged in
the garbage or burned (completely)
Contain it, control it, or cage it!

88. For Water Gardens
Always wash new introductions (think snails)
Keep water gardens separate from native waters
Never dump water garden materials or water
into native waters
Research plants for invasive potential—many
commonly used aquatics are!

89. Some Resources

91. http://plants.usda.gov/java/noxiousDriver

98. Invasive Spp. Web Resources
All of this information located at:
bit.ly/is4gip
Oregon Invasive Species Council
www.oregon.gov/OISC/
Oregon Invasive Species Hotline:
oregoninvasiveshotline.org/
National Invasive Species Clearinghouse:
www.invasivespeciesinfo.gov
USDA PLANTS Database:
plants.usda.gov/index.html
WA State Noxious Weed Board:
www.nwcb.wa.gov/index.htm
Idaho Weed Awareness:
idahoweedawareness.net/index.html
California Invasive Plant Council:
www.cal‐ipc.org
Be Plantwise:
www.beplantwise.org/

99. People and Organizations
Brooke Gray Eastern Oregon EDRR
Coordinator, Weed Educator: 541‐447‐6228
Dan Sherwin, Deschutes County Vegetation
Manager, dansh@co.deschutes.or.us ,
541‐322‐7135
Local Soil and Water Conservation Districts
OSU Extension Service offices in each county

100. Questions?
Robert M. Emanuel, Ph.D.
Water Resources & Community Development
Tillamook & Clatsop counties
2204 Fourth Street
Tillamook, OR 97141
(503) 842‐5708 X 2
robert.emanuel@oregonstate.edu
blogs.oregonstate.edu/h2onc