Stephenie Lazarus Brittany Lewis Amelia Clapp The Effect of Mangrove Forest Depletion on Biodiversity in Southern Florida Stephenie Lazarus Brittany Lewis Amelia Clapp

Outline Background Hypothesis Method Analysis Discussion Implications Solutions Conclusion

Background The Mangrove Problem The planet has lost 35% of its mangrove forests over the last twenty years. The rate of loss of mangroves each year tops the loss of the rainforest at 2.1% At the current rate of destruction all of the world’s mangroves will disappear in 50 years (Wells, 2006)

World Distribution of Mangroves Background World Distribution of Mangroves (“Coastal and Marine Habitats,” 2005)

Reasons for Mangrove Depletion Costal development of mangrove forest Background Reasons for Mangrove Depletion Natural and unnatural factors Recent tsunami activity in south-east Asia Ongoing human coastal development (Stone, Richard, 2006). Costal development of mangrove forest

The American Alligator Background The American Alligator ‘Alligator holes’ Estimated 1,000,000 in Florida Alligator mississippiensis Keystone species of mangrove forests (Mazzotti, 2006)

Hypothesis “Current natural and anthropogenic factors will deplete the mangrove forests and biodiversity of Southern Florida due to the elimination of the keystone species”

Method Data Used 1 acre= 4,046.8564 m^2 469000 acres of Mangroves exist in Florida (FMRI, 2006) Net primary production (NPP) of swamps and marshes = 9000 k cal/ m2/yr (Kling, 2006) =2.22394842 k cal/ acre/yr Rate of mangrove loss= 2.1% (Wells, 2006) Average plant efficiency= 35% (Kling, 2006) Average American Alligator per km^2=1.6916 (Mazzotti, 2006) = 0.00685 alligators/acre

Procedure to Test Hypothesis Method Procedure to Test Hypothesis Construct Stella Models from given data Determine future amount of Florida mangrove forest coverage Determine future population of American Alligator in Florida Determine whether models support the loss of mangroves coverage and elimination of American Alligator population

Projected Mangrove Forest Acreage Mangrove Acreage Stella Model Analysis Projected Mangrove Forest Acreage Mangrove Acreage Stella Model

Projected Mangrove Forest Acreage Analysis Projected Mangrove Forest Acreage

American Alligator Population Model Analysis American Alligator Population Model Assumptions Alligator population only effected by habitat depletion (birth rate = death rate) Alligators require mangrove acreage to live (0.00685 alligators can live in one acre of mangroves) 3211 American Alligators exist in the 469,000 acres mangroves analyzed Because alligators are the keystone species of the southern Florida mangrove ecosystem the elimination of alligators will cause the extinction of other species and the decline of biodiversity

American Alligator Population Model Analysis American Alligator Population Model

American Alligator Population Model Analysis American Alligator Population Model Projected American Alligator Population with Decline of Mangrove Forests

Projected Mangrove Forest Acreage Discussion Projected Mangrove Forest Acreage Mangrove acreage halved by 2009 Acreage so minimal significant re-growth almost impossible Mangrove acreage crash by 2032

Discussion Projected American Alligator Population with Decline of Mangrove Forests 2030 mangrove acreage dips below 2000 Alligator population levels off at 218

Effect Mangrove Forest Acreage on Biodiversity Discussion Effect Mangrove Forest Acreage on Biodiversity If trends continue the mangrove cover in southern Florida will be depleted beyond natural rebound ability This loss of habitat results in an immense reduction of the American Alligator The reduction of the American Alligator will cause the collapse of biodiversity in the southern Florida mangrove ecosystem (loss of ‘alligator holes’ = loss of habitat)

Implications The loss of mangroves in southern Florida would have a negative effect on both the sport and commercial fishing industries since many fish either live in or use the mangrove forest as a nursery. Natural buffering capacity of mangroves will disappear resulting in loss of protection from natural disasters Numerous endangered/ threatened species currently relying on mangroves will likely go extinct Ecotourism would decline resulting in a loss of income in the economy of southern Florida

Collect and plant propagules Re-growth usually quick Solutions Mangrove Propagule Collect and plant propagules Re-growth usually quick Rehabilitated mangroves lack the biodiversity they once had (Wells, 2006) Human conservation and education efforts (prevention is better than compensation) Currently many organizations implement mapping and monitoring programs (Vaiphasa, Skidmore, and de Boer, 2006)

Recap Mangrove forests in southern Florida projected to crash by 2032 Conclusion Recap Mangrove forests in southern Florida projected to crash by 2032 Loss of mangrove acreage will result in the population crash of the keystone species in the southern Florida ecosystem A loss of the keystone species results in the loss of biodiversity Our analysis affirms our hypothesis

Conclusion Take Home Message “Southern Florida’s Mangrove ecosystem is in serious danger, but steps to preserve these mangroves still can be taken!”