Front Cover
 Title Page
 Table of Contents
 Historical background
 Classification system
 Survey procedures
 Literature cited
 Back Cover

Title: Florida wetlands
Full Citation
Permanent Link: http://ufdc.ufl.edu/UF00000104/00001
 Material Information
Title: Florida wetlands status and trends, 1970's to 1980's
Physical Description: 31 p. : col. ill. ; 28 cm.
Language: English
Creator: Frayer, W. E
Hefner, J. M
U.S. Fish and Wildlife Service -- Region IV
Publisher: U.S. Fish and Wildlife Service, Southeast Region
Place of Publication: Atlanta Ga
Publication Date: [1991]
Subject: Wetlands -- Florida   ( lcsh )
Wetland conservation -- Florida   ( lcsh )
Genre: federal government publication   ( marcgt )
bibliography   ( marcgt )
non-fiction   ( marcgt )
Bibliography: Includes bibliographical references (p. 25).
Statement of Responsibility: by W.E. Frayer and J.M. Hefner.
General Note: Shipping list no.: 92-257-P.
General Note: "September, 1991."
 Record Information
Bibliographic ID: UF00000104
Volume ID: VID00001
Source Institution: University of Florida
Holding Location: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: ltqf - AAA0255
notis - AJE7052
alephbibnum - 001734387
oclc - 25930159

Table of Contents
    Front Cover
        Front Cover
    Title Page
        Page 1
        Page 1a
        Page 2
    Table of Contents
        Page 3
        Page 4
        Page 5
        Page 6
    Historical background
        Page 7
        Page 8
    Classification system
        Page 9
        Page 10
        Page 11
        Page 12
    Survey procedures
        Page 13
        Page 14
        Page 15
        Page 16
        Page 17
        Page 18
        Page 19
        Page 20
        Page 21
        Page 22
        Page 23
        Page 24
    Literature cited
        Page 25
        Page 26
        Page 27
        Page 28
        Page 29
        Page 30
        Page 31
        Page 32
    Back Cover
        Page 33
        Page 34
Full Text


STATUS AND TRENDS, 1970's TO 1980's
by W. E Frayer and J.M. Hefner
Sepmbr, 1991

rreat bgret


W. E. Frayer is Dean of the School of Forcstry
and Wood Products at Michigan Technological
University. He specializes in natural resources
survey design and analysis

J. M Hefner coordinates the National Wetlands


Special thanks for contributing to various parts of
this study are given to H. Ross Pywell and Tom
Dahl, U. S. Fish and Wildlife Service.

Many individuals from Martel Laboratones, Inc.
were responsible for photo interpretation, map
production, and change analysis. Principal among
these is Keith Patterson. The work of all of them
is greatly appreciated.

Funding support from the U. S. Army Corps of
Engineers is gratefully acknowledged.

Cover photograph: Color infrared aerial view of
area south ofNaples, showing dredge and fill
development ofMarco Island and nearby islands
Front Cover Inset: Anhinga

Back Cover Inet: Aerial view of Marco Island
I i" YAIRM 0151

U.S. Fish and Wildlife Service
Southeast Region
Atlanta, Georgia


.Agrulral lands increased by 528,500 acres

The loss between the md 1970's and md- Urban and other forms of development
accounted for 2,522,100 acres m the mid

to agriclture (175,100 acres) and urban and
other forms of delopmcnt (66,000 acres)
Su..anne. R-r

Myakka RIver Start Park


Highlights .............................. ........ 2
Introduction ...................................... 5
Historical Background...................... ...7
Classification System ..............................9
Survey Procedures .............................. 13
Results ..... ............. .......... .. ....... 15
D discussion .. .......................................23
Literature Cited ......... ..................... .25
Appendix ............. ............................27



The United Stares Fish and Wildlife Scrvnce has

and wildlife and their habitats. Of particular
concern are wetlands and associated deepwater
habitats. Since 1974 the U. S. Fish and Wildhfe
Service, through its National Wetlands Inventory
Pioject, has inventoiled the nation's wetlands.
The purpose is to develop and disseminate
comprehensive data concermng the characterls-
tics and extent of wetlands

