Strenuous, expensive attempts to keep invasive plants from gaining ground in Hawaii could be much more successful if the federal government would live up to its obligation to coordinate efforts to combat damaging alien species.

An executive order issued in 1999 calls for 12 U.S. departments and agencies to set priorities, enact management plans and work together to eradicate invasive species that can choke out native plants, disrupt use of natural resources and ruin a region’s physical and economic landscape.

Despite this long-standing order, the U.S. Department of Agriculture continues to wield the most clout. This is a problem, in Hawaii especially, as the USDA’s priorities don’t always jibe with those of individual states when it comes to keeping destructive plants from being introduced or removing those that have already taken root.

As the Star-Advertiser’s Gary Kubota reported on Sunday, critics contend that a lack of federal accountability drives up the cost of eradicating these unwanted species. Greater collaboration among U.S., state, county and local agencies across the country could inspire rapid improvements.

In Hawaii alone over the past five years, about $17.7 million in taxpayer funds has been spent to fight invasive plant species, under agreements with the USDA Natural Resources Conservation Service. This funding involved 369 contracts applying to 47,000 acres of land throughout the state.

Even as federal and state agencies spend this money throughout the state to snuff out what folks here consider stifling weeds, the USDA allows some of the very same plants to enter the country and be transported and sold between states. Placing more species on the Federal Noxious Weed List would prevent that, but the USDA has banned only 120 plants — of more than 250,000 known plant species — in the 37 years it has kept the list. This reluctance reflects the fact that encouraging international trade is one of the USDA’s top priorities, and banning imports could impair trade relations with other countries.

States such as Hawaii can and do keep their own lists, but enforcement can be difficult — especially on private property — if the plant isn’t also on the federal list.

Also a factor: One region’s pest plant might be another’s cash crop. Take the Arundo donax — the so-called "zombie plant" — a giant reed that clogs waterways and streams, increasing flood and fire hazards. Hawaii, California, Texas and Florida are trying to eradicate it; meanwhile last July, the U.S. Environmental Protection Agency listed it as an approved biofuel, allowing it to be planted like corn throughout the United States. The EPA established guidelines intended to keep the plant from spreading where it’s not wanted, but environmentalists are doubtful they’ll work — especially considering the difficult experience of states trying to kill it.

The battle against invasive species is sometimes viewed as a purely environmental endeavor, to preserve Hawaii’s unique, native endangered species from an encroaching world. That limited lens misses the broader societal impact: The loss of native species that support the air we breathe, the water we drink, the land we live on and the ocean that surrounds us does indeed affect everyone. Deterring invasive species that imperil any of those vital ecosystems is a priority.

The cost of that fight will continue to escalate unless the federal government fulfills its coordinating responsibilities and the USDA tightens its screening system and bans the import, transport and sale of more invasive plants. This is a national issue, of course, but Hawaii is at the forefront. The islands are home to nearly half the endangered plant species in the United States, and federal officials must recognize what’s at stake.