Download Ephemeral Pond - Wisconsin Initiative on Climate Change Impacts

Climate Change Vulnerability Assessment
for Ephemeral Pond in Wisconsin
Eric Epstein, WDNR
In 2014, the Wisconsin DNR’s Natural Heritage Conservation program conducted eight vulnerability assessment
workshops across Wisconsin to evaluate the potential impacts of climate change on over 50 natural communities. At one
workshop, a team of conservation professionals utilized experience and published literature to assess the vulnerability of
Ephemeral Pond based on the potential impact and adaptive capacity of the ecological processes, dominant and
important plant species, and stressors to the community. a
Distribution of Ephemeral Pond in
Wisconsin based on existing NHI data
(likely much more extensive than map
indicates, as many areas have not been
well-surveyed for this community)
Executive Summary
Ephemeral Ponds are often defined based on the amphibians and
invertebrates that use them, especially those for which ponds are
their primary breeding habitat. Warmer temperatures, higher
evapotranspiration rates and longer dry spells could lead to some
ponds drying up earlier, which could adversely impact species that
require inundation for larval development. Extreme precipitation
events could also adversely impact species as well as increase the
risk of invasion by non-native plants like reed canary grass. Ponds
usually occur in forested landscapes, and risk of rutting from
harvesting equipment could increase with shorter winters and fewer
days of frozen ground conditions. On the positive side, ponds are
widespread across the landscape and most of the plant and animal
species that use them are relatively common with at least moderate
dispersal ability. In addition, while many tree species associated
with ponds could decline, other, better adapted tree species could
take their place, with potentially minimal impact to obligate pond
breeders, provided pond hydroperiods remain similar.
a
Potential Impacts:
Moderately Negative to
Negative
+
Adaptive Capacity:
Moderate to Moderately Low
Overall Estimated Vulnerability:
Moderate to High
For information on how this assessment was conducted, please see the CCVA Vulnerability Determination Process on the WICCI
Plants and Natural Communities working group website.
Greatest Potential Impacts:
Ponds could dry earlier in the year due to higher rates of evapotranspiration and longer dry spells, which could shorten
the duration of inundation and adversely impact the reproductive success of the animal assemblages that largely define
Ephemeral Ponds.1, 2 These animals include many obligate pond-breeding amphibians (e.g., wood frog, spotted
salamander, blue-spotted salamander, etc.) and invertebrates (e.g., fairy shrimp, etc.). More episodic precipitation with
long rain-free periods punctuated by extreme precipitation events could result in a cycle of repeated drying and reinundation of Ephemeral Ponds, potentially impacting animal larval development as well as native plants.3 Extreme rain
events also increase the risk of erosion, sedimentation, nutrient enrichment and other run-off pollution (e.g., road salt),
especially in basins with human land uses such as agriculture, developed areas, or roads.4, 5 Excess nutrients, flooding,
and general disturbance also favor non-native species such as reed canary grass over native vegetation.6, 7
Direct disturbance to ponds via rutting or timber harvesting within ponds is also a concern, and a shortening of frozen
ground conditions may increase the risk of rutting or other soil disturbance.8 Trees within or directly adjacent to ponds
also have shallow root systems and may be vulnerable to windthrow, especially in the face of more extreme storms.8, 9
Key forest species may also experience a reduction in suitable habitat due to climate change10 or are vulnerable to pests
and disease (e.g., emerald ash borer).11 Loss of individual trees would alter forest structure surrounding the pond. While
decreased shading would increase water temperatures and speed rates of larval development,12 this does not make up
for higher tadpole mortality in rapidly drying ponds.13 In addition, most Ephemeral Pond obligates prefer at least
partially shaded ponds on average14 and a large reduction in the canopy in forest cover would also likely adversely
impact the pond community by increase the risk of desiccation of adults in the surrounding forest during the nonbreeding season.12
Factors that most influence Adaptive Capacity:
The extreme dependence of Ephemeral Ponds upon surface water as well as their generally small basins and shallow
depth makes them highly vulnerable to changes in precipitation patterns and diminishes their adaptive capacity in any
given year.1, 15 However, although ponds are by nature small, spatially fixed, and hydrologically isolated from one
another, ponds that are clustered in the landscape tend to have higher species richness, abundance, and more similar
species than isolated ponds.16 Thus, clusters of ponds presents opportunities for mobile species to seek out more
suitable breeding habitat if a subset of ponds become prone to early drying during periods of drought. In addition,
Ephemeral Ponds and the species that breed therein have a wide distribution across the landscape, and most species
have at least moderate dispersal ability.
