Controlling Invasive Exotics: A Tallow Tree Replacement Program Campaign in Florida

Horticultural And Ecological Features Of Tallow Trees

Garnering public support for an anti-tallow tree campaign was challenging because, in many ways, the species is horticulturally superb. This well-known species that originated in Asia grows rapidly under a variety of conditions (Jones and McLeod 1990), suffers little from pests or pathogens, requires little tending, produces attractive white fruits, and has foliage that turns bright orange in the autumn (Randall and Marinelli 1996). Unfortunately, tallow fruits are also attractive to birds and other wildlife that readily disperse the seeds. Given that a 3-year-old tree with a stem caliper of only 10 cm (3.9 in.) might already be producing 100,000 seeds per year (G. Jubinsky, personal communication), a high proportion of which are viable, the potential rate of tallow invasion is alarming. Tallow seeds also seem to be water dispersed, and the seedlings tolerate flooding to the same degree as red maple (Acer rubrum) and bald cypress (Taxodium distichum) (Jones and Sharitz 1990). Perhaps not surprisingly, it is in wetland communities that tallow trees seem to be having their most severe impacts.

Tallow trees are invading natural and semi-natural communities all over the southeastern United States. Many floodplain forests along the coastal plain now have understories dominated by tallow. In Texas, coastal prairies have been transformed into tallow forests (Bruce et al. 1995).

Land stewards and other environmentalists are aware of the problem posed by the tallow tree (Randall and Marinelli 1996), and legislation prohibiting its commercial propagation or sale has passed or is pending in Florida and several other states. Although Florida’s Exotic Plant Pest Council (1995) lists it as a Category I Species (i.e., a species that is invading and disrupting native plant communities), Florida Trend Magazine recently ran a full-color story on tallow in which its many horticultural virtues were extolled. The gardening sections of newspapers in the region also regularly promote tallow trees. Obviously, the battle against tallow is and will continue to be uphill.

Environmental Education About Invasive Exotic Species

To increase the likelihood that people in Gainesville, Florida, will realize that their horticultural decisions can have adverse effects on local parks and other nature preserves, we carried out a multifaceted environmental education campaign aimed at tallow eradication. First, the City of Gainesville arborist, together with the city’s Tree Advisory Board and the Department of Botany at the University of Florida, solicited support for the campaign from the Florida Native Plant Society, Kanapaha Botanical Garden, the City Beautification Board, various local garden clubs, and other county and state governmental agencies such as the Florida Department of Agriculture’s Division of Plant Industry, the state Division of Forestry, Alachua County’s Environmental Protection Department, and the Florida Department of Environmental Protection. Managers at Paynes Prairie State Preserve, a bit of natural Florida that is much beleaguered by tallow and other exotics, also endorsed the program. With the support of these organizations, we asked local members of the Florida Nursery Growers Association to offer discounts on trees of native species purchased as replacements for tallow trees removed from private property. Several nurseries agreed and advertised 30% discounts on desirable replacement trees. Supporting organizations were acknowledged individually on Arbor Day posters printed for the campaign (Figure 1). These 4-color posters were designed in such a way that they can be used in future years as well. The city arborist and the Tree Advisory Board also prepared a brochure about tallow trees to be distributed to tallow owners by the regional electric utility’s line clearance coordinators during their annual visits to homes with overhead utility wires. With a broad base of support in the community, we scheduled a series of events related to the Gainesville Arbor Week celebration.

Figure 1.

A black-and-white rendition of a color poster used on Arbor Days for the tallow tree replacement program.

In keeping with a local tradition, city staff together with volunteers from the University of Florida, Florida Cooperative Extension, and the Gainesville Garden Club held a series of tree planting ceremonies at local elementary schools. The volunteers helped the students at 11 schools plant trees and talked about the importance of trees. We planned to talk about the problem with tallow trees, but the students’ abundant enthusiasm (most were third-graders) and lack of time often made it difficult to introduce the concept that not all trees are beneficial.

During our Arbor Day ceremonies, in addition to acknowledging Gainesville as a Tree City U.S.A. (for the 13th year in a row) and applauding the “Treemendous” Gainesville Program (more than 1,000 trees planted per year on city lands and rights-of-way), Greg Jubinsky from the Exotic Plant Pest Council and Jim Weimer from Paynes Prairie State Preserve gave public lectures about the regional and local threat posed by tallow trees. The lectures were well attended (approximately 100 people) and received some media coverage.

We held 3 other media events that highlighted the tallow problem and the tree replacement solution. Prior to these events, we kept the environmental reporters at local newspapers informed about the programs. The results were 2 articles with pictures in The Gainesville Sun (circulation 59,000 daily), and several related stories in other newspapers and on local radio and television stations. The Sun published stories on the removal of tallows from Kanapaha Botanical Garden and on a Tree Advisory Board member cutting down a large tallow along a main thoroughfare. Unfortunately, by the third scheduled event (the allimportant replanting of a live oak by the City Beautification Board), the news media were apparently saturated with tallow-related stories. Nonetheless, our goal of informing the public about the campaign was achieved at almost no cost.

The tallow tree replacement campaign evoked considerable public response, not all supportive. Two letters to the editor of The Gainesville Sun, in particular, were scathing in their denunciation of the campaign, the city arborist, the Tree Advisory Board, and tree cutters in general. Published responses to these criticisms were numerous and very supportive but, more important, this heated public exchange seemed very effective at increasing awareness of the issue of invasive exotics. Months after commencement of the campaign, the University of Florida’s delays in complying with repeated requests to remove its tallow trees also received press coverage.

Lesson Learned And Recommendations

Although we were generally pleased with the outcome of the tallow tree replacement campaign, we learned some lessons that should help us in the future and may help other groups contemplating similar programs. First and foremost, environmental managers need to work harder at communicating to the public the concept of ecosystem management. The public needs to understand that maintenance of healthy natural ecosystems needs to begin in their own backyards. It is also critical that the public recognizes that maintaining natural ecosystems often requires active management. Where the seedsheds of nature preserves include suburban areas, problems with invasive, exotic, horticultural species are often severe. Management of these natural areas cannot stop at preserve boundaries but should encompass the surrounding areas. And finally, these messages need to be widely and clearly proclaimed.

The backlash against removing tallow trees might have been avoided if we had planted a native tree immediately in the place of the tallow tree we cut down. This arrangement was not possible at the site selected because there was only one appropriate planting spot and it was occupied by the herbicide-treated tallow stump. In retrospect, we should have selected a different site where tallow tree removal and replacement could have been more closely juxtaposed in time. Designers of tree replacement programs might generally be more careful about proceeding gently, lest the critical support of tree lovers is lost.

The message that not all trees are necessarily good is difficult to communicate. Because of this contradistinction, Arbor Day may not have been the best choice of times to start an exotic tree eradication campaign; perhaps Earth Day might have been more appropriate. Above all, we need to build awareness of the invasive exotic problem while simultaneously fostering support for the urban forest.