a natural features assessment for the shingleton forest

A Natural Features Assessmentfor the Shingleton Forest Management Unit

Prepared by:Ryan P. O’Connor

Michigan Natural Features InventoryP.O. Box 30444

Lansing, MI 48909-7944

For:Michigan Department of Natural Resources,

Forest, Mineral and Fire Management Division

September 30, 2008

Report Number 2008-10

Cover image: Extensive colonies of dwarf lake iris occur along Portage Bay Road.

Suggested citation: O’Connor, R. 2008. A Natural Features Assessment for the Shingleton Forest Management Unit.Report 2008-10. Michigan Natural Features Inventory. Lansing, MI.

Copyright 2008 Michigan State University Board of Trustees.

MSU Extention in an affirmative-action, equal-opportunity organization.

A Natural Features Assessment for the Shingleton Forest Management Unit Page-1

IntroductionDuring the summer of 2008, the Forest, Mineral andFire Management Division (FMFM) of the MichiganDepartment of Natural Resources (DNR)commissioned the Michigan Natural FeaturesInventory (MNFI) to conduct a rare species survey oftwo forest stands that had been prescribed fortreatment in Delta County within the Shingleton ForestManagement Unit (FMU).

The purpose of the MNFI survey was to search forpopulations of rare plant species that had beenpreviously documented in the general vicinity and werenoted as potentially occurring in the treatment areaduring the Shingleton Compartment Review. Thisreport summarizes the findings of MNFI’s surveys,discusses the threats to the ecological integrity of thestands, and provides site-specific managementrecommendations aimed at protecting biodiversity inthe Garden Peninsula.

MethodsIn preparing comments for the previous ShingletonCompartment Review for Compartment 96, MNFIbotanists and ecologists analyzed compartment andstand maps, aerial photographs, and MNFI’s Bioticsdatabase of rare species to determine which rare plantspecies could potentially occur within the compartment(MNFI 2008). Two species were identified asoccurring within section 31, dwarf lake iris (Irislacustris, state and federal threatened) and calypsoorchid (Calypso bulbosa, state threatened), with bothspecies having potential to occur in stands prescribedfor treatment.

On July 1, 2008, MNFI received a formal request fromFMFM for an Emergency Contingency survey fordwarf lake iris and calypso in Shingleton FMUCompartment 96, stand 58 and Compartment 97, stand16. A survey for these rare plants was conducted onSeptember 8, 2008. Rare plant surveys involvedmeander surveys, during which comprehensive specieslists were compiled and microhabitats weresystematically searched. Invasive plant species werealso recorded, and the ecological characteristics of thestands and surrounding habitat were noted.

ResultsRare speciesA large population of dwarf lake iris was documentedin openings adjacent to Portage Bay Road, but noplants were found in the stands prescribed fortreatment (Figure 1). Dwarf lake iris could beadversely impacted by timber harvest activities if

openings along Portage Bay Road are used as stagingareas, or if road maintenance activities are conducted,but otherwise should be unaffected by proposedmanagement. Due to the timing of the request for asurvey, it was not possible to conduct a thoroughsearch for calypso, which flowers early in the year andhas a narrow survey window of late May through mid-June (Higman and Penskar 1996).

Invasive speciesSurveys also documented a significant population ofthe invasive shrub glossy buckthorn (Rhamnusfrangula) in the stands prescribed for treatment. Glossybuckthorn is a rapidly spreading, highly invasivespecies that has the potential to outcompete nativetrees, shrubs, and herbaceous plants, eventuallyforming monocultures of low-quality wildlife habitatdevoid of timber value. Aggressive control of glossybuckthorn is strongly encouraged prior to conductingother timber management activities. Please see thediscussion section for more on the threats posed byglossy buckthorn as well as potential control strategies.A small population of European marsh thistle (Cirsiumpalustre) was also found in the treatment area. Atpresent, this species is sparse and does not pose athreat to the resources in the compartment, but itshould be monitored for potential spread.

