Developing an Incubator of Ideas
Public Outreach and Field Research Activities at Wachusett Mountain State Reservation
On April 30, 2007 the Friends of Wachusett Mountain received some great news from the University of Massachusetts at Lowell:
"We are pleased to notify you that your proposal entitled Public Outreach and Field Research Activities at Wachusett Mountain State Reservation: Developing an Incubator of Ideas has been approved, and you will receive $10,000 from the Joseph P. Healey and Public Service Endowment Grant fund."
The grant applicants/recipients are Brian Bettencourt, Ph.D., Principal Investigator and Scott Smyers, M.S., Field Coordinator. Brian Bettencourt is an Assistant Professor of Biology at UMass Lowell and Scott Smyers is a Field Biologist at Oxbow Associates, Inc. and the President of the Friends of Wachusett Mountain.
Many of our supplies have already begun to arrive including nets, waders, insect collecting supplies, field guides and scientific reference books to get the fieldwork off and running. Furthermore, we have even begun working with a corps group of students as well as teachers, instructors, and professors from surrounding schools to participate in some of our preliminary projects. We are looking for more dedicated, self-motivated volunteers to help with several specific projects soon and in the future. Or if you are someone who has an expertise and/or knows the mountain and would like to volunteer to train volunteers, we could use your help too.
Introduction and Significance
(excerpt from the proposal)
Figure 1. Adult Ambystoma maculatum.
Photograph by Scott Smyers.
We propose to utilize the Healey Public Service Grant to extend the scope of an existing field research site at Wachusett Mountain State Reservation (WMSR), to strengthen links between the public, private sector, and UML community. The proposed research will incorporate a mix of University resources, public volunteers, and organized students into a long-term ecological field station. Funding will provide research supplies, biological and environmental education, and volunteer and student research opportunities focused on the interplay of environment, ecology, and population genetics. Our previous and ongoing research involves WMSR populations of the spotted salamander, Ambystoma maculatum (Figure 1); this project has engaged UML students in both the field and the lab. Here we propose to extend this research to additional species whose population ecology may be shaped by Wachusett's unique environment. In the coming year, we propose to establish baseline long-term sampling stations and protocols in several basic monitoring areas. This work will involve a team of students from high schools in the WMSR region, led by their AP science teacher Fred Hohn (see attached letter of support). The laboratory of Brian Bettencourt, PI, at UML will serve as home for molecular biological investigations by UML and high school students. Both sets of activities -- field and laboratory -- will be coordinated by Scott Smyers (Oxbow Associates Inc.), a field biologist and UML alumnus actively involved in research at WMSR.
Preliminary Work - Field:
Figure 2. Salamander bone growth rings (lines)
examined in skeletochronological analysis.
Beginning in 2001, Scott Smyers and volunteer collaborators collected body size data on male spotted salamanders from five breeding populations at WMSR, along with 20 sites across Massachusetts and Rhode Island. These populations inhabit a diverse set of habitats and include three island populations (Martha's Vineyard, Naushon, and Prudence Island, RI). Salamander body length and mass were measured, and non-lethal tissue samples from regenerative tissues such as toes or tails were obtained for genetic and skeletochronological analysis (see Figure 2). Body size varies significantly among the populations, with most populations averaging 12-15 grams/individual. Strikingly, salamanders from the summit of Wachusett Mountain are the largest, averaging 18.3 grams/individual. In contrast, a population in Milford averages 10.5 grams/individual. Why are the Wachusett salamanders so large? Candidate non-mutually exclusive explanations include the effects of Wachusett's environment, the input of genetics, or both.
