There is a lot of concern regarding the preservation of natural habitats that serve as a home to wildlife in the United States. Urbanization seems to be responsible for the majority of habitat loss due to deforestation, however, other factors seem to be driving wildlife away from their habitats. Invading species of both animals and plants has sbeen hown to play a major role in the dispersal of native species.
Steen et al. conducted a study to determine the most effective methods of restoring reptile habitats to the reference conditions.
They noticed that forests that have been subject to fire suppression are more susceptiblbeingto be dominated by hardwood trees, this is believed to be a result of longleaf pines becoming degraded over time and not being restored by fire. The restoration process for longleaf pines usually includes the reintroduction of prescribed fires but burning an area that has not been burned for a long period may have a large number of negative effects such as excessive mortality of native species. To prevent such a devastating loss of native species, other methods have been adopted to rid a habitat of invading hardwoods such as herbicides and mechanical removal of these invading trees. The researchers, however, were not entirely sure whether these alternative methods had the same resetting capabilities possessed by the primary burning method.
The study took place on 16 different sites, each one measuring 81 ha in size in Eglin Air Force Base in Okaloosa and Santa Rosa Counties, Florida. Every one of the sites was a longleaf pine fire-suppressed area where they determined that bird-tree interaction was strong enough to use as an evaluating factor for the experiment.
All sites, except six of them which experienced a single burn between 1988 and 1989, had not experienced a burn since at least 1973, which is when record-keeping for such information began.
The experimental methods to remove hardwood trees included prescribed burning, tion, and mechanical removal within each of the sites, each site containing an area not affected by the removal methods, which was used as a control. After performing these removal methods, the researchers conducted an initial reptile count in each study site to determine the effects of each method of removal. To capture squamates in 1997 and 1998 they used drift fence arrays placed in the center of each of the 16 study sites as well as 4 reference sites. In the second phase of the study which was continued in 2009 and 2010, they reinstalled arrays in the same areas to evaluate the reptile response to each hardwood removal method since they were conducted.
The researchers found that reptile assemblages responded most rapidly to prescribed burning. While there were significant changes due to mechanical and herbicidal removal of hardwoods, none of them surpassed the positive effects of burning. Since herbicidal and mechanical methods did show to have some effect, perhaps those methods could be used in less severe cases of assemblage disturbance or in smaller habitats where fire treatment may be excessive for its particular situation. Regardless, assemblage disturbance due to invading species is a real issue caused by natural means, and should therefore be treated by natural methods.