Two general approaches are used in connection with mangrove restoration. One method only focuses on the replanting of mangroves to replenish those that were lost. The other concentrates on discovering the reason for losses and preventing further loss of mangrove habitat. This philosophy supports natural recovery of the ecosystem, once the sources of destruction have been discovered and eliminated (Lewis & Streever, 2000). Both of these approaches have merit for different reasons.
The first option is to plant mangroves to replenish areas that have been lost. This method is the most costly in terms of capital input. However, it will result in the most rapid recovery of the mangrove forests. Natural recovery of the forests takes between 15-30 years, and that is only if the sources of destruction can be adequately controlled (Lewis & Streever, 2000). However, as mentioned earlier, replanting may be difficult, especially if the area has been altered in such as manner that it will not support mangrove species. However, there are many different species of mangroves and it may be possible to find a species that will survive in the new environment (Lewis & Streever, 2000).
Manmade habitat destruction can be controlled to a certain degree. For instance, limits could be established that help to eliminate pollution from runoff and manufacturing wastes in order to preserve what is left of the mangrove forests. However, one cannot control destruction of mangrove forests due to increasing storm damage. This type of damage could significantly hinder slow natural recovery processes. Therefore, it is proposed that supplemental plantings of the mangrove forests be undertaken, in addition to programs to help eliminate further destruction of the stands my manmade means. This two-fold approach will result in rapid stand recovery and prevent further losses of newly established and existing mangrove trees.
Thus far, several mangrove repopulation projects have already begun with varying degrees of success. Local laws now prohibit the dumping of wastes and other forms of pollution into the Indian River Lagoon in compliance with the 1987 Estuaries and Clean Water Act (EPA, 2008). An aggressive program has been underway since the late 1980s to make people and businesses in the area more aware of the income and value of the Indian River Lagoon as a natural resource. However, these efforts are not enough, necessitating greater concentration on re-planting efforts.
Proposed Solution
The proposed solution will enhance current efforts to restore the mangrove replanting projects currently underway. Pollution control continues to be a priority in the local community. They understand the importance of the estuary from a natural and economic standpoint. The Indian River Lagoon has received national attention from the Federal EPA. Therefore, efforts for this proposal will focus on rapid environmental recovery.
As we discussed earlier, replanting efforts are highly risky for several reasons. The first is that conditions in the water and soil may have changed since the original mangrove stand was destroyed. This is highly likely because mangroves have mechanisms that interact with surrounding water and soil to help create the optimum growing conditions for themselves. It is difficult to get new plantings to establish, as mangroves are adapted to a narrow range of conditions (Hill, 2001). However, there are many different mangrove species available, even though a few species may dominate an area.
Replanting is necessary in order to rapidly establish the groves to a point where their root systems are anchored enough to withstand increasing storms. The strength of these storms cannot be determined, and there may be cases where replanting efforts are destroyed. Sources agree that rising ocean temperatures will have an impact on increasing storms and hurricanes along Florida coasts (CSIRA Australia, 2001). Established trees have a greater chance of survival than younger trees in the face of increasing storms. Therefore, planting efforts must be immediately increased and the success rate of these plantings must be increased as well, in order to make certain that newly planted stands have the best chances for survival in the near future.
Although many well-meaning agencies and groups have worked on replanting efforts, the number of trees planted is minimal, when compared to the rate of loss currently being experienced in the region. The Florida Department of
Numerous habitat restoration projects have been sponsored by private groups, such as Coastal Conservancy Association (CCA). However, these projects are typically small in scale, ranging from $20,000 to one project that divided $200,000 over a nine state area (CCA, 2007). These projects are helpful and demonstrate that some effort is being spent on mangrove restoration, but these projects are not enough. Furthermore, greater effort needs to be placed on ensuring that new plantings are able to establish successfully.
The project that is being proposed will increase the scale of planting activities currently being undertaken in the state of Florida. In addition, it will take additional methods to ensure that new plantings have a greater survival rate. The intended goal of the project is to ensure the planting of 200 acres of mangrove trees in one of the most heavily damaged, and most critical to protect areas of the Indian River Lagoon. The area chosen is the near the City of Fort Pierce (Nocera, 1998). This project is a follow-up to the 1998 study that demonstrated a significant potential loss of income from mangrove deforestation in this area.
The area chosen fro reforestation will be carefully studied to determine any environmental changes that could affect the viability of the reforestation project. Rather than simply choosing a section of land for reforestation, soil and water samples will help to determine the site with the greatest likelihood of success. The area will be mapped to determine the best locations for the establishment of mangrove stands. Species will be chosen that are best suited to the local conditions, with as little input as possible to amend soil and water conditions.
It is possible to amend soil and water conditions to support the new plantings. However, this represents additional expense and will incur a maintenance cost to keep it up. This is not considered to be a sustainable method and there may be negative effects on important species that are undesirable. This method has the potential to harm threatened or endangered species that the project is attempting to protect. Working with the existing natural environment is the most cost effective and sustainable method for the replanting project. Soil samples represent an additional expense, but also increase the chances of success by minimizing losses due to planting a species in an inappropriate environment.
Cost/Benefit Analysis
The average natural density of mangrove forests ranges from 1,520 trees pre-hectare to 25,000 trees per hectare, depending on trunk diameter and several other factors (Lara-Dominiguez et al., 2005). The optimum plant density for the Indian River Lagoon averages 10,000 trees per acre. This would allow approximately nine square meters per tree. This would allow trees to achieve an ample trunk diameter and canopy to support fish populations.
The estimated costs of the project are as follows.
200 acres replanted X 10,000 trees per acre = 2,000,000 trees
Cost of trees is estimated to be $1.00 per tree through a wholesale source
Labor will be free and will utilize community volunteers
Advertising to inform the
public and encourage participation = $5,000
Soil and Water Samples = $100,000
Total Costs of Project = $2,105,000
It is estimated that the St. Lucie County will realize an approximate $2 billion in
revenue from additional natural resources, including expanded fishing ability within ten years after the initial planting. In addition, the project will
play a significant role in helping to protect the eastern Florida coastline in the event of a storm surge. The costs of this protection are too high to estimate when one considers the potential for property loss and loss of lives.
Conclusion
The importance of achieving success in restoration of the mangrove forests along the Indian River is significant, particularly when one considers the protection from storm surges that mangroves provide. The cost of the project is minor and can be recouped over time through increased industry from the lagoon. However, this pales when compared to the ability to protect from storm surges, which are expected to increase in the future. The costs of not embarking on this project cannot be estimated.
This approach to mangrove restoration will result in a greater success rate of established plantings. Matching species to native soil and water conditions will help to guarantee success. Using this method will encourage the natural spread of species, once the replanting is established. It is wasteful to plant trees where they will not thrive. The extra effort expended in soil and water sampling will reap major benefits in the assured success of this project. The people of Florida and the world depend on the success of this project.
References
Coastal Conservancy Association (CCA). (2007). CCA Florida Habitat Restoration Projects. Retrieved April 9, 2008 at http://www.ccaflorida.org/habitat.html.
CSIRO Australia (2001, February 14). Storm Surges Increase with Warming Oceans. ScienceDaily. Retrieved April…
