Invasive Species in Hawaii

1. Invasive Species in Hawaii What can Gardeners & Community Gardens do to Help stem the tide of invasion Presented by: Patti Clifford Weed Risk Assessment Specialist Hawaii Invasive Species Council

2. NASA The Hawaiian islands are the most geographically isolated island chain on Earth. This isolation has limited plants, animals, humans, and diseases from reaching Hawaii.

3. TNC To get to Hawaii and establish a population requires adaptability.

4. Hawaii's First Arrivals Seed, Spores and Insects arrived on the Wind. Birds love islands. They transport seeds internally and attached to their feathers. Ocean currents carry: Seeds, Fish, Invertebrates, Algae. TNC photo TNC photo

5. CGAPS The plants and animals that arrived came from all over.

6. Why are Hawaii’s Native Species Impacted by Invasive Species? Hawaii’s native ecosystems are the result of 70 million years of isolation and very slow change. The Hawaiian island chain was never attached to a continent or close to any island. Chad Yoshinaga/NOAA

7. What is an Invasive Species? An invasive species is a species that is non-native or exotic to the local or regional ecosystem and whose introduction does or potentially can cause economic or environmental harm or harm to human health.

8. Invasive Plant Characteristics

9. Invasive Plant Characteristics

10. Dispersal Mechanisms

11. The Invasion Process The Invasion Process can be described as a series of stages. Transport Introduction Establishment Spread Impact Ecological, Economic, Human Health

12. Invasive Plants in Hawaii’s Natural Areas Purposeful introductions 91% Crop/other use 56 52% Ornamental 41 39% Accidental introductions 10 9% Smith, C. W. 1985 • The plants that pose the greatest threats are ones that we brought in on purpose.

13. Coqui FrogsEleutherodactylus coqui • Native to Puerto Rico • Can reach densities of 10,000 per acre, eat 40,000 insects a night • Eat native insects • Loud (70-90 decibels).

14. Little Fire Ant (LFA) Wasmannia auropunctata • Small stinging ants native to Central and South America. Introduced as hitchhikers on nursery plants • Infests yards, agricultural fields, and nurseries. • Sting animal eyes, causing blindness • Infestations on the Big Island. One small infestation on Kaua‘i and Maui (recent). • Not on Oahu Yet! Lori Oberhofer/USDA NRC

15. Invasive Vines The Ivy Gourd (Coccinia grandis), a tropical vine. Impacts: Smothers plants. Difficult to remove -tuberous root system. In Hawaii severe pest in gardens, on utility poles, roadsides, and in natural areas.

16. Invasive Nutsedge Purple nutsedge (Cyperus rotundus) is considered to be one of the world’s worst weeds Fast growing; difficult to eradicate because of tubers; agricultural, garden, natural area weed.

17. Prevention

18. Voluntary Codes of Conduct for Gardeners • Ask for only non-invasive species when you acquire plants. • Seek information on which species are invasive in your area. • Remove invasive species from your land and replace them with non-invasive species suited to your site and needs. • Do not trade plants with other gardeners if you know they are species with invasive characteristics. • Request that botanical gardens and nurseries promote, display and sell only non-invasive species. • Help educate your community and other gardeners.

19. What can Gardeners Do to Help?

20. Learn more about the impact of invasive species in Hawaii. Implement the Voluntary Codes of Conduct for Gardeners Verify that plants in your garden are not invasive. Spread the word not the weeds.

21. Let’s PlantPono :) • The PlantPono website will provide: • information on invasive plants and their impacts • information on non-invasive plants • access to the Hawaii-Pacific Weed Risk Assessments (>1,000 plants assessed) • www.plantpono.org