University of Alberta

Environmental Research and Studies Centre

newsenvironmental

Volume 1, Issue 1

November 2001

After three full years of university, the students in my fourth year course, “Management andthe Natural Environment,” had no idea of what ‘carbon sequestering’ is or why it might beimportant to the Planet, to Alberta’s economy, to their future well being. Like most of soci-ety, we are “ecologically illiterate” which, in my view, is as dangerous as being economicallyilliterate. In the class, we conceived the idea of students writing about the environmentfor students. In this first edition of Environmental News three students write about environ-mental issues that affect us here in Alberta. To have their article accepted, they had toundergo a review by an Editor of the Edmonton Journal for ‘journalistic quality’ and by oneProfessor for scientific accuracy. We will produce Environmental News as a quarterly journaland invite submissions from all students on campus. We also invite your letters in responseto this first edition.

Ray RasmussenTransAlta Professor of Environmental PolicyUniversity of Alberta School of BusinessDirector, Environmental Research and Studies Centre

Life on Earth as weknow it would notbe possible withoutthe protective ozone

layer in the stratosphere. Thenow famous ozone layer is thegaseous layer several kmsabove the Earth’s surface thatshields us from harmful UVradiation, particularly UV-Band the extremely energeticUV-C (which thankfully doesnot reach the earth’s surface).In 1985, three British scien-tists discovered a seasonal‘hole’ in the ozone layerabove Antarctica. This ozonehole increased ground-levelintensities of UV-B radiation atthe southern icecap andraised questions about result-ing effects on polar ecosys-tems. Not long after, scientistsalso found that the ozone

Lake Plants GetSunburned Too!by Marguerite A.XenopoulosPhD CandidateDepartment ofBiological Sciences

layer was thinning on a global scale. As an aside, the thinningozone layer increased the marketing and the usage of topicalsunscreens by health-conscious humans, who worried aboutstrong connections between sunburn and skin cancer.

It now appears that humans are not alone in their vulnerabil-ity to the damaging effects of sunlight. Negative effects of UVradiation have been found in many ecosystems, from polaroceans to temperate forests. Damage to plants and animalshas even been recorded in our own pristine lakes in theboreal forests. Lakes appear especially vulnerable becausethey can lose their own natural sunscreens. This protectionfor biota in lakes comes from dissolved organic carbon (it’swhat gives the tea-stained color to the water) that screensout harmful UV rays. Unfortunately for lake life-forms, thisprotection can be reduced by global stressors such as cli-mate warming and acid rain. For example, lake acidificationleads to the loss of dissolved organic carbon and increasedexposure of aquatic biota to UV radiation. Unlike humans,lake organisms cannot simply reduce their risk of sunburndamage by purchasing increased protection from the localdrugstore.

The lake organisms most susceptible to UV are thought to bemicroscopic, floating plants, which are also known as

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2 environmental news

Smokey the Bear hasbeen saying it foryears, and the public– not to mention the

kids which are next genera-tion wildlife mangers – lovehim for it. “Help PreventWildfires” is the most com-monly known phrase in theforest industry. But, could hu-man intervention supportingSmokey’s slogan be missingthe point – worse yet, elimi-nating a critical component tonatural forest succession.

Forest fire is the largest dis-turbance agent within theboreal ecosystem – acting asa natural “recycler” in foresthealth. When a forest standtype gets old, its resistance toflame diminishes. Its naturaldestiny is to succumb to themagnificent lightning stormsof spring and summer.

The boreal actually receivesits immense wealth of biologi-cal diversity (plants, insects,birds, fungi, mammals, etc.)due to the ever-changingforest structure caused bywildfires.

However, within the Provinceof Alberta there remains littleregard for the forest after wild-fire. Vast amounts of moneyare initially spent fighting fires,and inevitably, salvage-logging the remains of themerchantable timber leftbehind. The results of whichhave begun to raise someenvironmental concerns.

