Hydrology, Water Chemistry, and Vegetation Characteristics of a TamarackBog in Bath Township, Ohio: Towards Restoration and Enhancement^

TAKA E . MILKTTI, CAMERON N . CARLYLE, CHRISTIAN R . PICARD, KATHLKEN M , MLILAC, ADAM LANDA x AND LALCHLAN H . FR.'\SER-.

Department of Bioloj^y, University of Akron, Akron, OH 4^325-3908; Departmeni of Botany, University of British Columbia,VancoLivtT, DC, V6T 1Z4. Canada

ABSTRACT. The current state of the Bath Tamarack Bog has raised concern ahout the health and functionof the system. Only 6 tamarack (Larix laricina) trees remain, while deciduous trees, particularly redmaple (Acer rubrum) and invasive species such as glossy buckthorn (Jthamnus frangula) and multiflorarose (Rosa multiflora), dominate the hog. Our purpose was to assess the physical, chemical, andbiological properties of the tamarack bog. Environmental and biological properties of Bath Tamarack Bogwere measured from May 2001 through November 2002. In 2001, the center of the bog experiencedwater levels below those typieally found in bogs, yet experienced normal water levels in the followingyear. Water chemistry results indicate the pH is much greater than that characteristic of a typical bog,ranging from 5.94 to 7.41. Nutrient levels fluctuated and were generally higher for calcium, potassium,and phosphate than a typical hog, while nitrogen levels remained low. These results indicate that thebog is not functioning normally and is in decline. The degradation of the bog is most likely due toanthropogenic activity. Ditching occurred between 1963 and 1969 and seems to have induced theprogression of red maple trees and invasive species into the hog hy lowering water levels. Since 1938, thefirst aerial photo we have record of, the bog has reduced to approximately a third of its size, which isapproximately 1.99 hectares. The hog appears to be in a late successional stage, rapidly changing to aforested w^etland. We discuss possible management and restoration efforts needed to restore orenhance the tamarack hog, including 1) planting 5/iAa^nMm mats, 2) introducing tamarack seedlings,3) controlling invasive species, and 4) maintaining the hydrology close to the soil surface. All of thesemeasures are suggested in association with educational outreach.

OHIO J SCI 105 (2):21-30, 2005

INTRODUCTIONToday, wetlands occupy less than half the area they

occupied a century ago (Moscr and others 1996; Mitschand Gosselink 2000). Similarly, the lower 48 states of theUnited States have lost over 50% of its wetland area(Dah! 1990). Ohio has lost 90% of its wetland area, withan estimated 195,000 ha remaining (Dahl 1990). Ohio swetlands presently cover about 1.8% of the state (Dahl1990), Those wetlands remaining ser\c an important en-vironmental and economic resource; wetlands regulatewater flow, recharge groundwater supplies, provideflood control (Carter 1996), and are habitat for diversebiological communities (Mitsch and Gosselink 2000;Keddy 2000). Wetlands also retain essential sedimentsand nutrients while effectively buffering ecosystemsagainst contamination by removing toxins from effluentsand reducing the concentration of excess nitrogen andphosphorus from crop field drainage (Kadlec and Knight1996: Mitsch and Gosselink 2000).

Wetlands are classified ( n the basis of their hydrology,vegetation, and substrate, and include five major types:marsh, bog, fen. swamp, and wet meadow, all of whichcan be foimd in Ohio (Mitsch and Gosselink 2000;Keddy 2000). Our study focuses on a subcategory of the

'Maniiscripl reccivt'd 14 July 2003 ^nd in revised form 1 June 2004

'Corresponding Author: Department of Natural Resource Science,Thompson Rivers I'niversity, Kainloops, BC, V2C 5N3, Canada. Phone:(330) 972-6141: E-mail: 11 ra.ser@tru-ca