Results of a National Wetlands Inventon,
study of wetland gains and losses between the
1950's and 1970's were published by Frayer et
al (1983) and Tiner (1984). Of the wetlands at
the time of settlement in the area now compris
ing the 48 contiguous states, only 46 percent
remained in the mid-1970's. Bet een the mid-
1950's and mid 1970's, there was a loss of about
11 million acres of wetlands. During the same
period, approximately two nlllhilln acies of
wetlands were created This 20 vear net loss of
nine million acres equates to an average annual
net loss of 458,000 acres of wetlands

left. Collier County

right: Red Mangroves

Tile statistical design used in the national
trend study can be used w ith intensified sampling
to obtain reliable estimates for individual states or
other selected geographical areas This approach
was used to evaluate wetland trends in Florida
from the mid-1950's to mid-1970's (Hefner
1986). The current report presents results of a
study of wetland trends in Florida for the 10 year
period fi-om 1974 to 1984. While it p ovides
esimatcs of losses, gains and current status of
Flonda's wetlands and deepwater habitats, it does
not provide information on their quality


Historical Background

Since statehood in 1845, Florida's story has
been one of man's battle against water. This long
struggle was chronicled in detail by Blake (1980).
With abundant and seasonally concentrated
rainfall and an extremely flat terrain, as much as
two-thirds of the state consisted of marshes,
swamps, or other areas that were inundated
periodically. Therefore, especially in peninsular
Florida, preparation of the landscape for agricul-
tural or residential development meant draining
and filling of wetlands.

Large-scale drainage projects began in 1881
when Hamilton Diston purchased four million
acres of south Florida for 25 cents an acre.
Although Diston's drainage and navigation
improvement activities were only partially
successful, they called attention to the area,
leading to a population influx.

Man's assault on wetlands reached its peak
during the decades following World War II.
Florida's population mushroomed during this
period. From 1960 to 1970, the population
increased by 35 percent. By 1970, people were
migrating to Florida at the rate of over 5,000
new arrivals per week. Much of this increase was
directed toward south Florida, making the
southeast coast the nation's fastest growing
population center (Wade ct al. 1980).

From the 1950's to 1970's, wetlands were
destroyed at an average annual rate of 72,000
acres (Hefner 1986). With the dual pressures of
providing living space for new arrivals and
cropland for the production of winter vegetables,
sugar cane, and cattle pastures, the Everglades
was among the hardest hit areas. Long-term
drainage reduced the 3,600 square-mile wetland
area by 65 percent (Kushlan 1986). North of

left: Weeki Wachee River

Lake Okcechobee, channelization of the
Kissimmcc River destroyed 70 to 80 percent of
the basin's 40,600 acres of wetlands and de-
graded much of the remaining river marshes.
Along the border of Everglades National Park in
Collier County, a single development project
called Golden Gate Estates attempted drainage of
a 173-square-mile subdivision almost entirely
located in wetlands. Over 180 miles of canals
were dug, 813 miles of roads constructed, and
50,000 lots were sold worldwide. At the same
time, just south of Naples, a large resort complex
was being built on Marco Island. Approximately
5,300 acres of mangroves and uplands were
converted to finger-canal subdivisions. During
the period of massive construction from 1962 to
1973, 2,508 acres of mangroves were destroyed
in Collier County (Patterson 1986).

Wetland loss was not limited to south Florida.
For example, over a 50-year period in northeast
Florida, 62 percent of the 289,200 acres of
wetlands in the St. Johns River floodplain were
ditched, drained, and diked for pasture and crop
production (Fernald and Patton 1984). In 1972,
a single large agricultural corporation began
diking and draining 12,000 acres of forested
wetlands in the Apalachicola River floodplain for
pasture and soybean and rice growing. Else-
where, 81 percent of the seagrasses and 44
percent of the mangroves in Tampa Bay were
destroyed (Durako et al. 1988). In addition,
mangroves had been reduced by 86 percent and
seagrasses by 30 percent in the Indian River
Estuary (Durako et al. 1988).

