Picture this…you are on a tour of wetlands. Let’s make it a southeasternwetland tour, since the ecology lab where I work and conduct my researchon salamanders is in the Southeast. It is July—98oF, 85% humidity—and you are doing your best to ignore the deer flies and mosquitoes.First, you visit a cypress-tupelo swamp. At a tributary to the swampyou trek through a beaver pond. Then, just a few miles away, youcool off in a blackwater stream. Finally, at the last stop on yourtour, you hear “Go on ahead. Let’s meet at the edge of thewetland.” You plunge ahead, under the pine canopy, beyondthe band of sweetgums. You wade through greenbriar and cut-grass, looking for water. You dive between clumps ofbuttonbush, and emerge back in forest. Your feet remain dry.You curse the tour leader. What wetland?

Timing is everything. Were you to make the same hike in February,for example, in most years your feet would not stay dry. In some yearsyou would literally swim through cold water teeming with aquatic life.Again, you would curse the tour leader.

A “wetlands tour,” similar to the one described above, couldinclude tramping through seasonal wetlands in almost anyregion of the United States. The names of such wetlandsmay differ depending on where you are—prairie potholes,vernal pools, Carolina bays, rock pools, desert depressions,pocosins, swale ponds, snow melt pools, sandstone potholes.The geology and origin of the wetland may differ from one

place to the next, but the ecology is strikinglysimilar. They are all seasonal wetlands.

To some folks, “wetland” means onlythe sort of habitat where a duck can wetits feet all year round. But a glance at the

U.S. Fish and Wildlife Service’sClassification of Wetlands and DeepwaterHabitats of the United States or numerousother wetland manuals will illustrate that

wetlands come in many forms, shapes, andsizes. And although our appreciation of

the value of wetlands has increased inrecent years, the importance of the

general category of “seasonalwetlands” is still largely

unrecognized. In fact, in many cases,seasonal wetlands are still

under siege.

Seasonal wetlands—Seasonal wetlands—Seasonal wetlands—Seasonal wetlands—Seasonal wetlands—full-time wetland, part-time waterfull-time wetland, part-time waterfull-time wetland, part-time waterfull-time wetland, part-time waterfull-time wetland, part-time water

It helps to look at the big picture. It is easy toenvision a landscape that has lakes, farm

ponds, and marshes—permanent waters. Similarly,most of us can picture short-term flooding in

roadside ditches and old-field puddles. Theseconditions, however, are but the two ends, the

extremes, of a continuum of “wetness.”Different types and sizes of wetlands hold

water for differing amounts of time; thatis, the hydroperiods of the wetlandsdiffer. Across a landscape of moderate

size, perhaps only a few square miles, oneis apt to find wetlands that fall all along this

hydroperiod continuum. Biologists havelong recognized that hydroperiod variationis directly linked to species biodiversity.

Because different species have differenthabitat preferences, wetlands that

differ in hydroperiod are likely tosupport diverse sets of species.

Of all the vertebrate animals, amphibiansdemonstrate the importance of wetland

habitat diversity better than any other group.As most of us learned in elementary school, frogs andtoads and salamanders are amphibians because (in

general) they lay eggs in water that hatch into babies (larvae)that live in the water for part of their lives. At some point larvaeswitch physiological gears, change from aquatic infants toterrestrial juveniles, and move out onto land. Under this scenariowater is the key, both as a breeding site and as an environmentfor young to grow and mature. Water is water, right? So prettymuch any water will do, eh? Ah, but not so fast, salamander boy.

Believe it or not (you knew this was coming)—“NO, not allaquatic habitats are created equal.” Wetlands that are “good”for bullfrogs are not suitable for spadefoot toads, and a marbledsalamander would only be caught dead (literally) in a pond thatis great for sirens. The bottom line is that within the category of“seasonal wetlands” there are subcategories based largely on

the wetland’s average hydroperiod, and differentsuites of amphibian species

prefer different subcategoriesof wetlands.

Aside from hydro-period, the other keycomponent affecting

amphibian well-being is thetype of predators in theBlack-banded sunfish

Wetlands range from permanent ponds(above), to short-lived roadside ditches, toseasonal wetlands like Carolina bays(below) that may hold water for manymonths in some years and remainrelatively dry in others.

What many amphibians needWhat many amphibians needWhat many amphibians needWhat many amphibians needWhat many amphibians need

wetland. Withonly a fewexceptions, fishare the bane ofmost amphibians. Theequation, somewhat over-simplified, is straightforward: POND + FISH = NO AMPHIBIANS.It is puzzling that so many backyard wildlife guides suggestbuilding a small wetland to enhance the diversity of backyardcritters, and then suggest stocking those wetlands with fishthat would chow down on that very same diversity. Theevolutionary reason that so many amphibian species preferseasonal wetlands is because wetlands that dryfrequently usually do not contain fish. Yes,there are exceptions, such as bullfrogsand newts, which can survive with fish.And yes, fish occasionally eveninhabit seasonal wetlands, if theyare of the more permanentvariety. But again, let’s look at thebig picture. For example, on theCoastal Plain of South Carolina,an area of high diversity of pond-breeding amphibians, more thanhalf of the 40 or so amphibian speciesthat require “pond” habitats show a strong preferencefor fish-free waters. There is absolutely no doubt that themaintenance of amphibian diversity hinges on the

The presenceThe presenceThe presenceThe presenceThe presenceof fishof fishof fishof fishof fish

preservation of remainingseasonal wetlands.

