Oregon Undergraduate Research Journal: Vol. 3 No. 1 (2012)
https://scholarsbank.uoregon.edu/xmlui/handle/1794/23378
Fall 20122024-03-28T16:49:07ZStomata Density of Orchids and Cloud Forest Humidity
https://scholarsbank.uoregon.edu/xmlui/handle/1794/23385
Stomata Density of Orchids and Cloud Forest Humidity
Predovich, Sierra
This experiment compares stomata density of the epiphytic Pleurothallis aristata and Maxillaria sp. orchids under experimental conditions of dry and humid environments. Pleurothallis aristata is in the sub-tribe Pleurothallidinae and lacks pseudobulbs, while Maxillaria sp. has pseudobulbs. The study seeks to determine what differences in stomata density exist between the two species, and if there is a difference in mean percent stomata open in humid and dry environments. The study takes stomata impressions from the leaves of twenty individuals of each species using clear nail polish. The results show a significant difference in stomata density between the Pleurothallis aristata and the Maxillaria sp. (Rank Sum Test: t=55, n1=10, n2=10, p<0.05). Additionally, both species have a higher percentage of open stomata in humid environments than in dry environments (Wilcoxon sign rank test). An explanation for these results is that Maxillaria sp. has a pseudobulb for water storage, has a larger leaf surface area, and therefore has higher stomata density. The study showed both species closed their stomata in drier conditions in order to reduce water loss and desiccation. The results of this experiment help demonstrate how different orchid species function in humid and dry environments, and their ability to succeed in the event of global climate change and shifting of biomes.
10 pages
2012-11-08T00:00:00ZRestoration Monitoring on the McKenzie River, Oregon
https://scholarsbank.uoregon.edu/xmlui/handle/1794/23384
Restoration Monitoring on the McKenzie River, Oregon
Rau, Michelle; Stewart, Jenna; Kezer, Zachariah; Martin, Rebecca; Miller, Ben; Silverstein, Sean; Slivka, Olga; Swanson, Dane; Truelove, Valarie; Van Hevelingen, Thomas; Woods, Tyler; Young, Krystal
In the spring of 2012, we, the Stream Stewardship Team from the University of Oregon's Environmental Leadership Program (ELP), conducted post-monitoring surveys at a side channel of the Middle McKenzie River (side channel 4) to compare with baseline monitoring data collected by the 2011 ELP Restoration Stewardship Team. The goal of this restoration project was to enhance juvenile spring Chinook salmon (Oncorhynchus tshawytscha) rearing habitat within the channel. In 2011 the U. S. Forest Service placed large woody debris (LWD) in five sections of the channel after baseline monitoring to increase the complexity of the streambed within the channel and to create a distribution of sediment optimal for salmon spawning habitat. We conducted pebble counts, cross-channel surveys, and a longitudinal profile of the stream to observe changes since the addition of LWD. Median pebble size decreased downstream of the LWD placements at gravel count 1 and increased upstream at gravel count 2. The percent of embedded sediment decreased at both gravel count sites. We also detected noticeable changes in the stream morphology at four of the five crosssectional surveys as well as along the longitudinal profile. Sediment size distribution and the formation of pools at the downstream end of the channel showed an initial change in stream morphology since 2011, but further monitoring is warranted in order to fully assess the effects of LWD on streambed complexity and salmon spawning habitat.
11 pages
2012-11-08T00:00:00ZEditor's Letter
https://scholarsbank.uoregon.edu/xmlui/handle/1794/23383
Editor's Letter
Ward, Kelsey
1 page
2012-11-08T00:00:00ZEditorial: "A Legacy of Undergraduate Research"
https://scholarsbank.uoregon.edu/xmlui/handle/1794/23382
Editorial: "A Legacy of Undergraduate Research"
Frank, David
1 page
2012-11-08T00:00:00Z