Hydrology, Water Chemistry, and Vegetation Characteristics of a Tamarack Bog 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, O H 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 function of the system. Only 6 tamarack (Larix laricina) trees remain, while deciduous trees, particularly red maple (Acer rubrum) and invasive species such as glossy buckthorn (Jthamnus frangula) and multiflora rose (Rosa multiflora), dominate the hog. Our purpose was to assess the physical, chemical, and biological properties of the tamarack bog. Environmental and biological properties of Bath Tamarack Bog were measured from May 2001 through November 2002. In 2001, the center of the bog experienced water levels below those typieally found in bogs, yet experienced normal water levels in the following year. 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 the bog is not functioning normally and is in decline. The degradation of the bog is most likely due to anthropogenic activity. Ditching occurred between 1963 and 1969 and seems to have induced the progression of red maple trees and invasive species into the hog hy lowering water levels. Since 1938, the first aerial photo we have record of, the bog has reduced to approximately a third of its size, which is approximately 1.99 hectares. The hog appears to be in a late successional stage, rapidly changing to a forested w^etland. We discuss possible management and restoration efforts needed to restore or enhance 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 these measures are suggested in association with educational outreach. OHIO J SCI 105 (2):21-30, 2005 INTRODUCTION Today, wetlands occupy less than half the area they occupied a century ago (Moscr and others 1996; Mitsch and Gosselink 2000). Similarly, the lower 48 states of the United States have lost over 50% of its wetland area (Dah! 1990). Ohio has lost 90% of its wetland area, with an estimated 195,000 ha remaining (Dahl 1990). Ohio s wetlands presently cover about 1.8% of the state (Dahl 1990), Those wetlands remaining ser\c an important environmental and economic resource; wetlands regulate water flow, recharge groundwater supplies, provide flood control (Carter 1996), and are habitat for diverse biological communities (Mitsch and Gosselink 2000; Keddy 2000). Wetlands also retain essential sediments and nutrients while effectively buffering ecosystems against contamination by removing toxins from effluents and reducing the concentration of excess nitrogen and phosphorus from crop field drainage (Kadlec and Knight 1996: 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 which can 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, including tamarack bogs, are freshwater wetlands found in northern glaciated regions that receive more rainfall than they lose through evapotranspiration (Mitsch and Gosselink 2000). The suhstrate is largely composed of organic peat and is usually rainwater fed leading to ombrotrophic (low nutrient) conditions. However, the addition of surface runoff into the bog can lead to higher nutrient levels. Anoxic conditions below the surface of the peat, together with the chemical characteristics of the peat itself, lead to very slow decomposition and a thick accumulation of the peat layer (Hughes 2000; Van Breemen 1995). In addition, due to the presence of Sphagnum moss, 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 considerably in bogs depending upon the process by which the bog was formed, the environmental conditions (especially temperature, rainfall, and water level), the age of the bog, and the current stage of succession in the bog (Potter 1947; Glaser 1992). Generally, in addition to Sphagnum 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 a variety of interesting and rare species. The.se include cottongrass (.Eriophorum virginicum), leatherleaf (Chamacdaphne calyculata). pitcher plant (Sarracenia purpurea). sundew (Drosem rotundifulia). pink lady slipper orchid {Cypripedium acaule), and of course. 