Found 2 projects
Poster Presentation 1
11:00 AM to 1:00 PM
- Presenter
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- Rayna Koberstein, Senior, Environmental Studies, Portland State University McNair Scholar
- Mentor
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- Catherine de Rivera, Environmental Management Program, Portland State University
- Session
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Poster Session 1
- Commons East
- Easel #54
- 11:00 AM to 1:00 PM
The impacts of climate change may be partially ameliorated by positive interactions among species, such as native plants and arbuscular mycorrhizal fungi (AMF). Sea level rise caused by climate change will detrimentally impact saltmarsh habitats by increasing the elevation and rate of terrestrial salt water inundation, thereby reducing effective functionality of ecosystem services provided by saltmarshes. Facilitations, positive interactions between species, is key in determining which species can survive in habitats characterized by abiotic stress, such as salt marshes. Halophytic plants within salt marshes can benefit from symbiotic AMF facilitations through increased inundation tolerance, greater nutrient availability and uptake, and relief from saline stress. This study identifies the presence of AMF across multiple saltmarsh plant species and measures the impacts of AMF within Oregon’s Salmon River Estuary at Cascade Head. I have extracted samples from four monoculture plots within high and low marsh elevations across four species that grow at both elevations: jaumea (Jaumea carnosa), Lyngbye’s sedge (Carex lyngbyei), pickleweed (Salicornia virginica) and salt grass (Distichlis spicata). I have centrifuged soil samples from each plant, and calculated AMF spore abundance at each sample location. I am also processing soil samples for percent water in the sediment, soil salinity and pH. Additional samples from both elevations within polyculture plots have been collected to develop a secondary index to cross-reference my primary findings. Through this research, land managers developing sea-level rise mitigation plans will have data supporting which plants will be most resilient to sea level rise. Potential inoculation of host plants could protect estuaries from sea level rise and increased frequency and intensity of storm events in coastal regions. In identifying plants which host beneficial AMF, fungal inoculation of plants in marshes could help plants grow further into lower marsh elevations, increasing sediment accretion and decreasing erosion and soil degradation.
Oral Presentation 2
3:30 PM to 5:15 PM
- Presenter
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- Grant Gallaher, Junior, Environmental Studies, Biology, Whitman College
- Mentor
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- Lou Jost, Biology
- Session
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Session 2D: Biological Responses to Environmental Factors
- 3:30 PM to 5:15 PM
I present a baseline assessment of the plant family Melastomataceae along an elevational gradient of the Llanganates-Sangay ecological corridor in central Ecuador. Conservation efforts within this corridor aim to preserve the high levels of diversity and endemism present in the region. Melastomataceae, as the third most diverse plant family in Ecuador, contributes valuable biodiversity, biomass, and ecological services to the ecosystems of this corridor. On Cerro Mayordomo (max elevation: 3,383 m), 300 m transects were established at four different elevations, and six 5x5 m plots were assessed along each transect (600 m2 assessed total). All melastome species encountered in plots were grouped and counted based on morphological characteristics. My findings reveal a positive correlation of melastome diversity and abundance with elevation up to 2,500 meters. At 3,000 meters, species diversity decreases sharply, but total abundance remains high. Jaccard, Sorenson, and Morisita-Horn similarity indices indicate dramatic changes in melastome community composition over even slight differences in elevation. Eighteen species of flowering melastomes belonging to four genera were found, revealing a subset of the family's astounding diversity in this region. The results of my study will be used to inform future conservation efforts and ecological studies in this incredibly unique and important Andean corridor.