Zoology Newsletter - Department of Zoology - University of ...

Mixing It up with anInvasive SpeciesUniversity of Wisconsin-Madisonscientists, under the direction of AssociateProfessor of Zoology Jake VanderZanden, are mixing an entire lake —Crystal Lake, in Vilas County, Wisconsin— in an attempt to eradicaterainbow smelt, a fish that feasts on theyoung populations of other speciessuch as perch and walleye.Measures to remove rainbow smelttypically involve chemicals that destroymost of the lake’s ecosystem.But scientists at UW-Madisonmay have a better solution. The smeltrequire a cold-water habitat and relyon the thermal stratification of lakesto survive in the summer — and thisprovided the idea behind the CrystalLake Mixing Project.Mixing began on Crystal Lake inthe spring, and the team succeeded increating a near-uniform temperaturein the lake. The smelt began behavingirregularly in early August, with somedying and floating to the surface.Keep an eye out for furtherupdates from Crystal Lake in ournext newsletter.(Above top) Rainbow smelt have invadedaround 25 lakes in Wisconsin, forcingmanagers to restock them.The project uses devices called GradualEntrainment Lake Inverters (GELIs) —large trampoline-like objects that moveup and down — to mix the lake anddestroy the smelt’s cold-water haven.Turbulent EcologyProfessor Monica Turner’s lab studies landscapes in flux“Where we are now —this is the very edge ofthe science. Climate ischanging the rules of thegame for many ecosystems.”— Professor Monica TurnerIf you know that forests naturallyregenerated after the 1988 Yellowstonefires and that some trees (lodgepolepines, for example) actually evolved tobe fire dependent, then you probablyhave Monica Turner to thank.A pioneer in the field of landscapeecology, the professor of Zoology hasspent almost three decades studying,writing, and talking about forest firesand their aftermath, changing attitudesand shaping management techniques.Now Turner is trying to understandjust how much of what she thoughtwas true about fire and forests may nolonger apply.Turner’s lab is studying the effectsof climate change on fire regimes in thenorthern Rockies, and finding that as thelandscape gets warmer and drier, fires aremore frequent. With less time betweenblazes, trees may not have enoughtime to produce cones, and with morefrequent summer droughts, fewer treeseedlings may establish themselves afterfires. In 50 or even 20 years, that couldspell big changes for forests in YellowstoneNational Park and elsewhere.“We’ve created models for whatmight happen,” said Turner. “We maybe looking at a forest fire regime thatwill be different than anything seen sincethe last Ice Age, 10,000 years ago.”Will fires eventually kill the westernforests?Turner’s graduate students arestudying that very question. It may bethat bark beetles (whose populationshave surged in recent warmer years)actually help reduce the risk of catastrophicfires. The beetles thin the forestand deplete fuels in the canopy, Turnersaid. But, how forests will respond amidProfessor Monica Turner is a pioneer in thefield of landscape ecology.all of these new variables is anybody’sguess, and it makes for exciting work inTurner’s lab.“Where we are now — this is thevery edge of the science,” said Turner.“Climate is changing the rules of thegame for many ecosystems.”The trick, for Turner and hercolleagues, is to anticipate some ofthose changes.A new project encourages this approach.Turner’s lab is part of a NationalScience Foundation-funded projectto study the Yahara Watershed, whichincludes the five Madison-area lakes.The project is built on an interdisciplinaryteam made up of five UW-Madisonfaculty members: an atmosphericscientist, a limnologist (Steve Carpenter,also in Zoology), a social scientist, acivil engineer, and a landscape ecologist(Turner). They’ll be looking specificallyat “ecosystem services,” the term usedto describe the many benefits that peoplederive from nature, such as fresh water,food, bioenergy, hunting, fishing, andrecreation.“We’ll be looking at what can bedone to enhance sustainability in thefuture, given anticipated changes in climate,policy, and land use,” said Turner.“This is the watershed where we alllive and work, so we are committed tounderstanding it.”n n n6 Zoology Now