bog wetland type, called a tamarack bog. Bogs, includingtamarack bogs, are freshwater wetlands found in north-ern glaciated regions that receive more rainfall than theylose through evapotranspiration (Mitsch and Gosselink2000). The suhstrate is largely composed of organic peatand is usually rainwater fed leading to ombrotrophic(low nutrient) conditions. However, the addition ofsurface runoff into the bog can lead to higher nutrientlevels. Anoxic conditions below the surface of the peat,together with the chemical characteristics of the peatitself, lead to very slow decomposition and a thick ac-cumulation of the peat layer (Hughes 2000; Van Breemen1995). In addition, due to the presence of Sphagnummoss, the pH in bogs is normally very low. usually <4,2(Van Breemen 1995). Bogs are also characterized by a.stable water level. Characteri.stic vegetation varies con-siderably in bogs depending upon the process by whichthe bog was formed, the environmental conditions (es-pecially temperature, rainfall, and water level), the age ofthe bog, and the current stage of succession in the bog(Potter 1947; Glaser 1992). Generally, in addition toSphagnum spp., It^-diharle'df (Chamaedaphne calyculata),bog myrtle (Myricagale), black spruce (Picea mariana),and tamarack trees (Larix laricina) grow in bogs.

Tamarack bogs are unique ecosystems containing avariety of interesting and rare species. The.se includecottongrass (.Eriophorum virginicum), leatherleaf(Chamacdaphne calyculata). pitcher plant (Sarraceniapurpurea). sundew (Drosem rotundifulia). pink ladyslipper orchid {Cypripedium acaule), and of course.

11 TAMARACK BOG ENHANCEMENT PLAN VOL, 105

tamaracks iLarixlaricina) (Larsen 1982). Tamaracks aredeciduou.s conifers also known as larches, and can betoLind in Nortlieast Ohitj ringing kcltle holes, a.ssociatedwith borea! fens, and also found in shallow, infillinglakes (Andreas and Osterbrock 1985). Tamaracks rangefrom Newfoundland west to Alaska and south to Ohioand West Virginia (Duncan 1954; Little 1979), In Ohio,tamaracks have been found in Bath, Flatiron Lake, Kent,Singer Lake, and Triangle Lake, but also occur in othersites.

In bog environments, the tamarack is able to establishbecause of a tolerance for the acidic conditions createdby Sphagnum mosses (Tilton 1978: Larsen 1982; Johnston1990), However, tamaracks are intolerant of both com-petitors and low light conditions (Duncan 1954). Inwell-established bogs, tamarack populations may befound in associations with Sphagnum mosses, varioussedges, carnivorous plants, ericaceous shrubs, and afew species of deciduous and evergreen trees (Larsen1982; Denni.son and Berry 1993).

There are very few tamarack bogs remaining in Ohiodue to changes in land use and the consequence thattamaracks are at the southern extent of their range inOhio, and therefore preservation and restoration effortsfor these unique ecosystems must be a priority. Forexample, the Bath Tamarack Bog, in Summit County, is ina state of decline and has led to concerns regardingfuture enhancement or restoration plans. Human activ-ities (for example, ditching) and the encroachment ofwoody and invasive species are distinct threats. Wepredict that the ditching would have altered the naturalhydrology of the tamarack bog. The Bath Tamarack Bogis located in the Bath Nature Preserve (BNP), an area setaside by the township residents for recreational andeducational purposes. The question of whether or notto implement management practices is still being con-sidered.

The objective of this descriptive study was to measureen\-ironmental and biological properties of the BathTamarack Bog and to use the information gathered toassist in recommendations for renovation and en-hancement of the bog, as well as identifying furtherareas of research. Delineation of the present bog, analysisof water chemistry, and hydrology are the main focus,but vegetative characteristics and a historical analysisbased on aerial photographs have also been investigated.In addition, a detailed investigation has been done onred maple trees within the bog. It is hypothesized thatanthropogenic causes led to the progression of red mapletrees, as well as other invasive species, into the bog.

MATERIALS AND METHODSStudy Site

Bath Nature Preserve (BNP) is a 404-acre (163,62 ha)parcel located in the glaciateci plateau of northeasternOhio (Fig. la). The property (formerly part of tiremanufacturer Raymond Firestone's country estate) isnow owned by Bath Township, and preserves healthyexamples of habitats such as open grasslands, maturemixed deciduous forests, wetlands, streams, and ponds.Notably, the preserve includes a tamarack bog, located

in the southeast section (Fig, lb).In Spring 2001. the perimeter of the bog was delin-

eated with a Garmin GPS unit. The wet area encompas-sing the small stand of tamaracks is 0.6 ha. The currentinflow drainage area as.sociated with the ditches enteringand passing through the bog were estimated usingUnited States Geological Survey (USGS) photomaps andArc View GIS 3.2. Area measurements were derivedfrom the USGS data in Arc View by polygon outlining.

