Nurturing Nature

They used to stretch for hundreds ofmiles as a tawny sea of saw grass. Metal-lic-looking plankton added a golden pati-

na to the shallow, slowly moving water thatßowed between hammocks of tall grasses andstands of white-barked, high-kneed cypresstrees. Even now, at half their original size, theEverglades appear to stretch foreverÑgilded,green, punctuated by the white of an ibis or a pink roseate spoonbill. Nothing could seemmore natural.

Yet the most important aspect of this uniqueecosystem is anything but natural. Four greatgates at the northern end of Everglades Na-tional Park and 1,400 miles of canals and lev-ees determine the quantity of water that canenter the area. Sugarcane plantations and veg-etable farms to the north and east use fertiliz-ers and pesticides that determine the qualityof that same water. Demands for agriculture,urban living and ßood control have made theEverglades too wet in the wet season, too dry

in the dry season, too rich in nutrient phos-phorus and therefore too close to extinction.

Because control has undone the Everglades,it seems appropriate that chaos be their sal-vation. Biologists and engineers will try to re-create some of the irregularity of nature by,among other things, delivering water on an er-ratic schedule, putting uncontrolled, meander-ing curves into a straight canal and fosteringbotanic biodiversity rather than biomonotony.Thus, the formerly watery wilderness will bethe locus of the largest and most expensive at-tempt at ecological restoration yet undertaken.

The fact that restoration is being attemptedon such a grand scale is testament to the grow-ing status and popularity of ecological restora-tion, a young Þeld that already carries a heavyburden. Environmentalists, government oÛcialsand business managers increasingly perceiverestoration as a way to undo ecological dam-age and to compensate for development. Thepractice encompasses such diverse eÝorts as

TRENDS IN BIOLOGICAL RESTORATION

Nurturing Natureby Marguerite Holloway, staÝ writer

Copyright 1994 Scientific American, Inc.

Can we rebuild it? The field of ecologicalrestoration is evaluating techniques to restore nature

and is grappling with definitions of success

removing nonindigenous plants, reintroducingendangered fauna, transforming canals thatreplaced rivers back into rivers and donningscuba gear to plant sea grass on the ocean ßoor.Converts have swelled the ranks of the Societyfor Ecological Restoration to 2,200; when it wasestablished in 1989 the group had a mere 300members. A peer-reviewed journal, RestorationEcology, was launched last year.

Despite its newfound prominence, restorationremains controversial because it has raisedprofound and unresolved questions. The ideaof restoration seems disarmingly simple atÞrst, but the goals are elusive. If, for instance,scientists want to return an environment to itsÒnaturalÓ state, they need a full understandingof what that is, how the particular ecology isconstantly changing and how human beings Þtinto it. No one has, or is likely to have, such in-sight. Given, then, that an exact reconstitutionis not possible, should researchersÑand soci-etyÑbe content with achieving a semblance?

Should a restored system be self-sustaining, orshould it be managed? Given such uncertain-ties, how is one to judge success?

These fundamental complexities are furthercomplicated by political strategy and publicpolicy. Some biologists believe the promise ofrestoration fuels destruction. They argue thatsuch pledges encourage thoughtless develop-ment and exploitation: if people believe naturecan be rebuilt, there is no harm in losing moreof it. Other researchers see restoration as theonly possible way society can respond to an al-ready irreversibly impaired environment.

The Everglades will serve as the testing ground

FLORIDA EVERGLADES are drying up because they re-ceive only about one Þfth of the water that they did atthe turn of the century. This unique ecosystem, whichencompasses a saw-grass wilderness (left) as well asstands of cypress trees (right), will be the focus of per-haps the largest and most costly eÝort to restore anenvironment that has been attempted in the U.S.


and battleÞeld where business leaders,government oÛcials, biologists and therest of the population address thesequestions on a vast scale. ÒThe issue isso prominent, no one can aÝord not tohave their name on it,Ó comments Tho-mas V. Armentano, acting director ofresearch at Everglades National Park.ÒIf it works, it will be unprecedented.Ó

Just Add Water

The starting point for restoration in southern Florida is water. As manyconservationists working on the mat-ter joke, the solution to the EvergladesÕproblem is perceived as a Field of

Dreams theme: if you water it, they willcome. This sea-monkey, just-add-waterapproach derives from the hydrologichistory of the region. EÝorts at restora-tion began in the 1980s, when it be-came evident that the Everglades weredrying up. Only one Þfth of the waterthat used to reach the ecosystem at theturn of the century was getting there,often at the wrong times. Only 5 per-cent of the wading birds that used tonest in the wetlands were still doing so.