By the 1970's, wetlands losses were felt
throughout Florida and attitudes toward their
protection were changing. Wildlife populations
had decreased, water quality had been degraded,
and water supplies for urban and agricultural
usage were stressed. Fisheries were declining,
especially among wetland-dependent species like
spotted seatrout and shrimp (Durako et al.
1988). South Florida's wading bird population

to 70,000 birds in 1972 (Crowder 1974)
Drainage of the floodplain and channelization of
the Kissimmee River resulted m a 93 percent
reduction in waterfowl usage, and bald eagle
nesting declined by 74 percent (Perrin 1986). By
the early 1980's, in south Florida, 75 species of
plants and animals were endangered and another
103 were threatened with extinction (Gleason
1984). Many like the Florida panther, Everglades
snail kite, and wood stork required wetland

Saltwater contamination of underground
aquifers occurred as wetlands on the surface were
destroyed and withdrawals were increased
(Fernald and Patton 1984). With the loss of the
water cleansing capabilities of the wetlands along
the Kissimmee River and expanded agricultural
activity, Lake Okeechobee became noticeably
eutrophic. The water quality of formerly crystal-
clear lakes and rivers declined as urban run-off
increased and subdivision lot owners removed
emergent shoreline wetlands to "improve" their
properties. Subsequently, lakes and rivers became
murky, noxious vegetation like hydrilla and water
hyacinth grew, and fish kills became common-

Large-scale wetland destruction was also
implicated m the disruption of normal rainfall
patterns and a resultant long-term drought
throughout the St Johns River basin (Barada
1982). Loss of the water-storage capability of
wetlands and the placement of subdivisions in

floodplains caused increasing frustration as new
residents experienced recurring flooding of their
properties. Organic soils formed naturally in the
wetlands of the Everglades were lost at a rate of
one inch per year from subsidence due to
drainage. In some areas, over five feet of soil
disappeared (Stephens 1984).

Growing recognition and concern over an
array of environmental problems resulted m
passage ofsignificant legislation during the
1970's Between 1969 and 1977, at least six
Federal environmental statutes, including the
National Environmental Policy Act, the Endan-
gered Species Act, and the Clean Water Act, were
passed. Florida passed a large additional body of
state legislation that also improved wetland
management. The environmental movement in
Florida gained ground during this time period.
Opposition mounted by environmental action
I I- I i i i

in the Big Cypress Swamp. Also in the 1970's,
the state began to actively purchase valuable
wetlands through programs such as the Envron-
mentally Endangered Lands Program, the
Conservation and Recreational Lands Act, and
later the Save Our Rivers Program operated by
the water management districts. In 1983,
Governor Bob Graham announced a broad-based
mult-millon dollar program to restore the
ecology of the Everglades. In 1984, Florida passed
the Warren S. Henderson Wetlands Protection Act,
which increased Department of Environmental
Regulation lunsdicton over wetlands


Classification System

The definitions, classifications and categories of
wetlands and deepwater habitats used are those
described by Cowardin et al. (1979). In general
terms, wetland is land where saturation with
water is the dominant factor determining the
nature of soil development and the types of plant
and animal communities living in the soil and ont
its surface. Technically, wetlands are lands
transitional between terrestrial and aquatic
systems where the water table is usually at or near
the surface or the land is covered by shallow
water. Wetlands must have one or more of the
following three attributes: 1) at least periodically,
the land supports predominantly hydrophytes; 2)
the substrate is predominantly undrained hydric
soil; and 3) the substrate is nonsoil and is satu
rated with water or covered by shallow water at
some time during the growing season of each
year. Common terms used to describe various
Florida wetlands include marshes, swamps, bogs,
small ponds, sloughs, nver overflows, mud flats,
and wet prairies.

Deepwater habitats consist of certain perma-
nently flooded lands. In saltwater areas, the
separation between wetland and deepwater
habitat coincides with the elevation of the
extreme low water of spnng tide. In other areas,
the separation is at a depth of two meters (6.6
feet) below low water This is the maximum
depth in which emergent plants normally grow.
Common names used for Flonda deepwater
habitats include bays, lakes, and reservoirs.

left: Kissfmmee River

right: Everglades

Within the classification structure that follows,
wetlands and deepwater habitats are grouped
according to systems. A system consists of

Each system is further divided by the driving
ecological force, such as ebb and flow of tide, and
by substrate material and flooding regimes, or on

study and the detail to which aerial photography
could be interpreted.

The marine system extends from the outer
edge of the continental shelf to the high water of
spnng tides or to the boundary of other systems
as defined later. Marine subtidal includes that
portion that is continuously submerged. Because
of relatively small expected change in this por-
non, it was not included in the study. Marine
intertidalincludes areas in which the substrate is
exposed and flooded by tides, including the
associated splash zone.