Ephemeral Ponds and their assemblage of key amphibians and invertebrates also appear to relatively insensitive to
changes in the composition of the surrounding forest, provided litter quality (e.g., from deciduous trees) and
surrounding forest canopy cover remain stable over the long term.17, 18 Thus, even if some species such as quaking
aspen, big tooth aspen, sugar maple, or yellow birch decline as projected under high-change scenarios,10 increases in
other species such as red maple10, 19 may continue to provide suitable habitat structure at the local and landscape level.
In addition, ponds and their relatively cool, moist depressions may serve as local climate refugia for trees sensitive to soil
moisture stress.
Key uncertainties:
• Several amphibians that are obligate breeders in Ephemeral Ponds were ranked as Extremely Vulnerable or Highly
Vulnerable to climate change in a NatureServe CCVI in Michigan, including wood frog, blue-spotted salamander,
spotted salamander, and four-toed salamander.20 However, other researchers note some amphibians have an ability
to adapt to climate change in a variety of ways, including adult lungless salamanders (plethodontids, a group that
includes four-toed salamanders) responding to drought by seeking out local climate refugia with cooler summer
•
•
temperatures and higher relative humidity such as in or adjacent to caves and near-permanent streams.21 In
addition, adult headwater stream-dwelling salamanders have been noted to temporarily emigrate to more suitable
habitat to survive periods of drought, and return to their breeding areas when drought conditions end.22 Do other
groups of salamanders more common in Ephemeral Ponds (i.e., spotted salamander, blue-spotted salamander, and
other mole salamanders) and other pond-dependent amphibians also exhibit local-scale adaptive capacity?
While differences in forest canopy (e.g., oak vs. maple) have been anecdotally implicated in determining the use of
ponds by amphibians, few differences have been reported in literature synthesizing research across the Midwest
and Northeast.17, 18 With long -term climate projections that favor oak or other central hardwoods species, are there
significant differences in litter quality (e.g., higher levels of tannins, etc.) between climate-sensitive versus climateadapted tree species that could affect amphibian or macroinvertebrate use and reproductive success?
While precipitation-fed ephemeral wetlands have been ranked as the most vulnerable of all wetland types to
climate change,1, 23 are there consistently identifiable characteristics of individual ponds, clusters of ponds, or pond
landscapes that may make them less vulnerable to the adverse impacts of higher temperatures, greater
evapotranspiration, longer dry spells, and extreme events?
Climate Change Vulnerability Determination for Ephemeral Pond in Wisconsin
Low Change Scenario
(PCM B1)
High Change Scenario
(GFDL A1FI)
Potential Impacts:
Moderately negative
Negative
Adaptive Capacity:
Moderate
Moderately low
Overall Estimated Vulnerability: Moderate
Confidence:
High
Medium evidence, medium agreement
Participants at the non-forested wetlands workshop
Ephemeral Pond
Key Factors and Processes
Potential Impacts under Climate Change
Occurs throughout Wisconsin, typically in morainal
landscapes in depressions lined with clay/silt lens, although
can also occur in small bedrock basins, such as on portions
of the Apostle Islands and elsewhere.
Predominant ecological process is seasonal inundation by
spring snowmelt and rain followed by summer drawdown.
Community is confined to small depressions and is unable to
migrate. However, most plant and animal species are widespread
and have at least moderate dispersal ability.
