Changes in Island Landscape Persist Post-Ian
The storm surge from Hurricane Ian drastically changed much of the landscape on the island. Besides seeing the immense quantity of dead vegetation throughout Sanibel, many people wondered what vegetation would eventually replace the seemingly endless acres of brown or gray leafless trees and shrubs, especially in areas where it was removed by contractors.
“Well, approximately 16 months later, we continue to document what species are taking advantage of this opportunity and which have not rebounded,” said Wildlife & Habitat Management Director Chris Lechowicz. “Also, we have noticed several species appearing in areas where they were not present before.”
The most obvious vegetation loss, post-hurricane, was of hardwood trees, such as buttonwood (Conocarpus erectus), especially west of Tarpon Bay Road. This native, but extremely aggressive tree is the main invader responsible for open canopy wetland loss on the island due to more available ground water throughout the year and infrequent fire occurrence.
In buttonwoods’ absence, cordgrass (Spartina bakeri), water hyssop (Bacopa monnieri), and other wetland plants have started to come back in several areas. Cattails (Typha sp.) are also present in several wetlands where they did not occur.
“Although cattails are native as well, they are often a sign of high nutrient loads which could have been caused from septic tank failure due to the hurricane,” said Lechowicz. “If left unchecked, cattails could overtake a wetland. We will be managing them in specific wetlands.”
Fortunately, some invasive plants such as air potato (Dioscorea bulbifera), climbing cassia (Senna pendula), and younger Brazilian pepper (Schinus terebinthifolius) suffered heavy losses due to the surge. These species are starting to grow again from seed but are easier to eradicate at this size.
In areas where dead vegetation has been removed, aggressive native groundcover plants and vines quickly spread to all the open areas. SCCF land managers have noticed a barrage of hairy cowpea (Vigna luteola) coming in after areas are cleared of dead vegetation, as well as the non-native shrub, cure-for-all (Pluchea carolinesis), and the native flat sedge (Cyperus ligularis).
A multitude of seeds have been transported around the island to new areas by the storm surge.
“This can be a good thing or not-so-good thing depending on what floral and faunal species the habitat is being managed for,” said Lechowicz. “We are keeping a close watch, so we do not lose rare and sensitive species to habitat changes.”