Progress 10/01/02 to 09/30/07
Outputs
OUTPUTS: Featured film for Outdoor Heritage Fund recipients: vernal pools and volunteers, April 2003. Quest, 2003. Featured segment of vernal pools for PBS program on "Spring" Magazines: Downeast magazine. Spring Issue. Feature article on Calhoun and vernal pools. Natural New England. Summer 2003. Umaine Today November/December 2002. Conferences: Calhoun, AJK and P. deMaynadier. 2003. Forestry habitat management guidelines for vernal pools. The Wildlife Society Annual Meeting, Burlington, VT. *Calhoun, AJK. and M. Klemens. 2003. Pools and people: conserving pool-breeding amphibians in developed landscapes. The Wildlife Society Annual Meeting, Burlington, VT. *Morley, T. R., A.J.K. Calhoun, and M. Gahl. 2003. Cumulative Impacts of Wetland Permitting in the Casco Bay Watershed, Maine. Society of Wetland Scientists Annual Meeting, Fla. *Gahl, M., A. J. K. Calhoun, and T. R. Morley. 2003. Assessing cumulative wetland conversion on a watershed scale: a tool for wetland conservation
planning and policy. Society for Conservation Biology, Duluth, Minn. *Baldwin, R., P. deMaynadier, and A. Calhoun. 2002. Remote detection, gap analysis, and conservation strategies for vernal pools in Maine's southern coastal region: preliminary results. Northeast Fish and Wildlife Annual Meeting, Portland, ME. *Calhoun, A. J. K. and P. deMaynadier. 2002. Forestry habitat management guidelines for pool-breeding amphibians. Forestry Best Management Practices Research Symposium, NCASI, Atlanta, GA. *Calhoun, A. J. K. and Michael W. Klemens. 2002. Best development practices (BDPs) for conserving pool-breeding amphibians in Northeastern united states. Society for Conservation Biology Annual Meeting, Cambridge, UK. Workshops and Demonstrations: Lower Appalachicola and Flint River Research Conference. 2004. New England. Conservation Perspective on Isolated Wetlands. Albany, GA. NE Wildlife Society. 2003. Strategies for conserving pool-breeding amphibians in developing landscapes. NE Society
of Wetland Scientists. 2002. Habitat management guidelines for conserving pool-breeding amphibians in the northeastern US. New England Bioassessment Wetlands Working Group. 2002. Annual Workshop. Mystic, CT. Maine Forest Service. 2002. "Forestry Habitat Management Guidelines for vernal pool wildlife. Dover-Foxcroft, ME. Mead Paper Company. 2002. "Forestry Habitat Management Guidelines for vernal pool wildlife." Rumford, ME. Association of consulting foresters. 2002. "Forestry Habitat Management Guidelines for vernal pool wildlife." Waterville, ME Citizen Outreach and Education Mt Desert: Presentation on vernal pool conservation initiative Oct 2005 Orono middle and High School: Curriculum development and field work 2004, 2005 Maine Coast Heritage Trust: Vernal pool walk, Boot Head, Lubec, ME 2005. Downeast Audubon: Seasonal forest pool ecology for teachers, 2004. Maine Mathematics Science and Teaching Excellence Collaborative. 2003. Workshop for teachers on wetland outreach and
education. Cross-tier teaching initiative. Farmington River Watershed Association, CT. 2003. Training for watershed-wide vernal pool inventory and application of Best Development Practices for vernal pools.
PARTICIPANTS: Graduate Students: Damon Oscarson, M.S. current David Patrick, Ph.D 2007 Megan Gahl, Ph.D 2007 Robert Baldwin Ph.D 2005 Jesse Cunningham M.S., 2003 Daniel Vasconcelos,M.S. 2003 Mary Beth Kolozsvary, Ph.D 2003 Lesley Lichko, M.S. (non-thesis) 2001 Other Participants: Maine Audubon Society Maine Forest Service Acadia National Park Towns of Falmouth, Biddeford, North Berwick, and Kennebunk ME Towns of Simsbury, Farmington, and Sudbury Connecticut Metropolitan Conservation Alliance Maine Department of Inland Fisheries and Wildlife
TARGET AUDIENCES: Target audiences where natural resource managers at local, state, and non-governmental levels and town officials. Efforts to reach these audiences were made through development of manuals on vernal pools, designing and implementation of citizen-science programs, colloborations with middle and highschools, training and information workshops, and production of videos on vernal pools
Impacts
Our outcomes and impacts from the research in my lab can be measured by the exponential increase in public knowledge of the vernal pool resource, the ongoing work with towns on vernal pool conservation strategies that continues, and the change in wetland policy that culminated from the past 10 years of work on wetlands.
