Review Article Structuring Effects of Deer in Boreal …downloads.hindawi.com/archive/2014/917834.pdfReview Article Structuring Effects of Deer in Boreal Forest Ecosystems SteeveD.Côté,

Review ArticleStructuring Effects of Deer in Boreal Forest Ecosystems

Steeve D Cocircteacute1 Julien Beguin1 Sonia de Bellefeuille1 Emilie Champagne1

Nelson Thiffault12 and Jean-Pierre Tremblay1

1 Chaire de Recherche Industrielle CRSNG en Amenagement Integre des Ressources de Lrsquoıle drsquoAnticostiDepartement de Biologie et Centre drsquoEtudes Nordiques Universite Laval Quebec QC Canada G1V 0A6

2Direction de la Recherche Forestiere Ministere des Forets de la Faune et des Parcs 2700 Einstein Quebec QC Canada G1P 3W8

Correspondence should be addressed to Steeve D Cote steevecotebioulavalca

Received 2 June 2014 Accepted 19 August 2014 Published 16 September 2014

Academic Editor Junbao Yu

Copyright copy 2014 Steeve D Cote et al This is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

Many deer populations have recently increased worldwide leading to strong direct and indirect ecological and socioeconomicalimpacts on the composition dynamic and functions of forest ecosystems Deer directly modify the composition and structure ofvegetation communities but they also indirectly affect other species of the ecosystem by modifying the structure of the vegetationHere we review the results of a research program on overabundant white-tailed deer (Odocoileus virginianus) in the boreal forestof Anticosti Island (Quebec Canada) aimed at identifying deer densities compatible with forest regeneration Various silviculturalsystems and treatments failed to regenerate deer habitat at high deer densities but planting size-adapted seedlings could be effectiveat moderate densities Using a controlled deer density experiment we found vegetation recovery at deer densities le 15 deerkm2The same experiment revealed that other groups of organisms such as insects and birds responded favorably to a reduction of deerdensity We also found that alternative successional trajectories may occur after a certain period of heavy browsing during earlysuccession We conclude that one of the most important remaining research gaps is the need to identify habitat-specific thresholddensities at which deer impacts occur and then to design effective wildlife and forest management strategies to limit deer impactsand sustain ecosystem integrity

1 Introduction

Several populations of cervids (hereafter deer) have increasedworldwide during the last decades causing strong directand indirect ecological and socioeconomical impacts onthe composition dynamic and functions of forest ecosys-tems [1] In North America white-tailed deer (Odocoileusvirginianus Zimmermann) has become overabundant inseveral regions [2 3] forcing wildlife and forest managersto develop new ways of managing deer-forest systems Thisreview summarizes the results of a research program onAnticosti Island (Quebec Canada) that exemplified how anoverabundant white-tailed deer populationmodified a borealforest ecosystem We also address how a careful assessmentof changes in the ecosystem provides valuable science-basedguidelines for the development of innovative and integratedwildlife and forest management strategies

Heavy browsing caused by high deer densities directlyimpacts plant communities and tree regeneration dynamics

(Figure 1) These impacts often lead to dominance of plantspecies tolerant to browsing into communities [4] lowerabundance or extirpation of less tolerant species [5ndash7]and changes in compositional and functional patterns ofplant diversity [8ndash10] possibly reducing the productivity ofecosystems [11 12] Deer can also modify soil dynamics andvegetation by trampling and nutrient deposition via theirfeces urine and carcass [13 14] Moreover heavy browsingoften induces additional silvicultural costs by preventing theestablishment and height growth of palatable tree species [1516] When the magnitude of impacts caused by deer on veg-etation overcomes the resilience of forest ecosystems (sensu[17]) deer browsing can further alter trajectories of forest suc-cession [15 18] or possibly yield alternative stable states [6]The last two decades of research have greatly improved ourunderstanding of the role played by deer browsing on changesin vegetation patterns and dynamics Less is known howeverabout how the changes in patterns of primary producers

Hindawi Publishing CorporationAdvances in EcologyVolume 2014 Article ID 917834 10 pageshttpdxdoiorg1011552014917834

2 Advances in Ecology

Birds

Insects Deer

Small mammals

Vegetation patterns

Belowground

Aboveground

Fruit and seed

production

Structure and diversity of

plantcommunities

Soil properties

Patterns anddynamics of tree

regeneration

Forest succession and stand dynamics

Figure 1 Direct and indirect effects of deer overabundance on forest succession and other species in the ecosystem

indirectly impact assemblages of animal species at differenttrophic levels (Figure 1) For instance overabundant deerpopulationsmay limit the availability of plant species to otherprimary consumers (ie insects birds and small mammals)that directly depend on browsing intolerant plant species asa main source of forage hiding cover or for reproductionneeds [19ndash22] In turn the lower abundance of primaryconsumers might initiate trophic ricochets (sensu [23]) onpredators carnivores and decomposers altering the structureand interactions among the entire food web [24ndash27]

To answer these questions we have launched a long-termmultidisciplinary research program on deer-boreal forestrelationships [28] We first experimented different types oflarge cutblocks to regenerate deer habitat then we applied aseries of controlled and replicated experiments at large spatialscales to identify deer density thresholds compatible withforest regeneration In particular we have established a con-trolled deer density experiment to investigate the response ofseveral ecosystem components (eg soil properties vegeta-tion insects birds and small mammals) along a gradient ofdeer browsing intensity

2 ContextAnticosti Island (7 943 km2) is located in the Gulf of StLawrence in Quebec Canada (49∘281015840Nminus63∘00W Figure 2)The forest ecosystem belongs to the eastern balsam fir (Abiesbalsamea)mdashwhite birch (Betula papyrifera) bioclimatic sub-domain [29] The preindustrial forest was characterized by amatrix of overmature softwood stands dominated by balsamfir with the inclusion of younger stands [30] Stand regenera-tion is typically supported by banks of shade-tolerant balsamfir seedlings capable of reestablishing canopy dominancefollowing a disturbance (advance regeneration [31])

Approximately 200 white-tailed deer were introduced onAnticosti Island at the end of the 19th century and theyrapidly multiplied taking advantage of a suitable habitat in

the absence of predators The deer population now reaches adensitygt 20 deerkm2 locally [32] and appearsmainly limitedby the availability of winter food resources [33] fluctuatingannually according to winter severity [34]

Such a high deer density had strong repercussions onthe forest Major modifications in the woody and herbaceousvegetation layers related to intense deer browsing have beenreported such as the quasi-disappearance of the shrub layerand of most deciduous species [35ndash37] The regenerationof balsam fir forests a key habitat for deer winter survivalon Anticosti Island [38] is currently compromised by deerbrowsing on balsam fir seedlings Balsam fir stands are beingprogressively replaced by the less palatable white spruce(Picea glauca) through apparent competition [35 39 40] Inaddition despite the infrastructures and facilities in placetoday sport hunting removes less than 5 of the total pop-ulation annually a harvest insufficient to achieve populationcontrol [34 41]

