Patrick A. Raney
Sussman Fellowship Final Report Fall, 2009
Sponsoring Organization: New York Natural Heritage Program
Project Title: Climatic Buffering in Temperate Zone Fens, Implications for Climate
Change
Summary of Proposed Work
Fens are biologically diverse wetlands fed by cold, mineral rich groundwater that
may buffer these ecosystems from the effects of climate change. This groundwater
discharge maintains significantly cooler temperatures within fens than in their
surrounding mosaic of non-fen wetland and upland natural communities. As a result,
some boreal species found much farther north, and alpine species, have persisted within
these climatic refuges following post glacial warming. An internship through the New
York Natural Heritage Program (NYNHP) was undertaken with the following major
hypotheses:
1) Fens will continue to maintain cooler climates than their surroundings
2) Boreal and alpine species will be most abundant in terms of percent cover in
the coldest portions of the fen/non-fen landscape mosaic.
Narrative of Research
In the summer of 2009, I recorded air temperature at four forested fens in central
New York ranging in size from approximately 20 to 500 ha. In three of these fens,
arboreal vascular plants were identified within 87, 10 x 10 meter research plots.
Additionally, herbaceous vascular plants were recorded as a function of percent cover,
and the presence or absence of non-vascular plants was also recorded within 1x1 m plots.
With the support of the Sussman Fellowship, I was able to offer a small stipend to a
SUNY-ESF undergraduate student who assisted in field data collection (Andrew
McCadden). Andrew provided great company over the summer and collected a plethora
of environmental data which helped facilitate a thorough sampling of the vegetation. His
help turned out to be an essential component of the work conducted, as he vastly
extended the amount of raw data I was able to collect. Over the course of the summer, I
recorded several uncommon plant species, many state protected plants, and one heritage
element (Trollius laxus ssp. laxus) formerly a candidate for listing under the endangered
species act.
In the coming months, the data collected will allow us to examine the
environmental gradients affecting species in fens, and for the first time, we will couple
ground level temperature data recorded on daily intervals with species distributions data..
Preliminary Results
We have not yet found marked differences between fen and upland temperature
regimes for air temperatures (see Figure 1), we are focusing our future efforts on fens
with greater amounts of groundwater discharge that may have more significant cooling.
While there were not significant differences in air temperature at 1 m height, temperature
data recorded from ground level sensors appears to be more promising.
Preliminary analysis of plant community data shows a distinct clustering pattern
of the boreal species (see Figure 2). This was a rather informative result as it suggests
that at least some of these species may be responding to similar environmental gradients,
suggesting interesting results will be obtained in the full analysis. Future efforts aimed to
decipher the influences of environmental gradients on the boreal and alpine species
includes ordinative techniques that will allow us to observe the relative influences of all
variables sampled in relation to species distributions.
Nelson Swamp : Mean Daily Min; Mean
Daily Max. (May 15-Sept. 19, 2009)
Site Overview
Figure 1
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=boreal
=alpine
Figure 2
Note: alpine species are circled, species listed as undefined have predominantly
northeastern, or central distributions with the eastern U.S.
Future Research
Additional research aimed to elucidate the climate growth response of Pinus
strobus (eastern white pine), and Abies balsamea (balsam fir) is in the works for 2010.
Because balsam fir is near its southern range margin in New York State and comprises
approximately 30% of stand cover in many fens, it offers an excellent opportunity to
evaluate the influences of fen climatic conditions on a species that is otherwise expected
to be lost from the landscape in the next 100 years due to climate change. Additionally,
eastern white pine at Nelson Swamp DEC Unique area provides an opportunity to
develop a tree-ring chronology in excess of 300 years, including the oldest known
individual of the species in the United States at >450 years old. Additionally, I plan to
develop a temperature sensor network that will be closely associated with Trollius laxus
ssp. laxus (spreading globeflower). Trollius laxus is typically restricted to colder areas of
fens and to seeps with significant groundwater discharge and cooling. It is found under a
number of canopy conditions ranging from full sun to closed canopy comprised mainly of
conifers, allowing for the evaluation of various canopy conditions on ground level
temperature in these settings.
This internship has been a very positive experience for both Andrew and myself.
This internship has provided a base of knowledge that will serve me well in the
development and completion of my dissertation. A section of the work over the summer
and information regarding future research related to this project was featured as the cover
article in the NYNHP newsletter in the 2009 summer issue (Vol. 20 No.2). I would like
to thank the New York Natural Heritage Program (NYNHP) and the Edna Bailey
Sussman Foundation for this truly worthwhile experience.