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Limiting Factors in the Establishment of Marl Fen Vegetation on Calcareous Substrates at
the Great Swamp Conservancy
BettyJo Jivoff, M.S. Student
Introduction
The Great Swamp Conservancy is located in Canastota, NY and works towards the
restoration of wetlands in Madison County. The surrounding area includes many degraded
peatlands, such as agricultural fields, that feature exposed mineral deposits of calcium carbonate
known as marl.
Restoration of these degraded peatlands to forested swamps may not be possible due to
the highly alkaline nature of the exposed substrates. Therefore, patterning ecological restoration
after natural habitats that occur in the region and may have similar characteristics and functions
to the restoration site may be the best option. Ecosystems with alkaline, infertile substrates
should include plant species with tolerance to similar substrate conditions and can be used as a
template for restoration of degraded peatlands at the Great Swamp Conservancy.
Past ecological restoration projects in Solvay, NY have used marl fen plant species to
restore an urban industrial waste site with soil characteristics similar to those found on these
former agricultural fields. Marl fens are globally imperiled wetland ecosystems characterized by
marl substrates which are calcium-rich (alkaline), infertile, inorganic, and typically saturated,
resulting in a harsh environment for plant establishment. Plant species adapted to these
ecosystems may be utilized for ecological restoration of the degraded peatlands found in
Madison County. Native plant species from calcium-rich upland ecosystems were also included
for contrast. Some species were included which naturally occur in both upland and marl fen
ecosystems.
The goal of my research in 2012 was to (1) investigate the potential of restoring sites with
calcareous substrates using native plant species and (2) to assess environmental factors limiting
the establishment and survival of these plant species.
Methods
In order to assess the ability of native plant species of interest to establish under the
harshest possible conditions, all soil above the marl was removed from the restoration site on
May 21, 2012 (Figure 1A). This excavation also ensured homogenous substrate conditions for all
test plots. A total of 32 0.8 m2 test plots were subsequently established (Figure 1B). Plots were
planted (as plugs) or seeded between June 7 and June 14 (Figure 1C). A total of 20 species were
included in each plot and in total 22 species were included in the study (Table 1). Seeds of two
species (Juniperus horizontalis and Carex crawei) were not available, so in the seed plots two
alternate species (Parnassia glauca and Potentilla arguta) were included.
In order to assess whether fertility or alkalinity are limiting factors on this site, two
treatments and a combination of the two treatments were used. These treatments were a nitrogen
(fertility) amendment and a pH (alkalinity) amendment.
Germination was monitored weekly in all seed plots. Weekly counts of survival were
taken for all plots. Every three weeks estimates of cover and measurements of height of all
introduced species were made. Substrate saturation and alkalinity were measured every three
weeks. Soil samples for future assessment of substrate fertility were collected twice.
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A
B
C
D
Figure 1. Study site during the growing season. Initial excavation, May 21, 2012 (A),
completion of plot establishment, June 6, 2012 (B), completion of planting, June 14, 2012
(C), and the last data collection of the growing season, September 15, 2012 (D).
Preliminary Results
Marl fen plant species had lower survival than upland species and co-occurring species in
control plots (Figure 2). All treatments increased the percent survival of marl fen and cooccurring species relative to the control. Upland species had lower survival in all treated plots
than in the control. In the nitrogen and nitrogen plus pH amendment plots marl fen and cooccurring species had higher survival than upland species.
Plants introduced as plugs had nearly 100% survival in all treatments (Figure 3A).
Nutrient and pH amendments slightly increased seedling survival. Nutrient and nutrient plus pH
amendments increased plug but not seedling cover (Figure 3B). Nutrient plus pH amendments
increased plug and seedling height and nutrient amendments increased seedling height (Figure
3C). In general pH amendments alone did not increase cover or height of native species.
Future Work
Established native plant plots will be monitored for a second growing season in 2013.
Further data analysis will include contrasting the response of native marl fen species to native
upland calcareous species and analyzing the response of some individual species to treatments.
Soil samples will be analyzed for fertility levels.
Further studies for summer 2013 will include an assessment of the competitive ability of
one to a few marl fen plant species.
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Table 1. Native plant species included in study and native community type. Species
included in seed plots and plug plots are also indicated.
Species
Carex aquatilis
Cladium mariscoides
Eleocharis rostellata
Lobelia kalmii
Parnassia glauca
Senecio aureus
Aquilegia canadensis
Bromus kalmii
Carex crawei
Carex vulpinoidea
Potentilla arguta
Sporobolus heterolepis
Andropogon gerardii
Carex aurea
Carex eburnea
Juncus dudleyi
Juniperus horizontalis
Muhlenbergia glomerata
Potentilla fruticosa
Senecio pauperculus
Solidago ohioensis
Sorghastrum nutans
Marl Fens
Uplands
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Seeds
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Plugs
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Figure 2. Percent survival of introduced species in four treatments. Separated by native
community type.
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Acknowledgements
I’d like to thank my major professor Dr. Donald J. Leopold for his help and support. I am
also very grateful to the Edna Bailey Sussman Foundation for their financial support in 2012. I
would also like to thank Mike Patane, director of the Great Swamp Conservancy for logistical
and technical support during this internship.
A
B
C
Figure 3. Percent survival (A), percent cover (B), and total height (cm) (C) of introduced native plant species in four
treatments.