A forest management program was established on theisland in 1995 to favor balsam fir regeneration thus allowingthe reestablishment of balsam fir stands The core of theintegrated forest management strategy is based on fencingof large cutover areas (sim7ndash10 km2) comprising clear-cuts andresidual forests [42] (Figure 2) Deer density within fencedareas is greatly reduced by sport hunting Clear-cuts emulatenatural disturbances resetting the regeneration dynamicsof balsam fir forests by releasing the understory advanceregeneration When the stocking of balsam fir seedlings isdeficient the plan provides for plantation of nursery grownbalsam fir seedlings Once fir saplings will be high enough toescape browsing (up to 15 years) the fences will be removedThe residual forest stands act as winter cover interspersedwith forage patches providing adequate deer habitat [43]Managers were also concerned by the potential negativeeffects on other plant or animal species associated with thedisappearance of balsam fir forests In addition they feared

Advances in Ecology 3

Lac Simonne

Jupiter

0 5 10 20 30 40 50

NEW

S

A

B

C

1 2 3 40

1 2 3 40(km)

(km)

(km)

Figure 2 Location of the large management enclosures (119899 = 26) and the controlled browsing experimental sites on Anticosti Island QuebecCanada

that deer hunting the main economic activity on the islandmight be negatively affected [42] To address the complexrelationships between deer forests and the exploitation ofnatural resources in the boreal forest the Industrial ResearchChair in IntegratedResourceManagement ofAnticosti Islandwas created at Universite Laval (Quebec Canada) in 2001

The first objective of the Chair Research Program is todevelop forest and wildlife management approaches adaptedto high deer densities The four main research themes coverfundamental and applied aspects related to the sustainabledevelopment of resources and include the relationshipsbetween high deer densities and ecological processes of forestecosystems the habitat selection and foraging behavior ofwhite-tailed deer the development of silvicultural strategiescompatible with high herbivore densities and the definitionand development of integrated tools to manage biologicalforest resources exposed to high deer densities [28]

3 Research on Anticosti

31 Testing Silvicultural Systems and Treatments A key ele-ment of our research program is the use of in situ large-scale factorial experiments to unravel how local deer densitiesand habitat characteristics influence deer impacts on treeregeneration success Our first set of experiments specificallychallenged the ldquohabitat characteristicsrdquo hypothesis whichstates that the susceptibility of tree regeneration to deerbrowsing depends on the surrounding biotic and abioticconditions prevailing atmicrosite stand and landscape scales[44] This hypothesis predicts lower impacts of deer ontree regeneration at longer distances to forest edges within

cutblocks as a result of higher predation risk perceived bydeer with increasing distance from escape cover [45]

We tested this prediction in large clear-cut blocks usingreplicated pairwise fenced and unfenced plots located atvarious distances from the forest edge Results demonstratedthat in absence of natural predators the magnitude of deerimpacts on palatable tree regeneration was independentof distance from escape cover [46] In a second set ofexperiments we tested whether the susceptibility of treeregeneration to deer browsing depended on silviculturalsystems [44] We expected tree regeneration under a ldquoclose-to-naturerdquo silvicultural system (eg shelterwood and naturalregeneration) to create abundant regeneration via increasedseed supply of several species and allow balsam fir seedlingsto develop beyond the reach of deer [47 48] We experi-mentally tested this prediction under in situ deer densities(ge15 deerkm2) using a broad range of silvicultural systemsincluding shelterwood cutting of various intensities (0 25or 40 removal of the stand basal area) strip clear-cutting(strip width of 15 30 or 45m) group seed-tree cutting witha gradient of scarification intensity and large clear-cuts [4950] Overall deer browsing in natural conditions preventedthe growth in height of all palatable tree seedlings in everysilvicultural system even when seedling density was locallyhigh [49 50] Finally using planted balsam fir seedlings ofvarious sizes we tested the ldquoapparencyrdquo theory which statesthat herbivores aremost likely to feed on plants that are easierto find [51]We hypothesized that under low tomedium deerdensities seedlings that are either taller or grow faster thanthe average aremore susceptible to browsing than others [52]Indeed we showed that for seedlings planted in clear-cut


0deerkm275deerkm2

15deerkm2 Natural density

Figure 3 Vegetation after 7 years of the controlled browsing experiment in the boreal forest of Anticosti Island Quebec Canada (photos byE Cardinal)

areas the relative risk of being browsed increases withseedlings height at the end of the previous growing season[53]

Lessons can be drawn from these early studies Firstfood-dependent and -independent factors controlled by sil-vicultural systems such as distance to stand edge localseedling density species planted amount of woody debrisand size of opening areas play no significant roles inmitigating browsing impacts on natural regeneration whendeer population densities are ge15 deerkm2 [35 46 49 50]Second when deer densities are between 10 and 15 deerkm2there is a prominent bottom-up control of planted seedlingsduring early growth by interspecific competition instead ofa top-down control by deer which implies that the use ofsize-adapted stock could optimize the restoration schemefollowing deer population reduction [53] However the long-term evaluation of plantation success is required to confirmthis suggestion because seedling growth over time increasestheir browsing probability Overall these studies highlightthe critical role of high deer densities in the magnitude ofbrowsing impacts on tree regeneration

32 Estimating Deer Density Compatible with Natural Succes-sional Processes A recurrent theme in deer-forest literatureis the dearth of studies addressing threshold deer densitiescompatible with the maintenance of natural processes inforests [1] Progress in understanding how ungulates modifyecosystems both directly and indirectly and respond toecosystem changes requires controlled factorial experimentsthat manipulate deer density and other factors interacting toinfluence forest dynamics especially natural and man-madeperturbation regimes [54ndash57] We embraced this challengeusing a controlled browsing experiment that manipulatedboth deer densities (0 75 15 deerkm2 and in situ densityup to 56 deerkm2) and forest structure (clear-cut and uncutforest) during 8 consecutive years (2002ndash2009) Deer densi-ties and vegetation cover types were replicated in 3 blockswith 4 experimental units per block (Figure 2) The fenced

experimental units were dominated by balsam fir (gt70canopy cover) before the beginning of the experiment Ineach block we maintained a deer-free 10 ha exclosure 3 deerin a 40 ha enclosure made of 3-meter-high wire game fence(75 deerkm2) and 3more in a 20 ha enclosure (15 deerkm2)We controlled deer density by relocating 3 deer per enclosureeach spring and culling them in late autumn We monitoredin situ deer densities in unfenced sites located near theenclosures using distance sampling of summer feces (see [58]for details)