11 TAMARACK BOG ENHANCEMENT PLAN tamaracks iLarixlaricina) (Larsen 1982). Tamaracks are deciduou.s conifers also known as larches, and can be toLind in Nortlieast Ohitj ringing kcltle holes, a.ssociated with borea! fens, and also found in shallow, infilling lakes (Andreas and Osterbrock 1985). Tamaracks range from Newfoundland west to Alaska and south to Ohio and 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 other sites. In bog environments, the tamarack is able to establish because of a tolerance for the acidic conditions created by Sphagnum mosses (Tilton 1978: Larsen 1982; Johnston 1990), However, tamaracks are intolerant of both competitors and low light conditions (Duncan 1954). In well-established bogs, tamarack populations may be found in associations with Sphagnum mosses, various sedges, carnivorous plants, ericaceous shrubs, and a few species of deciduous and evergreen trees (Larsen 1982; Denni.son and Berry 1993). There are very few tamarack bogs remaining in Ohio due to changes in land use and the consequence that tamaracks are at the southern extent of their range in Ohio, and therefore preservation and restoration efforts for these unique ecosystems must be a priority. For example, the Bath Tamarack Bog, in Summit County, is in a state of decline and has led to concerns regarding future enhancement or restoration plans. Human activities (for example, ditching) and the encroachment of woody and invasive species are distinct threats. We predict that the ditching would have altered the natural hydrology of the tamarack bog. The Bath Tamarack Bog is located in the Bath Nature Preserve (BNP), an area set aside by the township residents for recreational and educational purposes. The question of whether or not to implement management practices is still being considered. The objective of this descriptive study was to measure en\-ironmental and biological properties of the Bath Tamarack Bog and to use the information gathered to assist in recommendations for renovation and enhancement of the bog, as well as identifying further areas of research. Delineation of the present bog, analysis of water chemistry, and hydrology are the main focus, but vegetative characteristics and a historical analysis based on aerial photographs have also been investigated. In addition, a detailed investigation has been done on red maple trees within the bog. It is hypothesized that anthropogenic causes led to the progression of red maple trees, as well as other invasive species, into the bog. MATERIALS AND METHODS Study Site Bath Nature Preserve (BNP) is a 404-acre (163,62 ha) parcel located in the glaciateci plateau of northeastern Ohio (Fig. la). The property (formerly part of tire manufacturer Raymond Firestone's country estate) is now owned by Bath Township, and preserves healthy examples of habitats such as open grasslands, mature mixed deciduous forests, wetlands, streams, and ponds. Notably, the preserve includes a tamarack bog, located VOL, 105 in the southeast section (Fig, lb). In Spring 2001. the perimeter of the bog was delineated with a Garmin GPS unit. The wet area encompassing the small stand of tamaracks is 0.6 ha. The current inflow drainage area as.sociated with the ditches entering and passing through the bog were estimated using United States Geological Survey (USGS) photomaps and Arc View GIS 3.2. Area measurements were derived from the USGS data in Arc View by polygon outlining. Vegetation In July 2000, a general walking survey of the tamarack bog was conducted to identify as many plant species as could be found. Voucher specimens were collected and are located at the University of Akron. The major plant focus within the bog was the tamaracks. In April 2001, the bog was surveyed in order to locate and GPS all the tamaracks. Diameter at breast height (DBH) of the tamaracks was taken and these measurements were used to estimate age, ln addition, three 50 m traasects were randomly located within the bog. Along each transect all of the trees were counted, identified, and DBH measured. Hydrology Three water table wells were placed in the approximate center of the bog and monitored on a monthly basis beginning in May 2001. Wells consisted of perforated PVC piping that was 6.35 cm in diameter and 4.5 m in length. The wells were sunk, capped, and marked with a Garmin GPS unit. These wells were monitored from 5 May 2001 to 9 November 2001, A more detailed monitoring of the bog hydrology began in June 2002. The bog was surveyed in order to locate areas of hydrological inflow and outflow, identified by the observation of flowing water. These areas were located along the edge of the bog. A 100 m transect was established which ran from the area of inflow to the area of outflow, bisecting the bog (Fig, lc). Water table wells, identical to the wells used in the previous monitoring, were placed at the ends of the transect and every 20 m in-between. Hence, the transect included a total of 6 water table wells, The.se wells were capped and marked with a Garmin GPS unit. Water level monitoring took place every two weeks from 