Amphibian Ecology and Conservation WFS 433/533 Spring Semester 2017 University of Tennessee-Knoxville

 

Instructor:                          Dr. Matthew J. Gray (mgray11@utk.edu), Dr. Patrick Cusaac (jcusaac@utk.edu), and Todd Pierson (tpierso1@vols.utk.edu) 

 

Phone:                                    974-2740

Office:                                    247 Ellington Plant Sciences Building (MG), 201 Ellington PSB (PC), and 435 Hesler (TP)

Meeting Time and Place:      3:40–4:55 pm  T,R      160 PBB (2 field trips required: 1 April and 21 April)

 

Course Goal:              To expose students to the life history, diversity, ecology, conservation, and management of amphibians through a combination of lectures, readings, class discussions, labs, and field experiences.

 

Expected Outcomes:             Students that successfully complete WFS 433/533 will have a basic understanding of amphibian identification (larvae and adults), physiology, life history, and ecology.  They will be aware of potential mechanisms of amphibian declines, understand how to sample amphibians, and be aware of conservation strategies.  

 

Required Text #1:     The Ecology and Behavior of Amphibians, 2007 (ISBN 9780226893341).  Available online via the UT Library. 

Author:                      Kentwood D. Wells

 

Required Text #2:     The Amphibians of Tennessee, 2011 (ISBN 1572337621)

 

Editors:                      Matthew Niemiller and R. Graham Reynolds

 

Journal Papers:         Occasionally journal papers will be assigned instead of or to supplement the required text.  Papers will be provided in class or on the course website.

 

 

Academic Assessment:

 

Weights of Academic Assessments:

WFS 433				WFS 533
· Test #1	20%			· Test #1	20%
· Test #2	20%			· Test #2	20%
· Test #3	20%			· Test #3	20%
· Amphibian ID Exam	15%			· Amphibian ID Exam	10%
· Mini-Presentation1	15%			· Lecture2	20%
· Participation3,4	10%			· Participation3,4	10%

¹Mini-presentations will be 13-15 minute persuasive presentations attempting to convince the audience of a specific cause of amphibian declines. Two minutes will be allowed following presentations for questions. The class will vote on the top 3 presentations, and the winners will receive a gift certificate to Gander Mountain.

²Graduate student lectures will be 28-35 minute presentations on an approved amphibian ecology topic. Topics must be approved by 7 February.

³Participation includes attendance during two field trips and the guest lecture by Dr. Mike Lannoo on 28 March. You will earn 4% for attending each field trip, and 2% for Dr. Lannoo’s lecture.  

⁴If you miss a field trip, you can either: (1) attend the Southeast PARC meeting (1 day), (2) write a 10-page scientific paper on an amphibian topic of your choice, or (3) accept the 4% deduction in your final grade.

   

Your course grade will be determined using the following scale:

 

Grade	Final Weighted Percent		Grade	Final Weighted Percent
A	90–100%		C	70–76%
B+	87–89%		D	60–69%
B	80–86%		F	<60%
C+	77–79%

 

Extra Credit:            

 

You can positively influence your grade as much as 4.5% by volunteering for extra credit. Volunteer work must be related to herpetofauna, and can include work on university projects, with government agencies, or NGOs. For every 8 hours of volunteer work, your final grade will be increased by 1.5% up to 4.5% (24 hours total). All volunteering must be completed by 9 May 2017. A volunteer form (see below) must be filled out by the supervising individual. Scott Dykes (scott.dykes@tn.gov), Chris Ogle (Chris.S.Ogle@tn.gov), and Chris Simpson (Chris.Simpson@tn.gov) with TWRA are often looking for volunteer assistance. You also may participate in TAMP surveys (organized by the UT Student Chapter of The Wildlife Society).

 

Extra Credit Form

 

Extra credit can be earned by attending the Annual Meeting of the Southeast Partners in Amphibian and Reptile Conservation (http://separc.org/meetings/). The meeting is 16 – 19 February at Ferncliff Camp and Conference Center in Little Rock, Arkansas. Your final grade will be increased by 4.5% for attending the meeting from 17 – 18 February. Transportation will be provided. If interested, you need to sign up by 2 February. Registration ($60 for students) is required. Group (bunk) housing is available for $20/night or $80/night for a hotel room.  