The estuarine system consists ofdeepwater
tidal habitats and adjacent tidal wetlands which
are usually semi-enclosed by land, but have open,
partially obstructed, or sporadic access to the
open ocean and in which ocean water is at least

plants and animals, such as mangroves and

oysters, are also included. Estuarine subtidal is
that portion that is continuously submerged
(considered deepwater habitat), while estuarine
intertidalls the portion exposed and flooded by
tides, including the splash zone. For the purposes
of this study, estuarine intertidal wetlands were
separated into the following groups:
Nonvegetated, which includes unconsolidated
shore and aquatic beds (i. e. seagrasses); and
vegetated, which includes emergent, and forested
and scrub/shrub. Emergent contains pnmarily

ized by the presence of trees, and scrub/shrub
includes areas dominated by shrubs and small or
stunted trees.

Loggerhead Key

The lacustrine system includes wetlands The palustrine system includes all nontidal
(littoral) and deepwater habitats (limnetic) wetlands not included within any of the other
situated in topographic depressions or dammed four systems and does not include any deepwater
river channels. Each area must exceed 20 acres or .1- I i .
be deeper than 6.6 feet or have an active wave- i .. I
formed or bedrock shoreline feature. Lacustrine which includes unconsolidated shore, unconsoli-
areas are grouped together as deepwater habitats dated booms (primarily ponds), and aquatic
in this study, bedr, and vegetated, which includes emergent,
forested, and scrub/shrub. Definitions are the
The riverine system includes wetlands and same as those for estuanne wetlands.
deepwater habitats contained within a channel
For this study riverine subsystems (tidal, lower
perennial, upper perennial, and intermittent)
were grouped together as deepwater habitats.

White water lilies

All remaining surface area (area not classed as
wetland or deepwater habitat) was placed in three
categories. These are agriculture, urban, and
other These correspond to classes described by
Anderson et al. (1979) at their Classification
Level I. Other includes Anderson's Level I classes
of forest land, rangeland, and barren land, as well
as lands that had been drained and cleared of
vegetation but had not been put to identifiable

This briefly describes the classification used in
this study. Itis difficult to differentiate the
i .. i I i, I iI

definitions, and fuller descriptions are presented
by Cowardin et al (1979) and Anderson et al.

Everglades agricultural area


Survey Procedures

The objectives of the study were to develop
statistical estimates for categories of wetlands and
deepwater habitats for the mid-1970's, the mid-
1980's, and the change for the period.

physical subdivisions described by E. H.
Hammond (1970) and a specially developed
coastal sratum encompassing most of the marine
and estuarine categories used in the study. The

strata in a prenous study (Frayer et al. 1983) in
proportion to expected amounts of wetlands and
deepwater habitats as estimated by U. S. Fish and
Wildlife Service personnel. The total number of
sample units used in this study was 644.

Each sample unit is a four-square mile area,
two miles on each side. The units had been
plotted or i i
maps fort i 1 1i 4111 :
i- nlr- ---1 --- --.vith

obtained for the mid-1970's The majority of this
photography was taken in the years 1972
through 1977 (mean of 1974). The mid-1980's
aenal photography consisted of 1-58,000 scale
color infrared transparencies taken primarily in
1983 through 1985 (mean of 1984)

tion system descnbed earlier and with procedures
developed by the U. S. Fish and Wildlife Service's
National Wetlands Inventory Project. The results
were compared with the mid-1970's photogra-
phy, and changes in classification were annotated
Both the recent classification and the classifica-
non for the mid-1970's were recorded for each
change. Ifa change was human-induced, that was
recorded also.

Apalacncola Natonal Forest



Thie intent of this sudy was to exainie wetland Olther category%, listed singl as in Table 1
change that occurred from the mid-1970's to the include agrcelturc, arban, and other
mid- 1980s. The average years hf the phoogra-
phy arc 1974 and 1984, itth an average interval Status and trends result pricnted in the
of 10 years Thus, the rceults should be interim rcmndei of i hlssection are based on inorma-
prctcd in terms of a 10-year inerval tion i ound m Tables I and 2

Results for the categories discussed in the

Table I werc grouped based on phyvscal, chmli
cal, and biological similarities and arc shown in
Table 2 of the Append\. Giopinpgs in Table 2
include the following'

WIetlands and drepwater habitats includes all
marine, est arlne, paliusltimi, ri nei and
laculstnl'c classliicatlons

W'rlands includes marine, estarinn, and
palustrine wetlamnds

Pstuariii wetlands includes all estuarne
categories except estua ie subtidal (a deepwater

palustrine sstmsi.

