Ross's original question revolved around a hurricane's affect on Liguus
populations. The 1935 hurricane that hit the Florida keys demolished the
entire "beach hammock" on Lower Matecumbe Key. This was the type locality of
L.f.dohertyi. This hurricane may have caused the extinction of this form
although there are records that dohertyi may have been planted in the
Homestead or Lauderdale areas and there is a slim chance that they survive
today in one or more of these locations. Hurricanes often cause extensive
damage to hardwood hammocks but rarely destroy an entire hammock. Cox
hammock(Monkey jungle) and many hammocks in the "Rocky Glades" area of ENP
were damaged by Hurricane Andrew. These hammocks have recovered and their
Liguus populations are alive and well.
There is a possibility that hurricanes may have actually helped spread
liguus from hammock to hammock and maybe even from Cuba to Florida. If this
did/does occur it is probably rarely. During hurricane season snails are
active and often attach themselves to leaves. Young liguus at this time of
year can be extremely small and lightweight and could possible ride a leaf a
great distance.
Thanks to collectors Liguus have been transplanted all over south Florida
over the last hundred or more years. Most forms, even ones that were
originally very rare, are now alive and well in many different locations.
People who claim Liguus are declining in numbers due to habitat destruction
are sadly mistaken. Many hammocks in the Keys have been set aside as natural
preserves. The snails in some of these hammocks were wiped out back in the
'80s by broad spectrum pesticides. However, thanks to collectors, most of
these hammocks have been restocked and now support thriving populations.
Also consider that ENP and Big Cypress Swamp together have 800 or so
hammocks that are forever off limits to development. Most of these hammocks
support thriving populations of endemic and/or introduced Ligs. Timm's, Cox,
Mattheson, even Brickell, famous old snail hammocks in Miami and Homestead
all have thriving populations, though there is little left of Brickell which
once covered most of south Miami. Pilsbry's prediction that collectors would
eventually wipe out all Lig populations never came true. In fact starting
with Archie Jones and Erwin Winte and probably continuing today there are
probably 400 hammocks that now have snails that never had them originally or
had them and the original stock was exterminated.
Don't feel sorry for Liguus. They are alive and well and probably as
plentiful as ever. Feel sorry for us lost souls who can no longer legally
enjoy collecting them.
-----Original Message-----
From: Conchologists List [mailto:[log in to unmask]]On Behalf Of
mike gray
Sent: Monday, October 31, 2005 12:54 PM
To: [log in to unmask]
Subject: Re: How do hurricanes affect the Everglades?
J. Ross Mayhew wrote:
> I was just thinking about how difficult it is to come across Liguus
> from old collections these days, which got me to wondering about how
> hurricanes affect the Everglades. A substantial storm surge would flood
> a substantial portion of this huge "river of grass" with sea water.
> Does this result in a die-off of the plants and animals with less salt
> tolerance than others? How would this affect the living systems
> involved? How long does it take large wetlands such as the Everglades to
> recover from a large hurricane?
> If anyone knows of studies which have been done along these lines,
> it would be great if they could post a summary of the results, with
> references!!
> When was the most recent time the Everglades were more or less
> directly hit by a substantial hurricane anyway?
>
> From a starry starry night in New Scotland,
> Ross Mayhew.
When the Everglades still existed, hurricanes would dump huge
amounts of water across them, and Lake O would experience a
storm surge that would empty the lake over the glades. The
result was a giant enema that washed detritus and nutrients into
the Florida Bay estuaries, carrying silt from the glades into
one of the greatest marine breeding grounds on earth, building
new banyan islands and hummocks.
Today, most of what used to be Everglades is farm land, the
entire area is channelized, the lake is surrounded by a dike,
and Florida Bay is sterile. All water flow is controlled by the
Army Corps of Engineers by a series of dams and dikes.
What Wilma did was destroy a lot of crops, scattering hundreds
of acres of plastic film used to protect some crops that had
just been started; filled the canals with debris; washed some
mercury from the sugar cane fields into Florida Bay; damaged
some Corps of Engineers dams and pumping stations; killed many
of the few remaining birds.
For the tourists, we have a few hundred acres of park that looks
much like the glades used to look, sans wildlife, and the
airboat rides and the souvenir shops are already re-opened.
Thanks to man's wisdom, planning, and technology, the Everglades
have been unaffected by the hurricanes.
m
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