 

 

Full Syllabus

 

Teaching Resources:

Handouts

Required Tennessee Anurans

Required Tennessee Salamanders

Anuran Sonograms

Key to Tennessee Salamanders

Practice Exam – TN Amphibian Identification (ignore tadpole questions)

Bob English Lectures (#11 - #14): https://itunes.apple.com/us/itunes-u/id1144479771  

 

Required Readings:

Students who have not taken a General Ecology course (e.g., BIO 260, FOR 215) should read: http://fwf.ag.utk.edu/mgray/wfs493/EcologyReadings.pdf .  (A copy of Molles is available for check out in 201 PSB).

 

TEST #1 Material

 

1)      Amphibian Evolution

Required Readings:

a.       What general physiological characteristics are shared by amphibians? How does amphibian diversity compare to that of other vertebrates?

Wells: pp. 1-3

b.       What characteristic of amphibians prevents them from living in saltwater?

Wells: pp. 2-3

c.      What does it mean for Lissamphibia to be ‘monophyletic’? What are some derived morphological characters that unite Lissamphibia? What would it mean for Lissamphibia to be polyphyletic?

Wells: pp. 9-11

d.      Describe one broad evolutionary trend found in modern amphibians.

2)      Amphibian Diversity

3)  Amphibian Anatomy and Physiology 

 

Required Readings:

For the Duellman and Trueb, please see: (a) amphibian integument

1. What are the two types of glands in amphibian skin? What are these glands responsible for producing? Duellman and Trueb 369-371.

2. What are three types of color producing structures in amphibian skin? Duellman and Trueb 374-377.

3. What anatomical adaptations have frogs evolved for locomotion? How are the movements of anurans different from caudates? Wells 46-48

4. What behavioral and anatomical adaptations have anurans evolved for a subterranean lifestyle? Please describe the anatomical and behavioral differences between “hind-feet” and “head-first” burrowing. Wells 48-49.

5. Know the anatomical adaptations frogs and salamanders have evolved for arboreal lifestyles. What epidermal features of a toe-pad permit a treefrog to adhere to a substrate? Wells 49-51 and 65-67.

6. What are the primary anatomical differences between the feedings mechanisms of anurans and caudates? Wells 52-56 and Wells 70-73.

7. How can amphibians maintain the temperature required for their metabolic functions without active basking (as seen in reptiles). Wells 137-140.

Supplemental Reading: Duellman and Trueb (b) organ systems.

 

4)  Amphibian Immunology

Supplemental Reading:  Robert and Ohta (2009). **Be able to answer the questions below either from the reading or lecture material**

 

1.      Describe differences in immune response between larvae and adult amphibians.     

2.      Explain the role of glucocorticoids in immune response and stress. 

 

TEST #2 Material

 

5)  Salamander Courtship

 

Required Readings:

a.         Know the median home range for anurans and salamanders, and how they compare with birds and mammals.

Wells: pp: 230-231

b.        Know the 4 ways that salamanders communicate, and be able to describe their primary function(s). 

Wells: pp. 404-411

c.         Know the 3 locations of chemical receptors in salamanders, and the 2 chemosensory organs in the nasal cavity.  Also, know which sex the chemosensory organs are usually larger and why this may occur.

Wells: pp. 417-418

d.        In the work performed by Robert Jaeger and Alicia Mathis on red-backed salamander territoriality, know the most important determinant of territory quality.  

Wells: pp. 424-425

e.         Be able to describe the adaptive significance of internal fertilization via a spermatophore, and the difference between the duration that sperm survive in the spermatheca in ambystomatids vs plethodontids. 

Wells: pp. 459-461

f.         Understand the relationships between female body size and clutch size, female body size and egg size, egg size and clutch size, egg size and hatchling size, egg size and development rate, and developmental rate and temperature.

Wells: pp. 497-500

g.        Be able to describe selective advantages of species that produce small vs. large eggs, and the environmental constraints that may drive these relationships. 

Wells: pp: 502-504

h.        Know which mode of development has species that produce the largest eggs relative to body size.

Wells: p: 504

 

Supplemental Readings

Wells: pp. 254-266 (orienteering)

Wells: pp. 452-461 (external vs. internal fertilization)

Organ (1958)

 

 

6)  Anuran Courtship

                                

Required Readings:

a.       Understand the difference between home range, migration and dispersal.

Wells: pp. 230-231

b.      Know which age class disperses most frequently in an amphibian population.

Wells: pp. 243-244

c.       Be able to provide some hypotheses for the adaptive significance of homing (i.e., site fidelity). 