Development, which began in theearly 1900s as areas were drained forfarming in the peat-rich soil, has been,and continues to be, rapid and intense.Southern Florida has one of the fastest-growing populations in the country;domestic water consumption is alsohigh at an average of 123 gallons perperson per day. (The national averageis 108 gallons per person per day.) Theremaining two million acres of the Ev-erglades are contained in the park, Big

Cypress National Preserve, the ArthurR. Marshall Loxahatchee National Wild-life Refuge and several water conserva-tion areas. Each site abuts residencesor farms.

Most of the chaos that has been in-troduced into the ecosystem so far hasbeen political, not scientiÞc. In the yearssince the ecological threats becamewidely known, nearly every agency andspecial-interest group has been on oneside or another of at least one lawsuitto promote or stall restoration. The larg-est case was brought in 1988 by thefederal government against the statefor failing to protect the water supply.Although the parties reached an agree-ment in 1991, sugar growers opposed it.A new compromise fell through in De-cember 1993. (Ironically, because sugaris federally subsidized at between $1.4billion and $3 billion a year, it appearsthat the federal government has paidmany of the court costs against itself.)

Despite the haggling about who willpay and the unresolved, baroque ques-tions about which agency will controlwhat, several restoration projects areunder way. The South Florida WaterManagement District, which regulateswater use in the watershed and over-sees the water conservation areas, hasconstructed a 3,700-acre wetland to re-move nutrients from agricultural water.

This runoÝ currently drains south-east into the wildlife refuge, whereerect stands of cattails along the north-ern border attest to the inßux of phos-phorus. Although scientists debate thesource of the mineral at some sites, thenutrient clearly fosters the growth of

cattails. Cattails, in turn, replace sawgrass and other indigenous plants, re-ducing ßoral diversity and habitat forwaterfowl. The constructed marsh willturn cattails to advantage, using themto remove 75 percent of the phospho-rus from incoming water.

The Everglades Nutrient RemovalProject, as the marsh is called, consti-tutes the largest cleansing wetlands cre-ated in the U.S. Cattails and other plantsused in the project are commonly em-ployed in smaller-scale managed wet-lands to purify water. Although con-ßicts in the approval process have heldup the release of water, it is intendedto serve as a demonstration. Similar fa-cilities, covering a total of 40,000 acres,are also being planned to cleansestorm water.

Cleanup is not cheap. The cost ofthese eÝorts could reach $465 millionor more, and it is this Þgure that makesmany of the large sugar companies andfarmers balk: under the most recentproposal, they would have been respon-sible for a total of between $232 mil-lion and $322 million over the next twodecades. In January, however, Flo-Sun,Inc., reached an independent settlementand agreed to Þnance part of the clean-up. Given that many farms may not bearound in several decades, the positionof the holdouts makes some sense. Be-cause growers keep the soil drier thanit would normally be, the peat is being

100 SCIENTIFIC AMERICAN April 1994

FOUR WATER-CONTROL GATES, including this one, punctuate the Tamiami Trail ,which runs across southern Florida from east to west. The gates regulate theamount of water that ßows south into Everglades National Park.

EVERGLADES AGRICULTURAL AREA

WATER CONSERVATION AREAS

BIG CYPRESS NATIONAL PRESERVE

EVERGLADES NATIONAL PARK

ARTHUR R. MARSHALL LOXAHATCHEE NATIONAL WILDLIFE REFUGE

FORTMYERS

LAKEOKEECHOBEE

MIAMI

KEYWEST

TAMPA

SOURCE: South Florida Water Management District

SARASOTA

WESTPALMBEACH

FLORIDA BAY


oxidized and blown away at the rate ofanywhere between one and three cen-timeters a year. Within a lifetime, manyfarmers may reach the limestone bed-rock of southern FloridaÑat which pointsoil restoration may become the newfocus of the region.

Scientists disagree on the relative im-portance of removing nutrients fromthe water or just getting the water backinto the Everglades. Water formerly trav-eled over the area in a sheet that wassometimes as many as 60 miles wideand as much as a foot deep. Now it isushered through a labyrinthine networkof canals, pumping stations, locks andgates. Because the regionÕs hydrologyis so disturbed and there are so manydemands for water, eÝorts to Þx ßowseem even more daunting than thosedesigned to remove pollutants. Despiteall the attention directed at the Ever-glades, the park only just recently re-ceived increased amounts of water. Ar-mentano says the strategy is not work-ing: the added water, which is coming

into a slough from a canal to the east,is seeping right back out again.

Regional agencies have devised sev-eral long-term plans to address the hy-drologic problems. Modelers at theSouth Florida Water Management Dis-trict are writing computer programs toreconstruct how water traveled beforethe region was crosshatched by canalsand levees. Once Þnished, this so-callednatural system model will be superim-posed on an existing model of how water currently ßows. Researchers arealso working to predict how hydrologicchanges will aÝect vegetation.