The response of the ground layer vegetation in the earlysuccession phase following forest harvesting revealed a fastrecovery rate of compositional reproductive and morpho-logical attributes of plants at densities below 15 deerkm2 andsuppression of growth or reproduction at higher densities[58] (Figure 3) Browse tolerant species such as grasses werepositively related to deer density through exponential growthfunctions [58] Such field layer can be hard to penetratefor woody species and has therefore been termed a recal-citrant understory [59] Sexual reproduction of commonlygrazed species such as Anaphalis margaritacea Aster sppCerastium vulgare Clintonia borealis Conioselinum chinenseChamerion angustifolium Geum macrophyllum Gnaphaliumuliginosum Hieracium spp Maıanthemum canadense Pet-asites spp Prenanthes spp Ranunculus acris Senecio sppStreptopus roseus Rubus idaeus Rubus spp Taraxacum offic-inale Trientalis borealis and Vaccinium spp was inhibitedby herbivory at local density levels exceeding 15 deerkm2but recovered exponentially at lower densities [58] Sixyears after forest harvest and deer density control plantsassociated with high deer density had functional traits suchas asexual reproduction abiotic pollination and gravitywindseed dispersal while traits favored at reduced deer densityincluded fleshy fruits large seeds and erected foliage [60]

In the first 3 years following timber harvesting andcontrolled browsing the mortality of individually taggedbalsamfir seedlings (heightlt 30 cm) decreased exponentially


with decreasing deer density in clear-cuts [40] Mortality ofseedlings at deer densities under 15 deerkm2 decreased overtime and with age and stem height converging eventuallytowards the mortality rate observed in exclosures with nodeer [61] Independently of deer density percentage of plotswith at least one recruit in clear-cuts dropped from 56 plusmn 5to 7 plusmn 1 within 3 years [61] The height of seedlings alsoincreased exponentially with decreasing deer density in clear-cuts after 3 years of control [61] We observed almost noregeneration into the sapling stage (gt30 cm) under in situdeer densities after 7 years [61] Overall the abundance of firsaplings recovered exponentially in clear-cuts but remainedlow and independent of deer density in uncut forest whilethe abundance of spruce Picea spp saplings was unrelated todeer density and increased with time Although wemeasureda relatively high stem density of balsam fir saplings 7 yearsafter the start of the treatment their ultimate contribution tothe canopy remains to be confirmed

The early responses of the ground layer and advanceregeneration can shape succession processes as they deter-mined the initial floristic composition and the competitiveinteractions between dominant species Changes imposedby deer browsing at this stage may determine successivecolonization events with long-term legacy effects eventuallyleading to alternative successional trajectories (AST sensu[62]) Legacy effects are defined as indirect effects persistingfor a long time in the absence of the causal species activities(sensu [63]) Legacy effects of deer browsing have beenreported a long time after localized deer exclusion [23 64 65]while other systems appear resilient to prolonged periods ofheavy browsing pressure [66] A conclusive experimental testof AST requires assessing whether a successional trajectoryinitiated under deer herbivory could be reversed To this endwe implemented a delayed herbivore removal experimentfor a period of 15 years we compared the composition andstructure of the forest community in (1) original exclosuresprotecting regeneration from deer browsing directly afterlogging (2) control plots and (3) delayed exclosures thatwerebuilt 8 years after logging on plots previously accessible todeer [18] Although the palatable paper birch and some palat-able herbs recovered in delayed exclosures we observed lega-cies from trees and herbs resistant to browsing (sensu [67])Woody regeneration in delayed exclosures was dominated bywhite spruce while Poaceae (grasses) were abundant in thefield layer [18] We concluded that AST might occur aftera limited period of heavy browsing during early successionbecause only early successional species managed to establishin exclosures constructed 8 years after logging whereas latesuccessional broadleaves and balsam fir remained rare Wesuggest that by acting as a chronic disturbance agent deercan undermine the resilience of balsam fir forests and makethem more vulnerable to AST

33 Managing White-Tailed Deer Density Hunting is themain management tool available to control deer populations[1] To improve deer management using sport hunting westudied the environmental variables that limit the efficiencyof hunting Using an innovative approach of monitoring thebehavior of hunters with GPS technology we found that

the spatial distribution of harvested deer at different scaleswas mainly determined by the presence of access roadsin open stands [68] The abundance of deer forage alsoinfluenced the spatial distribution of harvested deer acrossthe landscape but to a lesser extent (see also [69]) Thushabitat characteristics could be modified to increase deerharvest by improving accessibility and visibility near roadsfor instance by the creation of forest openings

Intensive and localized harvest of antlerless deer has beenproposed as another potential measure to reduce deer density[70] The philopatric behavior of females is expected to limitrecolonization of hunted zones [70 71] To test the efficiencyof this method under natural conditions we monitored deerdensity vegetation abundances and growth as well as deerlife-history traits during 6 years in five 20 km2 experimentalsites where harvest rate of antlerless deer was increased by 30to 50 and in 5 control sites where harvest rate was 5ndash7[72] Contrary to our expectations deer density vegetationabundance and deer life-history traits did not differ inexperimental and control sites [72] Given the large effortsrequired for localized management we conclude that thelocal control of overabundant deer populations through sporthunting may be difficult to achieve in areas where huntingpressure is limited

34 Assessing the Direct and Indirect Impacts of Deer on OtherSpecies Intense browsing by abundant large herbivores canthreaten the ecological integrity of ecosystems by inducingmodifications in the structure and composition of vegetationthat affect other animal communities [1 20 21 73ndash76] Usingour large controlled browsing experiment we investigatedthe relationships between deer density and different animalcommunities and species including songbirds insects andsmall mammals

341 Songbirds Compared to the vegetation the magnitudeof the positive effects of the reduction in deer density on song-birds was limited Nevertheless 6 years of reduced deer den-sity increased songbird richness and diversity [77] Higherbirch ground cover at reduced deer densities (le75 deerkm2)increased the total abundance species richness and diver-sity of songbirds by 30 on average The regeneration ofwhite spruce at high deer density maintained many shrub-dependent songbirds associated with forest canopy [77]Overall simplification of the vegetation structure by deerbrowsing homogenized the composition of songbird commu-nities [78]

342 Insects The sensitivity of insect taxa and feeding guildsto deer density decreased along a gradient representing theirdegree of association with plants [79] The abundance ofepigeal Carabidae which do not have any direct relationshipwith plants was independent of deer density Macro Lep-idoptera however a group intimately linked to vegetationhad higher species richness and a greater abundance ofindividuals from rare species at reduced than at in situ deerdensities [79] The reduction of deer density to le15 deerkm2might be sufficient to restore insect diversity on AnticostiIsland


343 Small Mammals Finally we assessed the influence ofdeer density and forest harvesting on deer mice (Peromyscusmaniculatus) the only small mammal species present onAnticosti Island [80] We found higher mice abundance inclear-cuts than in intact adjacent forests regardless of deerdensity Our findings suggest that the indirect effects of deerbrowsing on generalist species such as deer mouse may beweak possibly due to their omnivorous feeding habits Theinterspecific relationships between deer andmice thus appearneutral in this system