Publications
- Calhoun, A. J. K. and P. deMaynadier. 2003. Forestry habitat management guidelines for vernal pool wildlife in Maine. Wildlife Conservation Society Technical Paper #6 Rye, New York.
- Calhoun, A.J.K. 2003. Maine Citizen's guide to locating and documenting vernal pools (3rd edition). Maine Audubon Society, Falmouth, Maine.
- Calhoun, A.J.K. and M. W. Klemens. 2002. Best development practices for pool-breeding amphibians in commercial and residential developments. Wildlife Conservation Society Technical Paper #5. Rye, New York.
- Calhoun, A.J.K., N. Miller, and M. W. Klemens. 2005. Conservation strategies for pool-breeding amphibians in human-dominated landscapes. Wetlands Ecology and Management 13:291-304.
- Vasconcelos, D. and A.J.K. Calhoun. 2004. Movement patterns of adult and juvenile wood frogs (Rana sylvatica) and spotted salamanders (Ambystoma maculatum) in three restored vernal pools. Journal of Herpetology 38:551-561.
- Calhoun, A.J.K., T. Walls, M. McCollough, and S. Stockwell. 2003. Developing conservation strategies for vernal pools: a Maine case study. Wetlands 23:70-81.
- Calhoun, A.J.K., A. Reeve, and M. McGarry. 2003. Wetland connections: linking University research initiatives to high school science education. J. of Geoscience Education.
- Lichko, L. and A.J.K. Calhoun. 2003. An Assessment of vernal pool creation attempts in New England: A Review of project documentation from 1991-2000. Environmental Management 32: 141-151.
- Baldwin, R. and A.J.K. Calhoun. 2002 . Differential predation on ambystomatid egg masses by Rana sylvatica. Herpetological Reviews 33:44-45.
- Calhoun, A .J. K. and M. L. Hunter. 2003. Managing ecosystems for amphibian populations. Pages 228-241 in R. D. Semlitsch (ed). Amphibian Conservation. Smithsonian Institution Press, Washington, D.C.
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Progress 10/01/05 to 09/30/06
Outputs
Work with 7 graduate students on the role of vernal pools and/or forested wetlands in supporting ecosystem processes in both upland and wetland settings has culminated in 11 publications for 2006 and 2007 including an edited book on Science and conservation of vernal pools in northeastern North America. Significant findings of this body of work are that so-called isolated wetlands are linked to terrestrial ecosystems and conservation of wetland dependent biota must be effected at landscape scales. In turn, isolated wetlands contribute biomass and biogeochemical support/functions to terrestrial systems. Resource managers must rethink conservation strategies to evaluate ecosysystem functions at broader scales and must include stakeholders at all levels in conservation planning.
Impacts
Our studies provides guidance for resource managers conserving wetland dependent biota in hydrologically isolated wetlands. We conclude that conservation planning for pool-breeding amphibians and other wetland biota should place special emphasis on evaluating both terrestrial and wetland habitat and can best be accomplished through the efforts of local officials (including citizen groups. The tenure of wetland-specific regulation without regard to the integration of upland and wetland functions is over and needs to be replaced with a landscape approach to conservation of ecosystem processes
Publications
- Patrick, D., A.J.K. Calhoun, M. L. Hunter, Jr. 2006. The orientation of juvenile wood frogs, Rana sylvatica, leaving experimental ponds. In Press. Journal of Herpetology.
- Patrick, D., M.L. Hunter, and A.J.K. Calhoun. 2006. Effects of experimental forestry treatments on a Maine Amphibian Community. Forest Ecology and Management.
- Baldwin, R.F., A.J.K. Calhoun, and P.G. deMaynadier. 2006. The significance of hydroperiod and stand maturity for pool-breeding amphibians in forested landscapes. Canadian Journal of Zoology.
- Calhoun, A.J.K. and P.G. deMaynadier. 2007. Science and conservation of vernal pools in northeastern North America. CRC Press.
