Seasonal Nutrient Limitation in Taneum Creek, Washington
Document Type
Oral Presentation
Campus where you would like to present
SURC Ballroom B/C/D
Start Date
21-5-2015
End Date
21-5-2015
Keywords
Productivity, Autotrophic, Heterotrophic
Abstract
Two key determinants of stream ecosystem productivity are algal activity, the source of primary production of energy in a food web from solar radiation via photosynthesis, and heterotrophic activity, the bacterial and fungal consumers of this primary ecosystem production. Nitrogen (N) and phosphorus (P) concentrations often determine ecosystem productivity, and varying nutrient levels exist within an ecosystem seasonally. For example, during the fall, leaf input decomposes, possibly leading to different nutrient levels compared to winter, when few leaves remain in the stream. This variation can be applied to higher trophic levels via bottom up ecosystem production whereby increased primary production increases production at higher trophic levels such as fish. We used nutrient diffusing substrata to measure seasonal changes in ecosystem nutrient limitation in two sites in Taneum Creek, which has been of interest to the Yakama Nation due to their active migratory fish repopulation efforts. In the fall, we found that heterotrophic activity in Taneum Creek was co-limited by N and P at both study sites, p=0.006 upstream and p<0.001 downstream, whereas autotrophic activity was not nutrient limited. In the winter, upstream heterotrophic and downstream autotrophic production were co-limited by N and P, p=0.007 and p=0.019, respectively, but autotrophic productivity upstream and heterotrophic activity downstream were not nutrient limited. This study will continue in spring and summer for a comprehensive analysis of limiting factors to autotrophic and heterotrophic activity, which will form a better understanding of ecosystem productivity to support fisheries reintroduction.
Recommended Citation
Alling, Tyler; Clark, Desiree; and Awan, Samara, "Seasonal Nutrient Limitation in Taneum Creek, Washington" (2015). Symposium Of University Research and Creative Expression (SOURCE). 33.
https://digitalcommons.cwu.edu/source/2015/posters/33
Poster Number
40
Department/Program
Biological Sciences
Additional Mentoring Department
Biological Sciences
Seasonal Nutrient Limitation in Taneum Creek, Washington
SURC Ballroom B/C/D
Two key determinants of stream ecosystem productivity are algal activity, the source of primary production of energy in a food web from solar radiation via photosynthesis, and heterotrophic activity, the bacterial and fungal consumers of this primary ecosystem production. Nitrogen (N) and phosphorus (P) concentrations often determine ecosystem productivity, and varying nutrient levels exist within an ecosystem seasonally. For example, during the fall, leaf input decomposes, possibly leading to different nutrient levels compared to winter, when few leaves remain in the stream. This variation can be applied to higher trophic levels via bottom up ecosystem production whereby increased primary production increases production at higher trophic levels such as fish. We used nutrient diffusing substrata to measure seasonal changes in ecosystem nutrient limitation in two sites in Taneum Creek, which has been of interest to the Yakama Nation due to their active migratory fish repopulation efforts. In the fall, we found that heterotrophic activity in Taneum Creek was co-limited by N and P at both study sites, p=0.006 upstream and p<0.001 downstream, whereas autotrophic activity was not nutrient limited. In the winter, upstream heterotrophic and downstream autotrophic production were co-limited by N and P, p=0.007 and p=0.019, respectively, but autotrophic productivity upstream and heterotrophic activity downstream were not nutrient limited. This study will continue in spring and summer for a comprehensive analysis of limiting factors to autotrophic and heterotrophic activity, which will form a better understanding of ecosystem productivity to support fisheries reintroduction.
Faculty Mentor(s)
Clay Arango