4 OutlookBecause the ecological and socioeconomical impacts ofoverabundant deer are expected to further increase in thenear future a number of research questions need to beaddressed One of the most important remaining researchgaps is the identification of habitat-specific threshold densi-ties at which deer impacts occur [1 22 54 81] This wouldallow designing effective strategies to limit deer impactsand sustain ecosystem integrity In addition many factorshave been treated separately in the study of deer-forestrelationships but we need to understand the interactingfactors affecting ecosystem resilience [1] For example wemust build from previous studies and further investigate theinteractive effects of deer browsing pressure and other naturalor anthropogenic disturbances [65 82 83] The impacts ofdeer overabundance may be linear but most likely involvethresholds and nonlinear relations that should be included inresearch designs [1 6 84] We must determine the recoveryduration of ecosystems once deer density has been reduced[22 58] We also need to assess the impact of plant-plantassociations on the browsing risk that is the effect of thepresence of companion species on accentuating or decreasingthe risk of browsing on a particular (preferred) plant species(namely associative susceptibility and associative resistance[85ndash87]) Although we have made large progresses to addressthe impact of deer density on biodiversity (eg [77 79 88])since we outlined this gap as a research priority a decadeago [1] there is still a need to assess the effects of highdeer density on the structure of ecosystems and hencebiodiversity

Generally we need more experiments of controlled largeherbivore densities in several types of ecosystems [8 54ndash57 89 90] To date only boreal forest (our work on Anticostieg [58 91] for Alces alces) and temperate forest ecosystems[92 93] have seen experiments at controlled deer density Forinstance there is a lack of studies about the impacts of highbrowsing pressure in tropical and subtropical environmentsas well as in Arctic ecosystems where cases of caribou-reindeer (Rangifer tarandus) overgrazing have been reported[94ndash96] These studies would be particularly relevant forspecies such as lichens that take a long time to regenerate[97] In addition research on interactions between speciesin environments where a suite of large herbivore speciescoexist (eg Western Europe New Zealand) is needed Forinstance the combined effects of sympatric herbivore species

on ecosystems are not well known except perhaps in Africansavannas [98 99] We now know that deer browsing has thepotential to lead to alternate successional trajectories [18]but we still need to determine whether positive retroactioninduced by deer browsing can maintain forest ecosystemsinto alternate stable states or regimes on large spatial andtemporal scales [6 62 81]

From a forestry perspective there is a need to furtherinvestigate the interacting impacts of regeneration densityseedling origin (natural versus planted) competing vegeta-tion characteristics (composition cover and relative height)and deer density on stand regeneration success under highbrowsing pressure Furthermore these interactions shouldbe studied within a range of silvicultural treatments suchas precommercial and commercial thinning or shelterwoodcutting [53 100 101] We should determine how browsingpressure influences tree growth on sites of various fertilitiesin order to include the effect of deer in the estimation oftimber harvest levels Moreover the sole and interactingeffects of stock type characteristics time since plantingsoil and slash manipulation and vegetation control [102ndash104] must be integrated within a comprehensive model ofstand management to guide silviculture Within speciesindividual seedlings differ genetically in their susceptibilityto browsing [105ndash108] suggesting that selection for speciesvarieties and genotypes more resistant to browsing could bepossible

More locally on Anticosti Island the most crucial needremains to test the efficiency of large-scale fenced areasat reduced deer density to regenerate forests [42] Whenvegetation height will be judged sufficient for trees to escapedeer browsing the fences will be removed [42] The firstenclosures are now approaching this state and thus both theresponses of plants (see above) and animals to the removalof the fences need to be measured We need to assess how theremoval of the fence will impact the space use of surroundingdeer because it will increase the local abundance of forage andmay thus attract deer over long distances

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgments

The authorsrsquo research on white-tailed deer has been fundedby the Natural Sciences and Engineering Research Councilof Canada (NSERC) Produits Forestiers Anticosti UniversiteLaval SEPAQ Anticosti Petrolia Safari Anticosti and theMinistere des Forets de la Faune et des Parcs du QuebecTheauthors thank J Huot for his pivotal role in establishing theirresearch program on Anticosti Island and the community ofPort-Menier for continuous supportThe authors are gratefulto all the graduate students technicians and field assistantsfor their involvement and work on the research program onAnticosti over the years


References

[1] S D Cote T P Rooney J-P Tremblay C Dussault and DMWaller ldquoEcological impacts of deer overabundancerdquo AnnualReview of Ecology Evolution and Systematics vol 35 pp 113ndash147 2004

[2] M R Conover ldquoMonetary and intangible valuation of deer inthe United Statesrdquo Wildlife Society Bulletin vol 25 no 2 pp298ndash305 1997

[3] W J McShea H B Underwood and J H Rappole EdsThe Science of Overabundance Deer Ecology and PopulationManagement Smithsonian Institute Press Washington DCUSA 1997

[4] R Perea M Girardello and A San Miguel ldquoBig game or bigloss High deer densities are threatening woody plant diversityand vegetation dynamicsrdquo Biodiversity and Conservation vol23 no 5 pp 1303ndash1318 2014

[5] S B Horsley and D A Marquis ldquoInterference by weedsand deer with Allegheny hardwood reproductionrdquo CanadianJournal of Forest Research vol 13 no 1 pp 61ndash69 1983

[6] D J Augustine L E Frelich and P A Jordan ldquoEvidence for twoalternate stable states in an ungulate grazing systemrdquo EcologicalApplications vol 8 no 4 pp 1260ndash1269 1998

[7] J B McGraw andM A Furedi ldquoDeer browsing and populationviability of a forest understory plantrdquo Science vol 307 no 5711pp 920ndash922 2005

[8] N T Hobbs ldquoModification of ecosystems by ungulatesrdquo Journalof Wildlife Management vol 60 no 4 pp 695ndash713 1996

[9] T P Rooney R J McCormick S L Solheim and D M WallerldquoRegional variation in recruitment of hemlock seedlings andsaplings in the upperGreat Lakes USArdquoEcological Applicationsvol 10 no 4 pp 1119ndash1132 2000

[10] J Beguin D Pothier and S D Cote ldquoDeer browsing and soildisturbance induce cascading effects on plant communities amultilevel path analysisrdquo Ecological Applications vol 21 no 2pp 439ndash451 2011

[11] K A Brathen R A Ims N G Yoccoz P Fauchald T Tveraaand V H Hausner ldquoInduced shift in ecosystem productivityExtensive scale effects of abundant large herbivoresrdquo Ecosys-tems vol 10 no 5 pp 773ndash789 2007

[12] D A Wardle G M Barker G W Yeates K I Bonner andA Ghani ldquoIntroduced browsing mammals in New Zealandnatural forests aboveground and belowground consequencesrdquoEcological Monographs vol 71 no 4 pp 587ndash614 2001

[13] N T Hobbs ldquoLarge herbivore as sources of disturbance inecosystemsrdquo in Large Herbivore Ecology Ecosystem Dynamicsand Conservation K Danell R Bergstrom P Duncan and JPastor Eds pp 261ndash288 Cambridge University Press Cam-bridge UK 2006

[14] J K Bump C R Webster J A Vucetich R O Peterson JM Shields and M D Powers ldquoUngulate carcasses perforateecological filters and create biogeochemical hotspots in forestherbaceous layers allowing trees a competitive advantagerdquoEcosystems vol 12 no 6 pp 996ndash1007 2009

[15] W S Alverson and D M Waller ldquoDeer populations andthe widespread failure of hemlock regeneration in northernforestsrdquo in The Science of Overabundance Deer Ecology andPopulation Management W J McShea H B Underwood andJ H Rappole Eds pp 280ndash297 Smithsonian Institution PressWashington DC USA 1997