17 June 2002 until 18 November 2002, For the 2001 data, the water level values for the 3 wells in the center of the bog were averaged resulting in a single value. For the 2002 data, the mean water level value was calculated for the 4 wells in the middle of the bog. Water Chemistry Monthly 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 Accumet Portable Laboratory. All water chemistry analysis was done at the University of Akron using kits from PalintesLs Ltd. and read with a YSI 9100 Photometer, The following nutrients were measured: calcium, potassium, phosphate, nitrate, and ammonia. Monitoring continued from 13 May 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, and Bog represent the transect of water level wells kK-ated in the bog. A more detailed monitoring of the bog's water chemistry occurred between 17 June 2002 and 5 November 2002. Water samples from the surface inflow, surface outflow, and depression sites at the center of the bog were collected on a monthly basis. As in the previous monitoring, pH was measured in the field and samples were analyzed for nutrient concentrations at the lab using identical methods. Due to malfunctions of the pH probe, these data have been excluded from this report. Again, calcium, potassium, phosphate, nitrate, and ammonia were measured. As in the hydrology analysis, the nutrient concentration values from the middle of the bog in the 2001 and 2002 monitoring periods are reported as cumulative data. j,s the Tamarack Tlie crosses in the Tamarack Peat Depth In 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 was estimated based on the point at which it was not possible to push the rod further into the ground. Obvicnisiy. peat depth greater than 4,57 m could not be quantified. Two transects, one mnning north and the other east-west, through the center of the bog were marked, and peat depth was measured at 10-m intervals for a total of 50 m both east and west and 90 m north. History: Aerial Photographs Six aerial photographs ofthe research area (193H, 1951, VOL. 105 TAMARACK BOG KNHANCEMENT PiAN 24 1963. 1969, 1975. and 1995) were collected from Summit Soil and Water Conservation District and from Akron Metropolitan Area Transportation System (AMATS). The photographs were .scanned and any differences in scale were adjusted using Corel Photoshop. The photographs were analyzed visually to quantify loss of wetland and standing water area and to note any changes in the landscape. hydrology of the bog was more stable, ranging from +2.0 cm to -3.0 cm. The inflow and outflow both demonstrated high variance with the inflow being more severe. Inflow water levels ranged from 0.0 cm to -32.0 cm, while outflow levels ranged from 0.0 cm to -17,0 cm. - - • • • Inflow RESULTS Vegetation Only 6 live tamaracks are in the bog. The trees were located towards the northern extent of the moss hummocks near the channelized flow of water draining the area. No seedlings or young trees were found. Extensive growth of small deciduous trees over the majority of the moss hummocks was typical. The following woody species were identified along the Winter 2001 transects: tamarack (Larix laricina), red maple (Acer mhrum), alder (Alnns spp.). wild cherry (Frunus virginiana), blueberry {Vaccmium corymhosum), sumac (Toxicodendron vemix), glossy buckthorn {Rhamnus frangula) multiflora rose (Rosa miiltiflora), and honeysuckle (Loniceraspp.). Flora identified in the walking survey (Summer 2000) is listed in Table 1. A state endangered plant, the two-seeded sedge (Carex disperma), is included among the flora growing in the bog. Hydrology The tamarack wetland receives water from both direct precipitation and runoff from the surrounding drainage area north of the bog. Two ditches from the northern portion of the drainage area lead to the northern edge of the tamarack bog. The ditch to the west ends at the northern edge of the wetland creating marshy conditions within a buried pipeline right-of-way. The eastern ditch continues southward along the eastern edge of the wetland. Approximately fifty yards north of the wetland outlet, the eastern ditch is met by a channel from the interior of the wetland. The hydrology of the bog center demonstrated more variance in the 2001 season than the 2002 season (Fig. 2). In 2001, the water levels of the middle fluctuated from a high of -2.0 cm to a low of -20.0 cm. In 2002, the - Outflow -4- 5 Water Level (cm) Investigation of Acer rubrum (Red Maple) In November 2002, all red maple tree.s were identified along the aforementioned transect, beginning