Using these tools, experts hope ulti-mately to devise a politically acceptableand environmentally sound way to di-vide water in southern Florida, explainsJayantha T. B. Obeysekera, an engineerfor the district. Such answers will notbe available for a while. Models inevi-tably reveal the many gaps in data thathave to be Þlled in by Þeldwork. Fur-thermore, the graphic results must beviewed for what they are and with the

same careful scrutiny that all the con-ßicting climatic change models garner.ÒIt is like Disney World: it looks natu-ral, but you go outside, and you realizeit is not,Ó Obeysekera cautions.

While modelers are trying to antici-pate how the system could be manip-ulated, Þeld engineers and biologistshave been examining the feasibility ofrestoring the Kissimmee River. The Kis-simmee was formerly a 103-mile-longrambling river that ßowed south intoLake Okeechobee, which, in turn,sloshed into the Everglades. Togetherthe river and the lake were responsiblefor the unique hydrology of the region.Like many rivers, the Kissimmee wasunruly, inundating the wetlands adja-cent to it, overßowing the lake afterheavy rains, ßooding farms, damagingproperty. So, between 1962 and 1972,the Army Corps of Engineers straight-ened it out. The Kissimmee is now asubdued, 56-mile canal called C-38.

Public opinion, however, proved lessamenable to control. The army had only

SCIENTIFIC AMERICAN April 1994 101

COMPUTER MODELS designed by the South Florida WaterManagement District will be used to plan water use in an ef-fort to save the Everglades and simultaneously satisfy urbanand agricultural needs. The natural system model (left ) willillustrate how water moved in the region around 1900. The

managed system model (right ) shows how water ßows nowthat the area is crossed by 1,400 miles of canals. The naturalsystem model has not been Þne-tuned, but the comparison ofthe two models in this simulation conveys the magnitude ofdevelopment in the region and its eÝects on hydrology.

DAYS OF INUNDATION(FOR A YEAROF NORMALRAINFALL)

300 TO 365

240 TO 300

180 TO 240

120 TO 180

60 TO 120

0 TO 60


just completed its work when severalgroups, including the Fish and WildlifeService and the Audubon SocietyÑwhich had opposed the alignment inthe Þrst placeÑcalled for restoration.The conservationists, public and pri-vate, won their case, and the South Flo-rida Water Management District was re-quired to determine the feasibility ofputting the curves back into the Kis-simmee and water back onto its ßood-plains. The resulting study, as well as

others, revealed that the loss of 30,000acres of wetlands on either side of theriver had diminished bird and Þsh hab-itat and had degraded water quality.

Between 1984 and 1989 the SouthFlorida Water Management District con-ducted a demonstration project on 12miles of the river to determine if resto-ration was indeed possible. ÒIt wouldbe the purest restoration project that Iam aware of because it would eliminateany of manÕs interference in this area,Ó

yells Louis A. Toth, who directed theproject. He and several colleagues arehovering above the project site in a he-licopter, recording changes in vegeta-tion that have taken place since theyÞnished monitoring the project severalyears ago. A line of oaks a mile or soinland sketches the upper limit of theßoodplain. The researchers see the suc-cession they expected: in some sites,switchgrass is giving way to wax myrtle;willows are replacing woody species.

Toth is careful to emphasize that theproject has not restored the ßood-plainÑrather it shows that there is eco-logical beneÞt in trying to restore. As apair of sandhill cranes dash through amarsh trying to escape the downdraftof the helicopter, Toth remarks thatthere was a 1,000 percent increase inthe number of wading birds after re-ßooding: ÒIt indicates that the specieswill return if there is further restora-tion.Ó He also explains that it took near-ly 20 years to develop a deÞnitive goalfor the projectÑa span that exceedsthe lifetime of most restoration eÝortsand most political administrations.