In 1998, after the Chip Lakefire burned an estimated

Smokin’ Hot Habitatby Curtis Stambaugh,MSc CandidateDepartment ofRenewable Resources

14,000 hectares of forest west of Edmonton, researchers atthe University of Alberta took note. An experimental study toevaluate the bird community response to burned forest habi-tat was fast underway - with collaboration from WeyerhaeuserCompany and Alberta Sustainable Resource Development.

The study had two unique qualities: Monitoring beganalmost immediately after the fire and it was designed tocompare bird use between older growth “unburned forest”with older growth “burned forest”, including similar sizedareas within salvage-logged cutblocks. All areas weremerchantable forest by industry standards – none of whichhas been done before.

After three years of monitoring, the data is speakingvolumes. What most believe to be a charred, nonliving rep-lica of a “real” forest, is in actuality, a thriving Mecca of birdlife. While the total number of species within the unburned

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forests remained relatively constant between years, speciesnumbers within the burned forests were higher, and havecontinued to climb year-to-year. The study had also foundthat the burned forests supported a higher number of breed-ing songbirds during the three-year period. As well, many ofthe birds occurred in both habitat types but were simplyhigher in numbers within the burns – showing that the burnsare indeed providing a high degree of habitat value.

Not suprisingly, the biggest difference was found with thosespecies not occurring in both habitats but regarded as post-fire specialists – namely Black-backed and Three-toed wood-peckers. These two woodpeckers have evolved into theirroles as post-fire obligates. They have learned to efficientlyflake the loosened tree bark for food, while their colourationprovides them with the exact camouflage needed to flourishin these environments. Because burned and damaged treesquickly become colonised with wood inhabiting beetles –the primary food source of all woodpeckers – they areattracted to these burned areas immediately after forest fires.

What’s more important is that woodpeckers, along with mostother cavity nesting species in Alberta, do not migrate in thewinter. So, not only do these birds depend on this habitatduring the breeding season, they require it year round!

Forest fires have long been regarded as an interference withnormal forestry practices by removing potentially viabletimber allocations. Furthermore, provincial forest policies haveencouraged quick clearcut harvesting of any merchantabletrees (dead or alive) left within the mapped perimetre ofa fire – otherwise known as salvage-logging. And becausebeetles colonise immediately and bore into the trees –ruining their use for lumber – harvesting also happensimmediately to out race the economic loss to insects. Whenthis happens, the natural link in boreal forest succession isultimately broken.

History has provided us with numerous scenarios of humanmismanagement – knocking natural systems out of whack,primarily for economic gain. Scandinavians have virtuallyeliminated fire from their system, and the wildlife thatappears on endangered lists in those countries are typicallypost-fire specialists. Eventually, we have discovered theenvironmental cascades that we have incurred – but oftenit’s too late.

This research has provided needed insight into the non-timber values associated with burned forests. Ensuring the

long-term integrity of the boreal forest system means main-taining the natural variability within it. If we are to continuesalvage-logging after forest fires, we need to place more weighton the wildlife species dependent upon them by leavingportions of their habitat intact.

If we don’t start paying attention now, we can take a historylesson from the Scandinavians.

As for Smokey the Bear – perhaps a new slogan. “Not AllForest Fires Are Bad”!

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Soft spring nights inAlberta resound tothe amorous croaks,peeps, and trills of

mating frogs and toads; formany people, this is the onlytime that amphibians are anobvious component of ourwildlife. Few people, includ-ing those who studied am-phibians, realized that thisgroup of animals was experi-encing worldwide declineswhich started in the 1960’s insome areas. In Alberta, thenorthern leopard frog started

Ribbetting Newsby Brian EatonPhD CandidateDepartment ofBiological Sciences

to disappear from much of its range at about this time, and isjust now in the process of recovery; the reason behind theinitial decline remains a mystery.