Ponds are fishless and generally lacking in major
invertebrate predators with no inlets or outlets, making
Ephemeral Ponds the preferred (and sometimes obligate)
breeding area for certain amphibians as well as fairy
shrimp and other aquatic invertebrates.
Surrounding forest cover provides shade, physical structure
(coarse and fine woody debris), and leaf litter inputs, which
influences water chemistry and usage by amphibians.
Timing of amphibian use and successful breeding is highly
variable depending on spring temperatures, precipitation
patterns, and pond duration.
Increased winter rain and earlier snowmelt may shift periods of
24
inundation earlier in the growing season; however, droughts as
well as higher evapotranspiration rates could also lead to lower pond
1, 15
Ponds are naturally
water depths and shorter inundation periods.
flashy and may therefore be somewhat adapted to variable
precipitation, but nevertheless are likely vulnerable to sudden
1, 3
increases in water levels due to extreme rain events, which can
drown native plants and favor non-natives like reed canary grass if
already present at a site.
Potential changes to hydroperiod could affect faunal use in ponds. If
the period of inundation is shorter, it could reduce short-term
1, 2
amphibian breeding success. If the period of inundation is longer,
it could be beneficial for breeding, but colonization by predaceous
25
insects is also more likely. However, most ponds are unlikely to
become permanently invaded by fish as drawdowns or freeze-out
conditions will probably still occur.
As surrounding forest changes (see Dominant/Important Species
below), ponds may be impacted as well. Increasing wind speeds and
8
rates of wind throw could increase coarse and fine woody debris.
Localized canopy gaps around ponds speed the larval development
of Ephemeral Pond obligates such as wood frog and spotted
12
salamander by decreasing shading and increasing water, however,
this does not make up for higher tadpole mortality in rapidly drying
13
ponds. In addition, these species still prefer at least partially
14
shaded ponds on average and a large reduction in the canopy of
12
the adjacent forest increases the risk of desiccation of adults. Adult
amphibians residing in duff layer or in/under coarse woody debris
are also adversely impacted by drought.
Timing of amphibian breeding may shift earlier in year. Drought
1, 2
reduces the likelihood of successful larval development. With
more episodic precipitation and increased evapotranspiration, vernal
pools would dry earlier in the year and remain dry longer and
adversely affect the successful reproduction as well as isolate the
15
remaining productive pools.
Dominant/Important Species
10
Climate Change Tree Atlas
b
Modeled change in suitable habitat from 2000 to 2100 in northern and southern WI
Modifying Factors19
Change in suitable habitat
Model
reliability
Low
(PCM BI)
High
(GFDL A1FI)
Positive
Traits
High
No Change
Decrease
SES ESP COL
DISP
Negative
Traits
Adapt
Score*
Northern Wisconsin
Red maple
Black ash
High
Decrease
Decrease
Sugar Maple
High
No Change
Large Decrease
Red oak
Bigtooth aspen
High
Increase
No change
High
Decrease
Large Decrease
Quaking aspen
High
Decrease
Yellow birch
High
Eastern hemlock
Southern Wisconsin
Silver maple
Red maple
8.5
INS COL DISP
DRO SES FTK
ESP
5.8
COL ESP
INS
5.4
FRG DISP
COL DRO FTK
5.1
Large Decrease
SES FRG ESP
COL DRO FTK
4.7
Decrease
Large Decrease
DISP
FTK INS DISE
3.4
High
Increase
Large Decrease
COL
INS DRO
2.7
Medium
Large Increase
Large Increase
DISP SES COL DRO FTK
5.6
High
No Change
Decrease
SES ESP COL
DISP
8.5
Black ash
High
Decrease
Large Decrease
INS COL DISP
DRO SES FTK
ESP
Green ash
Medium
No Change
Increase
INS FTK COL
High
No Change
Decrease
Sugar maple
1.7
COL ESP
1.7
4.0
5.8
INS
Red oak
High
No Change
Large Decrease
5.4
COL
FTK
Basswood
Medium
No Change
No Change
4.6
* Species with an Adapt Score of 5.3 or greater have many positive traits, higher than average adaptability, and may perform better
than Tree Atlas habitat suitability models project. Species with an Adapt Score between 5.2 and 3.3 have average adaptability.