approximately 20 m outside of both ends and extending outward approximately 5.0 m either .side. The location and DBH of each tree was determined using a Garmin GPS unit and DBH measuring tape, respectively. In addition, the age of the trees were determined by removing a core sample from the tree with an increment borer. Smaller trees, generally less than 10 cm in diameter, could not be cored because the increment borer would not attach to these trees. The core samples were taken back to the lab, where the rings were enumerated. Arc View was used to place the tree.s according to their GPS onto an aerial map of the bog. —•—Mid 0 -10 -15 \ \ f / 4 a ' ^ s *• •. -20 ', -25 " - • • -30 .• ••'• 1' ' II i! ill III! Date F[c.rRH 2. WaitT levels of the Bath Tamarack Bog. There is a break in the data between 9 November 2D01 and 17 June 2002. The term "BREAK" on the x-axis refers to the break in data collection with respect to the middle of the bog. Error bars represent +1 standard error. Water Chemistry The pH, calcium, potassium, phosphate, nitrate, and ammonia levels for 2001 and 2002 are detailed in Figure 3 (a-0. pH (Fig. 3a) shows little variation between May and November of 2001. but quite high values from 6,0 to 7.7. Calcium (Fig. 3b) tended to increase in the fall. Generally the inflow values were greater than mid- and outflow. Similar to calcium, potassium (Fig. 3c), phosphate (Fig. 3d), nitrate (Fig. 3e), and ammonia (Fig. 30 had high values in October. The highest ammonia values were detected in the outflow (Fig. 3f)Peat Depth Peat depth is detailed in Table 2 and exceeded 4.5 m at the center of the bog. While following in a northward direction from the center of the bog, peat depth remained greater than 4.5 m for a 60 m distance. Peat depth began declining by 70 m and was absent by 90 m. While traveling west from the center of the bog, the peat depth gradually declined until the edge of the bog was reached just prior to the 50 m distance. The eastward transect remained at a depth greater than 4.5 m for 20 m at which point peat depth dipped then became greater than 4.5 m once again. However, at 50 m, peat depth declined dramatically. History: Aerial Photographs The 1938 aerial photograph of the bog, the oldest available, shows a bog of approximately 5.6 ha and provides evidence for standing water at the southeast end of the bog (Fig. 4a). Standing water is apparent in both the 1951 (Fig. 4b) and 1963 (Fig. 4c) photographs as well. In addition, gas lines appear to have been in- 25 T. A. MILETTI AND OTHERS OHIO JOURNAL OF SCIENCE TAHI.K 1 Floral list of Bulb Tamcinick Bo}> wilh authorities. Ctmimon Name VaM.'ular planl.*i (Cilfasun ami Oonqiiisl Acerruhn4nil. Red maple Acer saccharum Marshall Silver maple Achiiiea millefolium L. Yarrow AlliarialH.'tiolatai.\\\t:h.) Cavura i.S: Grandt Garlic mustard Alnus incana ru^usa Rejifl Speckled alder Carexutlantica\-jiT. capillacecC*'iV.. Bailey) Cronq. Howe s .sedge Carex (Ji.s^K'nna"' Of way Twoseeded s Conitis amomum Miller Silky dogwtxxl Dryopteris spp, Wood ffrn Eqitisetum an'ense L. Field horsetail Fraxinu.i niffra .Marshall Black ash Ilex tvrticilUita {L.) A. Gray Winlcrlx'rry Juncus effuses L. Common rush Larix laricin^"iX>\i Roi) K. Kwh Tamarack Loiiici'ra spp. Honeysuckle Ornxlea sensihilis I, Sensitive fem Osmumia ciunamiimea L. Cinnamon fem Osmunda regalisL. Royal tern Phalaris anmdinacca Canary' grass L. PhragmitesiittstraltsiOiv.) Trin. Common reed PrttntLS rir^iiniana L Wild cherry Rhaninusfranguld Glossy b I. kd.-^a mifltifloraThunh. Mulcillon rose Rosa palustris Marshall Swamp rose Scirpus atroiirensWWld. Dark jireen Toxicodendn^ii ct'n/tvd. ) Kiintzc Poison sumac Ulmus anwricana L, American elm Vaccimitm cotymfxtsum L. 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. Wliite cushion moss Platygrium rvpens (^ni\.) Schimp. Sphagnum palustre L. Sphagnum Tftraphis l>ellucida Hedw. Ihukiium delicatulum (Hedw ) Angsir. '•^Refers lo plant species thai are classified as slaie endangered by ODNR •^Refers to plant species that are classified as poieniially threatened by ODNR. Tlie delicate fem moss 2f) TAMARACK BOG ENHANCEMENT PLAN \OL. 8 8 6 K 3 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.siiim levels. d> is phosphate levels, e) is niiraie levels of iJie Barli Tamarack BOR. and f) is ammonia levels of the Bath Tamarack Bug. There is a 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 with respect to iht- middle of the bog. Stalled, crossing through the northern end of the liog in the 1963 photograph. The 1969 aerial photograph (Fig, 4ti) shows two ditches present, one ihrtjugh the tenter of the lx)g and the other along the casi side of the bog. Standing water is not present in this photograph, suggesting that the ditches were constnictcd between 1963 and 1969. The 1979 aerial photograph (Fig. 4e) shows little change occurring in the area. Lastly, the 1995 (Fig, 4f) photograph is the most recent and is tnore or less consistent with the current condition of the tamarack bog 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 in age were found around the edges of the tiog. Smaller, younger trees. 