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. NASA .
Community Gardens do to Help stem the tide of invasion
Weed Risk Assessment Specialist
Hawaii Invasive Species Council
The Hawaiian islands are the most geographically isolated island chain on Earth. This isolation has limited plants, animals, humans, and diseases from reaching Hawaii.
To get to Hawaii and establish a population requires adaptability.
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.
The plants and animals that arrived came from all over.
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.
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.
The Invasion Process can be described as a series of stages.
Ecological, Economic, Human Health
Purposeful introductions 91%
Crop/other use 56 52%
Ornamental 41 39%
introductions 10 9%
Smith, C. W. 1985
• 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).
Lori Oberhofer/USDA NRC
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.
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.
Implement the Voluntary Codes of Conduct for Gardeners
Verify that plants in your garden are not invasive.
Spread the word not the weeds.