Palustrine wtrlands includes all palustrne

Dieepwiatr habtats cliudesestuarinc subtidal,
rivc and lacustrme habitats

Mxakka River State Park

Near Sutanreec Riier

-AK W.!-OFT ""V.



4,1 .
r Ow



The mid 1970's csmnat ofwetlands and
d-eepwatr habitats -s 15,821,700 acr. The mid
1980's climate is 15,584,600 acres, a ot l- os of

Iglclurc and urban expansion.

The rind 1970's and mid 1980's estimates of
wetlands arc 11,298,600 acres and 11,038,300
Tcre, rpccncl Thi is a T t1 los of 260,300
acres, or a a\ eragt annual net loss f 26,030
acre, The va,t nalorty, of the loss -,'as to
ar"Lultutnc, ttrban expansion and other Fnrn- of

Marine Intetidal Wetlands

Esuarine Wetlands
Soeh loss n cstuarine e lands -hs crxpern ncd,
with 2 800 acre ,oumcd b i urbanizaion Of
this total, 2,700 acres i\ ere prc loJlyJ cstuarine
vgcetated wetlands.

Black Nedicrush Marsh, Herandi o Count,

Palustrine Wetlands
The mid-1970's and mid-1980's estimates of
palustrine wetlands are 9,902,200 acres and
9,644,800 acres, rspectvely. This is a net loss of

Palutrne Nonvegetated Wetlands
Palustnne nonvgctated wtilands increased by
32,400 acres. Most of tillS increase was in
I I I ,I I

Palustine Viegmted W ,lands
There was a net loss o289,800 acres (I


Broker Creek Park, Pmnellas County
rIst -Ion I I -~.Sli

Palustrine Emerent Wetlands
A net los of 110,000 acres of palustnn ru-

c,vertcd to, agriculture

Palustrine Forested Wetlands
There \as a lets of 184,100 acres of

Ho \eer, 39,200 a ncs ere coertHcd by
u'banjlbatlon, a-d an-orlde 43,600 acres arc nowl
,bas..d a, non-wcfl-nd s

Palustrine Scru b/Shrub Wetlands

aerc some significant losses that were othet bi

came prninarily from other palustrnne egetated

Matgoon Con.


-Isse d 1570',5 s s ld 19M)" F,,
dsat liabi, a,, s- 4,523,100 sosd 4,546,300
acres respectively Of this iet iocrease 4232.,200
aIct,, 22,400 acres k,,re clue to incre-sc5 in the
lacustrine category, (lakes andi rc- oilrs)


1980', )hs ss-lss-s-s of 528s500-scrc-,res
p odily f'onm 1111, fl), lo- g changes

-175,100 acres Of-passtrin -lands to
6 43,600 acres ohion-etlatinds t- griCulture


LUrban sicasexpanded ),s 551,600a1crcs As
ex-pecs-ed a-Is-s- p)oitis-(36,s 00-s-s (3 canic

-rcr connrcr s tr ssolss sCUlure asId 66,000
acres crc comerted fi oni wet~lrlands.b



Be the mid-1970's, attitudes toward wetlands

Perhaps inorc inaponianti) the effects of ramparit
wetland destruction ofthe previously decades were
felt th oughoot Flcuridal Clean sur cc wte isnd

Federal legislation was passed in response to a
growi ng national concern for the c-in n~incrit

Although the fig t to protect wretlands
continues, cent ,nraccpare particu larlv

q~Rhlt C-ric C-nryt

aurlionzed to acquire 107,60U acres to the Eaar
''~'~'~'~ ""~'~'~ I'
'' ''

Florida has jadc a concerted effortl~ to bov
imaportant wetlandd tracts State land purchasedd

acres, werr 60 pcrccnt of\hich are wetlands, at c
ILindel- consideration.

11,ssi ,c Ricer' and associated inarshes ad the
restoration and reconstruction ofthcrh St hilins
lbver nia, slics. Both pi ojcctrs n-c of treniendou,\

cnp"" action Inrtween I~oodtstnc and
cclcrai government In addition, marshes are

created to act as tcruarv wastewater rcatjncnt

waste management systems.