Dwarf lake iris along Portage Bay Road.


Site DescriptionThe stands prescribed for treatment are part of awooded dune and swale complex natural community.An alternating series of relatively dry, sandy ridges andwet swales parallel Kregg Bay on Lake Michigan tothe south. The dry sandy ridges are dominated by blackspruce (Picea mariana), northern white-cedar (Thujaoccidentalis), and balsam fir (Abies balsamea), alongwith lesser amounts of white pine (Pinus strobus) andred pine (P. resinosa). The ground layer on the ridgesis dominated by Canada blueberry (Vacciniummyrtilloides), trailing arbutus (Epigea repens), andbracken fern (Pteridium aquilinum).

Swales are dominated by black spruce and northernwhite-cedar, along with a high diversity of nativeshrubs including speckled alder (Alnus rugosa),Labrador tea (Ledum groenlandicum), Michigan holly(Ilex verticillata), mountain holly (Nemopanthusmucronata), American mountain-ash (Sorbus

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Figure 1. Location of dwarf lake iris along Portage Bay Road in the Garden Peninsula.

americana) and black chokeberry (Aronia prunifolia).Glossy buckthorn is also found in the shrub layer in theswales. Sphagnum mosses (Sphagnum spp.) areprevalent in the ground layer along with herbaceousspecies such as dwarf raspberry (Rubus pubescens),goldthread (Coptis trifolia), creeping snowberry(Gaultheria hispidula), bunchberry (Cornuscanadensis), blue flag (Iris versicolor), and roughgoldenrod (Solidago rugosa). In all, 48 native specieswere documented from the two stands (Appendix 1).

To the south of stand 16 are a series of dry ridges thatwere harvested for timber in the past 10 to 20 years. Asevere lack of tree regeneration and very low stockingwas noted in this area. Due to its relatively small sizeand previous management history, the wooded duneand swale complex does not qualify as an elementoccurrence natural community.


DiscussionRare speciesThe dwarf lake iris element occurrence documentedalong Portage Bay Road is one of just nine A-rankedoccurrences in the state. Although dwarf lake iris isalso found in Wisconsin and Ontario, Michigan is thestronghold of the species with 80 extant occurrences.Highly ranked due its large population size, largespatial extent, and high-quality habitat, this occurrenceis highly significant from both a state and globalconservation perspective. Dwarf lake iris thrives inupland calcareous soils beneath an open to semi-opencanopy and is most often found beneath northernwhite-cedar and balsam fir (Penskar et al. 2001). It isvery tolerant of mild physical disturbance such aswindthrow, and management that creates or maintainsan open canopy may benefit iris (NatureServe Explorer2008). However, operations that cause severe soildisturbance such as road grading or use of irisopenings as staging areas should be avoided. As longas these activities are confined to areas without dwarflake iris, the species should not be harmed by theproposed management. In addition, conducting timberoperations in the winter when the ground is frozen andcovered with snow will further minimize soildisturbance.

ThreatsThe primary threat to the ecological integrity of thestands is posed by the invasive shrub glossy buckthorn.Due to its rapid growth and ability to cast dense shade,glossy buckthorn outcompetes native trees, shrubs, andherbaceous plants (Czarapata 2005). As a result, theability of other tree species to regenerate can beseverely impaired over the long term. Originating fromEurope and Asia, glossy buckthorn was brought to theUnited States in the 1800s for landscaping purposes.