20 to 25 years of age, appeared to be encroaching towards the center. Very young trees, most probably less than 15 years of age were found cio.ser to the center of the bog. However, approximately a 40 in distance along the tran.sect at the center of the bog, was T. A. MILETIl AND OTHERS OHIO JOURNAL OF SCIENCE TABLE 2 f'ecil depth in Bath idiiHirack linfi. DisUncf Irnm tvniLT (m) F.,st Nuni, 0 4,S7- 4,SV. 10 4,57- 1,S3 4.V 20 4.57* 5.m 4,57* 30 2.60 2.0H 4.57* 40 4.57- 1,50 4.57" 50 1.46 O,(K1 4.57" 60 N/A N/A 4.57' 70 N/A N/A 2. SO HO N/A N/A 2.IS N'A N'A 000 4,57* •Pcat depth greater than -i,57 m. void of red maple trees. Overall, the invasion of red maple trees seems to have taken place somewhere hctwecn 3O-4S years ago, DISCUSSION The tamarack lx>g at the BNP is in a late successional phase. Unchecked, it is likely that the transition to a terrestrial forest will be rapid. We recognize that it may not be feasible to restore the bog. It was concluded by the NRC (2001) that peatland restoration is generally not very successful. However, since bogs are rare in Ohio, and they .serve an invaluable educational role, we suggest concrete ways of enhancing the present bog and possibly dela>ing the inevitable succession towards u terrestrial forest. The hydrological and water chemistry- data obtained trtHTi ihe bog at the liNP aid in describing the health of this wetland. The water table for a typical bog is at or near the surface throughout the year with little fluctuation (Mitscli and Gosselink 2(XK)). There is also practically no surface flow in a bog system, with the major input being prcivided by precipitaticjn. Due to ditching and other anthropogenic acti\ity (a natural gas line noith of the bog), the tamarack bog has a known source of inflow and outflow. It was predicted that this activity should have affected the hydrology of the wetland. In 2001, the center of the bog experienced below-normal water levels. However, the bog demonstrated a typical hydrological regime at its center in the following year. This annual contrast may be due to differences in precipitation levels and average .seasonal temperature. In the year 2001, the nearby Akron-Canton airport received 835,66 mm precipitation, compared to 1033.02 mm in 2002. The spring of 2002 was the third wettest spring on record. The ability of the bog to partially exhibit nonnal hydrological levels, even in drier years, is probably due tt) the high peat depth in the system. The water table of the bog drops well below the surface in the summer 27 months at the inflow and t)utfiow. Both these areas experienced fluctuations throughout the 2002 monitoring periotl. These fluctuations, while not drastic, may be facilitating the invasion of the wetland by vegetation not associated \\ ith bogs. By definition, bogs are sy.stems low in nutrients and exhibit un acidic environment. Howe\er, the bog ut the BNF had a pH as high as 7.41. In general, the tamarack bog had higher than nonnal levels of nutrients. Calcium was high throughout the bog in both years. Calcium carbonate, which was only monitored in 2001, was also found In high concentrations, possibly causing the high pH of the system. In 2002. potassium and phosphate demonstrated similar high levels and lluctuations In all areas of the wetland. These nutrients were found in lower levels the previous year. Nitrate was the only nutrient that was consistently found in the low concentrations typical of a boj». The outflow and middle samples contained high, fluctuating concentrations of ammonia, while the inflow exhibited lower levels. Ammonium, which was also only monitored in 2001, reached concentrations similar to ammonia. !n the fall months, there .seemed to be high concentrations of many nutrients in all areas of the bog. This event may be due to leaching of nutrients from recently fallen leaves. The high concentrations of nutrient in this system may be due to inputs from outside the bog through surlace