(1996-03) Kritsky, Gene; Horner, Leslie; Reidel, Susan; Savage, A. J.
A tiger beetle survey of the Ohio counties that border the Ohio, Great Miami, and Little Miami rivers located eleven new county records. Cicindela sexguttata is reported in Brown, Gallia, and Lawrence counties; C. repanda from Brown, Clermont and Warren counties, C. duodecimguttata from Brown County, C. unipunctata from Gallia County, and C. cuprascens from Brown, Clermont, and Scioto counties. A search for C splendida in Adams County and C. hirticollis in Hamilton County failed to locate specimens in their previous localities, suggesting they may be extirpated from those areas.
Ohio witnessed an unexpected emergence of periodical cicadas in 1995. The largest emergence occurred in Athens County where hundreds of cicadas emerged on 24 May 1995. Gallia County witnessed the emergence of less than fifty periodical cicadas and smaller emergences of only a few individuals were reported in Adams, Clermont, Hamilton, Highland, Hocking, and Washington counties. Athens and Gallia counties have Brood V cicadas which are expected to emerge in 1999, suggesting that this year's cicada emergence was a four-year acceleration of Brood V. The other counties were sites of Brood XIV emergences in 1991 and these may be cicadas emerging four years late.
An annual five-day Conservation Camp is attended by 176 14- to 18- year old 4-H members. The campers receive field instruction in soils, water, forestry, wildlife and recreation related to land use and develop a land use plan. In 1993, the water quality portion of the program was evaluated to determine the effect on knowledge and skills. Pre/post tests, land use plans, and oral presentations were examined. Camper knowledge of water quality principles was significantly increased when compared to a control group. Most campers included erosion control practices in land use plans and all positioned water supplies upslope of pollution sources. About 40% of the campers included waste treatment systems in land use plans.
This study evaluates several different delineation methods that are used for Wellhead Protection programs, as mandated by the Safe Drinking Water Act Amendments of 1986. The municipal well field for the village of Elmore utilizes the regional aquifer (Silurian Lockport Dolomite, a dense, extensively fractured carbonate) which is overlain by a leaky confining layer (glacial till). Drilling records and water surface elevations from 444 water wells within a region 330 km2 surrounding the well field were used to generate maps of the potentiometric surface, bedrock elevation and surficial layer thickness. In addition, field observations were made of the aquifer from local rock quarries for porosity types, percent porosity, fracture density, and fracture orientation. The data suggest that groundwater flow is directed northward, toward Lake Erie, and that recharge occurs through the leaky confining layer. Three groundwater flow models were used, an analytical (GPTRAC), semi-analytical (CAPZONE) and finite difference (MODFLOW) model. The three models predicted zones of influence that were generally the same size, however they differed in shape and asymmetry due either to implicit model assumptions or different model calculations for transmissivity and recharge. A sensitivity analysis identified aquifer transmissivity, porosity, and anisotropy as the critical variables in determining which model is appropriate to use in a Wellhead Protection Area delineation and in improving the accuracy of such a model.
(1996-03) Dwyer, Chris P.; Belant, Jerrold L.; Dolbeer, Richard A.
In 1994, we conducted aerial, mail, and telephone surveys to determine the distribution and abundance of roof-nesting gulls in states bordering the Great Lakes. We documented more than 7,922 nesting pairs of gulls at 30 colonies in four states; species composition was 71% ring-billed (Larus delawarensis^, 24% herring (Z. argentatus^, and 5% unknown. Colony size ranged from 1 to 1,003 nesting pairs. Proportions of ring-billed gulls nesting less that 5.0 and more than 10.0 km from the Great Lakes were 31% and 39%, in contrast to 63% and less than 1% for herring gulls, respectively. Maximum distances herring and ring-billed gull colonies were located from the Great Lakes were 23.5 and 58.0 km, respectively. Roof-nesting ring-billed and herring gulls represented approximately 2% and 4%, respectively, of the total nesting population for these species in the U.S. portion of the Great Lakes. As previous surveys of colonial waterbirds in the Great Lakes did not document roof-nesting gull colonies, future surveys should include potential inland colony sites, particularly roofs and other urban habitats, to obtain more accurate estimates of total population size and to monitor population trends of roof-nesting gulls.
(1996-03) Sherman, David E.; Kroll, Roy W.; Engle, Tracy L.
Undiked wetlands in Lake Erie experience fluctuating water levels, and diked wetlands are isolated from these natural hydrologic events. Growth and survival of vegetation within the two wetland types is influenced by different water level regimes. Our objective was to report the occurrence and abundance of flora in a 100 ha diked wetland (DW) and an adjacent 100 ha undiked wetland (UW) at Winous Point Shooting Club in southwestern Lake Erie (SWLE) during September 1991. Randomly sampled aquatic macrophytes were identified to species and number of stems was recorded. Water depth and land elevation readings were also made. Forty-six species of aquatic macrophytes were identified in the DW while no plants were found in the UW. The controlled water depth of the DW (28.40 ± 2.39 [SE] cm) was significantly lower (P <0.0001, t = 11.95) than the uncontrolled depth in the UW (95.41 ± 5.07 cm). Although the basin elevation of the DW was higher (P = 0.01) than the elevation of the UW, the mean difference in water depth between the two wetlands was much greater (P <0.0001) than the mean elevation differences. Thus, higher water levels were primarily responsible for floristic differences between the two wetlands. Because most ecological functions of wetlands are derived from processes requiring aquatic macrophytes, we suggest that unvegetated wetlands, such as undiked wetlands in SWLE, provide few of their potential ecological benefits. We propose that the relative ability of a SWLE wetland to advance landward is the most important factor in determining the need to construct dikes and control water levels for aquatic plant restoration. We generally recommend that dike systems should only be constructed on SWLE wetlands with restricted upland borders.