State programss requiring pennies for activities

of water manlagen-itr districts and ofsm sorri

been coonnitedh to their conservation. With
these positive signs, an analyst, 66lon6da's
wtland trends in the 1990's h..ld be ever,
note encouraging.

Literature Cited

Anderson, J.R., E. Hardy, J. Roach, and R.
Witmer. 1976. A land use and cover classification
system for use with remote sensor data. U. S.
Geol. Surv. Prof. Paper 964. 22 pp.

Barada, W. R. 1982. The St. Johns River: An
environmental time bomb.
Enfo. Rept. 82(2):1-8.

Blake, N. M. 1980. Land into water water into
land. A history of water management in Florida.
Univ. Presses of Fla., Tallahassee. 344 pp.

Cowardin, L. M., V. Carter, F. Golet, and E.
LaRoe. 1979. Classification of wetlands and
deepwater habitats of the United States. U. S.
Fish Wildl. Scrv. 103 pp.

Crowder, J.P. 1974. Some perspectives on the
status of aquatic wading birds in South Florida.
U.S. Bur. Sport Fish. Wildl. South Fla. Env. Proj.
Ecol. Rept. No. DI-SFEP-74-29. 16 pp.

Durako, M. J., M. Murphy, and K. Haddad.
1988. Assessment of fisheries habitat: northeast
Florida. Fla. Mar. Res. Publ. No. 45. 51 pp.

Fernald, E. A., and D. Patton. 1984. Water
resources atlas of Florida. Fla. St. Univ., Tallahas-
see. 291 pp.

Frayer, W. E., T. Monahan, D. Bowden, and F.
Graybill. 1983. Status and trends of wetlands and
deepwater habitats in the conterminous United
States, 1950's to 1970's. Colo. State Univ. 32 pp.

Gleason, P. J. 1984. Introduction. In P. J.
Gleason, Ed. Environments of south Florida:
present and past. Miami Geol. Soc. Memoir II,
Miami, Fla. pp. VIII-XXIII.

Hammond, E. H. 1970. Physical subdivisions of
the United States. In National Atlas of the
United States. U. S. Geol. Surv. 417 pp.

Hefner, J.M. 1986. Wetlands of Florida 1950's
to 1970's. In E.D. Estevez, J. Miller, J. Morris,
and R. Hamman, Eds., Proceedings of the
conference: managing cumulative effects in
Florida wetlands. New College Env. Studies
Prog. Publ. No. 37. Omnipress, Madison, Wise.
pp. 23-31.

Kushlan, J.A. 1986. The Everglades: manage-
ment of cumulative ecosystem degradation. In
E.D. Estevez, J. Miller, J. Morris, and R.
Hamman, Eds., Proceedings of the conference:
managing cumulative effects in Florida wetlands.
New College Env. Studies Prog. Publ. No. 37.
Omnipress, Madison, Wise. pp 61-82.

Patterson, S.G. 1986. Mangrove community
boundary interpretation and detection of areal
changes in Marco Island, Florida: application of
digital image processing and remote sensing
techniques. U.S. Fish Wildl. Serv. Biol. Rep.
86(10). 87 pp.

Perrin, L.S. 1986. Wetland status and restoration
agenda for the channelized Kissimmee River. In
E.D. Estevez, J. Miller, J. Morris, and R.
Hamman, Eds. Proceedings of the conference:
managing cumulative effects in Florida wetlands.
New College Env. Studies Prog. Publ. No. 37.
Omnipress, Madison, Wise. pp. 83-91.

Stephens, J.C. 1984. Subsidence of organic soils
in the Florida Everglades: a review and update.
In P.J. Gleason, Ed. Environments of south
Florida: present and past. Miami Geol. Soc.
Memoir II, Miami, Fla. pp. 375 382.

Tiner, R. W. Jr. 1984. Wetlands of the United
States: current status and recent trends. U. S.
Fish Wildl. Serv. 59 pp.

Wade, D., J. Ewel and R. Hofstetter. 1980. Fire
in south Florida ecosystems. U.S. Dept. of Agric.
For. Serv., Gen. Tech. Rep. SE-17. 125 pp.


