BUT, those plants that are invasive exotics combine the double punch of agressive hardiness and few to no natural controls on their proliferation. Return to top of page. Nonnative species are considered the second most important threat to biodiversity, only surpassed by direct habitat destruction. On the Refuge, cogongrass was planted to control dike erosion in the 1940's and 1950's, and has spread throughout the dike system in the St. Marks unit. Easily spread through disturbance, wind-blown seed may travel up to 15 miles.
Dense clumps crowd out all other native species.
The Refuge is also applying for grant monies to help in control costs, developing a comprehensive plan of attack for all exotic species at St. Marks N.W.R., and participating in regional workshops to share knowledge and tactics as we search for more effective and species-specific control methods. Return to top of page. Seeds are borne in conspicuous clusters that look like masses of popcorn kernels, giving rise to the other common name for this plant - popcorn tree. In the U.S., it is rapidly invading disturbed and natural areas in the Southeast from South Carolina to Texas, including 38 of Florida's 67 counties. There is significant concern that this tree is displaying a pattern of spread in Northern Florida similar to the explosive growth of Melaleuca in South Florida over the past four decades.