In 1996, Alberta biologists interested in amphibians met inEdmonton to discuss projects and exchange ideas. Two ofthe problems discussed were the lack of long-term monitor-ing data for amphibians and public education about theseanimals. In order to address these concerns, my supervisor,Dr. Cynthia Paszkowski, and myself started the ResearchingAmphibian Numbers in Alberta (RANA) project in 1997. Ouridea was to establish sites, usually in conjunction with a parkor research station, which could be used to monitor amphib-ian populations over a number of years and as focal pointsfor interpretive programs about amphibians.

We started the project slowly, with only three sites in 1997;these were located at Lesser Slave Lake Provincial Park,

Meanook Biological Research Station (near Athabasca),and Beaverhill Bird Observatory. We were fortu-

nate to have the Alberta Conservation Asso-ciation hire Lisa Takats to help run the

project in 1997; Lisa took over theproject following that pilot year, andhas done a great job expanding theproject. The number of RANA sites

has grown to eight, scattered through-out most of the various biomes found in

Alberta. Wetlands surrounding the RANAponds are also surveyed for amphibians; in

the 2000 season, 133 nearby wetlands were sur-veyed. Additional potential RANA sites were in a

pilot phase in 2001.

Counting amphibians does not sound hard, and it isnot in concept, but it does require a lot of work.

Most RANA sites consist of a discrete pond thatis entirely surrounded by a plastic or fabricfence at least 50 cm high; the bottom of thefence is buried so nothing can push under-neath. To capture amphibians, pitfall traps

are stationed every 10 m along each side of thefence. These traps are checked daily, and captured

animals are identified to species, weighed, measured,sexed (if possible), assigned to an age class, examined for

deformities or parasites, and released on the opposite sideof the fence from that on which they were captured. Trap-ping occurs for 30 days in spring to sample adults moving to

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ponds to breed, and 30 days in late summer/early fall tosample young amphibians moving away from the water.

Amphibian populations are notorious for fluctuating wildlyfrom one year to the next; this makes detecting declines inamphibian abundance difficult, and is one of the reasonsthat long-term monitoring sites are so necessary for this groupof animals. The data collected though the RANA project from1997 to 2000 reflects what we feel are natural changesin abundance, as our sites are relatively free from humanimpacts such as pollution and land development. For exam-ple, fluctuations in abundance are evident at two of the long-est-running RANA sites, Lesser Slave Lake and Meanook Bio-logical Research Station (Figure 1). There was a large declinein number of amphibian captured at Meanook from 1998 to1999, which corresponds with a large drop in water level inthe RANA pond at that time. There is no corresponding dropat Lesser Slave Lake, a site where amphibian abundanceshowed relatively mild fluctuations (Figure 1). It is not theyear-to-year fluctuations that indicate an amphibian popula-tion is in trouble, but the long-term trend in the abundanceof that population; this is the reason long-term studies are soimportant in detecting true declines.

Monitoring amphibian populations to determine if they arestable, increasing, or declining is a valid and important exer-cise. However, without public appreciation of the importantrole amphibians play in the ecosystem, and their current plightin the face of increasing human impact on the landscape, weare monitoring the symptoms without addressing the causeof the illness. Though there are multiple causes for globalamphibian declines, many can be traced back to human ac-tivities ranging from the draining of wetlands to increasingUVB penetrating the atmosphere. An important componentof the RANA project is to expose the public to amphibiansthrough interpretive talks, visits to the RANA sites, and inter-action with live amphibians. How many people know thatAlberta is home to ten species of amphibians, including somewith incredible adaptations to survive some of the relativelyharsh environments found in Alberta, including the ability tofreeze solid and survive? Over the first four years of the RANAproject a total of almost 8000 people learned about amphib-ians through the RANA project, with a steady increase inpublic education since the inception of the project (Figure2). Hopefully everyone who has visited a RANA project site,or talked with RANA summer staff, has a better appreciationof amphibians, and will act with environmental responsibil-ity so that future generations can also listen in awe to thedeafening spring chorus of mating frogs and toads.

Figure 2. Number of peopleeducated about amphibiansthrough RANA project.

Figure 1. Abundance ofamphibians at two RANAproject sites.