Wells: p. 253

d.      Know the principal site of extraocular photoreception and how amphibians use polarized light to orienteer.

Wells: pp. 261-264

e.       Be able to describe the 2 auditory channels in amphibians, and know which is sensitive to low frequencies (<300 Hz). 

Wells: pp. 322-324

f.       Be able to provide a couple examples of anurans that do not have vocal sacs, and an explanation of why this may have occurred.

Wells: p. 277

g.       Be able to describe unison bout calling and be able to provide some explanations why it may occur.

Wells: p. 297

h.      Schwartz (1991) proposed 3 hypotheses for the duration of unison bouts.  Be able to describe those and know which is most plausible.

Wells: p. 297

i.        Understand the difference between explosive vs. prolonged breeders, and be able to provide some reasons why cold-weather breeders and species that inhabit xeric environments may breed explosively.

Wells: pp. 339-341

j.        Understand factors that influence sexual selection in prolonged vs. explosive breeding systems.  Also, understand how energy allocation differs between prolonged and explosive breeders, and a few strategies that prolonged breeders may use to reduce energy spent on calling.

Wells: pp. 342-343

k.      Be able to provide at least 2 explanations why inguinal amplexus is considered more primitive than axillary amplexus.

Wells: pp. 454-456

 

Supplemental Readings

Wells: pp. 269-304, 314-316 (anuran calls)

                                    : Types of Anuran Calls: MP3 file from The Calls of Frogs and Toads by Lang Elliot (Stackpole Books)

 

7)      Parental Care

 

Required Readings: Wells (2007): Chapter 11, Kupfer et al. (2006)

1. What are the major types of parental care among anurans and which is considered to be the most common form? Wells, p. 517
2. In what ways have Anurans evolved to carry eggs on their bodies? Wells, p. 526-530
3. How do members of the genus Leptodactylus communicate with their tadpoles? Wells, p. 530
4. Which sex of the family Sooglossidae provides the parental duties? Wells, p 531-532
5. What is considered the most unusual form of parental care among Anurans? Wells, p. 536
6. How does parental care in Urodeles compare to parental care among Anurans? Wells, p. 540
7. What is an important consequence of salamanders that leave eggs too early? Wells, p. 541
8. What are the potential benefits of parental care that have been proposed? Which is considered to be the most reasonable benefit? Wells, p. 543
9. What are the costs associated with parental care? Wells p. 547
10. What unique form of parental care is exhibited in the caecilian species Boulengerula taitanus? Kupfer et al. (2006), p. 926
11. What is the cost to the mother using this particular form of parental care? Kupfer et al. (2006), p. 927

 

8)      Tadpole Ecology

 

Required Readings:

            What do tadpoles eat?  Altig et al. (2007)

            Wells:

a.       Understand how limb development is different between larval salamanders and tadpoles.

Wells: p. 559

b.      Be able to describe a few oral adaptations of larval salamanders that assist in suction feeding.

Wells: pp: 561-562

c.       Know whether salamander larvae are herbivorous, omnivorous or carnivorous.

Wells: p. 562

d.      Be able to explain some of the costs and benefits of cannibalism for larval salamanders.  What are some explanations for cannibalizing different species?

Wells: pp. 563-564

e.       Be able to provide some examples of tadpole species that delay lung development and why this may occur.

Wells: pp. 565

f.       Be able to provide some explanations why the limbs of tadpoles emerge late in development compared to salamanders.

Wells: pp. 565-566

g.      Understand the mechanism that induces carnivory in spadefoots found in the southwestern United States.  Also, understand how frequency of cannibalistic and omnivorous phenotypes differs between spadefoot species (S. bombifrons and S. multiplicata) and why this may occur. 

Wells: pp. 575-576

h.      Although most amphibian larvae are solitary, be able to provide some benefits of aggregation behavior and what may be the adaptive significance of each benefit. 

Wells: pp. 588-590

i.        Be able to describe the “selfish herd” effect and provide an example.

Wells: p. 589

j.        Be able to describe kin recognition and offer some explanations why this may be advantageous.

Wells: pp. 591, 593-596

k.      Be able to explain the factors that drive a larval amphibian to decide when to initiate metamorphosis according to Werner (1986, 1988) and Rowe and Ludwig (1986, 1988).  NOTE:  Your explanation should discuss differential mortality and growth rates in the aquatic and terrestrial environments and the amount of time between metamorphosis and the age of first reproduction.