VegetationIn July 2000, a general walking survey of the tamarack

bog was conducted to identify as many plant species ascould be found. Voucher specimens were collected andare located at the University of Akron. The major plantfocus within the bog was the tamaracks. In April 2001,the bog was surveyed in order to locate and GPS all thetamaracks. Diameter at breast height (DBH) of the tama-racks was taken and these measurements were used toestimate age, ln addition, three 50 m traasects were ran-domly located within the bog. Along each transect all ofthe trees were counted, identified, and DBH measured.

HydrologyThree water table wells were placed in the approxi-

mate center of the bog and monitored on a monthlybasis beginning in May 2001. Wells consisted of per-forated PVC piping that was 6.35 cm in diameter and4.5 m in length. The wells were sunk, capped, andmarked with a Garmin GPS unit. These wells were mon-itored from 5 May 2001 to 9 November 2001,

A more detailed monitoring of the bog hydrologybegan in June 2002. The bog was surveyed in order tolocate areas of hydrological inflow and outflow, identi-fied by the observation of flowing water. These areaswere located along the edge of the bog. A 100 m tran-sect was established which ran from the area of in-flow to the area of outflow, bisecting the bog (Fig, lc).Water table wells, identical to the wells used in theprevious monitoring, were placed at the ends of thetransect and every 20 m in-between. Hence, the transectincluded a total of 6 water table wells, The.se wells werecapped and marked with a Garmin GPS unit. Waterlevel monitoring took place every two weeks from 17June 2002 until 18 November 2002,

For the 2001 data, the water level values for the 3wells in the center of the bog were averaged resultingin a single value. For the 2002 data, the mean waterlevel value was calculated for the 4 wells in the middleof the bog.

Water ChemistryMonthly water samples were taken from depression

sites in the middle of the bog beginning in May 2001,The pH was measured in the field using an AccumetPortable Laboratory. All water chemistry analysis wasdone at the University of Akron using kits from PalintesLsLtd. and read with a YSI 9100 Photometer, The followingnutrients were measured: calcium, potassium, phosphate,nitrate, and ammonia. Monitoring continued from 13May 2001 to 9 November 2001.

OHIO lOURNAL OF SCIENCE T. A. AND OTHERS

a)

FiGiiKK 1, L<>f;ition map of study site; where a) is Ohio, b) is ilie Bath Niiture Presene, andBog represent the transect of water level wells kK-ated in the bog.

j,s the Tamarack Tlie crosses in the Tamarack

A more detailed monitoring of the bog's water chem-istry occurred between 17 June 2002 and 5 November2002. Water samples from the surface inflow, surface out-flow, and depression sites at the center of the bog werecollected on a monthly basis. As in the previous moni-toring, pH was measured in the field and samples wereanalyzed for nutrient concentrations at the lab usingidentical methods. Due to malfunctions of the pH probe,these data have been excluded from this report. Again,calcium, potassium, phosphate, nitrate, and ammoniawere measured.

As in the hydrology analysis, the nutrient concentra-tion values from the middle of the bog in the 2001 and2002 monitoring periods are reported as cumulative data.

Peat DepthIn Spring 2002, peat depth was measured, up to a

maximum of 4.5 m, by manually pushing a 1.0-in diameter,4.57 m long metal rod into the peat. Peat depth wasestimated based on the point at which it was not possibleto push the rod further into the ground. Obvicnisiy. peatdepth greater than 4,57 m could not be quantified. Twotransects, one mnning north and the other east-west,through the center of the bog were marked, and peatdepth was measured at 10-m intervals for a total of 50 mboth east and west and 90 m north.

History: Aerial PhotographsSix aerial photographs ofthe research area (193H, 1951,

24 TAMARACK BOG KNHANCEMENT PiAN VOL. 105

1963. 1969, 1975. and 1995) were collected from SummitSoil and Water Conservation District and from AkronMetropolitan Area Transportation System (AMATS). Thephotographs were .scanned and any differences in scalewere adjusted using Corel Photoshop. The photographswere analyzed visually to quantify loss of wetland andstanding water area and to note any changes in thelandscape.