Species with an Adapt Score of 3.2 or lower have many negative traits, lower than average adaptability, and may perform worse
than Tree Atlas habitat suitability models project.
In much of glaciated Midwest, Ephemeral Ponds (also called Vernal Pools) are defined and managed primarily by their
animal assemblages rather than plant composition. The dominant biotic factors influencing animal assemblage and pond
use are primarily landscape context (forested vs. unforested), degree of pond shading, leaf litter inputs, fine woody
debris, and coarse woody debris, most of which is contributed by the surrounding forest.12, 17 Although shrub and
herbaceous vegetation may be locally important in some ponds, composition is highly variable and comparably less
important to the defining characteristics of this community. Thus, shrub and herbaceous vegetation is not further
considered here.
b
For more information on Tree Atlas, please see Explanation of Tree Atlas Model on the WICCI Plants and Natural Communities
working group website.
Stressors/Threats
Potential Changes to Stressors/Threats under Climate Change
Invasive species (e.g., reed canary grass)
Reed canary grass capitalizes on warmer temperatures, longer
6, 7
growing seasons, and higher nutrients.
Loss of surrounding forest canopy (e.g., from logging,
windthrow, pests and disease, etc.)
Risk of windthrow could increase with higher intensity storm
8, 9
events. Emerald Ash Borer will cause over 99% mortality to all
11
species of ash. Pests and diseases are likely to increase in
abundance and distribution and tend to be exacerbated by moisture
26, 27
Loss of forest canopy increases the risk of
stress and disturbance.
more rapid pond drying, which reduces reproductive success for
13
amphibians.
Increases in extreme storms as well as winter and spring rain could
lower water quality in erosion-prone landscapes or local basins with
4, 5
roads, development, or agriculture.
Demand on regional water supplies could increase for agriculture
28
and municipal use, but impacts likely will be basin-specific.
Changes to water quality (e.g., from sedimentation,
pollution run off)
Hydrologic alteration (e.g., ditching, groundwater
withdrawal)
Rutting
Logging in or adjacent to pond without appropriate
18
buffers
18
Fragmentation of pond clusters and corridors
Pond deepening for fishing/recreation
Wetland filling
A shortening of frozen ground conditions may increase the risk of
9
rutting or other soil disturbance.
Preemptive or salvage logging for ash impacted by Emerald Ash
Borer or other trees impacted by pests could increase. Climateinduced stress can increase susceptibility of trees to pests and
9, 29
diseases.
Fragmentation is likely to increase with development over time,
though this is likely driven more by socio-economic and policy
factors.
References
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
Brooks, R.T. 2009. Potential impacts of global climate change on the hydrology and ecology of ephemeral freshwater
systems of the forests of the northeastern United States. Climatic Change 95 (3):469-483.
Donald, D.B., W.T. Aitken, C. Paquette, and S.S. Wulff. 2011. Winter snowfall determines the occupancy of northern prairie
wetlands by tadpoles of the Wood Frog (Lithobates sylvaticus). Canadian Journal of Zoology 89 (11):1063-1073.
Brooks, R.T. 2005. A review of basin morphology and pool hydrology of isolated ponded wetlands: implications for seasonal
forest pools of the northeastern United States. Wetlands Ecology and Management 13 (3):335-348.
Zedler, J.B. 2009. How frequent storms affect wetland vegetation: a preview of climate-change impacts. Frontiers in
Ecology and the Environment 8 (10):540-547.
Wisconsin Initiative on Climate Change Impacts [WICCI]. 2010. Water Resources Working Group Report. Nelson Institute for
Environmental Studies, Universty of Wisconsin-Madison and the Wisconsin Department of Natural Resources. Madison, WI.