Unfortunately for the amphibiansand other species that needseasonal wetlands, thesewetlands are not wellprotected. Scarcely acongressional session goes

by when there is not aproposal to reduce whatlittle protection alreadyexists, usually by

redefining what a wetlandis. So would it matter? If we were to

destroy all small, seasonalwetlands—the final blow to thoseremaining wetlands beyond the50-90% already destroyed inmany states—who would notice?Well, the amphibians would, both

directly and indirectly. Whensmall wetlands aredestroyed, the local pop-ulations of plants and

animals are eliminated. Andwith the passing of every tiny

wetland and its associatedfauna, other nearbyamphibian populationsbecome increasinglyseparated from oneanother, making it more

difficult for populations torecover from disturbances of

all kinds, including natural eventssuch as droughts.

So why not just make more wetlands?If we must, for whatever progressive

reason, eliminate a few seasonalwetlands here and there, why notjust dig a big one elsewhere? Orbuild additional small wetlandsin places more in line with ouraesthetics and economics? Theanswer to the first questionshould be obvious at this point.One 10-acre wetland and ten 1-acre wetlands do not sum to thesame amphibian community. Onthe question of construction of

Many amphibian species canreproduce successfully only in fish-free, seasonal wetlands.

Remaining seasonal wetlands are often isolated from one another (asshown in the upper aerial photo), increasing the chances that populationsusing these wetlands will be unable to recover from natural or human-induced disturbances.

small, artificial seasonal wetlands, the future may holdpromise. The problem is that it is no easy task to make atruly “natural” artificial wetland from scratch—itmay be impossible. Yes, in many cases it is easyenough to restore what once was a wetland backto its original wetland state. But to create awetland where there never was one…well, it ismore likely you’ll end up with a fast-drying puddleor a permanent pond, rather than a functionalseasonal wetland. Perhaps we could attempt toconstruct new wetlands to supplement thosenow existing, but we certainly shouldn’tconsider replacing natural wetlandswith our feeble attempts. Brain surgeryand rocket science are far moresimplistic than ecology, for we are noteven close to understanding thecomplexities of Mother Nature.

The ecology of amphibians presents anadditional layer of complexity when it comes tounderstanding wetlands and habitat needs.Many amphibians exhibit what is known as a“complex” life cycle, similar to many invertebrates,in that the young undergo a dramatic transition (ametamorphosis) into subsequent life stages. Inamphibians this means going from aquatic tadpoles or larvae toterrestrial frogs or salamanders. So what about the terrestrialneeds of pond-breeding amphibians? Even though we may callthem “pond-breeding amphibians,” a more apt name might be“woodland-for-9/10-of-their-lives-except-for-a-brief-period-when-they-are-pond-breedingamphibians.” Afterm e t a m o r p h o s i smany pond-breeding

Protected wetlands?Protected wetlands?Protected wetlands?Protected wetlands?Protected wetlands?

And another thing…And another thing…And another thing…And another thing…And another thing…

Seasonal wetlands in a South Carolina woodland habitat (top) and in themountains of Wyoming.

Many amphibian species dependnot only on seasonal wetlands,but also on the surroundingterrestrial habitat.

This PARC-sponsored document was produced by theSavannah River Ecology Laboratory in cooperation withthe National Audubon Society. Printing was sponsored bythe SREL Environmental Outreach Program.

amphibians return to water for only a monthor less out of the entire year. A corollary of

this biology is that these “wetland” speciesneed habitat adjacent to the wetland. At

present, very few state regulationsstipulate that the boundary of ajurisdictional wetland extendbeyond the high water mark.

Without simultaneous protection ofthe upland habitat, sometimes several

hundreds of meters beyond the highwater mark, many amphibian speciescould not persist even if the seasonal

wetland itself is left intact. Usingecological fact rather than politicsas a decision-making tool wouldlead one to revise the definition of

a wetland to include much more,rather than less, acreage, and not just

the water itself.

It is unfortunate that wetland policy andlegislation are often politically driven

rather than biologically based. Ifdecisions were based on the best

ecological knowledge, then itwould be a no-brainer thatsmall, isolated wetlanddepressions, no matter whatthe name or size or how long

they hold water, would remainundisturbed because of theirvalue as critical breeding sitesfor many amphibians. In this

fantasy world of rational decision making,small wetlands of only a few acres or

less (which in some regions maycollectively total 50% of alandscape’s total wetland acreage)

would not be filled or drained orseparated from one another byunsuitable habitat. Seasonalwetlands, in conjunction with all

other wetlands across a landscape,provide a varied habitat through

space and time that enhancesbiodiversity. Without seasonalwetlands the amphibiandiversity and our naturalheritage in every region of thecountry will suffer.

If it holds wIf it holds wIf it holds wIf it holds wIf it holds waaaaaterterterterter,,,,, k k k k keeeeeeeeeep itp itp itp itp it

For an answer to the question “Why protect small seasonalwetlands?” we should just ask the frogs. The answer would comein a resounding chorus (in five-species harmony) of “Listen tome when I talk to you—ribbit—’cause you’ll miss me when I’mgone.”