Investigation of Acer rubrum (Red Maple)In November 2002, all red maple tree.s were identified

along the aforementioned transect, beginning ap-proximately 20 m outside of both ends and extendingoutward approximately 5.0 m either .side. The locationand DBH of each tree was determined using a GarminGPS unit and DBH measuring tape, respectively. Inaddition, the age of the trees were determined by re-moving a core sample from the tree with an incrementborer. Smaller trees, generally less than 10 cm in di-ameter, could not be cored because the increment borerwould not attach to these trees. The core samples weretaken back to the lab, where the rings were enumerated.Arc View was used to place the tree.s according to theirGPS onto an aerial map of the bog.

RESULTSVegetation

Only 6 live tamaracks are in the bog. The trees werelocated towards the northern extent of the moss hum-mocks near the channelized flow of water draining thearea. No seedlings or young trees were found. Extensivegrowth of small deciduous trees over the majority of themoss hummocks was typical.

The following woody species were identified alongthe Winter 2001 transects: tamarack (Larix laricina),red maple (Acer mhrum), alder (Alnns spp.). wildcherry (Frunus virginiana), blueberry {Vaccmiumcorymhosum), sumac (Toxicodendron vemix), glossybuckthorn {Rhamnus frangula) multiflora rose (Rosamiiltiflora), and honeysuckle (Loniceraspp.). Flora iden-tified in the walking survey (Summer 2000) is listed inTable 1. A state endangered plant, the two-seededsedge (Carex disperma), is included among the floragrowing in the bog.

HydrologyThe tamarack wetland receives water from both

direct precipitation and runoff from the surroundingdrainage area north of the bog. Two ditches from thenorthern portion of the drainage area lead to the northernedge of the tamarack bog. The ditch to the west endsat the northern edge of the wetland creating marshyconditions within a buried pipeline right-of-way. Theeastern ditch continues southward along the easternedge of the wetland. Approximately fifty yards north ofthe wetland outlet, the eastern ditch is met by a channelfrom the interior of the wetland.

The hydrology of the bog center demonstrated morevariance in the 2001 season than the 2002 season (Fig. 2).In 2001, the water levels of the middle fluctuated froma high of -2.0 cm to a low of -20.0 cm. In 2002, the

hydrology of the bog was more stable, ranging from+2.0 cm to -3.0 cm. The inflow and outflow bothdemonstrated high variance with the inflow being moresevere. Inflow water levels ranged from 0.0 cm to -32.0cm, while outflow levels ranged from 0.0 cm to -17,0 cm.

Wat

er L

evel

(cm

)

5

0

-10

-15

-20

-25

-30

- - • • • Inflow

\ f\ /

—•—Mid

a ^

•.

Date

- -4-

I I

i!

Outflow

4' s

'," - • • '

ill

*• . •

••'•1 '

III!

F[c.rRH 2. WaitT levels of the Bath Tamarack Bog. There is a break inthe data between 9 November 2D01 and 17 June 2002. The term"BREAK" on the x-axis refers to the break in data collection withrespect to the middle of the bog. Error bars represent +1 standard error.

Water ChemistryThe pH, calcium, potassium, phosphate, nitrate, and

ammonia levels for 2001 and 2002 are detailed in Figure3 (a-0. pH (Fig. 3a) shows little variation between Mayand November of 2001. but quite high values from 6,0to 7.7. Calcium (Fig. 3b) tended to increase in the fall.Generally the inflow values were greater than mid- andoutflow. Similar to calcium, potassium (Fig. 3c), phos-phate (Fig. 3d), nitrate (Fig. 3e), and ammonia (Fig. 30had high values in October. The highest ammoniavalues were detected in the outflow (Fig. 3f)-

Peat DepthPeat depth is detailed in Table 2 and exceeded 4.5 m

at the center of the bog. While following in a northwarddirection from the center of the bog, peat depth re-mained greater than 4.5 m for a 60 m distance. Peatdepth began declining by 70 m and was absent by 90 m.While traveling west from the center of the bog, the peatdepth gradually declined until the edge of the bog wasreached just prior to the 50 m distance. The eastwardtransect remained at a depth greater than 4.5 m for 20 mat which point peat depth dipped then became greaterthan 4.5 m once again. However, at 50 m, peat depthdeclined dramatically.