The full-scale project, slated to beginnext year, will bring back 26,500 acresof wetlands. To obviate demands forßood control, the district will also haveto purchase farms. In total, restorationof the Kissimmee will cost at least $372million. ÒIt is the new environmentalpork barrel,Ó comments Daniel E. Wil-lard of Indiana University. ÒIt will cost100 times as much to put the curves inas it did to take them out.Ó

Exorcists of Exotics

The last big piece of the restorationwork in southern Florida has not re-ceived as much press as have pollu-tants and hydrology. Nevertheless, thatelementÑthe removal of nonindigenousplants, sometimes referred to as exot-icsÑhas become a pressing concern. Ac-cording to a recent report by the OÛceof Technology Assessment, more than2,000 plant species that came fromsomewhere else thrive in the U.S. today.Fifteen of them have caused over a halfa billion dollarsÕ worth of damage since1906. But even committed restoration-ists are divided on the necessity of de-stroying them. Some feel any growth ina disturbed area is better than nothing.ÒIn some places, we have phragmites,which are hated by everyone,Ó Willardsays, describing a marsh plant that cangrow rife in areas outside its naturalhabitat. ÒBut black night herons nest inphragmites. Is it a failure if we havethem there?Ó

The exorcists of the exotics counterthat native ecosystems and biodiversity


Several Nonindigenous Pest Plants in Southern Florida

MELALEUCA (Melaleuca quinquenervia )—This Australiantree in the myrtle family was brought to southern Floridato drain the Everglades in 1906. It is now considered theregion’s most serious problem. The rapidly growing tree,which crowds out native vegetation and reduces habitatfor animal life, can flower five times a year. It currentlycovers some 500,000 acres. Annual efforts to control itsspread will cost about $1 million by 1995.

WATER HYACINTH (Eichhornia crassipes )—A fast-grow-ing aquatic weed, water hyacinth originated in SouthAmerica. It was introduced into Florida in the 1880s be-cause of its beautiful purple flowers, and by the 1960s itcovered 125,000 acres of public lakes and rivers. Theplant blocks waterways, interferes with flood control andreduces biodiversity by preventing other species fromgrowing. Possession of water hyacinth can lead to a $500fine and 60 days in jail. Controlling this exotic weed costsabout $3 million a year.

BRAZILIAN PEPPER (Schinus terebinthifolius )—This or-namental tree was brought to Florida in 1892 and is nowrampant. After Hurricane Andrew, it spread into mangrovestands in Everglades National Park, where it has been dif-ficult to remove. The pepper’s seeds are mildly hallucino-genic, and some biologists report seeing birds so intoxi-cated on these seeds that they cannot fly.

HYDRILLA (Hydrilla verticillata )—This plant from Sri Lan-ka was introduced in the 1950s as vegetation for aquari-ums. More than 40 percent of Florida’s public lakes andrivers are infested with hydrilla: a total of some 66,000acres are covered with the exotic species. Hydrilla crowdsout other plants and clogs waterways. It travels easily onboats and can produce millions of underground tubersthat lie dormant for years. The state spent $48 million be-tween 1980 and 1989 attempting to control the weed.

AUSTRALIAN PINE (Casuarina )—This tree, sometimesreferred to as an oak, was brought to Florida in the late1800s. It is replacing mangroves and other native vegeta-tion, rendering habitats sterile because nothing thrives inits vicinity. It shades plants growing on dunes, therebykilling them and opening the dunes to erosion (the rootsystem of Casuarina does not serve to stabilize the dunes).

SOURCES: Dan Thayer, South Florida Water Management District; Greg Jubinsky and Jeff Schardt, Florida Depart-ment of Environmental Protection.


cannot truly be restored as longas foreign species are present. ÒIam very antiÐexotic species, evenwhen they are not causing a prob-lem,Ó says Peter White, director ofthe North Carolina Botanical Gar-den. ÒThey are the most irrevers-ible of all human eÝects: we canclean the air, we can clean thewater, we can restore wetlands,but exotic species are diÛcult toget rid of.Ó

In the Everglades the most un-wanted aliens are a Brazilian pep-per plant and melaleuca, an Aus-tralian tree imported to help drainmarshes. Both tend to grow invery dense stands, as do cattails,driving out other plants and re-ducing wildlife habitat. Keepingmelaleuca controlled in the Ever-glades requires vigilance. Thickforests of the trees can be seenrunning along the canal border-ing the eastern boundary; insidethe saw-grass Þelds, hundreds ofwhite corpses of the poisonedtrees reveal the scope of theseek-and-destroy mission. In ad-dition, two insect pests are beingimported from Australia to con-trol the pines.

At a site called the hole-in-the-doughnut, an even more dramat-ic campaign is being wagedagainst the Brazilian pepper. Sit-uated in the middle of the park, thehole-in-the-doughnut was farmed untilthe 1970s. It is now the location of theparkÕs hurricane-decimated researchcenter. The soil the farmers had brokenup and tilled for so many years provedto be ideal for the pepper plant. So parkbiologist Robert F. Doren, who startedthe Exotic Pest Plant Council 10 yearsago, decided to remove the topsoil thefarmers had worked. Doren found thatthe pepper plants did not return to areas from which the soil had beenstripped. But what will take their placeremains unclearÑthe results of the suc-cession experiment will become evidentonly in the next few decades. In thattime, $44 million will be invested inclearing 100 acres of topsoil each yearfor 15 or 20 years, at a cost of $16,500an acre, while the hole-in-the-doughnutis rehabilitated. ÒOne of the questionsis, What do you actually get?Ó Armen-tano says.