[16] Z T Long T H Pendergast IV and W P Carson ldquoTheimpact of deer on relationships between tree growth and

mortality in an old-growth beech-maple forestrdquo Forest Ecologyand Management vol 252 no 1ndash3 pp 230ndash238 2007

[17] C S Holling ldquoResilience and stability of ecological systemsrdquoAnnual Review of Ecology and Systematics vol 4 no 1 pp 1ndash231973

[18] B Hidding J-P Tremblay and S D Cote ldquoA large herbivoretriggers alternative successional trajectories in the boreal forestrdquoEcology vol 94 no 12 pp 2852ndash2860 2013

[19] D S deCalesta ldquoEffect of white-tailed deer on songbirds withinmanaged forests in PennsylvaniardquoThe Journal of Wildlife Man-agement vol 58 no 4 pp 711ndash718 1994

[20] S Allombert A J Gaston and J-L Martin ldquoA natural experi-ment on the impact of overabundant deer on songbird popula-tionsrdquo Biological Conservation vol 126 no 1 pp 1ndash13 2005

[21] S Allombert S Stockton and J-L Martin ldquoA natural exper-iment on the impact of overabundant deer on forest inverte-bratesrdquo Conservation Biology vol 19 no 6 pp 1917ndash1929 2005

[22] S D Cote ldquoImpacts on ecosystemsrdquo in Biology and Manage-ment of White-Tailed Deer D G Hewitt Ed pp 379ndash398 CRCPress Boca Raton Fla USA 2011

[23] TNuttle EH Yerger SH Stoleson andT E Ristau ldquoLegacy oftop-downherbivore pressure ricochets back upmultiple trophiclevels in forest canopies over 30 yearsrdquo Ecosphere vol 2 no 1pp 1ndash11 2011

[24] W J McShea and J H Rappole ldquoManaging the abundance anddiversity of breeding bird populations through manipulation ofdeer populationsrdquo Conservation Biology vol 14 no 4 pp 1161ndash1170 2000

[25] R Smit J Bokdam J den Ouden H Olff H Schot-Opschoorand M Schrijvers ldquoEffects of introduction and exclusion oflarge herbivores on small rodent communitiesrdquo Plant Ecologyvol 155 no 1 pp 119ndash127 2001

[26] S D Cote ldquoExtirpation of a large black bear population byintroduced white-tailed deerrdquo Conservation Biology vol 19 no5 pp 1668ndash1671 2005

[27] K R Greenwald L J Petit and T A Waite ldquoIndirect effects ofa keystone herbivore elevate local animal diversityrdquo Journal ofWildlife Management vol 72 no 6 pp 1318ndash1321 2008

[28] S D Cote C Dussault J Huot F Potvin J-P Tremblay andV Viera ldquoHigh herbivore density and boreal forest ecologywhite-tailed deer on Anticosti Islandrdquo in Lessons from theIslands Introduced Species and What They Tell Us about HowEcosystems Work A J Gaston T E Golumbia J-L Martinand S T Sharpe Eds Proceedings from the Research Groupon Introduced Species Conference Canadian Wildlife ServiceOccasional Papers British Columbia Canada 2008

[29] J-P Saucier A Robitaille and P Grondin ldquoCadre bioclimatiquedu Quebecrdquo inManuel de Foresterie Second Edition R Doucetand M Cote Eds Ordre des ingenieurs forestiers du Quebecpp 186ndash205 Editions Multimondes Quebec Canada 2009

[30] M Barrette L Belanger and L De Grandpre ldquoPreindustrialreconstruction of a perhumid midboreal landscape AnticostiIsland Quebecrdquo Canadian Journal of Forest Research vol 40no 5 pp 928ndash942 2010

[31] S Parent M-J Simard H Morin and C Messier ldquoEstablish-ment and dynamics of the balsamfir seedling bank in old forestsof northeastern Quebecrdquo Canadian Journal of Forest Researchvol 33 no 4 pp 597ndash603 2003

[32] B Rochette and A Gingras Inventaire aerien du cerf deVirginie de lrsquoıle drsquoAnticostimdashEte 2006 Ministere des Ressourcesnaturelles et de la Faune Direction de lrsquoamenagement de lafaune de la Cote-Nord Sept-Iles Canada 2007


[33] A Masse and S D Cote ldquoLinking alternative food sourcesto winter habitat selection of herbivores in overbrowsed land-scapesrdquo Journal of Wildlife Management vol 76 no 3 pp 544ndash556 2012

[34] MA Simard T Coulson A Gingras and S D Cote ldquoInfluenceof density and climate on population dynamics of a largeherbivore under harsh environmental conditionsrdquo Journal ofWildlife Management vol 74 no 8 pp 1671ndash1685 2010

[35] F Potvin P Beaupre andG Laprise ldquoThe eradication of balsamfir stands by white-tailed deer on Anticosti Island Quebec a150-year processrdquo Ecoscience vol 10 no 4 pp 487ndash495 2003

[36] J-P Tremblay I Thibault C Dussault J Huot and S D CoteldquoLong-term decline in white-tailed deer browse supply canlichens and litterfall act as alternative food sources that precludedensity-dependent feedbacksrdquo Canadian Journal of Zoologyvol 83 no 8 pp 1087ndash1096 2005

[37] M Barrette L Belanger L De Granpre and J-C Ruel ldquoCumu-lative effects of chronic deer browsing and clear-cutting onregeneration processes in second-growth white spruce standsrdquoForest Ecology and Management vol 329 no 1 pp 69ndash78 2014

[38] J Taillon D G Sauve and S D Cote ldquoThe effects of decreasingwinter diet quality on foraging behavior and life-history traitsof white-tailed deer fawnsrdquo Journal ofWildlifeManagement vol70 no 5 pp 1445ndash1454 2006

[39] D G Sauve and S D Cote ldquoWinter forage selection in white-tailed deer at high density balsam fir is the best of a bad choicerdquoJournal of Wildlife Management vol 71 no 3 pp 911ndash914 2007

[40] J-P Tremblay J Huot and F Potvin ldquoDensity-related effects ofdeer browsing on the regeneration dynamics of boreal forestsrdquoJournal of Applied Ecology vol 44 no 3 pp 552ndash562 2007

[41] M Anouk Simard S D Cote R B Weladji and J HuotldquoFeedback effects of chronic browsing on life-history traits ofa large herbivorerdquo Journal of Animal Ecology vol 77 no 4 pp678ndash686 2008

[42] P Beaupre C Bedard C Dufour A Gingras CMalenfant andF Potvin Plan general drsquoamenagement integre des ressources dumilieu forestier de lrsquoıle drsquoAnticosti Produits forestiers AnticostiQuebec Canada 2004

[43] J Huot F Potvin and M Belanger ldquoSoutheastern Canadardquo inWhite-Tailed Deer Ecology and Management L K Halls Edpp 293ndash304 Wildlife Management Institute Stackpole BooksHarrisburg Pa USA 1984