Kercher, S.M., and J.B. Zedler. 2004. Flood tolerance in wetland angiosperms: a comparison of invasive and noninvasive
species. Aquatic Botany 80:89-102.
Zedler, J.B. 2007. Climate Change and Arboretum Wetlands. edited by University of Wisconsin Arboretum. Madison, WI.
Frelich, L.E., and P.B. Reich. 2010. Will environmental changes reinforce the impact of global warming on the prairie—forest
border of central North America? Frontiers in Ecology and the Environment 8 (7):371-378.
Janowiak, M.K., L.R. Iverson, D.J. Mladenoff, E. Peters, K.R. Wythers, W. Xi, L.A. Brandt, P.R. Butler, S.D. Handler, P.D.
Shannon, C. Swanston, L.R. Parker, A.J. Amman, B. Bogaczyk, C. Handler, E. Lesch, P.B. Reich, S. Matthews, M. Peters, A.
Prasad, S. Khanal, F. Liu, T. Bal, D. Bronson, A. Burton, J. Ferris, J. Fosgitt, S. Hagan, E. Johnston, E. Kane, C. Matula, R.
O'Connor, D. Higgins, M. St. Pierre, J. Daley, M. Davenport, M.R. Emery, D. Fehringer, C.L. Hoving, G. Johnson, D. Neitzel, M.
Notaro, A. Rissman, C. Rittenhouse, and R. Ziel. 2014. Forest ecosystem vulnerability assessment and synthesis for northern
Wisconsin and western Upper Michigan: a report from the Northwoods Climate Change Response Framework project. Gen.
Tech. Rep. NRS-136. U.S. Department of Agriculture, Forest Service, Northern Research Station. Newtown Square, PA.
https://www.fs.fed.us/nrs/pubs/gtr/gtr_nrs136.pdf.
Iverson, L.R., A.M. Prasad, S.N. Matthews, and M. Peters. 2008. Estimating potential habitat for 134 eastern U.S. tree
species under six climate scenarios. Forest Ecology and Management 254 (3):390-406.
Wisconsin Department of Natural Resources [WDNR]. 2010. Emerald Ash Borer and Forest Management. Wisconsin
Department of Natural Resources. Madison, WI.
Semlitsch, R.D., and D.K. Skelly. 2007. Ecology and Conservation of Pool-Breeding Amphibians. Pp. 127-147 in Aram J. K.
Calhoun and Phillip G. DeMaynadier (Eds.), Science and Conservation of Vernal Pools in Northeastern North America. CRC
Press.
Amburgey, S.M., M. Murphy, and W. Chris Funk. 2016. Phenotypic plasticity in developmental rate is insufficient to offset
high tadpole mortality in rapidly drying ponds. Ecosphere 7 (7):e01386.
Skelly, D.K., M.A. Halverson, L.K. Freidenburg, and M.C. Urban. 2005. Canopy closure and amphibian diversity in forested
wetlands. Wetlands Ecology and Management 13 (3):261-268.
Brooks, R.T. 2004. Weather-related effects on woodland vernal pool hydrology and hydroperiod. Wetlands 24:104-114.
Van Dyke, F., A. Berthel, S.M. Harju, R.L. Lamb, D. Thompson, J. Ryan, E. Pyne, and G. Dreyer. 2017. Amphibians in forest
pools: Does habitat clustering affect community diversity and dynamics? Ecosphere 8 (2):e01671.
Colburn, E.A. 2004. Vernal Pools: Natural History and Conservation. The McDonald and Woodward Publishing Company.
Granville, OH.
Calhoun, A.J.K., and P.G. DeMaynadier. 2007. Science and Conservation of Vernal Pools in Northeastern North America:
Ecology and Conservation of Seasonal Wetlands in Northeastern North America. CRC Press. New York, NY.