Wells: pp. 601-602

l.        Know what hormone likely is responsible for initiating metamorphosis in response to an environmental stressor.

Wells: p. 608

Supplemental Readings

            Walsh et al. 2008: Plasticity and Metamorphosis

Petranka and Kennedy 1999: Tadpoles: Macrophagous Predators

                                    Wells: pp. 564-566, 604-608

 

9)      Graduate Student Topics: Predators and Ecosystem Services

 

Required Readings:  Predators

 

1. Name and discuss two types of coloration adaptations that larval and adult amphibians possess to avoid predation. (Wells 698, 709-715)
2. What are the trade-offs associated with larval chemical defenses? (Wells 708-709)
3. Explain the adult behavioral responses that amphibians have as a response to avoid predation. What is the unken reflex? (Wells 715-719)
4. How do amphibians use chemical cues to avoid predation? (Wells 706-708)
5. Why are chemical defenses an important evolutionary response to predation? Why aren’t chemical defenses found in all amphibians? (Wells 719-721)
6. What is aposematic coloration? Why is it advantageous? How does it relate to mimicry? Discern the differences in Batesian and Mullerian mimicry. (Wells 721-727)
7. How does predation affect larval growth rates? (Wells 708)
8. What is a trophic loop? (Wells 655)
9. Discuss the tradeoffs associated with larval behavior in response to predation. (Wells 702-706)
10. What predator defenses are associated with reproduction timing and oviposition? (Wells 694-697)

Supplemental reading:
 

Chivers, D. P., Kiesecker, J. M., Marco, A., Devito, J., Anderson, M. T., and Blaustein, A. R. 2001. Predator‐induced life history changes in amphibians: egg predation induces hatching. Oikos, 92: 135-142.
 

Required Readings: Importance of Amphibians

Wells- pg. 850-853
1. What tradeoffs might be associated with amphibian conservation efforts? Why might you need to argue that amphibians are an important part of the ecosystem? Pg. 850
2. Give two reasons why it might be difficult to estimate ecosystem services provided by amphibians that directly benefit humans. Pg. 851
3. Why are amphibians “efficient at converting food into biomass”? How might this ability be beneficial in an ecosystem? Pg. 851
4. Of the potential predators of amphibians, which group would most likely be effected by their absence in an ecosystem? Pg. 851
 

Hocking, D. J., and K. J. Babbitt. 2014. “Amphibian Contributions to Ecosystem Services”. Herpetological Conservation and Biology 9:1-17
 

1. Hocking and Babbitt describe four categories that ecosystem services can be divided. What are they? Pg.1
2. Give one example of amphibians fulfilling each of the ecosystem service categories described in the article. Pg.2-6
3. Describe one area of research Hocking and Babbitt believe is underexplored? Pg 9-10
 

     10)      Phenotypic Plasticity

 

Required Readings: 

 

TEST #3 Material

 

 

11)      Amphibian Declines

Required Readings:

a.       What makes amphibians especially vulnerable to declines?

Wells: pp. 787-792

b.      What are some species in North America with relic populations?

Wells: pp: 793-794

c.       What is the region of the United States with the greatest number of species declining?  Also, be able to list a few species with distributions east of the Mississippi that are declining.

Wells: pp: 800-803

d.      Know which island in the South Pacific likely has the highest diversity of amphibian species per unit area in the world.

Wells: p. 795

e.       Be able to provide an argument for why we should care that amphibians are declining.

Wells: pp. 850-853

Supplemental Readings

Wells: pp. 816-850 (hypotheses for declines)

                       

12)      Amphibian Physiological Ecology

Required Readings: (Wells)

p. 82 – 89: Understanding how water availability influences amphibian habitat use and the underlying physiology behind water regulation.
p. 104 – 110 (stop at physiology of dessication tolerance): Understand the behavioral and physiological adaptations to regulating water uptake and storage.
p. 122 – 124: Introduction to post-metamorphic thermoregulation
p. 128 – 136: Ecological aspects of thermoregulation, including acclimation, latitudinal and altitudinal correlates, and circannual aspects of ecology.
p. 157 – 168: Introduction to terrestrial amphibian respiration
p. 173 – 174: Respiration in larval amphibians
 

Supplemental Readings

                    Shoemaker V, Nagy KA. 1977. Osmoregulation in amphibians and reptiles. Ann Rev Physiol 39(1):449-71.

