By Rita Hess, USAEC ContractorMarch 6, 2018
HONOLULU -- Stretching across several tropical island sites, the Hawaii Army National Guard installation encompasses 1,300 total acres. Some locations are home to rare, threatened, and/or endangered ecosystems and species, which can make managing these areas an immense challenge.
However, the Hawaii Army National Guard Natural Resources Conservation Program was successful enough to earn a 2017 Secretary of the Army Environmental Command award for its efforts to find the right balance between managing unique and fragile ecosystems with important training activities.
"Training areas in Hawaii are valuable resources for our Army National Guard," said Maj. Gen. Joe Logan, Hawaii's State Adjutant General. "Our HIARNG Environmental office has done a phenomenal job by not only caring for our installation by protecting native species and cultural sites but also virtually ridding our properties of invasive plants.
We have units deploying in 2018, and the critical work they have accomplished has kept maneuver areas clear and our Soldiers can maintain their readiness and train on our own land."
Taking a different approach than previous attempts, the NRC Program focused on one invasive species at a time and targeted seed sources -- specifically for miconia, albizia, kiawe, and strawberry guava.
The past two years saw complete removal of all mature miconia trees and a renewed focus on juveniles and seedlings. This allowed HIARNG to transition from treatment to monitoring. The elimination of adult trees slashed herbicide use by 95 percent.
Next, the NRC Program turned to albizia, which can quickly overtake the installation's vehicle corridors and pass-through areas. The tree grows over 100 feet tall, but high winds can easily uproot it, causing power disruptions and road barricades. The program removed 4,000 adult and juvenile albizia trees over the past two years and now considers this invasive species as fully controlled.
At Kekaha Firing Range, nearly 20 percent of the training site was overrun by long-thorn kiawe, an invasive, noxious tree that can grow to 30 feet tall with long thorns capable of piercing shoes and truck tires. Over the past two years, approximately 5,000 plants were removed; each was capable of producing thousands of seeds per year.
People enjoy strawberry guava fruit. Feral pigs do, too, which contributes to the trees' spread. Working with the U.S. Department of Agriculture, the NRC Program introduced a biological control agent using a scale insect, Tectococcus ovatus, to reduce fruit production.
Eradicating invasive and/or non-native species means less pesticide use and more accessible training land. It also benefits wildlife that relies on native forests, such as the endangered Hawaiian hawk and Hawaiian hoary bat. The NRC Program's success was due in large part to its use of goat and sheep grazing.
This cost- and resource-effective approach slashed herbicide use, safeguarded sensitive habitat, and enabled re-opening 46 acres of the Keaukaha Military Reservation for training. About half of the site's 504 acres are endangered lowland wet forest ecosystems, which are thriving in harmony with military readiness activities due to the NRC Program's innovative approach to ecosystem management.
Use of the animals began in 2016 on 46 acres with a portable paddock and a herd of 194 animals. The goats and sheep clear an average of one acre a day, including terrain that is difficult for machines to access. Grazing herds also reduce fire fuel loads, thereby minimizing interruptions in training. Elephant grass grows at a rate of 1 foot per week with the rainy conditions of KMR, so keeping areas cleared for Soldier training is essential.
The NRC Program also partners with Invasive Species Committees, University of Hawaii, U.S. Geological Service and U.S. Department of Agriculture to ensure invasive species management goes hand in hand with forest restoration, data collection and wildlife habitat improvement. The overall goal of the NRC Program is to reduce the impact of invasive species on military training land while improving the health and longevity of the once native ecosystems.
Many installations could easily adopt similar strategies for invasive species management. Indeed, avoiding the cost and the risks of herbicides and returning acreage to training access more quickly seems a definite win-win for natural resources and for Soldiers at the Hawaii Army National Guard.
"The innovative techniques and the dedicated staff of the HIARNG Environmental office have saved the department money and preserved Hawaii's installations," said Karl Motoyama, Environmental Program Manager. "We are working to both prepare our Soldiers for their missions and to be responsible stewards of our lands for our future generations."