Publication Date

2018

Document Type

Thesis

Committee Members

Megan Rúa (Advisor), Don Cipollini (Committee Member), Thomas Rooney (Committee Member)

Degree Name

Master of Science (MS)

Abstract

Since industrialization, anthropogenic carbon emissions have led to excess atmospheric carbon dioxide that may alter the stability of ecosystem processes. Microorganisms are essential in mitigating excess carbon and play a notable role in the breakdown of organic material. This process, decomposition, is essential in forested ecosystems where microorganisms can recycle nutrients and store carbon in soil organic matter or release it through respiration. Fungi participate in decomposition through the release of enzymes responsible for carrying out the chemical reactions that break down plant material. Species introductions have the potential to alter decomposition dynamics. In the Midwestern US, the invasive shrub species Lonicera maackii has overtaken many forests and is likely altering decay dynamics and the destiny of carbon within the region. Thus, it is essential to monitor the decay of woody debris under invasion pressures of L. maackii in order to monitor nutrient cycling in this region. I placed blocks of native Quercus rubra and economically important Pinus radiata in an L. maackii invaded forest for one year to determine environmental, enzymatic and fungal drivers of decomposition. Decomposition was faster for oak wood than pine wood, and decomposition rate was not directly altered by L. maackii. Instead, L. maackii increased the moisture of the decomposing wood, leading to higher amounts of hydrolytic enzyme activity which structured fungal communities within decaying wood. This insinuates that despite not altering decomposition rates directly, L. maackii is priming native woody debris for faster decomposition and therefore increasing the rate of nutrient turnover. Thus, L. maackii imposes shifts to fungal communities and their functionality and the soil environment. These changes could become especially important in later stage decay where there will likely be perceptible differences in decay rates as altered by L. maackii. The changes L. maackii imposes on decomposition will likely lead to faster carbon release from forested ecosystems and shorter retention times. Consequently, to ensure effective management strategies that mitigate excess carbon dioxide from the atmosphere, monitoring decomposition of woody material in invaded forests is imperative

Page Count

70

Department or Program

Department of Biological Sciences

Year Degree Awarded

2018


Included in

Biology Commons

COinS