Estimates produced include acreages with
associated standard errors. Many estimates are
not considered reliable enough to recommend
their use for making decisions. An indication is
given of the reliability of each estimated acreage
in the summary tables included in this appendix.
The standard error of each entry expressed as a
percentage of the entry (SE%) is given in paren-
theses. Reliability can be stated generally as "we
are 68 percent confident that the true value is
within the interval constructed by adding to and
subtracting from the entry the SE%/100 times
the entry." For example, if an entry is one million
acres and the SE% is 20, then we are 68 percent
confident that the true value is between 800,000
and 1,200,000 acres. An equivalent statement for
95 percent confidence can be made by adding
and subtracting twice the amount to and from
the entry.

Therefore, a large SE% indicates low reliabil-
ity, if any, in the estimate. In fact, if the SE% is
100 or greater, we cannot even say that we are
68 percent confident that the true value is not

This discussion on reliability is meant to aid in
interpretation of the study results. It was ex-
pected that only certain estimates would be
precise enough to be meaningful. However, all
entries are included in the summary tables for
additivity and ease of comparison.

Estimates for the mid-1970's, the mid-1980's
and change during the period were produced for
categories described in Chapter Two. These
estimates are summarized in Table 1 of the
Appendix. Totals for columns are estimates of
total acreage by category for the mid-1980's.
Row totals (the extreme right column) are
estimates of total acreage by category for the
mid-1970's. Entries are interpreted as in the
following examples (all from the ninth row or
column of Table 1):

* 2,716,300 acres classified as palustrine emer-
gent in the mid-1970's were again classified
palustrine emergent in the mid-1980's.

* 107,900 acres classified as palustrine emergent
in the mid-1970's had changed to agriculture
by the mid-1980's.

* 32,400 acres classified as palustrine scrub/
shrub in the mid-1970's had changed to
palustrine emergent by the mid-1980's.

* The estimate of palustrine emergent area in
the mid-1970's is 2,975,500 acres.

* The estimate of palustrine emergent area in
the mid-1980's is 2,865,500 acres.

**The estimate of net change in palustrine
emergent area between the mid-1970's and
the mid-1980's is -110,000 acres.

left: Hernando County

TABLE 1 Area, in thousands of acres, by surface area classification.


Sampling error, in percent, is
given in parentheses below

* Standard error of estimate is
equal to or larger than estimate.





34 3
(37. 2



1 9.5
( 1 4)


170 41



AQUATIC 0 6.8 203.6 0 <0 1
BEDS 12 1 (25 0)

EMERGENT 0 0.1 0 283 0 4 1
( 50 4) (18.8) (234.0)









<0. 1 0 .1 0 2 7 661 .8
( 9190 01) (190 51 (114 41 )


1 .4
(35 6)

0 1
(98 3)


0 1
(60 0)

<0. 1

(50 o0

I( s4

(1 ( 2 4)


I (Ib 51)

5 2
(23 4)

1 8
(20 1 )

D H ESTUARINE 0 0 6 0 3 1 7 0 2 0 1 0
E B (58 9) (90 4) (73 4) (80 6) (96 9)
W T RIVERINE 0 0 0 0 0 0 0
E S LACUSTRINE 0 0 0 0 0 0 2 0.4
R ___ 7) (67 1)

AGRICULTURE 0 0 0 0 0 3 0.3 6.1
(98.2) (55 2) (31 5)

URBAN 0 0.1 0 0 0 0 1 .2
(83 7) (33 1)

OTHER <0.1 <0.1 0 0 0 2 1.4 12.6
_____ 74 2) (42 1) (18 2)

TOTAL SURFACE AREA 34.3 199.2 204.3 287.7 668.0 3.6 140.7
137 1) (16 0) (24 9) (18.9) (14 2) (24 5) (8 )6

1.1 5.1 -6.2 0 .1 0.8 -1 .0 31 .5
(51 91 ( 14 7)


Florida Wetlands, 1970's to 1980's





0 0 0 0 0 1.1 35 4
5_1 41 (36 2)

0.3 0 0 0 0 .1 0 .1 194.1
(43 7) (97 3) (83 01 (16 3)

<0.1 0 1 0 0 0 0 0 210.5
(96 5) ( 24.4)

0.2 0 0 0 0.2 0 287.6
(50 2) __ (163 3) (18 51

0 7 0 0 0 2.5 1.0 668 8
(57 5) ( __57 3) (55 5 (14 2)