History: Aerial PhotographsThe 1938 aerial photograph of the bog, the oldest

available, shows a bog of approximately 5.6 ha andprovides evidence for standing water at the southeastend of the bog (Fig. 4a). Standing water is apparent inboth the 1951 (Fig. 4b) and 1963 (Fig. 4c) photographsas well. In addition, gas lines appear to have been in-

OHIO JOURNAL OF SCIENCE T. A. MILETTI AND OTHERS 25

TAHI.K 1

Floral list of Bulb Tamcinick Bo}> wilh authorities.

Name Ctmimon

VaM.'ular planl.*i (Cilfasun ami Oonqiiisl

Acerruhn4nil.

Acer saccharum Marshall

Achiiiea millefolium L.

AlliarialH.'tiolatai.\\\t:h.) Cavura i.S: Grandt

Alnus incana ru^usa Rejifl

Carexutlantica\-jiT. capillacecC*'iV.. Bailey) Cronq.

Carex (Ji.s^K'nna"' Of way

Conitis amomum Miller

Dryopteris spp,

Eqitisetum an'ense L.

Fraxinu.i niffra .Marshall

Ilex tvrticilUita {L.) A. Gray

Juncus effuses L.

Larix laricin^"iX>\i Roi) K. Kwh

Loiiici'ra spp.

Ornxlea sensihilis I,

Osmumia ciunamiimea L.

Osmunda regalisL.

Phalaris anmdinacca L.

PhragmitesiittstraltsiOiv.) Trin.

PrttntLS rir^iiniana L

Rhaninusfranguld I.

kd.-^a mifltifloraThunh.

Rosa palustris Marshall

Scirpus atroiirensWWld.

Toxicodendn^ii ct'n/tvd. ) Kiintzc

Ulmus anwricana L,

Vaccimitm cotymfxtsum L.

Red maple

Silver maple

Yarrow

Garlic mustard

Speckled alder

Howe s .sedge

Twoseeded s

Silky dogwtxxl

Wood ffrn

Field horsetail

Black ash

Winlcrlx'rry

Common rush

Tamarack

Honeysuckle

Sensitive fem

Cinnamon fem

Royal tern

Canary' grass

Common reed

Wild cherry

Glossy b

Mulcillon rose

Swamp rose

Dark jireen

Poison sumac

American elm

h blucberrj"

Non-vascular plants (Crum and Anderson !9H1)

Brachythecium nV'u/ara'.Sthimp.

Calliergtini'lUi cuspidate (Hedw.) An^str.

Climacium ameriumum Brid.

Uptodictyum riparium (Hcdw.) Wamst,

Leucohiyum gUtucum {Hcdw.) Anystr.

Platygrium rvpens (^ni\.) Schimp.

Sphagnum palustre L.

Tftraphis l>ellucida Hedw.

Ihukiium delicatulum (Hedw ) Angsir.

Wliite cushion moss

Sphagnum

Tlie delicate fem moss

'• Refers lo plant species thai are classified as slaie endangered by ODNR• Refers to plant species that are classified as poieniially threatened by ODNR.

2f) TAMARACK BOG ENHANCEMENT PLAN \OL.

8

8

6

K3

2

1

0

Data

• -Htow — W d •* OuKtow

FiGiRE 3. Wilier I'hemisiry mea.si.iremcni.s; whcrt- ;i) is pH Ic-vt'ls from tiie center ot' the Bath Tanwnuk Bop, b) i.s ailcium leveLs. v) is pcitas.siiimlevels. d> is phosphate levels, e) is niiraie levels of iJie Barli Tamarack BOR. and f) is ammonia levels of the Bath Tamarack Bug. There isa break in ihe data between 9 November 2001 and 17 June 2002. The term BREAK" on the x-axis refers to the break In data collection withrespect to iht- middle of the bog.

Stalled, crossing through the northern end of the liog inthe 1963 photograph. The 1969 aerial photograph (Fig,4ti) shows two ditches present, one ihrtjugh the tenterof the lx)g and the other along the casi side of the bog.Standing water is not present in this photograph, sug-gesting that the ditches were constnictcd between 1963and 1969. The 1979 aerial photograph (Fig. 4e) showslittle change occurring in the area. Lastly, the 1995 (Fig,4f) photograph is the most recent and is tnore or lessconsistent with the current condition of the tamarackbog and surrounding area. The wet area encompassing

the sm;tll statui of tamaracks is 1,99 ha.

