Impacts of storm advance restoration of grasslands
The Sanibel-Captiva Conservation Foundation reported the current clearing of dead vegetative debris that created a fire hazard on many of its preserve lands will have the long-term effect of accelerating the restoration of native habitats.
“State contractors are doing their best to maneuver through the habitats with minimal disturbance to living native flora,” Wildlife and Habitat Management Director Chris Lechowicz said.
The dead trees and shrubs created a fuel load that increased the chance of wildfires.
“Removing them will provide native grasses and ground cover plants an opportunity to take hold again from remaining seed sources in the ground and from any plantings we do to fill in the areas,” he said.
The SCCF reported Sanibel was mostly a vast open canopy grassland prior to development that was kept in that state by wildfires and a hydrology that limited freshwater to the center of the island along the Sanibel Slough during the long dry season.
Historical aerial photographs show that buttonwood, a freshwater-loving tree in the white mangrove family Combretaceae, bordered the Sanibel Slough because it was the wettest part of the island.
“Historically, natural wildfires would consume young buttonwoods that attempted to establish outside of this buffer of the river on higher land,” Lechowicz said.
In the early 1990s, the city adopted a weir control policy to better manage surface water on the island. The objective of the policy is to attempt to retain as much fresh surface water as possible for the environmental benefit of the interior wetlands, as long as developed areas are not adversely impacted.
The weir system allows the water level to be kept higher on the west end of the island as opposed to the east end because there are more conservation lands and less developed areas west of Tarpon Bay Road.
The SCCF reported that post-Hurricane Ian, saltwater inundation of the freshwater wetlands caused highly brackish water to stand for long periods of time. As a result, woody vegetation had higher mortality on the west end because the salty water inundated the root systems longer.
“The storm surge seemed to ‘turn back the clock’ slightly by decreasing living hardwood densities that overtook the expansive grasslands we once had,” he said.