- Calhoun, A. J. K. 2007. Principles for conserving wetlands in the context of landscape management. In: Hobbs, R. and D. B. Lindemayer (eds.) Managing and designing landscapes for conservation: moving from perspectives to principles.
- Calhoun, A.J. K. and P. Reilly. 2007. Conserving vernal pool habitat through community based conservation. In: Calhoun, A. J. K. and P.G. deMaynadier (eds). Science and conservation of vernal pools in northeastern North America. CRC Press.
- Windmiller, B. and A.J.K. Calhoun. 2007. Conserving vernal pool wildlife in urbanizing landscapes In: Calhoun, AJK and P.G. deMaynadier (eds). Science and conservation of vernal pools in northeastern North America. CRC Press.
- Oscarson, D. and A.J.K. Calhoun. 2007. Developing vernal pool conservation plans at the local level using citizen scientists. Wetlands.
- Vasconcelos, D. and A.J.K. Calhoun. 2006. Monitoring created seasonal pools for functional success: a six-year case study of amphibian responses, Sears Island, Maine, USA. Wetlands 26:992-1003.
- Cunningham, J., A.J.K. Calhoun, W. E. Glanz. 2006. Patterns of beaver colonization and wetland change in Acadia National Park: Implications for pond-breeding amphibian species distribution. Northeastern Naturalist.
- Baldwin, R., A.J.K. Calhoun, and P.G. deMaynadier. 2006. Conservation planning for amphibian species with complex habitat requirements: a case study using movements and habitat selection of the wood frog (Rana sylvatica). Journal of Herpetology 40:443-454.
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Progress 10/01/04 to 09/30/05
Outputs
We have analyzed results from a two year study on the role of aquatic and surrounding adjacent forested habitat on pool-breeding amphibian breeding and post-breeding success. Effect of Hydroperiod and Forest Characteristics Ongoing loss of seasonal breeding wetlands, combined with fragmentation of adjacent forest habitats, is a major threat to pool-breeding amphibians in North America. Identifying environmental correlates important for breeding success in relatively intact landscapes is a critical first step in planning for the conservation of their populations. Specifically, little is known about how pool-breeding amphibian populations respond to variations in hydroperiod or other local elements of forest structure and composition. We studied these associations for wood frogs (Rana sylvatica) and spotted salamanders (Ambystoma maculatum) in a mostly forested New England landscape (southern Maine, U.S.A.). Egg mass counts across two seasons at 87 seasonal pools were
used to indicate local population size. The influence of aquatic (pool), local (150m) and landscape (500m) scale habitat data was investigated using negative binomial regression, and best approximating models were selected using AICc. Longer hydroperiod seasonal pools (greater than or equal to 18 weeks post-breeding) that were relatively isolated from other breeding wetlands at local (less than 13 neighboring pools within 150m) and landscape scales; (less than19 within 500m) supported larger breeding populations of both wood frogs and spotted salamanders. Additionally, spotted salamander breeding populations were highest in more mature forests. Finally, naturalized, anthropogenic pools supported comparable levels of breeding effort to that of natural pools, highlighting their potential conservation value. Post-breeding habitat needs of wood frogs Conservation of fauna breeding in vernal pools is challenging given their complex life histories. Many pool-breeding amphibian species,
including the wood frog (Rana sylvatica), require both aquatic and terrestrial habitat, yet little information exists about their movements between these environments, nor fine-scale selection patterns within them. To inform conservation planning for such species, we conducted a radio-telemetry study of wood frog movements and habitat selection in southern Maine, USA. Forty-three frogs were tracked an average of 25.6 days each, April to November 2003. In early spring, wood frogs generally selected damp leaf litter retreats on the margins of seasonal forest breeding pools. Following breeding, and throughout the summer, wood frogs selected forested wetlands (9.3% of the landscape) over forested uplands (90.7% of the landscape) in 75.3% of radio locations (N=544). Post-breeding movements from breeding pools to nearby, closed-canopy, forested wetlands ranged from 102-340 m (median 169 m, N=8) and frequently included stopovers in upland forest floor habitat ranging from one to 17 days
(median two days, N=7). Summer forested wetland refugia were characterized by shady, moist (nonaquatic), and sphagnum-dominated microhabitats.