Whether it is used by scientists toplay gardener and weed out exotics orto play God and part the waters, infor-mation about the eÝects of restorationis in great demand in southern Flori-daÑand elsewhere. Knowledge is inad-equate in all areas of science, includingthe interaction between hurricanes, Þre

and nutrient recycling in the Everglades,the characteristics of the soil and itsmicrobial communities, and the eÝectsof sea-level rise on the ecosystem. Inaddition, basic components of the hy-drology are not understood. What isthe role of changed water patterns anddrainage on bird nesting and feedinghabits? Has reducing the ßow of freshwater through the Everglades causedthe demise of Florida Bay?

But because there is little precedentfor restoration of this magnitude, manyscientists are advocating a one-day-at-a-time approach. Such a strategy wouldallow experts to experiment and reviseplans if a particular line of attack didnot seem to be working. ÒWe have totake an adaptive approach. We are notgoing to have the degree of predictabil-ity that we want,Ó explains Steven M.Davis of the South Florida Water Man-agement District, an editor of the re-cent book Everglades: The Ecosystem

and its Restoration. Davis thinks thisconcept is diÛcult for some research-ers to accept. Many want to set targetsfor certain species: restoration is work-ing if, say, the anhinga population in-creases by x percent. ÒWe may have theillusion of control,Ó he notes. ÒBut nomatter what we do, we are not going to

put the Everglades back to theway they were. There are going tobe surprises.Ó

Indeed, many biologists arguethat the ßexible approach Davischampions should be the key ele-ment of restoration. Its absenceis one of the biggest ßaws in ef-forts to compensate for econom-ic development, says Charles A.Simenstad of the University ofWashington. Simenstad has doneextensive work on the restora-tion of rivers and Þsh habitats inthe PaciÞc Northwest. He foundthat when the failure of some as-pect of a plan becomes apparentthere is often little chance to cor-rect the mistake. An inappro-priate goal, dear to the agencygranting the permit, is often thesource of constraint.

To make matters worse, manyof these compensatory eÝorts donot yield information, becausethey are not framed in the con-text of experimentation and arenot monitored. In an attempt tomake projects more sound andmore adaptive, Simenstad is en-couraging multistage plans: try afew approaches, wait a few years,see which works best and thenfollow it.

Even though Simenstad, Davisand many other restorationists

are trying to escape what may be a re-stricting emphasis on precise endpoints, this focus has arisen preciselybecause so many restoration projectshave not had clearly deÞned goals. Theadaptive strategy may make very goodsense in places where engineers or sci-entists have a reasonable expectationthat they can improve the functioningof an ecosystem. In those cases, per-haps rehabilitation is a better word:there is still a clear sense of what theoriginal environment was, and gettingback to it seems a somewhat reason-able feat. But a look at many past res-toration projects suggests that such re-habilitation is not always possible, par-ticularly where an entire ecosystem isbeing created. Furthermore, when theincentive for restoration is to compen-sate for development rather than to re-deem an ecosystem, the lack of clearlydeÞned goals for a project can concealtechnical failureÑor let a developer oÝthe hook.

Joy B. Zedler of the PaciÞc EstuarineResearch Laboratory at San Diego StateUniversity has conducted one of themost thorough dissections of one suchrestoration attempt. Since 1989 she hasmonitored a salt marsh that was builtto mitigate the construction of a high-

SCIENTIFIC AMERICAN April 1994 103

JOY B. ZEDLER monitors a San Diego marsh that wasbuilt 10 years ago to compensate for the construc-tion of a nearby highway. The new wetland still doesnot resemble a natural one.


way. The project was designed as ahabitat for the endangered light-footedclapper rail. Ten years of salt-marshbuilding later, the rails still have not ar-rived. ÒI donÕt think we are ever goingto get functional equivalency for themarsh,Ó Zedler says.