Matthews, S.N., L.R. Iverson, A.M. Prasad, M.P. Peters, and P.G. Rodewald. 2011. Modifying climate change habitat models
using tree species-specific assessments of model uncertainty and life history factors. Forest Ecology and Management
262:1460-1472.
Hoving, C.L., Y.M. Lee, P.J. Badra, and B.J. Klatt. 2013. Changing Climate, Changing Wildlife: A Vulnerability Assessment of
400 Species of Greatest Conservation Need and Game Species in Michigan. Michigan Department of Natural Resources.
Lansing, MI.
Briggler, J.T., and J.W. Prather. 2006. Seasonal Use and Selection of Caves by Plethodontid Salamanders in a Karst Area of
Arkansas. The American midland naturalist 155 (1):136-148.
Price, S.J., R.A. Browne, and M.E. Dorcas. 2012. Resistance and Resilience of A Stream Salamander To Supraseasonal
Drought. Herpetologica 68 (3):312-323.
Bates, B., Z.W. Kundzewicz, S. Wu, and J. Palutikof. 2008. Climate Change and Water. Technical Paper of the
Intergovernmental Panel on Climate Change. IPCC Secretariat. Geneva.
Pyke, C.R., and J. Marty. 2005. Cattle Grazing Mediates Climate Change Impacts on Ephemeral Wetlands. Conservation
Biology 19 (5):1619-1625.
25
26
27
28
29
Higgins, M.J., and R.W. Merritt. 1999. Temporary woodland ponds in Michigan: invertebrate seasonal patterns and tropic
relationships. Pp. 279-297 in D.P. Batzer, R.B. Rader and S.A. Wissinger (Eds.), Invertebrates in freshwater wetlands of North
America: ecology and management. John Wiley and Sons. New York, NY.
Weed, A.S., M.P. Ayres, and J.A. Hicke. 2013. Consequences of climate change for biotic disturbances in North American
forests. Ecological Monographs 83 (4):441-470.
Dukes, J.S. 2011. Responses of invasive species to a changing climate and atmosphere. Pp. 345-357 in David M. Richardson
(Eds.), Fifty years of invasion ecology: The legacy of Charles Elton. Blackwell Publishing Ltd. Oxford, UK.
Eheart, J.W., and D.W. Tornil. 1999. Low‐flow frequency exacerbation by irrigation withdrawals in the agricultural midwest
under various climate change scenarios. Water Resources Research 35 (7):2237-2246.
Dukes, J.S., J. Pontius, D. Orwig, J.R. Garnas, V.L. Rodgers, N. Brazee, B. Cooke, K.A. Theoharides, E.E. Stange, and R.
Harrington. 2009. Responses of insect pests, pathogens, and invasive plant species to climate change in the forests of
northeastern North America: What can we predict? Canadian Journal of Forest Research 39 (2):231-248.
Non-forested Wetlands Workshop Participants
Workshop Date: October 6, 2014
Location: Ashland, WI
Peggy Burkman
National Park Service, Apostle Islands National Lakeshore
Mike Gardner
Northflow, LLC
Paul Hlina
University of Wisconsin-Superior Lake Superior Research Institute
Sarah Johnson
Northland College
Carly Lapin
WDNR-Natural Heritage Conservation
Amanda Little
University of Wisconsin-Stout
Tracey Ledder
Lake Superior National Estuarine Research Reserve
Colleen Matula
WDNR-Forest Sciences
Linda Parker
USDA Forest Service, Chequamegon-Nicolet National Forest
Michele Wheeler
WDNR-Water Resources
Facilitators:
Ryan O’Connor
WDNR-Natural Heritage Conservation
Amy Staffen
WDNR-Natural Heritage Conservation
dnr.wi.gov
WICCI.WISC.EDU
Suggested Citation: Wisconsin Initiative on Change Impacts [WICCI]. 2017. Climate Vulnerability Assessments
for Plant Communities of Wisconsin. Wisconsin Initiative on Climate Change Impacts, Madison, WI.