0.1 0.5 0 0.7 <0 1 0 0.9 <0.1 0.1 0.4 4.6
(74 1) 69 6) (75 9) (97 0 ) (84 6) 69 7) (30 4)

0.9 1.8 <0.1 0.5 0.1 0.1 1 8 0 5 0 9 1.0 109.2
(34 9) (31 5) (47 0) (95 9) (98 0) (44 81) 83 6) (44 5) (41 8) (110 O)

17.6 0.3 0 <0.1 0 0 0 4 0 <0.1 0.2 19.6
(18.2) (59 0) (98 5 (374 (1 117 2)

1.1 2716.3 2.9 96.3 <0.1 0.8 10.6 107.9 11.5 17.8 2975.5
(40.0) (10 2) (45 2) (53 2) ( 56 5) (27. 2) (29.2) (30 6) (28 5) (9 6)

0 4 85.4 5378.2 82.7 0 0.3 2.2 8.7 39.2 32.4 5634.8
(50.4) (21 4) (5 1) 1 (20 1 ) (58.3) (46.2) (40 4) (33 0) 133 71 (5 1

0.2 32.4 65.4 979.6 0 0 7 2.4 58.0 11.5 6.5 1158.5
(47 6) (26 9) (25 5) (12 3) (68 1) ( 40 6( 5 5) (45 2) (28 1) (11 8)

0 0 0 0 2726.7 0 0 0 0 2 0.2 2730 0
5 1 I (88.3) 112 9) (5 1)

0 0.7 0 0.2 0 137.6 0 <0.1 0 0 138.5
(54 5) (98 5) (32 8) (32 6)

0.3 12.3 0.2 <0.1 0 0 1637.8 0 0.1 3 3 1654.6
(98.0) (39.6) (66 5) ( 17 1 ) (97 3) (88 1) (16 9)

0.6 6.6 0.3 0.9 0 0 1.3 6725.9 125.0 148 8 7016.1
(75.5) (32 I) (92.5) (61 5) (56 B) (5 8) (25 5) (17 9) (5 6)

<0.1 0.1 0.1 0.1 0.1 0 0.3 0 2520.1 0 2522 1
(50.0) (98.4) (97.8) (90 6)9) (91 3) (__10 8) (10 8)

0.3 9.1 3.6 1.8 0.8 0.8 19.3 643.6 362.3 13047 5 14103.3
(45.4) (44 6) (71.7) (50.6) (46 5) 171 3) (36 5) (14 9) (15 3) (3 3) (3 0)

21.5 2865.5 5450.7 1162 8 2729.0 140.3 1677.0 7544.6 3073.7 13260.3 39463.2
15 81) (9 6) (5 1) 111.8) ( 5.1) (32.2) (16 7) (5 5) (10 0) (3 2) 101

1.9 -110.0 -184.1 4.3 -1.0 1.8 22.4 528.5 551.6 -843.0 0
(45 8) (59 7) (19 7) (69 3) (40 3) (23 1) (14 5) (13 5) 10)

TABLE 2 Area, in thousands of acres, by selected surface area groups.




rphng error, in percent, 1s
en in parentheses blow WETLANDS

standard error ofestimate is
al to or larger than tiat. ESTUARINE INTERTIDAL PALUSTRINE


EUST 0 <0 <0






Florida Wetlands, 1970's to 1980's



3 0 0 0 11 354

0 04 0 01 01 404

01 09 0 27 10 9564
--------- - wb
01 3 0 28 11 13610

33 05 10 10 1334

S170 1746 622 567 97688

203 1751 632 583 99022

1751 660 605 112986

144 172 4502 1 <0 1 03 35 4523 1

148 151 13 164 67259 1250 1488 70161

15 16 04 20 0 25201 0 25221

288 290 209 499 6436 362.3 13047 141033

96448 110383 45463 155846 7546 30737 132603 394632

-2574 260 3 23 2 237 1 5285 551 6 43 0
,os 106 "i 1221 "1 "4" "11( 10

University of Florida Home Page
© 2004 - 2010 University of Florida George A. Smathers Libraries.
All rights reserved.

Acceptable Use, Copyright, and Disclaimer Statement
Last updated October 10, 2010 - - mvs