 

13)      Biotic Stressors

Required Readings: (Wells)

      p.107-111: What are the hormones associated with water conservation in anurans and how do they affect water storage and reuptake from the bladder? Also, what are the consequences of approaching the limits of desiccation tolerance?
p.127-128: How does temperature affect locomotion in amphibians?
p.741-753: What are the drivers of competition in terrestrial salamanders, and what are the resulting ecological implications?
p.764-775: What are the inter and intra-specific interactions of anuran larvae, and how do these interactions affect larval ecology?

Supplemental Readings

Blaustein AR, Han BA, Relyea RA, Johnson PT, Buck JC, Gervasi SS, Kats LB. 2011. The complexity of amphibian population declines: understanding the role of cofactors in driving amphibian losses. Ann NY Acad Sci 1223(1):108-19

 

14)      Abiotic Stressors

Required Readings: Sih et al. (2004)

a.       What are the implications for multiple stressors synergizing to affect amphibians?”

Supplemental Readings

15)      Sampling Techniques

 

Required Readings:

           Marsh and Haywood (2010): Area based surveys

Wilson and Gibbons (2010): Drift fences, coverboards, and other traps

Skelly and Richardson (2010): Larval Sampling

 

a.       Know the difference between passive and active sampling methods and be able to provide an example of each.  Willson and Gibbons: pp. 230 – 241

b.      Be able to identify factors that a researcher must consider when determining “the best” trap type to use to sample amphibians.  Willson and Gibbons: p. 232

c.       What are the 3 main factors that are critical for interpreting data on amphibian capture rates using passive sampling methods?  Willson and Gibbon: p. 235

d.      What are some of the advantages and disadvantages of passive vs. active sampling methods for amphibians in terms of types and numbers of species captured, intensity of monitoring, and mortality threats?  Willson and Gibbons: pp. 234 – 240

e.       What are the median dimensions for plot/quadrat surveys and transect surveys for sampling amphibians?  Marsh and Haywood: p.249

f.       Be able to provide examples of some of the common uses/methods of area-based surveys for sampling amphibians and the main taxonomic groups they are associated with.  Marsh and Haywood: pp. 249 – 252

g.      What are the 3 main assumptions associated with drawing inferences from data collected during area-based surveys?  Marsh and Haywood: pp. 259 – 260

h.      Why is timing (e.g., breeding phenology, larval development) a critical factor in determining larval sampling efforts?  Skelly and Richardson: p.57

i.        What are some of the difficulties when using marking techniques for larval amphibians and what method is most recommended in terms of ease of marking and longevity of marks by the authors?  Skelly and Richardson: pp. 65 – 66

 

Miller and Gray (2009): SE PARC Disinfection Information Sheet #10 (know disinfectant concentrations)

 

 Supplemental Readings:

a.       Gray et al. 2013: Wetland Wildlife Monitoring and Assessment (section 7.3.1)

b.   PARC Inventory and Monitoring Guide (Graeter et al. 2013)

c.      Larval Sampling Data Sheet

 

15)      Amphibian Diseases 

Required Readings: available at http://separc.org/products/#/diseases-herpetofauna/

                                    a.    Ranaviruses (Information Sheet #1)

                                    b.    Batrachochytrium dendrobatidis (Information Sheet #2)

                                    c.    Batrachochytrium salamandrivorans (Information Sheet #18 -- listed as #20)

 

Supplemental Readings:

           

                                    a.    Ranaviruses:  http://link.springer.com/book/10.1007/978-3-319-13755-1

                                    b.    Batrachochytrium dendrobatidis: Voyles et al. (2011)

                                    c.    Batrachochytrium dendrobatidis vs Batrachochytrium salamandrivorans: Van Rooij et al. (2015)

Podcasts: (MP4 Format unless noted otherwise)

1.      iTunes Instructions: (NOTE: it is best to watch videos using iTunes)

1)      Go to: http://www.apple.com/itunes/download

2)      Download Software

2.      Link to iTunes to Listen to Podcasts:  Launch Podcasts in iTunes U 

Slides: (PDF Format)

Lectures:  ID Exam

“Tennessee Anuran Identification”     (Matt Gray, UTK)

“Tennessee Salamander Identification” (Guest: Dr. Bill Sutton, Tennessee State University)

