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2015 student research

Dan Herrera & Megan Lipke

The Effects of Urbanization on Amphibian Diversity

Megan Lipke

The purpose of the project is to obtain data on the diversity of the amphibian community in the Quad Cities, and to see how urbanization has altered the level of diversity. Amphibians can serve as indicators of ecosystem health, and previous research only samples for vocal species and includes observer bias.

Past research

This project will include a non-biased sampling method by using amphibian pit falls traps. The traps will be checked at least once a day while left open. They will be kept open for three days at a time. This sampling period is to be repeated three times.

Upon identification, the specimen are to be released. Their objectives are: To obtain and compare a general survey of species richness between highly urbanized, moderately urbanized, and minimally urbanized ecosystems. And to compare the amphibian species and prevalence at each plot with the species and prevalence of native and invasive plants present.

Kass Tyra

Kass Tyra

An Investigation of Butterfly Species Diversity along Urban-Suburban-Exurban Gradient in the Upper Mississippi River Conservation Opportunity Area

The purpose of this project is to assess the abundance and diversity of urban butterfly populations in Rock Island and Moline. The study area will consist of a subset of 22 forest plots established by the Upper Mississippi Center.

This project will be conducted by walking timed transects and making visual observations in order to measure butterfly abundance and diversity. Butterfly surveys will be conducted every two weeks, in conjunction with the carabid beetle surveys.

Carabid beetle surveys are being conducted by Dr. Brosius and will look at how urbanization impacts the Family of beetles known as carabid beetles. Carabid beetles are predators and are found at the top of the trophic scale. Butterflies are considered to reside at the mid trophic scale, so they will complement the data being collected from plants (bottom of the trophic scale) and carabid beetles (top of the trophic scale).

Previous research in these plots provide an existing dataset which will allow an assessment of the relationship between the structure, composition and diversity of the overstory and understory communities, as well as butterfly abundance and diversity. Because these span across areas of habitat fragmentation and degradation, this research will be able to make correlations with plant and carabid beetle populations as well as forest structure. Patterns that arise from surveying these different taxonomic groups at differing trophic scales within this diverse landscape will greatly increase our knowledge of urban landscape dynamics.

Victoria Lason

Victoria Lason (right)

The Spatial Distribution and Density of the Emerald Ash Borer Larvae

Victoria will be continuing Morgan Conley’s survey of Emerald Ash Borer larvae in Rock Island. The research objective of this study is to determine the spatial distribution and density of EAB larvae populations within Rock Island.

The emerald ash borer was previously found in Hasselroth Park in Rock Island County. Branch sampling protocols at Hasselroth Park completed in 2014 determined the presence of high larval densities.

Ash trees will be selected for surveys based on their DBH (diameter at breast height), which will preferably fall between 15 and 50 centimeters. Two live branches will be cut from the middle crown and cut at the base (near the trunk) using a pole saw, pursuant to protocols. The branches will be sawed 50 centimeters from the base, and these sections will be used to conduct the survey.

The branch samples will be whittled so that the bark and conductive tissue will be removed in 1-millimeter-thick strips until the cambium is reached. And the number of galleries and larvae will be recorded. This branch sampling method is being used because symptoms of EAB are not apparent until the tree is heavily infested.

The time lag between the initial infestation and the appearance of visible signs is problematic, as the invasion front is able to progress past an area for 1-2 years before resource managers are aware of its presence. Branch sampling is particularly effective at determining the presence of an EAB infestation before visual symptoms and adult EAB beetles are apparent.

Diana Schultz

Three-Way Plant Competition Study

The purpose of this research project is to more closely examine plant competition between native and invasive species. A better understanding of how these competitions happen can have an impact on treating plant invasions.

In order to obtain this information I am growing a combination of garlic mustard, enchanter's nightshade and slippery elm in the greenhouse in a variety of combinations and densities. When the plants have fruited, I will cut and measure the above ground biomass and run statistics in order to determine the effects of competition on the species.