Everglades - Past

1
Everglades - Past

• A century ago, interconnected rivers, lakes, and
  wetlands spread across much of S. FL

2

• Beginning near Orlando, it extended south through
  the Kissimmee River to Lake Okeechobee,
• water seeped into an expanse of marshland
  reaching all the way to the tip of Florida, into
  Florida Bay,

3
Then Now
4
(No Transcript)
5

• eventually spilled over the Florida Keys onto the
  coral reef tract.
• People (1800s) reported hundreds of thousands of
  wading birds
• ibis, egrets, storks, and spoonbills
• Florida panthers, roamed the marshes.
• Alligators lived in the inland marshes,
  crocodiles along the coast.

6
(No Transcript)
7
(No Transcript)
8
Everglades - Present

• Everglades ecosystem is the most endangered
  ecosystem in the country.
• 1/2 have been drained and lost to urban and
  agricultural development.
• Remaining marshes are criss-crossed with 1,400
  miles of canals.
• Natural water flow patterns have been altered and
  regulated.

9

• Water flowing from farms and urban areas is often
  polluted with fertilizers pesticides
• Wading birds - decreased by 90 to 95
• More than a dozen species endangered among the
  Florida panther, American crocodile, wood stork,
  and snail kite.

10
LESS WATER ...

• Marsh now comprises about 2,300 sq. mi. 3/5 is
  impounded in the Water Conservation Areas.
• 2/3 now subsists on the rain that falls on 1/3 of
  the original watershed.
• These changes have reduced the availability of
  water and altered the Everglades hydroperiod.

11

• Impounded pools that accumulated during the wet
  season are rapidly drawn down.
• Most habitat vanished as a result of these
  massive changes
• Less water is available for the remaining
  wildlife.

12

• Much ecologically specialized wildlife has died
  or been forced out of the region.
• The alligator population has dropped from 50,000
  to 10,000.

13

• Snail kites (500 are left), and
• Wood storks are now seen in Central Florida
  because their habitat is gone.

14
Melaleuca Tree - Exotic

• Melaleuca is a pest introduced from Australia.
• In the Everglades the trees grow into immense
  forests, virtually eliminating all other
  vegetation.
• During the 50 years since its introduction,
  melaleuca has taken over hundreds of thousands of
  acres of Everglades, threatening the very
  existence of this internationally known
  eco-treasure.

15
Brazilian Pepper - Exotic

• Brazilian pepper tree is native to Argentina,
  Paraguay, and Brazil.
• Its bright red berries and brilliant green
  foliage are used frequently as Christmas
  decorations.
• It is an aggressive invader of disturbed
  habitats.
• Many plant communities such as hammocks,
  pinelands and mangrove forests are often invaded
  and dominated by Brazilian pepper

16
Air Potato - Invasive

• A native to tropical Asia, air potato, Dioscorea
  bulbifera, was introduced to Florida.
• Due to its ability to displace native species and
  disrupt natural processes such as fire and water
  flow, air potato has been listed as one of
  Floridas most invasive plant species since 1993.

17
Shoebutton ardisia - Invasive

• Ardisia elliptica is native to Asia but escaped
  cultivation
• Evergreen, small tree to 5 m (17 ft) tall, new
  foliage often reddish.
• Abundant in hammocks, disturbed wetlands, and
  tree islands in marshes, forming dense stands in
  forest understory and crowding out native plants.

18
ALTERED WATER CHEMISTRY

• Everglades is a highly oligotrophic system.
• Its native communities are in balance with the
  very low nutrient supplies provided by unpolluted
  rainfall.
• The rate of plant growth is probably limited by
  phosphorus

19

• Nutrients such as N and P due to human activities
  result in cultural eutrophication (fig. 14-23)
• 1. Mats of algae and microorganisms disappear
• 2. Blue-green algae appear in their place.

20

• 3. Dense monocultures of cattails force out
  native plant and take over marsh, wet prairie,
  and slough
• 4. Rapidly closing off open places where birds
  once fed.

21

• Because of the plants' rapid growth rate,
  detritus forms an anaerobic ooze under the
  cattails.
• Dissolved oxygen in the water is nearly zero.
• Other than air-breathing gambusia, no fish can
  survive in the water.

22

• When the Everglades Agricultural Area was
  drained, oxygen entered the soil, and
  microorganisms then completed the process of
  consuming it.
• The soil continues to oxidize, turning to a fine
  dust.
• In 60 years the soil surface of the EAA has
  dropped about five feet.

23

• The microbes also excrete phosphorus-which
  eventually enters the Everglades.
• Individuals who dispute the nature, extent, and
  significance of Everglades degradation appear to
  be employed, directly or indirectly, by
  agribusiness, the major pollution source.

24
Saving Our Future

• The Everglades restoration effort is the
  largest-scale project ever attempted
• Plans are underway to restore the water flow
  throughout in a way that mimics the natural flow.

25

• Clean up the polluted waters of the Everglades.
• Buy privately owned lands -- through federal and
  state acquisition programs -- before they are
  lost to development.