[44] F Reimoser and H Gossow ldquoImpact of ungulates on forestvegetation and its dependence on the silvicultural systemrdquoForest Ecology and Management vol 88 no 1-2 pp 107ndash1191996

[45] S Kay ldquoFactors affecting severity of deer browsing damagewithin coppiced woodlands in the south of Englandrdquo BiologicalConservation vol 63 no 3 pp 217ndash222 1993

[46] C Casabon and D Pothier ldquoBrowsing of tree regeneration bywhite-tailed deer in large clearcuts onAnticosti IslandQuebecrdquoForest Ecology and Management vol 253 no 1ndash3 pp 112ndash1192007

[47] J W Hughes and D A Bechtel ldquoEffect of distance from forestedge on regeneration of red spruce and balsam fir in clearcutsrdquoCanadian Journal of Forest Research vol 27 no 12 pp 2088ndash2096 1997

[48] D F Greene J C Zasada L Sirois et al ldquoA review of theregeneration dynamics of North American boreal forest treespeciesrdquo Canadian Journal of Forest Research vol 29 no 6 pp824ndash839 1999

[49] J Beguin D Pothier and M Prevost ldquoCan the impact of deerbrowsing on tree regeneration be mitigated by shelterwoodcutting and strip clearcuttingrdquo Forest Ecology andManagementvol 257 no 1 pp 38ndash45 2009

[50] J BeguinM Prevost D Pothier and S D Cote ldquoEstablishmentof natural regeneration under severe browsing pressure fromwhite-tailed deer after group seed-tree cuttingwith scarificationon Anticosti Islandrdquo Canadian Journal of Forest Research vol39 no 3 pp 596ndash605 2009

[51] P Feeny ldquoPlant apparency and chemical defenserdquo in Biochemi-cal Interactions between Plants and Insects J W Wallace and RL Mansell Eds vol 10 of Recent Advances in Phytochemistrypp 1ndash40 Plenum Press New York NY USA 1976

[52] A M Miller C McArthur and P J Smethurst ldquoCharacteristicsof tree seedlings and neighbouring vegetation have an additiveinfluence on browsing by generalist herbivoresrdquo Forest Ecologyand Management vol 228 no 1ndash3 pp 197ndash205 2006

[53] J Faure-Lacroix J-P Tremblay N Thiffault and V Roy ldquoStocktype performance in addressing top-down and bottom-upfactors for the restoration of indigenous treesrdquo Forest Ecologyand Management vol 307 pp 333ndash340 2013

[54] A J Hester L Edenius R M Buttenschoslashn and A T KuitersldquoInteractions between forests and herbivores the role of con-trolled grazing experimentsrdquo Forestry vol 73 no 4 pp 381ndash3912000

[55] R J Fuller and R M A Gill ldquoEcological impacts of increasingnumbers of deer in British woodlandrdquo Forestry vol 74 no 3pp 193ndash199 2001

[56] R Bergstrom and L Edenius ldquoFrom twigs to landscapesmdashmethods for studying ecological effects of forest ungulatesrdquoJournal for Nature Conservation vol 10 no 4 pp 203ndash211 2003

[57] T P Rooney and D M Waller ldquoDirect and indirect effectsof white-tailed deer in forest ecosystemsrdquo Forest Ecology andManagement vol 181 no 1-2 pp 165ndash176 2003

[58] J-P Tremblay J Huot and F Potvin ldquoDivergent nonlinearresponses of the boreal forest field layer along an experimentalgradient of deer densitiesrdquo Oecologia vol 150 no 1 pp 78ndash882006

[59] A A Royo and W P Carson ldquoOn the formation of denseunderstory layers in forests worldwide consequences andimplications for forest dynamics biodiversity and successionrdquoCanadian Journal of Forest Research vol 36 no 6 pp 1345ndash1362 2006

[60] M Bachand S PellerinMMoretti et al ldquoFunctional responsesand resilience of boreal forest ecosystem after reduction of deerdensityrdquo PLoS ONE vol 9 no 2 Article ID e90437 2014

[61] B Hidding J-P Tremblay and S D Cote ldquoSurvival and growthof balsam fir seedlings and saplings under multiple controlledungulate densitiesrdquo Forest Ecology and Management vol 276pp 96ndash103 2012

[62] K N Suding K L Gross and G R Houseman ldquoAlternativestates and positive feedbacks in restoration ecologyrdquo Trends inEcology and Evolution vol 19 no 1 pp 46ndash53 2004

[63] K Cuddington ldquoLegacy effects the persistent impact of ecolog-ical interactionsrdquo Biological Theory vol 6 no 3 pp 203ndash2102012

[64] A J Tanentzap D R Bazely S Koh et al ldquoSeeing the forestfor the deer do reductions in deer-disturbance lead to forestrecoveryrdquo Biological Conservation vol 144 no 1 pp 376ndash3822011


[65] A A Royo R Collins M B Adams C Kirschbaum and WP Carson ldquoPervasive interactions between ungulate browsersand disturbance regimes promote temperate forest herbaceousdiversityrdquo Ecology vol 91 no 1 pp 93ndash105 2010

[66] D P J Kuijper B Jedrzejewska B Brzeziecki W Jędrzejewskiand H Zybura ldquoFluctuating ungulate density shapes treerecruitment in natural stands of the Białowieza Primeval ForestPolandrdquo Journal of Vegetation Science vol 21 no 6 pp 1082ndash1098 2010

[67] J P Rosenthal and P M Kotanen ldquoTerrestrial plant toleranceto herbivoryrdquo Trends in Ecology and Evolution vol 9 no 4 pp145ndash148 1994

[68] F Lebel C Dussault A Masse and S D Cote ldquoInfluenceof habitat features and hunter behavior on white-tailed deerharvestrdquo Journal ofWildlife Management vol 76 no 7 pp 1431ndash1440 2012

[69] M-A Simard J Huot S de Bellefeuille and S D Cote ldquoInflu-ences of habitat composition plant phenology and populationdensity on autumn indices of body condition in a northernwhite-tailed deer populationrdquoWildlife Monographs vol 187 no1 pp 1ndash28 2014

[70] W F Porter N E Mathews H B Underwood R W Sage JrandD F Behrend ldquoSocial organization in deer implications forlocalizedmanagementrdquoEnvironmentalManagement vol 15 no6 pp 809ndash814 1991

[71] S AMcNultyW F Porter N EMathews and J AHill ldquoLocal-ized management for reducing white-tailed deer populationsrdquoWildlife Society Bulletin vol 25 no 2 pp 265ndash271 1997

[72] M A Simard C Dussault J Huot and S D Cote ldquoIs huntingan effective tool to control overabundant deer A test using anexperimental approachrdquo Journal of Wildlife Management vol77 no 2 pp 254ndash269 2013

[73] S E Van Wieren ldquoEffects of large herbivores upon the animalcommunityrdquo in Grazing and Conservation Management M FW DeVries J P Bakker and S E Van Wieren Eds pp 185ndash214 Kluwer Academic Boston Mass USA 1998

