Widener University Journal of Undergraduate Ecological Research

Widener University Journal of
Undergraduate
Ecological Research

    The research inquiry journal for the course
         Biology 301, Introduction to Ecology.

         Volume 5, Number 1, Summer 1997

         Dr. Bruce W. Grant, "Editor"
         Department of Biology,
         Widener University , Chester, PA, 19013.
         office Kirk. 200, 610-499-4017.
         grant@pop1.science.widener.edu

Please Read This Comment.

       The abstracts at this site were written by junior or senior undergraduates and are the culmination of semester long ecological research inquiries that are a core component of my ecology course at Widener University. These students are biology, environmental science, or science education majors and minors for whom my course is required.

       These abstracts (and the manuscripts to which they refer) have been peer reviewed by other students in the class according to specific guidelines I have generated for format, clarity, and the student reviewers' assessment of the scientific merit of their peer's manuscript.

       It is important for interested visitors of this site to understand that the results of the research inquiries reported in this journal are the results of course projects designed, conducted, and reviewed by undergraduate students in an ecology course.

       You are welcome to download some or all of the material I have posted at this site for your use in your ecology course. This does not include commercial uses for profit. If you do use any lengthy exerpts (more than 2 lines) of the material above, I request that you formally acknowledge this site and/or sites I have acknowledged as the source(s). I also request that you reciprocate and send me a copy of your ecology materials so that I may see what you have put together.

Please send comments to me: grant@pop1.science.widener.edu.

Volume 5, Number 1, Biology 301, Summer 1997.

1. A Study of the Biodiversity of Insect Populations at Rural, Suburban, and Urban Settings. Alexander Kobb, Joseph Jenkins, and Kelly Sweeney.

2. Bacterial Biodiversity on Maple Leaves from Urban and Suburban Environments. Melanie Gleave, Kruti Patel, and Selina Taylor.

3. Ecology of the Eastern Fence Lizard, Sceloporus undulatus, from the New Jersey Pine Barrens: Assessing Thermal Environment and Body Temperature Preferences. Robert Hopkins.

4. Ecology of the Eastern Fence Lizard, Sceloporus undulatus, from the New Jersey Pine Barrens: Are Growth Rate Differences Between Males and Females Due to their Behavior? Stephanie Skelly.

5. Effects of Structural Habitat Type on Insect Diversity in an Intertidal Marsh. Ilona Burykovski. (abstract unavailable)

A Study of the Biodiversity of Insect Populations at Rural, Suburban, and Urban Settings. Alexander Kobb, Joseph Jenkins, and Kelly Sweeney.

       As humans, we contribute an enormous amount to the world’s pollution each day. For this simple reason, we should all become more aware of how much we depend on the plants and animals that surround us. David Mussared says, “...you depend in one way or another on millions of fellow species every minute of every day just to stay alive.”
       In our research, we are hoping to determine the insect biodiversity in three sites differing in the amount of pollution and urbanization each has sustained: Ridley Creek State Park (rural), a wooded lot in Nether Providence (suburban) and areas on the campus of Widener University, Chester, PA (urban).
       Our hypothesis is that increased concentrations of air pollution will lead to a less diverse population of insects.
       To test our hypothesis, net sweeps were made in four areas at each of the three above-mentioned sites. The insects and foliage were placed in zip lock bags, then placed in a freezer for 2 - 3 hours. Insects were separated from the foliage, classified to their taxonomic Order and representatives were placed on slides. The Shannon Index was used to determine the diversity.
       We classified 1415 insects, 416 from the Chester site among ten Orders, 457 from the site at Nether Providence among nine Orders and 542 from the Ridley Creek State Park site among ten Orders.
       The Shannon Index showed that the diversity of Orders at the Chester site was significantly greater than at the Nether Providence site and slightly greater than the Ridley Creek State Park site, which does not support our hypothesis.
       The Nether Providence site was much smaller and more isolated than the other two sites which may account for its lower diversity. For instance, insects with a large home range would not be able to inhabit the Nether Providence site. Furthermore, although the Chester site seemed slightly more diverse than the Ridley Creek State Park site, when classified to Order the results might be different if the classification was carried to the Family level or beyond.
       In the future, we would like to continue our research over an increased period of time. We would like to collect a larger sample set, study the differences between night and day insects and attempt to classify to either Family or Genus.