Investigation of Acer rubrum (Red Maple)As expected, tree size was positively correlated with

age. Larger, older tree,s, approximately 30-45 years inage were found around the edges of the tiog. Smaller,younger trees. 20 to 25 years of age, appeared to beencroaching towards the center. Very young trees, mostprobably less than 15 years of age were found cio.ser tothe center of the bog. However, approximately a 40 indistance along the tran.sect at the center of the bog, was

OHIO JOURNAL OF SCIENCE T. A. MILETIl AND OTHERS 27

DisUncf IrnmtvniLT (m)

0

10

20

30

40

50

60

70

HO

TABLE

f'ecil depth in Bath

F.,st

4,S7-

4,57-

4.57*

2.60

4.57-

1.46

N/A

N/A

N/A

N'A

2

idiiHirack linfi.

4,SV.

1,S3

5.m2.0H

1,50

O,(K1

N/A

N/A

N/A

N'A

Nuni ,

4,57*

4 . V

4,57*

4.57*

4.57"

4.57"

4.57'

2. SO

2.IS

0 0 0

•Pcat depth greater than -i,57 m.

void of red maple trees. Overall, the invasion of redmaple trees seems to have taken place somewherehctwecn 3O-4S years ago,

DISCUSSIONThe tamarack lx>g at the BNP is in a late successional

phase. Unchecked, it is likely that the transition to a ter-restrial forest will be rapid. We recognize that it maynot be feasible to restore the bog. It was concluded bythe NRC (2001) that peatland restoration is generally notvery successful. However, since bogs are rare in Ohio,and they .serve an invaluable educational role, we sug-gest concrete ways of enhancing the present bog andpossibly dela>ing the inevitable succession towards uterrestrial forest.

The hydrological and water chemistry- data obtainedtrtHTi ihe bog at the liNP aid in describing the health ofthis wetland. The water table for a typical bog is at ornear the surface throughout the year with little fluctu-ation (Mitscli and Gosselink 2(XK)). There is also practicallyno surface flow in a bog system, with the major inputbeing prcivided by precipitaticjn. Due to ditching andother anthropogenic acti\ity (a natural gas line noith ofthe bog), the tamarack bog has a known source ofinflow and outflow. It was predicted that this activityshould have affected the hydrology of the wetland. In2001, the center of the bog experienced below-normalwater levels. However, the bog demonstrated a typicalhydrological regime at its center in the following year.This annual contrast may be due to differences in pre-cipitation levels and average .seasonal temperature. Inthe year 2001, the nearby Akron-Canton airport received835,66 mm precipitation, compared to 1033.02 mm in2002. The spring of 2002 was the third wettest spring onrecord. The ability of the bog to partially exhibit nonnalhydrological levels, even in drier years, is probably duett) the high peat depth in the system. The water table ofthe bog drops well below the surface in the summer

months at the inflow and t)utfiow. Both these areas ex-perienced fluctuations throughout the 2002 monitoringperiotl. These fluctuations, while not drastic, may befacilitating the invasion of the wetland by vegetationnot associated \\ ith bogs.

By definition, bogs are sy.stems low in nutrients andexhibit un acidic environment. Howe\er, the bog ut theBNF had a pH as high as 7.41. In general, the tamarackbog had higher than nonnal levels of nutrients. Calciumwas high throughout the bog in both years. Calciumcarbonate, which was only monitored in 2001, was alsofound In high concentrations, possibly causing the highpH of the system. In 2002. potassium and phosphatedemonstrated similar high levels and lluctuations In allareas of the wetland. These nutrients were found inlower levels the previous year. Nitrate was the onlynutrient that was consistently found in the low concen-trations typical of a boj». The outflow and middlesamples contained high, fluctuating concentrations ofammonia, while the inflow exhibited lower levels.Ammonium, which was also only monitored in 2001,reached concentrations similar to ammonia. !n the fallmonths, there .seemed to be high concentrations of manynutrients in all areas of the bog. This event may be due toleaching of nutrients from recently fallen leaves. Thehigh concentrations of nutrient in this system may bedue to inputs from outside the bog through surlace flow.However, the immediate water catchment area sur-rounding the bog is relatively undisturbed and consistsmosrly of a mixed beech, oak, and maple forest, exceptfor a mowed gas line that traverses the northern top ofthe bog (Fig. 1). Potential inputs and changes in waterlevel could be disrupting the functions of this systemcausing an increase in pH. These disruptions could alsobe causing the loss of Sphagnum moss and tamaracktrees, while favoring the encroachment of inxasive species.