Impacts
Our study provides guidance for resource managers conserving pool-breeding amphibians. We conclude that conservation planning for pool-breeding amphibians should place special emphasis on the protection of longer-hydroperiod seasonal pools in pre-urbanized forested landscapes. Whenever possible, we recommend a shift from a core-habitat conservation model based on uniform radial migration distances, to a locally specific approach that considers pool-breeding amphibian habitat as a network of discrete but migration-connected habitat elements (e.g., breeding pools, upland forest, nearby forested wetlands). In our study, this approach reduced the amount of land requiring protection by 25 to 30% from that of traditional core habitat models. With the rapid assimilation of GIS technology by governmental and environmental organizations, a locally informed, complex spatial planning approach for pool-breeding fauna is increasingly feasible.
Publications
- Calhoun, A.J.K., N. Miller, and M. W. Klemens. 2005. Conservation strategies for pool-breeding amphibians in human-dominated landscapes. Wetlands Ecology and Management 13:291-304.
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Progress 10/01/03 to 09/30/04
Outputs
We conducted a 2-year study to assess the role of aquatic, local forest and landscape in determining breeding population size of wood frogs (Rana sylvatica) and spotted salamanders (Ambystoma maculatum). Egg mass counts at breeding pools were conducted 2002-2003 and used as the dependent variable in negative binomial regression in 30 iterations of spatially independent pools. AICc model selection was used to select best approximating models. Both species bred in greater numbers in longer hydroperiod pools (18-21 weeks post breeding), with wood frogs utilizing intermediate-range hydroperiods (12-18 weeks) more frequently than did spotted salamanders. Adjacent forest conditions were more important for spotted salamanders, with larger breeding aggregations more positively associated with more mature forest. Analyses underway are looking at the role of hydroperiod in determining breeding population sizes and will further examine the role of local and landscape scale
variables when hydroperiod is held constant. These analyses may provide more information on non-breeding habitat variables critical for maintaining breeding populations of wood frogs and spotted salamanders. We conducted an 8-month radiotelemetry study of wood frogs, Rana sylvatica, in southern Maine USA to determine their non-breeding habitat requirements. Forty-three frogs from four separate wetland complexes were tracked post-breeding from April-November, an average of 25.5 days each. Canonical variates analysis was used to examine habitat selection. Prior to leaf out, wetland use was focused on margins of breeding pools in upland settings, and shifted to neighboring forested wetlands (red maple swamps), by mid-summer through overland migrations (60 to 340 m; median 82 m). Connectivity of breeding (vernal pools) and non-breeding wetlands (forested wetlands), and migration and upland overwintering habitat are necessary components of conservation plans for wood frogs. We used gap and
threat analyses to assess risk to pool-breeding amphibian habitat in southern Maine. Delineation from recent 1:12000 CIR photos produced 542 densely distributed vernal pools (1.77 km2; mean 0.07ha), greater than 50 percent of which were not represented on National Wetland Inventory (USFWS) maps. Fine-scale conservation lands assessment revealed that 46 percent of pools received no protection and were below the size threshold (0.04 ha) necessary to trigger minimal regulatory protections. Potential habitat for wood frogs (Rana sylvatica) and spotted salamanders (Ambystoma maculatum) was delineated using pool location and literature-based migration and dispersal estimates, totaling fully 0.9 of the project area. Potential habitat was then modified by a land-use intensity index based on permeability to create a landscape raster (1ha) of actual habitat values. Actual habitat values were then combined with development pressure, and modified by existing land protection levels to produce a
landscape-scale threat analysis. The resulting pool threat ratings of 5.1% (high threat), 44.4% (medium threat) and 50.5% (low threat) should be used by the study towns to inform short and long-term conservation strategies.
Impacts
Results of this research on the effect of terrestrial habitat quality, breeding pool characteristics, and wetland position in the landscape on isolated pool-breeding amphibian populations will be used to inform both amphibian and isolated wetland conservation efforts in the northeastern United States. Our investigation of both wood frogs and ambystomatid salamanders will highlight differences in post-breeding terrestrial habitat use by these animals and help to fine-tune conservation strategies.
Publications
- Vasconcelos, D. and A.J.K. Calhoun. 2004. Movement patterns of adult and juvenile wood frogs (Rana sylvatica) and spotted salamanders (Ambystoma maculatu) in a restored wetland in Maine. Journal of Herpetology In Press.