The Bacterial Biodiversity on Maple Leaves from Urban and Suburban Environments. Melanie Gleave, Kruti Patel, and Selina Taylor

       Biodiversity, which keeps the environment stable, is relied on for many things throughout the day. In nature there are two types of bacteria, some bacteria are beneficial to the environment and others are pathogenic. Both have their own characteristics and functions.
       We investigated the bacterial biodiversity of maple leaves found in urban and suburban environments. We hypothesized that there would be less biodiversity in the urban setting compared to the suburban setting. A total of ten sites were used, five urban and five suburban. The five urban sites were Penns Landing, Spruce Street, Philadelphia Museum of Art, The Philadelphia Zoo, and Brandywine Avenue. The five suburban sites were Heinz Wildlife Refuge, Swarthmore College, Tyler Arboretum, Rose Tree Park, and Taylor Arboretum.
       The leaf samples were brought back to the lab, and using aseptic techniques, the top sides of the leaves were plated. Once the colonies were established, tests were performed. The tests included gram stain, motility, nitrate, morphology, and oxygen requirement. The results of these five tests were recorded and sorted. We found a total of twenty-two different types of bacteria. Using the Shannon Diversity index we found a higher biodiversity in the urban environment than in the suburban environment. This means that we rejected our hypothesis. There are several factors for this. For one, the pollution plays and important role in bacterial biodiversity. With an increase of population in urban environments the amount of air particulates increases. Air particulates are a vehicle of motion for the vast movement of various forms of bacteria. The increase of air particulates allows a wider variety of bacteria to be transported from one place to another.

Ecology of the Eastern Fence Lizard, Sceloporus undulatus, from the New Jersey Pine Barrens: Assessing Thermal Environment and Body Temperature Preferences. Robert Hopkins.

A population of Sceloporus undulatus, commonly known as the Eastern Fence Lizard, found in Wharton State Forest, located in the New Jersey Pine Barrens, is the focus of this project. There are eleven distinct populations of fence lizards in the United States, and the New Jersey population is the northernmost. This population of S. undulatus, exhibits several unusual life history characteristics, including slow juvenile growth rate, delayed sexual maturity, and reverse sexual size dimorphism. Our goal is to construct a bioenergetic model of S. undulatus to better understand the mechanistic “how” and evolutionary “why” these unusual life history characteristics came about for this New Jersey population. The acquisition of energy by the organism and the energy allocation from its energy budget play an important role in understanding the development of the life history characteristics of this particular population. There is a need for a knowledge of the environmental conditions of the organism’s habitat to be studied in order to understand how it functions within that habitat. Temperature data, in collaboration with a demographic, behavioral, and physiological study will form a much clearer picture of this complete bioenergetic model.
Within the habitat there is broad range of light intensities giving rise to a wide range of temperatures. In addition to taking the temperatures of the lizards upon capture, hollow body copper model lizards linked to a data logger, will be used in order to find the upper and lower limits of the temperature range in which they must operate. The habitat's temperatures will be simulated within a laboratory setting to measure lizard's thermal preference within a simulation of the natural environment. Appropriate temperature is essential for the lizard to function and participate in activities needed for survival. Temperature can affect whether lizards can digest food, affect digestive efficiency, activity time, and muscle function (capturing prey, predator avoidance, mating, defending territory). Accurately assessing the thermal environment, can give insight into the lizard’s role in that habitat, and what it needs to thrive. Temperatures from the field were obtained and used to impose the thermal range of the lab gradient. The lizard’s temperature preferences were obtained from both environments. These figures were then compared with each other and the field data from last year's demographic study can be referenced to compare with this year’s.

Ecology of the Eastern Fence Lizard, Sceloporus undulatus, from the New Jersey Pine Barrens: Are Growth Rate Differences Between Males and Females Due to their Behavior? Stephanie Skelly

       Sceloporus undulatus occur in 11 areas throughout the U.S and show geographic variation among the populations. Due to their sensitivity to the environment and their wide array of habitats, these ectothermic iguanid lizards could be key bioindicators of the changing ecosystem. The Eastern Fence lizard found in New Jersey exhibits several unusual life history characteristics. This includes: 1) slow juvenile growth rate; 2) slower male juvenile growth rate than female juvenile growth rate resulting in reverse sexual size dimorphism where females are larger than males; and 3) delayed sexual maturity.
       A multi-year demography and field behavioral ecology study has been established on a permanent study site in the Wharton State Forest of New Jersey. The research began in hopes to determine the mechanisms responsible for generating the unusual life history characteristics found in the population. The subject of this research is to examine if the difference in male and female growth rate is due to a difference in behavior. Continuous focal observations of free ranging lizards can provide an activity rate comparison of juvenile males and females and a possible correlation between sex and behavior which could affect growth rate patterns.
       Data indicate variation in growth rate patterns among years. The 1995 data show a significant difference in growth rate among sexes, whereas, 1996 and 1997 showed no significant difference in growth rate between juvenile males and females. These variations could be due to differences in thermal environment, activity patterns, or digestive efficiencies. Data from 20 minute focal observations of juvenile animals show no significant differences among the sexes in any category of behavior, including feeding behavior and movement. This correlates with the data showing insignificant difference of growth rates between male and female animals in 1996 and 1997. A continuation of growth and behavioral data would provide insight in to how and why growth differences emerge.