With its rapid growth, tolerance of a wide variety ofmoist soil conditions, abundant seed production, andbird-dispersed fruit, glossy buckthorn has spreadrapidly. It is particularly pernicious in calcareouswetlands but tolerates an array of substrates and isaggressive in uplands as well. A deciduous shrub orsmall tree, it grows up to 20 feet tall, and often hasmultiple stems at the base with an open spreadingcrown and a trunk that can grow up to 10 inches indiameter (Borland et al. 2008). Leaves are simple,alternate, oblong, 1.0 to 2.5 inches long, withuntoothed margins, and are frequently shiny or glossy.Often leafing out prior to other plants in the spring andholding its leaves longer in the fall, glossy buckthorneffectively has a longer growing season and thereforeexerts a competitive advantage over other species.Easily recognized in winter, mature stems haveprominent white lenticels on the bark, and a flexible,naked brown bud that looks furry due to its lack of budscales.

Although tolerant of shade and filtered lightconditions, glossy buckthorn exhibits the mostaggressive growth and prolific fruit production whenreceiving ample sunlight. Currently poised in thesapling layer, it would likely be released in the event ofa harvest. Since opening the canopy may exacerbatethe buckthorn problem, it is strongly recommendedthat timber operations in swales be delayed until aproper control strategy can be enacted. Moreinformation on control of glossy buckthorn can befound in the Management Recommendations sectionbelow.

Glossy buckthorn can be identified by its shiny alternateleaves and gray bark with prominent white lenticels. Photoof bark by John M. Randall, The Nature Conservancy.

Large colonies of dwarf lake iris occur in openings alongPortage Bay Road.


The second threat to the ecological integrity of theforest in the compartment is a high level of deerbrowsing. This was evident on tree seedlings whichhad been repeatedly browsed, as well as on maturetrees exhibiting a high browse line. Moreover, highdeer densities likely contributed to the regenerationfailure noted in the previously harvested stand (18)immediately south of the stand (16) prescribed fortreatment in compartment 97. Other factors may havecontributed to the lack of regeneration as well. It isstrongly recommended that the DNR make a fullassessment as to the reasons behind the previousregeneration failure and take steps to mitigate thesefactors in prescribed stands above and beyond plantingadditional trees as noted in the compartment reviewcomments.

Management recommendationsLong-term control of glossy buckthorn is critical to thehealth of the forests in this compartment andthroughout the Garden Peninsula. Failing to addressthis threat may have long-term impacts on timber andwildlife resources. Elsewhere in the Upper Peninsula,glossy buckthorn has become a severe problem at theSeney Wildlife Refuge, and in the northern Lower

Peninsula, it has completely overrun areas formerlydominated by native wetland shrubs, and threatens tointerfere with regeneration of northern white-cedar.

The first step in establishing a plan to control invasivespecies is determining the extent of the problem.Buckthorn is known to occur in the general region ofthe Garden Peninsula, but the size and distribution ofthe invasion is currently unknown, making it difficultto accurately assess the relative importance ofcontrolling the species in these particular standscompared to other areas. Therefore, it is highlyrecommended to conduct a ground-based survey toinventory the location, extent, and relative patch sizeof glossy buckthorn within the stands prescribed fortreatment, other stands in the compartment, and othercompartments in the Shingleton FMU. Once the fullspatial extent of the infestation is known, a controlstrategy can be developed that most efficientlyaddresses the larger scale problem. Failure to fullyassess the problem is one of the leading causes offailure in invasive species control.

It is often important to prioritize areas for control.High-value areas with minimal invasion should take

Adjacent stands showed signs of regneration failure,likely due to excessive deer browsing.

Glossy buckthorn threatens the ecological integrityof forest resources in the Garden Peninsula.


priority over low-value areas that are already highlydegraded. In particular, known locations of high-qualitynatural communities and threatened or endangeredspecies should be treated first. The spatial extent of theinvasion should be used to prioritize control efforts aswell. Outliers and large, fruiting individuals should beaddressed first to contain the spread, and largerconcentrations should be addressed later (Czarapata2005).