- Calhoun, A.J.K.,M. W. Klemens, and N. Miller. 2004. Conservation strategies for pool-breeding amphibians in human-dominated landscapes. Wetlands Ecology and Management. In Press.
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Progress 10/01/02 to 09/30/03
Outputs
Findings of this project are still being analyzed. The project includes three major study foci: 1. Egg mass response of spotted salamanders and wood frogs to terrestrial habitat variables 2. Amphibian breeding responses at landscape scales 3. Wood frog post breeding habitat use: behavior and movement study. Below is an account of the status of data collection to date. Data are being analyzed this winter and will be reported next year. 1. Egg mass response of spotted salamanders and wood frogs to terrestrial habitat variables We have completed 2 field seasons of data collection. Egg masses by species were counted in 97 vernal pools 3 times over 2 breeding months in 2002 and in 102 vernal pools 2 times over 2 breeding months in 2003. Forest structure habitat variables have been collected adjacent to each pool by sampling 308 1/20th ha plots at 102 vernal pools. Our data include 13,591 trees (dbh and species) 6,167 pieces of coarse woody debris (width, length, decay
class, species), and 2200 sets of understory measurements (leaf litter depth and composition, density burrow entrances, hemispheric photos, etc. Breeding pool structure (depth, area, vegetation), hydroperiod, and pool gap fraction have all been measured at 102 vernal pools. 2. Amphibian breeding responses at landscape scales Four thousand land use polygons have been created in ArcGIS from CIR 1:12000 air photos for three study towns encompassing the 102 vernal pools. Polygons are coded as to amphibian permeability, a raster file is created showing density of permeability, and land use data has been collected from various organizations using GIS in southern Maine. 3. Wood frog post breeding habitat use: behavior and movement study. Telemetry data has been collected on 44 wood frogs resulting in 543 location descriptions and 2,120 associated use and non-use habitat plots. Animals were tracked from April 16-November 6, 2003. Expected publications that will result from analysis of this
work include: Wood frog (Rana sylvatica) post-breeding behavior: interwetland movements, seasonal microhabitat selection and importance of red maple (Acer rubrum) swamps. Local and landscape associations of wood frog (Rana sylvatica) and spotted salamander (Ambystoma maculatum) with breeding densities: pool and forest structure, landscape fragmentation, and land use. Conservation gap analysis for small-scale conservation: using a developable lands inventory to predict future wetland and land use conflicts for wood frog (Rana sylvatica) conservation.
Impacts
Results of this research on the effect of terrestrial habitat quality, breeding pool characteristics, and wetland position in the landscape on isolated pool-breeding amphibian populations will be used to inform both amphibian and isolated wetland conservation efforts in the northeastern United States. Our investigation of both wood frogs and ambystomatid salamanders will highlight differences in post-breeding terrestrial habitat use by these animals and help to fine-tune conservation strategies.
Publications
- Calhoun, A.J.K., A. Reeve, and M. McGarry. 2003. Wetland connections: linking University research initiatives to high school science education. J. of Geoscience Education 51:387-397.
- Lichko, L. and A.J.K. Calhoun. 2003. An assessment of vernal pool creation attempts in New England: A Review of project documentation from 1991-2000. Environmental Management 32: 141-151.
- Baldwin, R. and A.J.K. Calhoun. 2002 . Differential predation on ambystomatid egg masses by Rana sylvatica. Herpetological Reviews 33:44-45.
- Calhoun, A. J. K. and P. deMaynadier. 2003. Forestry habitat management guidelines for vernal pool wildlife in Maine. Maine Department of Inland Fisheries and Wildlife. Wildlife Conservation Society Technical Paper #6 Rye, New York.
- Calhoun, A.J.K. and M. W. Klemens. 2002. Best development practices for pool-breeding amphibians in commercial and residential developments. Wildlife Conservation Society Technical Paper #5. Rye, New York.
- Calhoun, A .J. K. and M. L. Hunter. 2003. Managing ecosystems for amphibian populations. Pages 228-241 in R. D. Semlitsch (ed). Amphibian Conservation. Smithsonian Institution Press, Washington, D.C.
- Calhoun, A.J.K., T. Walls, M. McCollough, and S. Stockwell. 2003. Developing conservation strategies for vernal pools: a Maine case study. Wetlands 23:70-81.
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