Gastropod abundance at Hubbard Brook Experimental Forest, Watershed 1 and West of Watershed 6, 1997-2006
Gastropod abundance at Hubbard Brook Experimental Forest, Watershed 1 and West of Watershed 6, 1997-2006
Steven Hamburg
Environmental Defense Fund
18 Tremont Street, Suite 850
Boston, MA 02108
Matthew Vadeboncoeur
Monica Skeldon
Snail and slug abundance were measured for a 10 year period between 1997 - 2006 at three elevations on Watershed 1 as well as in a reference area west of Watershed 6. Watershed 1 received calcium additions as wollastonite (CaSiO3) during the study period. This data set includes counts of snails and and slugs for the entire study period.
KEYWORD SET: Hubbard Brook Ecosystem Study LTER
calcium amendment, gastropod, HBEF Watershed 1, HBEF Watershed 6, HBR, Hubbard Brook LTER, organism, slug, snail.
KEYWORD SET: LTER Core Research Areas
Watershed 1
West bounding coordinate: -71.730866
East bounding coordinate: -71.725832
North bounding coordinate: 43.959356
South bounding coordinate: 43.952121
Bear Brook Watershed, west of Watershed 6
West bounding coordinate: -71.743462
East bounding coordinate: -71.735649
North bounding coordinate: 43.957001
South bounding coordinate: 43.949928
We have assembled a 10-year record (1997-2006) of snail and slug abundance at three elevations on watershed 1, which was treated with Ca in 1999, as well as in a reference area west of watershed 6. Total snail abundance increased over the time series in both watersheds, but the increase was much more significant on watershed 1. Slug abundance did not change significantly over the time series in either watershed.
The most commonly encountered snails included Discus catskillensis; Striatura exigua; and Zonitoides arboreus. Slugs were not identified to species.
Snails were collected once in the summer of 1997 and twice each summer from 1998 thru 2006, using the cardboard sheet method (Hawkins et al. 1998; Boag 1982), which produces acceptably representative samples of the gastropod community in northern hardwood forests (Strayer et al. 1986).
Cardboards 0.56m2 in area were deployed in a systematic grid on the forest floor at three elevations (520m, 610m, and 700m) both in W1 and west of W6 each June. The location of each cardboard was flagged to allow its reuse each year (within a few meters), and cardboards were only placed on an intact litter layer, avoiding the exact location of the previous year's cardboard.
Snails were collected from the underside of each cardboard in early July and early August, one to two days after a >7 mm rain event, so that the cardboards were still moist but not saturated at the time of collection. Only snails adhering directly to the cardboard were collected; those in leaf litter stuck to the cardboard were not collected due to the highly variable amount of litter adhering to each cardboard. Slugs were counted, but not collected.
Snails samples, preserved in 95% ethanol, are stored in Steven Hamburg's lab at Brown University.
  • Boag, D.A. 1982. Overcoming sampling bias in studies of terrestrial gastropods. Canadian Journal of Zoology 60:1289-1292.
  • Hawkins, J.W., Lankester, M.W., and Nelson, R.R.A. 1998. Sampling terrestrial gastropods using cardboard sheets. Malacologia 39:1-9.
  • Skeldon, M.A., Vadeboncoeur, M.A., Hamburg, S.P., and Blum, J.D. 2007. Terrestrial gastropod responses to an ecosystem-level calcium manipulation in a northern hardwood forest. Canadian Journal of Zoology 85:994-1007.
  • Strayer, D., Pletscher, D.H.., Hamburg, S.P., and Nodvin, S.C. 1986. The effects of forest disturbance on land gastropod communities in northern New England. Canadian Journal of Zoology 64:2094–2098.
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Citation example: Holmes, R.T. 2012. Bird Abundances at Hubbard Brook (1969-2010) and on three replicate plots (1986-2000) in the White Mountain National Forest. Durham, NH. Hubbard Brook Data Archive [Database]. (23 July 2012)

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Acknowledgment example: Data on [topic] were provided by [name of PI] on [date]. These data were gathered as part of the Hubbard Brook Ecosystem Study (HBES). The HBES is a collaborative effort at the Hubbard Brook Experimental Forest, which is operated and maintained by the USDA Forest Service, Northern Research Station, Newtown Square, PA. Significant funding for collection of these data was provided by [agency]-[grant number], [agency]-[grant number], etc.

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Information Manager, Hubbard Brook LTER
234 Mirror Lake Road
North Woodstock, NH 03262

Phone: (603) 726-8902

Data file: gastropods.txt
Description: Gastropod abundance on Watershed and west of Watershed 6, 1997-2006, Hubbard Brook Expermental Forest
ColumnVariableDescriptionUnitsCoded?Missing value label
1DATEDate of observationYYYY-MM-DDn
2WATERSHEDWatershed of observation (W1 was treated with wollastonite in fall 1999; the area west of W6 is untreated, and used as a reference.)noneynone
3ELEV_BANDElevation band (n = 3 per watershed)noneynone
4CARDBOARDcardboard number (n=15 per elevation band)noneynone
5N_SNAILSNumber of snails observednumbern
6N_SLUGSNumber of slugs observednumbern


Watershed of observation
Variable: ELEV_BAND
Elevation band
cardboard number

Missing Value Code
Code Explanation
Unkown date
Data missing or not taken
Data missing or not taken