Zedler also determined that for wantof a bee, a marsh can be jeopardized.Some plants at the site were not settingenough seed, because pollinators wererare. The insects were not crossing thehighway or making their way throughurban areas to reach the wetland.ÒThere are millions of pieces in an eco-system, and we have looked only at atiny fragment of them,Ó Zedler cau-tions. ÒIt is not as easy to restore thesesystems as developers would have usthink. When you are trying to improveconditions, I think you can do a lot, butyou can never get back what we lost.Ó

This conclusion Þts into a nationalpattern of restoration failures. Mary E.Kentula, director of the EnvironmentalProtection AgencyÕs Wetlands ResearchProgram, and Jon A. Kusler, director ofthe Association of State Wetland Man-agers, edited a 1990 report on the sta-tus of the science of wetlands restora-tion. As Kentula notes, they determinedthat Òthe efficacy of restoration and

creation methods remains uncertain.The technology is unproved for manytypes of wetlands, and the quality ofcompleted projects is inconsistent.Ó

Kentula also conducted a study of150 young restoration projects in Ore-gon. She found that most of the newwetlands were very wet indeed. Theywere in fact about 90 percent open wa-ter. The natural sites they were meantto substitute were only 20 to 22 percentwater; the rest was vegetation and wild-life habitat. The reason is that creatingponds is easier and cheaper than ensur-ing all the species that should be thereare there, Kentula explains. But Òwet-lands are where we have the most ex-perience in restoration, and we see thesame mistakes being made over andover again.Ó According to Kentula andKusler, one of the hardest features of aproject to get right is its hydrology.

Correct hydrology is precisely whatZedler ultimately found to be the mostcrucial missing element in the San Di-ego marsh. ZedlerÕs observations haveled her to be very outspoken about thedangers of mitigationÑa position thathas earned her the epithet ÒJoyless Zed-lerÓ among some of her colleagues. Zed-ler conÞnes most of her concern tosouthern California. This region has lost

more than 75 percent of its coastal wet-landsÑleaving only 31,700 acres of es-tuarine habitat, of which 18,600 is openwater. Ninety-four animal and 187 plantspecies are endangered or threatenedin the state. ÒCalifornia shows that iflosses continue, you eventually get to apoint where they cannot rebound ifthere is a catastrophic event,Ó Zedlersays. ÒSpecies have to come back fromsomewhere, and there is not enoughhabitat left so that they can recover.Ó

Zedler and others believe science maynot yet be up to the task of ecosystemduplication. The Þeld is so young thatit is lacking the quality control that itneeds, states John Cairns, Jr., distin-guished professor at the Virginia Poly-technic Institute and State University.Cairns chaired the committee that pro-duced a 1992 National Research Coun-cil report on restoring aquatic ecosys-tems. Restoration needs Òthe kind ofcontrol in which ludicrous statementsand publications are immediatelypounced on and eliminated,Ó he says.ÒThe reason the new journal was found-ed was because of all the aggravationpeople in the Þeld go through dealingwith reviewers who do not know theexisting literature, small as it is.Ó

Other ecologists think these conclu-


Restoration of Prairie Potholes

There is a widely held belief that prairie potholes, manyof which were drained for agricultural purposes, are

easy to restore: just return the water. But the ecosystemsof these ponds, originally created by the surging of gla-ciers, may not be so amenable to quick rehabilitation, saysSusan M. Galatowitsch of the University of Minnesota. Thebotanist examined records of more than 1,000 restorationsconducted by the Fish and Wildlife Service and closely scru-tinized 62 of them. She and others found that the longer

the pothole had been dry, the less viable the seeds lyingdormant in the soil proved to be. Certain types of plantsalso did not return, and as a result, few birds came back.“There is a whole suite of species that rely on sedge mead-ows,” Galatowitsch notes. “Wrens, yellow-throats, bitternsand rails need dense vegetation. So they have not come in.”She says it may be necessary to reseed areas to get theoriginal vegetation to come in again. “The important thingis for people to be constantly improving restoration.”

SOURCES: Susan M. Galatowitsch and Diana Lobien, University ot Minnesota.

6 GREATER BLADDERWORT (Utricularia vulgaris)7 AMPHIBIOUS SMARTWEED (Polygonum amphibium)8 SILVER CATTAIL (Typha glauca)9 SMOOTH BROME (Bromus inermis)

10 ALFALFA (Medicago sativa)

11 SMARTWEED (Polygonum pensylvanicum)12 BUR MARIGOLD (Bidens cernua)13 BARNYARD GRASS (Echinochloa crusgalli)14 SAGO PONDWEED (Potamogeton pectinatus) 15 LEAFY PONDWEED (Potamogeton foliosus)

1 BIG BLUESTEM GRASS (Andropogon gerardi)2 CORD GRASS (Spartina pectinata)3 BLUEJOINT GRASS (Calamagrostis canadensis)4 SEDGE (Carex languinosa)5 RIVER BULRUSH (Scirpus fluviatilis)

15

14

13

11

12

10

6

5

4

3

2

1 9

8

7

NATURAL RESTORED


sions are unwarranted. They believe theshortcomings of many restoration proj-ects are often perfectly explainable forseveral reasons. Regulations are one ofthe culprits. ÒFor those projects thatclearly failed, I would take the perspec-tive that it is an agencyÕs failure,Ó ar-

gues Dennis M. King of the Center forEnvironmental and Estuarine Studies atthe University of Maryland.