The monitoring of the bog at the liNP demonstratesthat this wetland is not functioning as a true bog. Thebog is losing its important characteristics (for example,low pH and low nutrient levels) and typical bog vegeta-tion is l>ecoming sparse. Sphagnum cover is sparse, whichis mo.st likely due to changes in hydrology and canopyshading, thus the typically acidic bog conditions cannotlie maintained, In\asive ntin-bog species are now en-croaching into the bog. It is recommended that certainmeasures be taken to restore the bog and prevent itfrom becoming a forested wetland.

The invasion of the tamarack bog by red maple treesindicates the transition of the tamarack lx>g to a forestedwetland. Red maples are designated us faculiuti\-e wet-lund plants and are commonly foimd in Ooodplainforests and swamps. The age of the red maple treescoincide with the same time that the ditches were in-stalled into the Ixjg, between 30 and 45 years ago. Thisprobably led to lower water levels and grounding ofthe peut mat. Once the peatland is grounded, it enabledthe seeds to gertninute and the saplings to survive inpreviously flooded conditions. Once the young maplesbecame established, this likely reduced the ability oftamarack saplings to compete, resulting in their loss (seeTable 3 for a comparison of the habitat requirements of

TAMARACK BOG ENHANCEMENT PLAN VOL. 105

a. 1938 h. 1951

K>,--^K^ 1

, %

'

4. Aerial photographs ot llif liaih Tamarack

OHIO JOURNAL OK SCIENCE T. A. MILETTI AND OTHERS 29

TABU- 3

Coinpansoii hettiwn lunuiiuck trees and red maples Ih'arrar 1995: Burns dud lloiikala

Adults

Tainanick Irees

[uveniles

Maple Trees

Adults luveniles

Height

Tolerate Flooclinj^

Tolerait- Saturated Soil

Tolerate Low Light

Tok'raie Competition

Heavy Seed Crop

65 Feet

yes

Yes

No

No

Every 6 years

No

Yes

No

No

60-90 feel

2 yrs.

Yes

Yes

Yes

Every spring

Yes

Moderately

Yes

Yes

red maplc'S and tatnarack trees). Red maple trees arenative to the United States and can probably succeed ina wider range of habitats than any other forest speciesin Nonli America. They are al^le to tolerate a wide rangeof soil types, textures, moisture, pH, elevation, and light(Hepting 1971).

In a study of 10 peatlands in Indiana, all exhibitedSLtccessional trends towards lowland forests dominatedby red maple trees (Swinehart and f'arker 2000). Thepeatlands lacked black spruce and northern whitecedar, as does the Bath Tamarack Bog, and thus did notdevelop into the typical muskegs and cedar swamps ofthe North but into red maple swamps. This seems to betypical of later stage peatlands in the southern GreatUikes Region {Swinehart and Parker 2000). In the case ofthe Bath Tamarack Bog, it is believed that while thismay be the natural successional fate of this systetn, iiwas accelerated by the installation of the ditch. Evidenceseems to support the hypothesis that anthropogeniccauses induced the red maple trees and invasive speciesto progre.ss into the bog.

Environmental Assessment and RecommendationsAssessment of the Tamarack bog reveals a bog in the

later stages of succession. We suggest possible steps thatcould be taken towards restoration. In addition, directionfor future work is readily appareni from current ob-servations.

Figure 5 shous the effects of the identified hazards onthe bog. Invasive species and ditching have both con-tributed to the loss of tamarack and 'Sphagnum viachanges in vegetation and hydrology. The goals of anyrestoration shoLild be to increa.se the cover of sphagnutnand the nimiber of tamaracks in the bog. Further goals,such as a self-sustaining population of tamaracks maynot be practical (NRC 2001).

Recommendations for EnhancementTo achie\e the goals of increased Sphagnum and

tamaracks, the initial hazards that contributed to their lossneed to be addressed. Solutions to the invasive speciesprt)blem are more apparent than those of the hydrology.