Ribbetting News continued…

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Environmental News is published on a quarterly basis by theCentre. Articles, photos, commentary and suggestions should besubmitted to:

Environmental News8901 HUB Mall,University of Albertawww.ualberta.ca/ERSCersc@ualberta.ca

University of Alberta

Environmental Researchand Studies Centre

Tel: (780) 492-5825Guidelines for authors: www.ualberta.ca/ERSC/guide.htm

Mailing Address:3-23 Business BuildingUniversity of AlbertaEdmonton, Alberta,T6G 2R6

phytoplankton. As photosynthesizers, phytoplankton mustlive in surface waters of lakes where sunlight is plentiful.Ironically, this restriction to surface waters increases theirrisk of damage from sunlight’s UV rays. Recently, I foundthat UV-B radiation reduces the growth of lake phytoplanktonfrom boreal lakes, particularly during spring but less so inmid-summer. It appears that after boreal lakes thaw and losetheir surface ice in late April-early May, the cumulative expo-sure of phytoplankton to UV radiation is low and theyexhibit high susceptibility. As summer progresses,phytoplankton are increasingly exposed to high UV radia-tion and their protective processes become more prevalent.This protection would be similar to that acquired as yourbeach time increases through the summer and you becomemore tanned. An alternative explanation for my results, isthat the type of lake phytoplankton changes through thesummer to taxa able to cope with high irradiances. Thismechanism would be akin to changes in the type of peopleon a beach, from unpigmented (fair-skinned) and sensitiveones to darker and less susceptible ones.

In the same study, which I conducted with Drs Jim Elser andPaul Frost from Arizona State University, I found that algalgrowth was controlled by interactions between UV and theconcentration of phosphorus, a very important nutrient in theselakes. Phosphorus, known to cause excessive algal growth inlakes where it is found at high concentrations, strongly limitsthe growth of phytoplankton in these boreal lakes. As a result,I found weak effects of UV radiation on algal growth at thenormally low concentration of phosphorus in these lakes.However, when I increased phosphorus concentrations I foundmuch greater UV damage to the phytoplankton as they wereno longer limited by phosphorus.

In another study, I found that phytoplankton can becometrapped near the surface of lakes during sunny, warm andwindless days. This phytoplankton ‘trap’ occurs when the

temperature at the surface of the lake increases and an invis-ible physical barrier is formed between warmer, upper lay-ers and the cooler, lower layers. This physical barrier (a.k.a.thermocline), can trap the microscopic plants in the very topsurface layers where they are exposed to high levels of UV-B. This exposure is compounded by their relative inabilityable to escape, many can’t actively swim, to the darker coolerwater layers in the lake. However, the news may not be allbad as phytoplankton have evolved over millions of years,some during the high UV years preceding the developmentof the ozone layer. Many have in their physiological arsenala variety of ways to protect themselves including the pro-duction of compounds that block UV light. On the otherhand, the species having these self-induced sunscreens areprimarily in the cyanobacteria, which are viewed by many asundesirable due to their tendancy to form large, smelly andtoxic blooms.

Why is it so important to protect these microscopic plants?As primary producers, phytoplankton take up carbon diox-ide to produce the food required for their survival. As car-bon sinks, destroying the phytoplankton would furtherexacerbate climate warming effects caused by excesscarbon dioxide. The phytoplankton further play an impor-tant role in sustaining the lake’s food web. They’re used asfood by zooplankton (microscopic floating animals), which,in turn, support fish!

Luckily, the protection of the stratospheric ozone layer isone of the greatest environmental success stories. Since theratification of the Montreal protocol in 1987, many substancesthat destroy the ozone layer have been reduced and/orbanned and the ‘hole’ is expected to come back to normallevels in roughly 50 years. But unless we address other envi-ronmental stressors, particularly climate warming and acidrain, UV radiation will remain a serious problem for the healthof our lake ecosystems!

Lake Plants Get Sunburned Too, continued from page 1

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