Native Species? In US prior to European settlement

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1 INVASIVE SPECIES

2 Native Species? An organism that is a part of the balance of nature that has developed over hundreds or thousands of years in a particular region or ecosystem. In US prior to European settlement

3 What is an Invasive Species? Invasive species are plants, animals, fungus, or pathogens that are non-native (or alien) to a specific ecosystem and whose introduction is likely to cause damage to the environment, human economy or human health. Global Issue!

4 Globalization

5 Other Terminology Noxious weed- is any plant designated by a Federal, State or county government as injurious to public health, agriculture, recreation, wildlife or property. Exotic/Alien species- a non native species that does not pose a threat.

6 Why Do We Care? In Nevada ALONE, invasive plants cause between $6 million and $12 million per year in reduction of wildlife-related recreation (Eiswerth et al., Weed Science, 2005). The annual cost to the United States economy is estimated at $120 billion a year $1.4 trillion world wide! They lower Biodiversity

7 Characteristics of an Invasive They tolerate a variety of habitat conditions

8 Characteristics of an Invasive They grow and reproduce rapidly

9 Characteristics of an Invasive They compete aggressively for resources (like food, water, and nesting sites)

10 Characteristics of an Invasive They lack natural enemies or pests in the new ecosystem

11 Recap Generalists/able to tolerate a variety of habitat conditions Grow and reproduce rapidly Aggressive competitors Lack natural enemies

12 Disturbance! What Makes an Ecosystem Susceptible?

13 Great Basin Invasives

14 Cheatgrass Bromus tectorum Where: Eurasia When: late 1800 s but multiple introductions (accidental) How: Generalist, grows and reproduces rapidly, very competitive, and lacks natural predators. Status: Invasive How much: Over 100 million acres Biggest Problem: Alters fire regime Control?

15 Medusa-Head Taeniatherum caput-medusae Where: Eurasia When: Late 1800 s in OR with multiple other introductions (accidental) How: Generalist, grows and reproduces rapidly, very competitive, and lacks natural predators. Status: Noxious, Invasive How much: 2.5 million ac Biggest Problem: Alters fire regime Control?

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17 Russian Thistle Salsola tragus Where: Eurasia When: Mid 1870 s (accidental) How: Generalist, grows and reproduces rapidly, very competitive, and lacks natural predators. Status: Invasive How much: 100 million ac Biggest Problem: reduced crop yields Control?

18 Diffuse Knapweed Russian Knapweed Squarrose Knapweed Spotted Knapweed The Knapweeds! Centaurea sp.

19 Spotted Knapweed Centaurea stoebe Where: Eurasia When: Late 1800 s (accidental) How: Generalist, grows and reproduces rapidly, very competitive, and lacks natural predators. Status: Noxious/Invasive How much: 4.7 million ac Biggest Problem: Crowd out native sp. Control?

20 Thistles Canada thistle-cirsium arvense Bull thistle-cirsium vulgare Musk thistle-carduus nutans Scotch thistle-onopordum acanthium Yellow star thistle-centaurea solstitialis Milk thistle-silybum marianum

21 Native Thistles Cirsium occidentale Cirsium andersonii

22 Where: Eurasia Scotch Thistle Onopordum acanthium When: 1800s (intentional) How: Generalist, grows and reproduces rapidly, very competitive, and lacks natural predators. Status: Noxious/Invasive How much:???? Biggest Problem: Reduces forage Control?

23 Where: Eurasia Yellow Star Thistle Centaurea solstitialis When: Late 1800 s (accidental) How: Generalist, grows and reproduces rapidly, very competitive, and lacks natural predators. Status: Noxious/Invasive How much: 100million ac in CA alone! Biggest Problem: Crowd out native sp. Control?

24 Perennial Pepperweed Lepidium latifolium Where: Eurasia When: Late 1800 s (accidental) How: Generalist, grows and reproduces rapidly, very competitive, and lacks natural predators. Status: Noxious/Invasive How much:20,000 acres just along Truckee River Biggest Problem: Alters nutrient cycling Control?

25 Where: Eurasia Salt Cedar Tamarix ramosissima When: Early1800 s (intentional) How: Generalist, grows and reproduces rapidly, very competitive, and lacks natural predators. Status: Noxious/Invasive How much: Over 1 million ac Biggest Problem: Water stealer/salt deposits Control?

26 Lots of Others! White pine blister rust European Starling Eurasian Watermilfoil Asian Long-horned Beetle

27 So What Can We Do? Know invasives/noxious weeds in your area!

28 DON T BE A VECTOR!

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31 Questions?

32 References noxiousweeds/pages/aboutoregonweeds.aspx -det-athr_prof-art_hdr d_list/ chnical/ecoscience/invasive/?cid=nrcs142p2_011124