We analyzed salamander bone growth rings to estimate ages of individuals from a subset of our study sites, including extremes of the body size spectrum. These data indicate that salamanders from Wachusett delay maturity, live longer, and grow at a steady rate through their lives. In contrast, Milford salamanders mature early and slow their growth soon after maturity. Next we investigated differences in the aquatic environment, where eggs and larvae develop, and the terrestrial (underground) habitat where juveniles and adults spend over 95% of their lives. Sizes of late stage larvae at two ponds located at the summit were significantly different, likely due to the fact that one pond is shallow and dries every year, while the other is deep and never dries. The deep pond contained larger larvae than did the shallow pond; however, the adults that breed in each pond are equivalent in body size. Therefore, it is unlikely that larval development and subsequent size at metamorphosis influences adult body size. In the terrestrial habitat, we investigated soil conditions during a normal dry period of summer 2005. Soil in the summit forest of Wachusett Mountain was significantly more saturated and contained more topsoil compared to similar soils in Milford. Therefore, we hypothesize the salamander populations have developed alternative life history strategies to adapt to their corresponding habitat conditions. Milford populations may maximize fitness by maturing early, to respond to summer stress imposed by limited organic topsoil and moisture. Conversely, the moist, rich soil at Wachusett Mountain provides a more predictable and less stressful habitat; accordingly, individuals can allocate more energy to growth than reproduction. In the proposed research, we will collect additional field data and design a series of laboratory and field experiments to test these environmental hypotheses. Furthermore, we propose to build upon our preliminary molecular genetic analyses (below) to determine if any of the salamanders' varying life-history and body-size traits are associated with population or lineage-specific genetic structure.
Preliminary Work - Laboratory:
Proving local adaptation of the Wachusett salamanders requires demonstration that the summit individuals are genetically distinct from lowland individuals. Such demonstration would provide evidence that the observed phenotypic variation is due to genetics.
Veronica Conant, a UML undergraduate in the Bettencourt lab, developed an assay to measure mitochondrial DNA variability in individual salamanders. Her work is currently being supported by a UML Faculty-Student collaborative research grant. Mitochondrial DNA is ideal for measuring fine-scale variation within and between populations, because of its high mutation rate and maternal inheritance. Recently, K. Zamudio (Cornell Univ.) found that populations of A. maculatum in New England are highly divergent in the sequences of the "ND4" mitochondrial gene (Evolution 57:1631–1652, Mol Ecol. 16:257–274). Veronica researched these studies, quickly mastered the basics of bench molecular biology in the lab, and has now successfully extracted mitochondrial DNA from multiple salamander tissue samples provided by Scott. She has successfully amplified the ND4 gene from numerous samples using the Polymerase Chain Reaction, and quickly determined that a common sequence variation causes a Restriction Fragment Length Polymorphisim (RFLP). Basically, the presence or absence of a particular basepair in the sequence causes a restriction enzyme (AvaII) to be able to cut the sequence or not. Veronica has also demonstrated that she can discriminate the two alleles, based on whether they are cut by the restriction enzyme, via gel electrophoresis (Figure 3). Individual salamanders are thus differentiated by whether their ND4 gene displays two bands or one in the gel.
Figure 3. Representative gel image of RFLP genotyping.
Lane 6: DNA size Markers. Lanes 3, 5 and 8: "cut" alleles.
All other lanes: "uncut" alleles.
Veronica's initial results look promising (Figure 3). She has processed 142 samples completely (including 49 from the summit populations and the remainder from nearby populations). Her latest data indicate that the "cut" allele is found in 21% of summit salamanders, but approximately 80% in lowland populations. However, in an interesting twist, the cut allele is found at only 4% frequency in a salamander population from a nearby (non-summit) pond in WMSR. Clearly, there are strong differences in mitochondrial allele frequencies among local populations. Our plan (below) is to further refine the technique, increase sample sizes, and develop assays of nuclear genes, to refine our characterization of these populations' genetic structures.
Both sets of preliminary experiments establish the strong likelihood that Wachusett Mountain imposes unique conditions upon its animal inhabitants, and that further research on the environmental and genetic components of local adaptation will likely be fruitful. This work has already fostered collaborations between UML faculty, students, and a researcher in the private sector. To continue this research and expand its potential, we propose to utilize teams of local high school students, educators, and other volunteers organized by the Friends of Wachusett Mountain (see below). This extension will have the added benefit of establishing environmental biology initiatives that will demonstrate the potential of WMSR as a site for collaborative science education. WMSR is a vastly underutilized resource: The mountain attracts over 800,000 visitors per year, contains large tracts of old growth forest and other unique environmental features, and possesses numerous locally adapted plant and animal populations, yet the opportunity for environmental education in conjunction with collecting important scientific data remains almost completely unutilized. By expanding our study of salamander populations, involving the public in field and laboratory studies, and investigating long-term environmental trends on the mountain, we seek to establish this valuable state resource as a site for increasing future endeavors and UML involvement.
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