The most effective means of controlling glossybuckthorn involves a combination of cutting and theuse of herbicides. Saplings and small trees can behand-cut, followed by an immediate application of aconcentrated herbicide to the cut stump. Cut-stumptreatments are effective anytime between July andMarch. Herbicides with the active ingredient triclopyr(Garlon) or glyphosate (RoundUp, Rodeo, etc) areeffective. If left untreated, cut stumps will vigorouslyresprout, and will have to be treated with a foliarherbicide. An alternative that avoids hand-cutting is toconduct a basal bark application using triclopyr mixedwith an oil-based carrier. Basal bark treatment can beconducted any time during the year except when snowprevents the wetting of the bark down to the rootcollar (Czarapata 2005).

Controlling invasive species such as glossy buckthornmust be viewed as a multi-year effort. It is critical tomonitor the effectiveness of control efforts andconduct follow-up treatment when necessary. Severelyinfested areas will have a large seedbank, and seedlings

released by the removal of larger shrubs must be dealtwith promptly. After addressing high-priority sites,lower-priority areas can be subsequently targeted.

Finally, every effort should be made to minimize thespread of glossy buckthorn to new areas. In particular,this should include contract specifications with timberoperators that require the thorough cleaning andwashing of equipment, especially vehicle tires ortreads which have the potential to pick up seeds andtransport them to other sites (USDA Forest Service2001). Equipment should be cleaned before entry intostands and prior to moving to new areas.

It is strongly recommended that surveys for invasivespecies like glossy buckthorn be incorporated into theforest inventory process throughout the ShingletonFMU in order to address threats before they becomewidespread problems. Control of small infestations isfeasible if invasions are detected early, but becomeexponentially more costly and more difficult ifinvasive species are allowed to spread (Figure 2).Implementing an “early detection, rapid response”program is critical to successfully limiting the impactof invasive species on timber and wildlife resources.

Overall, invasive species are likely to grow inimportance as they become more widespread andawareness of their potential negative impacts deepens.Efforts should be made to educate all field staff on theidentification and control of invasive species in orderto detect invasions early and treat them before theybecome problematic and adversely impact timber,wildlife, natural areas, and rare species.

Figure 2. Controlling invasive species is much morecost-efficient before they become widespread problems.

Diverse structure and species compositioncharacterizes the forest in Compartment 96stand 58 and Compartment 97 stand 16.


Referemces

Borland, K., S. Campbell, B. Schillo, and P. Higman.2008. Invasive Plant Species of Michigan: APocket Guide. Michigan Natural FeaturesInventory, Lansing MI. 59 pp. Available online at:http://web4.msue.msu.edu/mnfi/education/invasives.cfm

Czarapata, E.J. 2005. Invasive plants of the UpperMidwest: An illustrated guide to theiridentification and control. University of WisconsinPress, Madison, WI. 215 pp.

Higman, P.J., and M.R. Penskar. 1996. Special plantabstract for Calypso bulbosa (calypso orchid).Michigan Natural Features Inventory, Lansing, MI.2 pp.

Michigan Natural Features Inventory (MNFI). 2008.Biotics database. Michigan Natural FeaturesInventory, Lansing, MI.

AcknowledgementsFunding for this project was generously provided bythe Forest, Mineral and Fire Management Division ofthe Michigan Department of Natural Resources.Special thanks to Bob Burnham who requested thesurvey and provided compartment maps and standprescriptions. Thanks also to Jeff Stampfly and CaraBoucher who helped administer the project. NumerousMNFI staff supported the project in many ways. In

NatureServe. 2008. NatureServe Explorer: An onlineencyclopedia of life [Web application]. Version7.0. NatureServe, Arlington, VA. Available http://www.natureserve.org/explorer. (Accessed:September 29, 2008.)

Penskar, M.R., S.R. Crispin, and P.J. Higman 2001.Species Account for Iris lacustris (dwarf lake iris).Michigan Natural Features Inventory, Lansing, MI.3 pp.