flow. However, the immediate water catchment area surrounding the bog is relatively undisturbed and consists mosrly of a mixed beech, oak, and maple forest, except for a mowed gas line that traverses the northern top of the bog (Fig. 1). Potential inputs and changes in water level could be disrupting the functions of this system causing an increase in pH. These disruptions could also be causing the loss of Sphagnum moss and tamarack trees, while favoring the encroachment of inxasive species. The monitoring of the bog at the liNP demonstrates that this wetland is not functioning as a true bog. The bog is losing its important characteristics (for example, low pH and low nutrient levels) and typical bog vegetation is l>ecoming sparse. Sphagnum cover is sparse, which is mo.st likely due to changes in hydrology and canopy shading, thus the typically acidic bog conditions cannot lie maintained, In\asive ntin-bog species are now encroaching into the bog. It is recommended that certain measures be taken to restore the bog and prevent it from becoming a forested wetland. The invasion of the tamarack bog by red maple trees indicates the transition of the tamarack lx>g to a forested wetland. Red maples are designated us faculiuti\-e wetlund plants and are commonly foimd in Ooodplain forests and swamps. The age of the red maple trees coincide with the same time that the ditches were installed into the Ixjg, between 30 and 45 years ago. This probably led to lower water levels and grounding of the peut mat. Once the peatland is grounded, it enabled the seeds to gertninute and the saplings to survive in previously flooded conditions. Once the young maples became established, this likely reduced the ability of tamarack saplings to compete, resulting in their loss (see Table 3 for a comparison of the habitat requirements of VOL. TAMARACK BOG ENHANCEMENT PLAN h. 1951 a. 1938 K>,--^K^ , ' 4. Aerial photographs ot llif liaih Tamarack % 1 105 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 Tainanick Irees Adults Height Maple Trees [uveniles 65 Feet yes No Tolerait- Saturated Soil Yes Tolerate Low Light No Tok'raie Competition No 2 yrs. Yes Yes Yes Moderately No Yes Yes No Yes Yes Every 6 years red maplc'S and tatnarack trees). Red maple trees are native to the United States and can probably succeed in a wider range of habitats than any other forest species in Nonli America. They are al^le to tolerate a wide range of soil types, textures, moisture, pH, elevation, and light (Hepting 1971). In a study of 10 peatlands in Indiana, all exhibited SLtccessional trends towards lowland forests dominated by red maple trees (Swinehart and f'arker 2000). The peatlands lacked black spruce and northern white cedar, as does the Bath Tamarack Bog, and thus did not develop into the typical muskegs and cedar swamps of the North but into red maple swamps. This seems to be typical of later stage peatlands in the southern Great Uikes Region {Swinehart and Parker 2000). In the case of the Bath Tamarack Bog, it is believed that while this may be the natural successional fate of this systetn, ii was accelerated by the installation of the ditch. Evidence seems to support the hypothesis that anthropogenic causes induced the red maple trees and invasive species to progre.ss into the bog. Environmental Assessment and Recommendations Assessment of the Tamarack bog reveals a bog in the later stages of succession. We suggest possible steps that could be taken towards restoration. In addition, direction for future work is readily appareni from current observations. Figure 5 shous the effects of the identified hazards on the bog. Invasive species and ditching have both contributed to the loss of tamarack and 'Sphagnum via changes in vegetation and hydrology. The goals of any restoration shoLild be to increa.se the cover of sphagnutn and the nimiber of tamaracks in the bog. Further goals, such as a self-sustaining population of tamaracks may not be practical (NRC 2001). Recommendations for Enhancement To achie\e the goals of increased Sphagnum and tamaracks, the initial hazards that contributed to their loss need to be addressed. Solutions to the invasive species prt)blem are more apparent than those of the hydrology. luveniles 60-90 feel Tolerate Flooclinj^ Heavy Seed Crop Adults Every spring Invasive species Ditching Increased vegetation & shading Altered hydrology Hazards Attfibiite Effectt Loss of tamarack & sphagnum Ena Ki S, Ha:^ards affecting the Bath Tamaraek Bog. Tamarack Management Tatnarack management programs must be able to provide, at minimum, the following conditions: 1. Maintenance c^f cotisiant w:uer levels, especially for 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 glossy buckthorn, which compete with and shade seedlings. 