Alien Species: USAG-HI native plantings prevent spread
March 11, 2014
WHEELER ARMY AIRFIELD, Hawaii (March 7, 2014) -- The State of Hawaii is hosting the annual Hawai'i Invasive Species Awareness Week, March 3-9.
While it's only the second year for this event, word on invasive species is spreading -- toward, hopefully, less invasive species in the process.
An invasive species is a plant, animal, pathogen or other organism that is non-native (not naturally found in) Hawai'i, and which may cause economic or environmental harm or adversely affect human health
What's the big deal with invasive species?
Most of the plants in our current environments -- in our schools, our streets or even our own yards -- have been imported to Hawai'i from various locations throughout the world. Referred to as "non-native" or "exotic" species, these plants are often very beautiful -- one of the reasons people brought them here, and they thrive in the lush climate Hawai'i offers.
Despite their beauty and success, they have not been a part of the natural ecosystem in Hawai'i and therefore could severely throw off the balance of the one we already have, becoming what scientists and natural resource managers call "invasive."
Joby Rohrer, senior Natural Resource manager with the O'ahu Army Natural Resources Program, who is contracted with the U.S. Army Garrison-Hawaii Natural Resources Program, talked about how non-native, invasive ornamental plants impact Hawai'i's natural areas.
"We continue to deal with invasive ornamentals," said Rohrer. "We are still finding coral tree (Erythrina poeppigiana) in new natural areas. … We have been spending a lot of time controlling them in (Schofield Barracks') West Range.
"Planting natives is preferred," added Rohrer. "It makes our job easier (with less weeds to control), so this policy is a great step towards protecting the natural areas we have left."
Coral tree is just one of many examples of non-native ornamental plants that have "escaped" their landscape setting and gone into natural areas.
Invasive species also come in the form of pests that sneak into the islands with other imports. The invasive black twig borer (Xylosandrus compactus) is one such pest, accidentally introduced to O'ahu in the 1960s on a shipment of plants. Now spread throughout the Hawaiian Islands, the black twig borer impacts many crops by creating destructive tunnels within plants to lay their eggs. Coffee farmers, in particular, have felt the economic impact of this pest and have been forced to get rid of many of their crops because of infestations.
The black twig borer is also decimating one of Hawai'i's rarest trees, the endangered mehamehame (Flueggea neowawraea). The largest member of Hawai'i's forests, mehamehame can reach heights over 100 feet and can stretch as wide as 10 feet in diameter.
Despite its stature, the meheamehame is extremely vulnerable to the tunnels created by the black twig borer. USAG-HI's environmental team continues to research methods to control this tiny, lethal enemy that is leading the endangered mehamehame into extinction.
Planting native on post
Jan. 7, USAG-HI formalized its commitment to environmentally beneficial landscape practices, and Hawai'i Invasive Species Awareness Week marks a perfect opportunity to celebrate that commitment.
The policy, which applies to all Army installations, facilities and work sites in the state, requires the use of native Hawaiian plants in landscaping. The policy also includes a list of recommended native plants for landscaping, which was developed by DPW Environmental staff.
"We selected plants that were beautiful and appropriate for the climate at Schofield," said Kapua Kawelo, biologist for DPW Environmental's Natural Resource Program, who spearheaded the effort. "We looked at similar policies that have been developed. All of them emphasized the reduction of the need to water plants, so we chose xeriscape-type plants that didn't need additional water or a lot of maintenance.
"These plants won't need to be replaced again and again and are attractive plants to use for landscaping," Kawelo added.
By implementing this policy, USAG-HI will not only reduce water resource requirements, but will provide habitat for native animals and create a Hawaiian cultural landscape on post.