[74] O Suominen and O K Danell ldquoEffects of large herbivores onother faunardquo in Large Herbivore Ecology Ecosystem DynamicsAnd Conservation K Danell R Bergstrom P Duncan and JPastor Eds pp 383ndash412 Cambridge University Press Cam-bridge UK 2006

[75] K M Mathisen and C Skarpe ldquoCascading effects of moose(Alces alces) management on birdsrdquo Ecological Research vol 26no 3 pp 563ndash574 2011

[76] C N Foster P S Barton and D B Lindenmayer ldquoEffects oflarge native herbivores on other animalsrdquo Journal of AppliedEcology vol 51 no 4 pp 929ndash938 2014

[77] E Cardinal J-L Martin J-P Tremblay and S D Cote ldquoAnexperimental study of how variation in deer density affectsvegetation and songbird assemblages of recently harvestedboreal forestsrdquo Canadian Journal of Zoology vol 90 no 6 pp704ndash713 2012

[78] E Cardinal J-LMartin and SD Cote ldquoLarge herbivore effectson songbirds in boreal forests lessons from deer introductionon anticosti Islandrdquo Ecoscience vol 19 no 1 pp 38ndash47 2012

[79] P-M Brousseau C Hebert C Cloutier and S D CoteldquoShort-term effects of reduced white-tailed deer density oninsect communities in a strongly overbrowsed boreal forestecosystemrdquo Biodiversity and Conservation vol 22 no 1 pp 77ndash92 2013

[80] G Darmon B Hidding S De Bellefeuille J-P Tremblay andS D Cote ldquoA generalist rodent benefits from logging regardlessof deer densityrdquo Ecoscience vol 20 no 4 pp 319ndash327 2014

[81] M Scheffer and S R Carpenter ldquoCatastrophic regime shifts inecosystems linking theory to observationrdquo Trends in Ecologyand Evolution vol 18 no 12 pp 648ndash656 2003

[82] T Nuttle A A Royo M B Adams and W P Carson ldquoHis-toric disturbance regimes promote tree diversity only underlow browsing regimes in eastern deciduous forestrdquo EcologicalMonographs vol 83 no 1 pp 3ndash17 2013

[83] T Nuttle T E Ristau and A A Royo ldquoLong-term biologicallegacies of herbivore density in a landscape-scale experimentforest understoreys reflect past deer density treatments for atleast 20 yearsrdquo Journal of Ecology vol 102 no 1 pp 221ndash2282014

[84] J Pastor B Dewey R J Naiman P F McInnes and Y CohenldquoMoose browsing and soil fertility in the boreal forests of IsleRoyale National Parkrdquo Ecology vol 74 no 2 pp 467ndash480 1993

[85] J O Tahvanainen and R B Root ldquoThe influence of vegetationaldiversity on the population ecology of a specialized herbivorePhyllotreta cruciferae (Coleoptera Chrysomelidae)rdquo Oecologiavol 10 no 4 pp 321ndash346 1972

[86] C D Thomas ldquoButterfly larvae reduce host plant survival invicinity of alternative host speciesrdquo Oecologia vol 70 no 1 pp113ndash117 1986

[87] P Barbosa J Hines I Kaplan H Martinson A Szczepaniecand Z Szendrei ldquoAssociational resistance and associationalsusceptibility having right or wrong neighborsrdquoAnnual Reviewof Ecology Evolution and Systematics vol 40 no 1 pp 1ndash202009

[88] M Bachand S Pellerin S D Cote et al ldquoSpecies indicatorsof ecosystem recovery after reducing large herbivore densitycomparing taxa and testing species combinationsrdquo EcologicalIndicators vol 38 no 1 pp 12ndash19 2014

[89] J Hjalten K Danell and L Ericson ldquoEffects of simulatedherbivory and intraspecific competition on the compensatoryability of birchesrdquo Ecology vol 74 no 4 pp 1136ndash1142 1993

[90] R A Riggs A R Tiedemann J G Cook et al ldquoModificationof mixed-conifer forests by ruminant herbivores in the BlueMountains Ecological Provincerdquo Research Paper PNW-RP-527USDA Forest Service Portland Ore USA 2000

[91] I-L Persson K Danell and R Bergstrom ldquoDifferent moosedensities and accompanied changes in tree morphology andbrowse productionrdquo Ecological Applications vol 15 no 4 pp1296ndash1305 2005

[92] N G Tilghman ldquoImpacts of white-tailed deer on forestregeneration in Northwestern Pennsylvaniardquo Journal ofWildlifeManagement vol 53 no 3 pp 524ndash532 1989

[93] S B Horsley S L Stout and D S deCalesta ldquoWhite-tailed deerimpact on the vegetation dynamics of a northern hardwoodforestrdquo Ecological Applications vol 13 no 1 pp 98ndash118 2003

[94] J Olofsson H Kitti P Rautiainen S Stark and L OksanenldquoEffects of summer grazing by reindeer on composition ofvegetation productivity and nitrogen cyclingrdquo Ecography vol24 no 1 pp 13ndash24 2001

[95] M Manseau J Huot and M Crete ldquoEffects of summer grazingby caribou on composition and productivity of vegetationcommunity and landscape levelrdquo Journal of Ecology vol 84 no4 pp 503ndash513 1996

[96] J Moen and A Lagerstrom ldquoHigh species turnover anddecreasing plant species richness on mountain summits in


Sweden reindeer grazing overrides climate changerdquo ArcticAntarctic and Alpine Research vol 40 no 2 pp 382ndash395 2008

[97] R E Longton The Biology of Polar Bryophytes and LichensCambridge University Press Cambridge UK 1988

[98] A R E Sinclair and P Arcese Eds Serengeti II DynamicsManagement and Conservation of an Ecosystem University ofChicago Press Chicago Ill USA 1995

[99] G P Asner S R Levick T Kennedy-Bowdoin et al ldquoLarge-scale impacts of herbivores on the structural diversity of Africansavannasrdquo Proceedings of the National Academy of Sciences of theUnited States of America vol 106 no 12 pp 4947ndash4952 2009

[100] S C F Palmer A J Hester D A Elston I J Gordon and S EHartley ldquoThe perils of having tasty neighbors grazing impactsof large herbivores at vegetation boundariesrdquo Ecology vol 84no 11 pp 2877ndash2890 2003

[101] K Boege and R J Marquis ldquoFacing herbivory as you growup the ontogeny of resistance in plantsrdquo Trends in Ecology andEvolution vol 20 no 8 pp 441ndash448 2005

[102] J Bergquist and G Orlander ldquoBrowsing damage by roe deer onNorway spruce seedlings planted on clearcuts of different ages1 Effect of slash removal vegetation development and roe deerdensityrdquo Forest Ecology and Management vol 105 no 1-3 pp283ndash293 1998

[103] J Bergquist and G Orlander ldquoBrowsing damage by roe deer onNorway spruce seedlings planted on clearcuts of different ages2 Effect of seedling vigourrdquo Forest Ecology and Managementvol 105 no 1ndash3 pp 295ndash302 1998