King makes a strong case. The surgein contemporary restoration activitywas set in motion by changes in federalwetlands legislation in the 1980s. Be-

fore then, restoration in the U.S. hadbeen largely nostalgic, such as the cre-ation of a prairie because this symbol of the American landscape had disap-peared, or practical, such as the preven-tion of erosion in a pit mine. Ten yearsor so ago mitigation was introduced. Itis the process of last resort : compen-sating for development by creating,restoring or rehabilitating an ecosys-tem if destruction was unavoidable. If,for instance, a company wanted tobuild a mall on a marsh, it was unlikelyto get a permit to do so from the ArmyCorps of Engineers unless it made amarsh elsewhere.

A Mall for a Mud Puddle

In 1981 President Ronald ReaganÕsTask Force on Regulatory Relief pushedthe Army Corps of Engineers to speedup the approval process. According toa 1990 study by William L. Kruczynski,then at the Environmental ProtectionAgency, the new rules limited the powerof the EPA, the Fish and Wildlife Serviceand the National Marine Fisheries Ser-vice to review permits. The three agen-cies, charged with commenting on theenvironmental impact of development,increasingly recommended mitigationbecause it was clear that they could notinßuence the armyÕs judgments.

But there were no mechanisms inplace to monitor compliance. ÒThe reg-ulations had not been enforcing qualitycontrol,Ó King explains. ÒAnd the mar-ket has been for low-cost permits, nothigh-quality restoration.Ó One of KingÕsfavorite examples is a developer whochose a site on which to construct awetland after receiving his permit tobuild a shopping center. He hit graniteone foot below the surface at the siteof the proposed marsh. Rather than goback through the permit process, thecontractor blasted the granite and builta mud puddle that King says has noecological value. The cost of the Òres-torationÓ was $1.5 million an acre.

With the right amount of money andfollow-up, King says, anything is possi-ble. ÒYou see all those statistics on fail-ure rates, and you talk to all the scien-tists and scratch below the surface andask them why they failed, and they al-ways know,Ó he argues. ÒIt is not a fail-ure of science. The institutions are notholding the scientistsÕ feet to the Þre.Ó

Mark S. Fonseca, a research ecologistat the National Marine Fisheries Ser-vice, agrees. He has been working onthe restoration of sea-grass beds onthe eastern seaboard for more than adecade. ÒThe technical ability is there,ÓFonseca says. ÒIt is more a problem ofthe scale of the losses.Ó Fonseca ex-


Restoration of Mined Land

Mined lands are some of the major sites of restoration efforts, often con-ducted in an attempt to prevent topsoil erosion. Nine years ago Andre F.

Clewell was hired to restore a 3.8-acre forest that had been wiped out byphosphorus mining southeast of Tampa, Fla. The American Cyanamid Com-pany had been required to mitigate—that is, to compensate for the destruc-tion wrought by mining the area (top ). Clewell, who runs A. F. Clewell, Inc., inQuincy, Fla., says the Hall Branch Restoration Project has turned out to beone of his most successful. Because adjacent forests had not been disturbed,the botanist had good data for how the site was originally—something heneeded because “the regulatory agencies had those presettlement forests asstars in their eyes.” The most crucial aspect of the work was getting the ele-vation of the land right, which, in turn, ensured proper hydrology. “A matterof a few centimeters in elevation could cause drastic changes in the project,”Clewell explains. After re-creating the original topography, he was able tofoster the growth of reforested wetland, including the characteristic trees,shrubs and herbs (bottom ). “We do not have to do any more to the system,”Clewell notes. “We just have to make sure that the land is protected.”


plains that to be successful, res-toration has to take place withinthe context of the preservationor rehabilitation of an entire eco-system. He notes that he can re-store an entire bay, even replantthe entire seaßoor with sea grass,but if the water column is notcleaned up and pollution persists,the grass will die all over again.

The importance of the Ever-glades plan derives from the factthat this vast wetlands providessuch a context. The region is onefocus of the attention of the Na-tional Biological Survey (NBS), anew agency established within theDepartment of the Interior to in-ventory all animal and plants aswell as to study and identify ar-eas at risk. The NBS will attemptto consider entire ecosystemsrather than individual species,such as the northern spotted owl.

