| Summary: | Thesis (Ph.D.), School of the Environment, Washington State University Turnbull National Wildlife Refuge (henceforth Refuge) is located in east central Washington State. This area, within the Channeled Scablands, was created by numerous and enormous floods over 15,000 years ago. The refuge is over 16,000 acres and contains over 130 wetlands. Phalaris arundinacea is an invasive grass species present on all continents with the exception of Antarctica. It forms monotypic stands, reducing native plant diversity and can reproduce either sexually or by rhizomes and tillers. Prior to the onset of the first study we hypothesized that there was one population of Phalaris arundinacea at the Refuge. The entire length and breadth of the refuge was sampled for 90 specimens of Phalaris arundinacea, 99 and 111meters apart respectively. Two geographically distinct meadows were also sampled for 45 specimens each at 1.5 meter intervals between Phalaris arundinacea plants. Through use of Amplified fragment Length Poylmorphism, NTSYSpc, STRUCTURE, DISTRUCT and GenAlEx we were able to determine the presence of 5 populations of Phalaris arundinacea at the Refuge. Out of 166 plants sampled from the two large and two small transects combined, we were also able to conclude that reproduction on the Refuge is mainly sexual. In order to determine the ploidy number in Phalaris arundinacea at the Refuge, a second study began in July of 2013.We used the same large transects for a second study on the Refuge as well as an area called Lower Pine Lake. Lower Pine Lake was the site of several plantings, according to annual and bi-annual manuscripts kept at the refuge since 1938. Prior to the onset of the second study, we hypothesized that the Phalaris arundinacea ploidy number could either be tetraploid or hexaploid. Through evaluation in the ARS-USDA lab using of a Partec Cyflow unit, we concluded that tetraploid was the only ploidy number present. School of the Environment, Washington State University
|
|---|