[104] M Dufresne R L Bradley J-P Tremblay and S D CoteldquoEvidence that soil depth and clay content control the post-disturbance regeneration of balsam fir and paper birch underheavy browsing from deerrdquo Ecoscience vol 18 no 4 pp 363ndash368 2011

[105] R M A Gill ldquoA review of damage by mammals in northtemperate forests 3 Impact on trees and forestsrdquo Forestry vol65 no 4 pp 363ndash388 1992

[106] B M Roche and R S Fritz ldquoGenetics of resistance of Salixsericea to a diverse community of herbivoresrdquo Evolution vol 51no 5 pp 1490ndash1498 1997

[107] M Rousi J Tahvanainen H Henttonen D A Herms andI Uotila ldquoClonal variation in susceptibility of white birches(Betula spp) to Mammalian and insect herbivoresrdquo ForestScience vol 43 no 3 pp 396ndash402 1997

[108] G Vourcrsquoh B Vila D Gillon et al ldquoDisentangling the causesof damage variation by deer browsing on youngThuja plicatardquoOikos vol 98 no 2 pp 271ndash283 2002

Submit your manuscripts athttpwwwhindawicom

Forestry ResearchInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Environmental and Public Health

Journal of



EcosystemsJournal of


MeteorologyAdvances in

EcologyInternational Journal of


Marine BiologyJournal of


Hindawi Publishing Corporationhttpwwwhindawicom

Applied ampEnvironmentalSoil Science

Volume 2014

Advances in


Environmental Chemistry

Atmospheric SciencesInternational Journal of



Waste ManagementJournal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal of

Geophysics


Geological ResearchJournal of

EarthquakesJournal of


BiodiversityInternational Journal of


ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

OceanographyInternational Journal of


The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Journal of Computational Environmental SciencesHindawi Publishing Corporationhttpwwwhindawicom Volume 2014


ClimatologyJournal of


Birds

Insects Deer

Small mammals

Vegetation patterns

Belowground

Aboveground

Fruit and seed

production

Structure and diversity of

plantcommunities

Soil properties

Patterns anddynamics of tree

regeneration

Forest succession and stand dynamics

Figure 1 Direct and indirect effects of deer overabundance on forest succession and other species in the ecosystem

indirectly impact assemblages of animal species at differenttrophic levels (Figure 1) For instance overabundant deerpopulationsmay limit the availability of plant species to otherprimary consumers (ie insects birds and small mammals)that directly depend on browsing intolerant plant species asa main source of forage hiding cover or for reproductionneeds [19ndash22] In turn the lower abundance of primaryconsumers might initiate trophic ricochets (sensu [23]) onpredators carnivores and decomposers altering the structureand interactions among the entire food web [24ndash27]

To answer these questions we have launched a long-termmultidisciplinary research program on deer-boreal forestrelationships [28] We first experimented different types oflarge cutblocks to regenerate deer habitat then we applied aseries of controlled and replicated experiments at large spatialscales to identify deer density thresholds compatible withforest regeneration In particular we have established a con-trolled deer density experiment to investigate the response ofseveral ecosystem components (eg soil properties vegeta-tion insects birds and small mammals) along a gradient ofdeer browsing intensity

2 ContextAnticosti Island (7 943 km2) is located in the Gulf of StLawrence in Quebec Canada (49∘281015840Nminus63∘00W Figure 2)The forest ecosystem belongs to the eastern balsam fir (Abiesbalsamea)mdashwhite birch (Betula papyrifera) bioclimatic sub-domain [29] The preindustrial forest was characterized by amatrix of overmature softwood stands dominated by balsamfir with the inclusion of younger stands [30] Stand regenera-tion is typically supported by banks of shade-tolerant balsamfir seedlings capable of reestablishing canopy dominancefollowing a disturbance (advance regeneration [31])

Approximately 200 white-tailed deer were introduced onAnticosti Island at the end of the 19th century and theyrapidly multiplied taking advantage of a suitable habitat in

the absence of predators The deer population now reaches adensitygt 20 deerkm2 locally [32] and appearsmainly limitedby the availability of winter food resources [33] fluctuatingannually according to winter severity [34]

Such a high deer density had strong repercussions onthe forest Major modifications in the woody and herbaceousvegetation layers related to intense deer browsing have beenreported such as the quasi-disappearance of the shrub layerand of most deciduous species [35ndash37] The regenerationof balsam fir forests a key habitat for deer winter survivalon Anticosti Island [38] is currently compromised by deerbrowsing on balsam fir seedlings Balsam fir stands are beingprogressively replaced by the less palatable white spruce(Picea glauca) through apparent competition [35 39 40] Inaddition despite the infrastructures and facilities in placetoday sport hunting removes less than 5 of the total pop-ulation annually a harvest insufficient to achieve populationcontrol [34 41]

A forest management program was established on theisland in 1995 to favor balsam fir regeneration thus allowingthe reestablishment of balsam fir stands The core of theintegrated forest management strategy is based on fencingof large cutover areas (sim7ndash10 km2) comprising clear-cuts andresidual forests [42] (Figure 2) Deer density within fencedareas is greatly reduced by sport hunting Clear-cuts emulatenatural disturbances resetting the regeneration dynamicsof balsam fir forests by releasing the understory advanceregeneration When the stocking of balsam fir seedlings isdeficient the plan provides for plantation of nursery grownbalsam fir seedlings Once fir saplings will be high enough toescape browsing (up to 15 years) the fences will be removedThe residual forest stands act as winter cover interspersedwith forage patches providing adequate deer habitat [43]Managers were also concerned by the potential negativeeffects on other plant or animal species associated with thedisappearance of balsam fir forests In addition they feared


Lac Simonne

Jupiter

0 5 10 20 30 40 50

NEW

S

A

B

C

1 2 3 40

1 2 3 40(km)

(km)

(km)









0deerkm275deerkm2



























Acknowledgments



References






















































































































Journal of












Volume 2014

Advances in









Geophysics















Lac Simonne

Jupiter

0 5 10 20 30 40 50

NEW

S

A

B

C

1 2 3 40

1 2 3 40(km)

(km)

(km)









0deerkm275deerkm2



























Acknowledgments



References






















































































































Journal of












Volume 2014

Advances in









Geophysics















0deerkm275deerkm2



























Acknowledgments



References






















































































































Journal of












Volume 2014

Advances in









Geophysics
































Acknowledgments



References






















































































































Journal of












Volume 2014

Advances in









Geophysics























Acknowledgments



References






















































































































Journal of












Volume 2014

Advances in









Geophysics















References






















































































































Journal of












Volume 2014

Advances in









Geophysics


































































































Journal of












Volume 2014

Advances in









Geophysics

































































Journal of












Volume 2014

Advances in









Geophysics
































Journal of












Volume 2014

Advances in









Geophysics


















Journal of












Volume 2014

Advances in









Geophysics














Documents

Review Article Structuring Effects of Deer in Boreal …downloads.hindawi.com/archive/2014/917834.pdfReview Article Structuring Effects of Deer in Boreal Forest Ecosystems SteeveD.Côté,