U.S. Department of Agriculture Forest Service. 2001.Guide to Noxious Weed Prevention Practices. 25pp. Availabe online at: http://www.fs.fed.us/rangelands/ftp/invasives/documents/GuidetoNoxWeedPrevPractices_07052001.pdf.

particular, Josh Cohen coordinated the project andprovided assistance in writing and reviewing thereport. Mike Penskar provided botanical expertise andKraig Korroch and Rebecca Rogers assisted withreport formatting. Helen Enander assisted with GPStechnology. Finally, Yu Man Lee, Nancy Toben, SueRidge, and Connie Brinson provided helpfuladministrative support.


Appendix 1. Species list

A list of plant species observed was compiled for thesite. Only one survey was conducted in early fall, andthe species list should not be considered a thoroughinventory or a comprensive survey for all rare species.Non-native species are listed in all caps. In the

lifeform column, the abbreviations are as follows:Nt - native; Ad - adventive (non-native); P - perennial;B - biennial. Thus, Nt Shrub is a native shrub, Nt P-Forb is a native perennial forb, etc.

Scientific name Common Name Lifeform

Abies balsamea balsam fir Nt Tree

Acer rubrum red maple Nt Tree

Alnus rugosa speckled or tag alder Nt Shrub

Amelanchier arborea juneberry Nt Tree

Aralia nudicaulis wild sarsaparilla Nt P-Forb

Aronia prunifolia black chokeberry Nt Shrub

Aster lateriflorus side-flowering aster Nt P-Forb

Betula papyrifera paper birch Nt Tree

Calamagrostis canadensis bluejoint grass Nt P-Grass

Carex intumescens sedge Nt P-Sedge

Chelone glabra turtlehead Nt P-Forb

CIRSIUM PALUSTRE EUROPEAN MARSH THISTLE Ad B-Forb

Clintonia borealis bluebead lily Nt P-Forb

Coptis trifolia goldthread Nt P-Forb

Cornus canadensis bunchberry Nt Shrub

Cornus stolonifera red-osier dogwood Nt Shrub

Danthonia spicata poverty grass Nt P-Grass

Diervilla lonicera bush honeysuckle Nt Shrub

Dryopteris carthusiana spinulose woodfern Nt Fern

Epigaea repens trailing arbutus Nt Shrub

Gaultheria hispidula creeping snowberry Nt Shrub

Glyceria striata fowl manna grass Nt P-Grass

Gymnocarpium dryopteris oak fern Nt Fern

Ilex verticillata Michigan holly Nt Shrub

Iris versicolor wild blue flag Nt P-Forb

Juniperus horizontalis creeping juniper Nt Shrub

Ledum groenlandicum Labrador tea Nt Shrub

Lonicera canadensis American fly honeysuckle Nt Shrub

Lycopodium annotinum stiff clubmoss Nt Fern Ally

Maianthemum canadense Canada mayflower Nt P-Forb

Nemopanthus mucronata mountain holly Nt Shrub

Osmunda cinnamomea cinnamon fern Nt Fern

Osmunda regalis royal fern Nt Fern

Picea mariana black spruce Nt Tree

Pinus resinosa red pine Nt Tree

Pinus strobus white pine Nt Tree

Polygala paucifolia gay-wings Nt P-Forb

Pteridium aquilinum bracken fern Nt Fern

Rhamnus alnifolia alder-leaved buckthorn Nt Shrub

RHAMNUS FRANGULA GLOSSY BUCKTHORN Ad Shrub

Ribes lacustre swamp black currant Nt Shrub

Rubus flagellaris northern dewberry Nt Shrub

Rubus pubescens dwarf raspberry Nt P-Forb

Solidago rugosa rough goldenrod Nt P-Forb

Sorbus americana American mountain-ash Nt Tree

Thuja occidentalis northern white-cedar Nt Tree

Trientalis borealis starflower Nt P-Forb

Trillium cernuum nodding trillium Nt P-Forb

Vaccinium myrtilloides Canada blueberry Nt Shrub

Viburnum lentago nannyberry Nt Shrub

a natural features assessment for the shingleton forest

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