Lectures:  Test 1

                  “Amphibian Evolution and Systematics” (Todd Pierson, UTK)

                  “Anuran Evolution and Diversity” (Todd Pierson, UTK)

                  “Salamander Evolution and Diversity” (Todd Pierson, UTK)

                  “Amphibian Physiology and Development” (Guest: Dr. Kate McCusker, UMass-Boston)

                  “Amphibian Immunology” (Guest: Dr. Leon Grayfer, George Washington University)

Lectures:  Test 2

               “Salamander Courtship” (Guest: Dr. Kevin Hamed, VHCC)

               “Anuran Courtship” (Matt Gray, UTK-- Podcast)

               “Amphibian Parental Care” (Todd Pierson, UTK)

               “Tadpole Ecology” (Matt Gray, UTK)               

“Hibernation and Estivation”  (Guest: Emily Hockman, UTK-- MP3 Podcast)

 “Phenotypic Plasticity” (Guest: Dr. Jason Hoverman, Purdue)

WFS 533 Lectures: Test 2

1)     Davis Carter

2)  Katie Harris

 

Lectures:  Test 3

“Global Amphibian Declines” (Guest: Dr. Dede Olson, USFS)

“Amphibian Physiological Ecology” (Patrick Cusaac, UTK)

“Habitat Management and Restoration” (Guest: Dr. Mike Lannoo, Indiana University)

“Biotic Stressors” (Patrick Cusaac, UTK)

“Abiotic Stresssors” (Patrick Cusaac, UTK)

“Amphibian Sampling I”  (Guest: Gabrielle Graeter, NCWRC and PARC)

“Amphibian Sampling II”  (Todd Pierson, UTK  -- MP3 Podcast)

“Amphibian Diseases” (Matt Gray, UTK)

“Amphibian Conservation Strategies: Zoos" (Guest: Dr. Joe Mendelson, Zoo Atlanta)

Undergraduate Presentations: Test 3 (Possible Factors Associated with Die-offs and Declines)

(1)    Group 1

(2)    Group 2

(3)    Group 3

(4)    Group 4

(5)    Group 5

(6)    Group 6

(7)    Group 7  

(8)    Group 8

(9)    Group 9   

(10)   Group 10  

(11)     Group 11 

(12)     Group 12  

 

Videos:

1. Salamander Courtship (Jim Organ, 1957): https://www.youtube.com/watch?v=J-c8CtIgTVk

 

Websites:

TWRA Amphibian Identification:      https://www.tn.gov/twra/article/frogs-of-tennessee (frogs) and https://www.tn.gov/twra/article/salamanders-of-tennessee (salamanders) 

LEAPS Anuran Identification:                       http://www.leaps.ms/Tn.%20Frogs%20ID%20Page.htm

 

Dr. Matt Niemiller's TN Amphibian and Reptile ID site: http://www.herpetology.us/tnherps/ 

 

Dr. Matt Niemiller's Key to TN Salamanders: http://fwf.ag.utk.edu/mgray/wfs493/salamanderkey.pdf

 

Frogs and Toads of Georgia:                 http://wwknapp.home.mindspring.com/GAFrog.Toad.html

 

Amphibians of the Great Smoky Mountain National Park:            http://www.nps.gov/grsm/naturescience/amphibians.htm

 

Larvae Identification:            https://www.pwrc.usgs.gov/tadpole/  and http://fwf.ag.utk.edu/mgray/wfs493/HovermanLarvaeID.pdf

 

PARC Habitat Management Guidelines: http://www.parcplace.org/parcplace/publications/habitat-management-guidelines.html

 

Previous WFS 433/533 Websites

Spring 2015:  http://fwf.ag.utk.edu/mgray/wfs493/493home_2015.htm

Spring 2014:  http://fwf.ag.utk.edu/mgray/wfs493/493home_2014.htm

Spring 2013:  http://fwf.ag.utk.edu/mgray/wfs493/493home2013.htm

Spring 2012:  http://fwf.ag.utk.edu/mgray/wfs493/493home2012.htm

Spring 2010:  http://fwf.ag.utk.edu/mgray/wfs493/493home2010.htm

Spring 2009:  http://fwf.ag.utk.edu/mgray/wfs493/493home2009.htm

Spring 2008:  http://fwf.ag.utk.edu/mgray/wfs493/493home2008.htm

Spring 2007:  http://fwf.ag.utk.edu/mgray/wfs493/493home2007.htm