Hazards

Attfibiite

Effectt

Invasive species

Increased vegetation &shading

Ditching

Altered hydrology

Loss of tamarack & sphagnum

Ena Ki S, Ha:^ards affecting the Bath Tamaraek Bog.

Tamarack ManagementTatnarack management programs must be able to pro-

vide, at minimum, the following conditions:

1. Maintenance c f cotisiant w:uer levels, especiallyfor seedling establishment.

2. Removal of other trtt'S, purticularly red maple,which compete with and shade adults and.seedlings.

3. Removal of invasive species, espL-cially glossybuckthorn, which compete with and shadeseedlings.

4. Space seedlings to limit intraspecific cotnpetition,5. Seed or seedling .source from niultiplf regicjns,

but preferably limited to southern populationgenotypes, to reduce the amount of inbreed-ing (Park and Fowler 1983).

Invasive species and Their ControlThe Tatnarack bog at BNF currently has two tnajor

invasive species, glo.ssy buckthorn (Rhamnns fmngula)and muitiflora rose {Rosa mullijlora) both of whichtolerate a wide range of habitats. The multiflora ro.se isprimarily found along the edges of the bog, whereas thebuckthorn is found in the center of the bog near thetamarack trees.

Multiflora rose is a shrubby vine that can exist for

TAMARACK BOG ENHANCEMENT FLAN VOL. 105

several years as low growing runners. This growth habitmakes it difficult to find until it has become well estab-lislicd. Once it does appear in an area, it can persist forlong period.s of time due mainly to a persi.stent seedbank that can remain viable for up to twenty years(IMderwood and Stroube 1986; ODNR 2001). Glossybuckthorn is characterized by a rapid growth rate andan extensive root system. Its primary method of dis-persal is through fruits eaten by birds (Converse 1999;ODNR 2001). These shrubs are able to attain a Iieight oftwenty feet, posing a serious threat to tamarack seedlings.

Removal of in\'asive species would release their com-petitive effect on tamaracks. It would potentially allow forthe establishment of juvenile tamaracks, which are par-ticularly susceptible to shading. Additionally, the pa.stdrainage and consequent alteration of the hydrology ofthe bog may have facilitated the invasion of thesespecies. Re-establishing the previous hydnjiogy mayexclude them from the site.

HydrologyRestoration of the bog's hydrology is extremely com-

plicated because current data is not well understoodand there arc information gaps. Site monitoring revealedthat water le\-els in the bog were consistent with atypical bog. However, water quality analysis revealed ahigh pH and higher than normal nutrient levels. Abetter understanding of water and nutrient inflow isnecessary- before steps can be taken. For example, anapparent first step is to fill the drainage ditch. It is un-known how this will affect water levels in the bog.especially since they now appear normal. A completesurvey of the bog's water budget is needed. A model ofthe water budget will allow for prediction of possibleconsequences of altering the flows in or out of the bog.Continued and long term monitoring would need to becoupled with any actions to remediate hydrology.

ConclusionsImpoitant information has Ix en collected towards un-

derstanding the current state of the BNP bog. Some im-mediate steps must be implemented if the goal is to slowthe succession of the bog to a forest. Removing invasivesand planting bog species, such as tamarack seedlings andSphagiUini. would be a good first step towards en-hancing the bog. A better understanding of the hy-drology of the bog is necessary\

The tamarack bog is an irreplaceable and rare habitattype that benefits the community. The tamarack bogcould be utilized for educational purposes, not only forunderstanding a bog community but also as a case studyfor restoration and enhancement and the inevitableconsequences of ecological succession. In addition, thebog houses Carex dispenna, the two-seeded sedge, aplant species considered state endangered, as well astwo potentially threatened plant species, Carex atlanticavar. capillacea (Howe's sedge) and Larix laricina(tamarack). Controlled public access could be made tothe bog with the addition of a boardwalk. The bog notonly adds diversity to the RNF but also houses rarespecies of ecological significance.

AcKNrjwLHixiMtNTs. We thank Jim Bissel for ltadinn the pknt idc-ntifiailionsurvey in ihe bog, Diani.' H. l.iicafi For lir)ophytc vouthors. j . ' . wdi as RandyMitfhfll, Alice: Phillips, and the University of Akron's Field Biology Class(."Spring 2002) for their help with data collt'ction. We also thank the BathTrustees, Rosalie Sterner, and Mike Rorer for allowing; u,s access to the site.

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