Repository logo
 

Response and recovery of grassland plant communities exposed to multiyear drought differs across a precipitation gradient

Simple item page
dc.contributor.authorRoss, Maggie, author
dc.contributor.authorSmith, Melinda D., advisor
dc.contributor.authorKnapp, Alan, committee member
dc.contributor.authorHavrilla, Caroline, committee member
dc.contributor.authorWilkins, Kate, committee member
dc.date.accessioned2023-01-21T01:24:24Z
dc.date.available2023-01-21T01:24:24Z
dc.date.issued2022
dc.description.abstractDrought events are expected to increase in grassland ecosystems in many regions of globe due to climate change. Much is known about the effects of drought on grassland plant communities, yet it is difficult to compare responses across different grassland ecosystems because studies impose drought with varying characteristics. Further, few studies have documented plant community recovery, even though the impacts of drought can persist for multiple years. We experimentally imposed four years of extreme, growing season drought at four sites representing the major Central US grassland types (shortgrass steppe, mixed grass prairie, tall grass prairie) spanning a precipitation gradient. Growing season drought was imposed in two ways: 1) by reducing each rainfall event by 66% (chronic) or 2) by completely excluding rainfall until a similar reduction in precipitation as the chronic treatment was achieved (intense). Plant community responses to the two drought treatments were monitored for each year of the four-year drought treatments and four years following the drought to assess recovery. Overall, plant communities at the drier sites responded sooner to drought and took longer to recovery than the wetter sites. Plant composition was altered at all sites, which was largely driven by shifts in the dominant C3-C4 grasses and subsequent species reordering and to a lesser extent by changes in richness in evenness. There was a significant decrease in C4 graminoid abundance in response to drought at all sites with a corresponding increase of C3 annual grasses during the drought at the mixed grass sites but not until the recovery period at the shortgrass steppe. Cheatgrass (Bromus tectorum) invaded the shortgrass steppe during the drought and proliferated during the recovery period, which likely pushed the communities into an alternate state, and inhibited recovery after four years of ambient conditions. The northern mixed grass prairie also did not fully recovery after four years, which indicates that full plant community recovery can extend longer than the drought itself at these drier sites. While there is some indication that intense drought had a greater impact on communities than chronic drought, there is limited evidence to suggest that drought type significantly influenced plant community responses or recovery. These findings indicate that while the shortgrass steppe is water limited with drought adapted species, these xeric grassland plant communities are less resistant and resilient to multiyear drought than those in mesic grasslands.
dc.format.mediumborn digital
dc.format.mediummasters theses
dc.identifierRoss_colostate_0053N_17575.pdf
dc.identifier.urihttps://hdl.handle.net/10217/235989
dc.languageEnglish
dc.language.isoeng
dc.publisherColorado State University. Libraries
dc.relation.ispartof2020-
dc.rightsCopyright and other restrictions may apply. User is responsible for compliance with all applicable laws. For information about copyright law, please see https://libguides.colostate.edu/copyright.
dc.subjectgrasslands
dc.subjectrecovery
dc.subjectplant community
dc.subjectdrought
dc.titleResponse and recovery of grassland plant communities exposed to multiyear drought differs across a precipitation gradient
dc.typeText
dc.typeImage
dcterms.rights.dplaThis Item is protected by copyright and/or related rights (https://rightsstatements.org/vocab/InC/1.0/). You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s).
thesis.degree.disciplineEcology
thesis.degree.grantorColorado State University
thesis.degree.levelMasters
thesis.degree.nameMaster of Science (M.S.)

Files

Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
Ross_colostate_0053N_17575.pdf
Size:
1.18 MB
Format:
Adobe Portable Document Format
Download

Collections

2020-
Theses and Dissertations