Because every gallon of waterthat ßows through the Evergladesis tracked by the South FloridaWater Management District orthe Army Corps of Engineers, thebureaucratic structure needed tomonitor the region as a whole ap-pears to be already in place. ÒKus-ler and Kentula were looking atmuch smaller systems,Ó Davissays. ÒYou can set up end pointswhen you have smaller areas. You havecaptive ecosystems: they are so highlymanaged they are like circuses. But theEverglades are huge. They will be lesspredictable in their responses.Ó

The NBS approach, which embodiesthe prevailing ethic of sustainable de-velopment, resembles the perspectivefrom which landscape architects andsome western Europeans have tradi-tionally viewed restoration. ÒThey areused to looking at much larger systemsthan most ecologists are,Ó Cairns says.ÒMost ecologists in the American andBritish mold try to Þnd places wherehumans are not part of the system. TheEuropeans assumed that humans arealways in the landscape. They are notrunning oÝ to the Gal�pagos to Þndsome untouched ecosystem.Ó

Achieving that kind of perspective atthe level of the evolving science is alsocrucial. At the moment, the Þeld ap-pears to be missing the very quality thatecologists are demanding from restor-ation projects: integration. The disci-pline is by its nature broadly based:good restoration includes informationon soil, microbes, botany, hydrologyand population ecology, to name a fewaspects of any ecosystem. But special-ists rarely come together because ofwhat Cairns describes as tribal lan-

guage and an intellectual electric fence.At meetings, some scientists Òwant totalk about the number of bugs theyhad after using a certain fertilizer. It isalmost like gardeners talking to eachother,Ó King laments. ÒThe perspectivehas got to widen.Ó

It is also clear that a degree of snob-bishness exists on the part of peopledealing with landscape-based projectstoward those working on fragments ofecosystems. But doing one without tak-ing the other into consideration may beuseless, as the death of the pines insouthern Florida attests. Barren pines,some with dead needles swinging fromnearly naked branches, protrude fromplush undergrowth on a 3.5-acre plot inMiami. Until Hurricane Andrew rippedthrough in 1992, this fragment wasone of the last remnants of a coastalforest that covered southern Florida de-cades ago. Every tree on the site is nowdead, as are most of the small pineforests in the regionÑonly an 11,000-acre stand in the park remains.

No one knows what happened to thepines. Was it the force of the hurri-cane? Had the size of the forests madethem vulnerable? Had municipal chang-es in water ßow diminished the amountof sap the trees usually produced to

push insect pests out of bore-holes? ÒEveryone is watching thepark, waiting to see what hap-pens there,Ó says George D. Gann-Matzen, president of EcoHori-zons, a restoration Þrm, as hegazes at the dead trees. He washired to remove an exotic Asianvine that had been smotheringthe pines, camoußaging them asgreat green druids, and to man-age the tiny woods as if it werestill wild, when the hurricanestruck. Absent trees, Gann-Mat-zen is unsure whether to burn orplant seedlings.

Gann-MatzenÕs restoration andmanagement problems appearisolated. But without this forestfragment in downtown Miami,the pines in Everglades NationalPark, just to the south of the city,could be in jeopardy. Ten ofsome 26 species of birds that in-habited the parkÕs forest havenot been seen in the past severalyears, or longer. And biologistsspeculate that the disappearanceof the last few woods destroyedan arboreal corridor that thesebirds traveled southward along,down into the park.

So few large tracts of un-touched land are left that restor-ation must work in tandem with

preservation. Areas of conservation areneeded to ensure that species can sur-vive, particularly as the human popula-tion explodes and the pressures thatregions such as southern Florida expe-rience increase. There seems to be tacitagreement that most of nature is hard-ly natural anymoreÑthe orchestrationof water in the Everglades is but oneexample. Ultimately, the state of thescience does not matter to the majorityof restorationists. Their attitude is justdo it, do something.


JOHN CAIRNS, JR., chair of a National ResearchCouncil report on the restoration of aquatic ecosys-tems, is outspoken about the need for quality con-trol and synthesis in the young Þeld.

FURTHER READING

THE EVERGLADES: RIVER OF GRASS. Mar-jory Stoneman Douglas. PineapplePress, Sarasota, 1988.

THE CONTROL OF NATURE. John McPhee.Farrar Straus Giroux, 1989.

ENVIRONMENTAL RESTORATION: SCIENCEAND STRATEGIES FOR RESTORING THEEARTH. Edited by John J. Berger. IslandPress, 1990.

WETLAND CREATION AND RESTORATION:THE STATUS OF THE SCIENCE. Edited byJon A. Kusler and Mary E. Kentula. Is-land Press, 1990.

RESTORATION OF AQUATIC ECOSYSTEMS:SCIENCE, TECHNOLOGY, AND PUBLIC POL-ICY. National Research Council. Nation-al Academy Press, 1992.


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Nurturing Nature