4. Space seedlings to limit intraspecific cotnpetition, 5. Seed or seedling .source from niultiplf regicjns, but preferably limited to southern population genotypes, to reduce the amount of inbreeding (Park and Fowler 1983). Invasive species and Their Control The Tatnarack bog at BNF currently has two tnajor invasive species, glo.ssy buckthorn (Rhamnns fmngula) and muitiflora rose {Rosa mullijlora) both of which tolerate a wide range of habitats. The multiflora ro.se is primarily found along the edges of the bog, whereas the buckthorn is found in the center of the bog near the tamarack trees. Multiflora rose is a shrubby vine that can exist for TAMARACK BOG ENHANCEMENT FLAN several years as low growing runners. This growth habit makes it difficult to find until it has become well establislicd. Once it does appear in an area, it can persist for long period.s of time due mainly to a persi.stent seed bank that can remain viable for up to twenty years (IMderwood and Stroube 1986; ODNR 2001). Glossy buckthorn is characterized by a rapid growth rate and an extensive root system. Its primary method of dispersal is through fruits eaten by birds (Converse 1999; ODNR 2001). These shrubs are able to attain a Iieight of twenty feet, posing a serious threat to tamarack seedlings. Removal of in\'asive species would release their competitive effect on tamaracks. It would potentially allow for the establishment of juvenile tamaracks, which are particularly susceptible to shading. Additionally, the pa.st drainage and consequent alteration of the hydrology of the bog may have facilitated the invasion of these species. Re-establishing the previous hydnjiogy may exclude them from the site. Hydrology Restoration of the bog's hydrology is extremely complicated because current data is not well understood and there arc information gaps. Site monitoring revealed that water le\-els in the bog were consistent with a typical bog. However, water quality analysis revealed a high pH and higher than normal nutrient levels. A better understanding of water and nutrient inflow is necessary- before steps can be taken. For example, an apparent first step is to fill the drainage ditch. It is unknown how this will affect water levels in the bog. especially since they now appear normal. A complete survey of the bog's water budget is needed. A model of the water budget will allow for prediction of possible consequences of altering the flows in or out of the bog. Continued and long term monitoring would need to be coupled with any actions to remediate hydrology. Conclusions Impoitant information has Ix^en collected towards understanding the current state of the BNP bog. Some immediate steps must be implemented if the goal is to slow the succession of the bog to a forest. Removing invasives and planting bog species, such as tamarack seedlings and SphagiUini. would be a good first step towards enhancing the bog. A better understanding of the hydrology of the bog is necessary\ The tamarack bog is an irreplaceable and rare habitat type that benefits the community. The tamarack bog could be utilized for educational purposes, not only for understanding a bog community but also as a case study for restoration and enhancement and the inevitable consequences of ecological succession. In addition, the bog houses Carex dispenna, the two-seeded sedge, a plant species considered state endangered, as well as two potentially threatened plant species, Carex atlantica var. capillacea (Howe's sedge) and Larix laricina (tamarack). Controlled public access could be made to the bog with the addition of a boardwalk. The bog not only adds diversity to the RNF but also houses rare species of ecological significance. VOL. 105 AcKNrjwLHixiMtNTs. We thank Jim Bissel for ltadinn the pknt idc-ntifiailion survey in ihe bog, Diani.' H. l.iicafi For lir)ophytc vouthors. j.'. wdi as Randy Mitfhfll, Alice: Phillips, and the University of Akron's Field Biology Class (."Spring 2002) for their help with data collt'ction. We also thank the Bath Trustees, Rosalie Sterner, and Mike Rorer for allowing; u,s access to the site. LITERATURE CITED Andreas iJK, Osterbrock AJ, 1985, Vegelationa! analysis ot" thrt-e Ohio lio^s. OhioJ Sti 85:9-10. Burns RM. Honkala BH. t990. Silvics of North America: 1. 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