| dc.contributor.author | Kobiela, Breanna Lyn Paradeis | |
| dc.description.abstract | Although more than half of the annual production within North American grasslands occurs beneath the soil surface, this portion is oftentimes overlooked in ecological studies. In this study, we investigated the above- and belowground responses in restored grassland plots that were subjected to different nutrient and mowing treatments. This study was conducted at two locations in North Dakota: the Dickinson Research Extension Center (DREC); and the Albert K. Ekre Grassland Preserve (Ekre). We evaluated the above- and belowground responses using visual surveys, biomass harvesting, and minirhizotrons.
At the DREC site, we found the belowground variables to be relatively unresponsive to the nutrient and mowing treatments – there were no significant differences in root length, surface area, number of tips, or branches. The aboveground variables did exhibit responses to repeated nitrogen applications (200 kg/ha·yr). Nitrogen applications were found to increase aboveground biomass over the control (660 g/m2 vs. 265 g/m2, respectively) and decrease the species richness in comparison to the control (3.25 vs. 7.29, respectively). There was a decrease in the ratio of root volume to average aboveground biomass in the DREC nitrogen plots that resulted from the increase in aboveground biomass despite no apparent changes in the root systems, indicating that the root systems in the nitrogen plots were able to support significantly more aboveground biomass than similarly sized root systems in plots that did not receive nitrogen.
At the Ekre site, there were no significant differences in the belowground variables attributed to mowing. However, aboveground biomass was higher in the mowed sub-plots (xM=530 g/m2) than in the control sub-plots (xC=485 g/m2). Species richness was lower in the nitrogen (xN=4.46) than in the phosphorus plots (xP=5.66). Species richness was also lower in the plots that received the high application rates (200 kg/ha·yr nitrogen or 40 kg/ha·yr phosphorus) (xH=4.30) than the low application rates (20 kg/ha·yr nitrogen or 4 kg/ha·yr phosphorus) (xL=5.90). Root growth was highest in the low phosphorus and the high nitrogen plots. There were different responses in the root variables throughout the growing season as a function of nutrient type and application rate. | en_US |
| dc.publisher | North Dakota State University | en_US |
| dc.rights | NDSU policy 190.6.2 | |
| dc.title | Above and Belowground Effects of Nutrient Applications and Mowing Treatments on Restored North Dakota Grasslands | en_US |
| dc.type | Dissertation | en_US |
| dc.type | Video | en_US |
| dc.date.accessioned | 2015-06-30T13:33:15Z | |
| dc.date.available | 2015-06-30T13:33:15Z | |
| dc.date.issued | 2015 | |
| dc.identifier.uri | http://hdl.handle.net/10365/25187 | |
| dc.description.sponsorship | National Science Foundation (NSF) (DEB-9627928) | en_US |
| dc.description.sponsorship | USDA-NRICGP (93-0051 and 99-00979) | en_US |
| dc.rights.uri | https://www.ndsu.edu/fileadmin/policy/190.pdf | |
| ndsu.degree | Doctor of Philosophy (PhD) | en_US |
| ndsu.college | Agriculture, Food Systems and Natural Resources | en_US |
| ndsu.department | Natural Resources Management | en_US |
| ndsu.department | School of Natural Resource Sciences | en_US |
| ndsu.program | Natural Resources Management | en_US |
| ndsu.advisor | Biondini, Mario E. | |
| ndsu.advisor | Sedivec, Kevin K. | |
