Butzler, Julia M
(2002)
The role of nutrient variability in aquatic ecosystems.
Master's Thesis, University of Pittsburgh.
(Unpublished)
Abstract
The effects of nutrient input into aquatic systems has been studied frequently; typically, these studies report an increase in algal biomass and a decrease in species diversity in response to an increase of nutrients. However, it is not clear why similar aquatic communities will respond differently to nutrient additions of similar magnitudes, resulting in alternative communities. Because variance in natural ecosystems is pervasive, perhaps it is this variability that helps determine the final community. I proposed that the total amount of nutrient input and the variability of nutrient input would affect the abundances and composition of species. A natural survey was conducted to measure the variable levels of nutrients in several aquatic systems. Experimental ponds were used to test the effects of variable rates and timing of nutrient inputs upon an aquatic community; experimental treatments manipulated the total amount of nutrient input (high v. low), the rate of nutrient input (annually, monthly or weekly), the timing of the nutrient input (early v. mid- season), and the trophic status at which these treatments were imposed (mesotrophic v. eutrophic). The effects of the variability of nutrient input was at least as important as the total amount of the nutrient input. There were large impacts upon species diversity, abundances and composition. Although these effects were manifested in many trophic groups, the response to the variability was most strikingly found within the primary producers, which showed large shifts in abundance and composition.
Share
| Citation/Export: |
|
| Social Networking: |
|
Details
| Item Type: |
University of Pittsburgh ETD
|
| Status: |
Unpublished |
| Creators/Authors: |
|
| ETD Committee: |
|
| Date: |
16 July 2002 |
| Date Type: |
Completion |
| Defense Date: |
28 November 2001 |
| Approval Date: |
16 July 2002 |
| Submission Date: |
3 May 2002 |
| Access Restriction: |
No restriction; Release the ETD for access worldwide immediately. |
| Institution: |
University of Pittsburgh |
| Schools and Programs: |
Dietrich School of Arts and Sciences > Biological Sciences |
| Degree: |
MS - Master of Science |
| Thesis Type: |
Master's Thesis |
| Refereed: |
Yes |
| Uncontrolled Keywords: |
aquatic systems; community structure; environmental variability; nutrient input; rate; timing; trophic state |
| Other ID: |
http://etd.library.pitt.edu:80/ETD/available/etd-05032002-143502/, etd-05032002-143502 |
| Date Deposited: |
10 Nov 2011 19:43 |
| Last Modified: |
15 Nov 2016 13:43 |
| URI: |
http://d-scholarship.pitt.edu/id/eprint/7763 |
Metrics
Monthly Views for the past 3 years
Plum Analytics
Actions (login required)
 |
View Item |
![[feed]](/images/feed-icon-32x32.png){kind=icon}