Assessing the impact of greentree reservoir water management on red oak growth and anatomy in the lower Mississippi Alluvial Valley

Bottomland hardwood forests in the Lower Mississippi Alluvial Valley have significantly diminished over the past two centuries due to land clearing and hydrologic alteration. To preserve migratory waterfowl habitat, greentree reservoirs (GTRs) were established, providing artificial flooding during the fall and winter. Red oak species within GTRs provide vital resources, such as mast and habitat for wildlife, and make up an important part of waterfowl conservation. However, many GTRs are facing a decline in the regeneration of desirable red oak species and an increase in the mortality of mature trees, possibly due to artificial flood regimes. Our objectives were to: 1) determine the effects of GTR water management on annual tree growth and 2) determine if GTR water management produces anatomical abnormalities typical of oaks that experience prolonged root inundation. If anatomical abnormalities consistent with flooding do occur in GTRs, our further aims were to 3) identify the anatomical responses of trees in GTRs, 4) develop a chronology of flooding events Pool 8 at Mingo National Wildlife Refuge (MNWR) in Southeastern Missouri, and 5) discover if vessel size is related to annual tree growth. Overall, 176 tree core samples were crossdated and converted to basal area increment to analyze tree growth. During years of recorded spring flooding, tree growth was not negatively affected. Basal area increment was used to place individual trees into vigor classes, trees in the lowest elevations of the GTRs displayed a distinct separation in the growth trajectories of the 3 vigor classes that coincided with changes in water management. Anatomical abnormalities associated with spring flooding were identified, and a chronology of decreases in mean vessel area and visual anatomical abnormalities was created from 1960-2022. Tree growth and mean vessel area have a significant 2 positive relationship when correlated over the entire period of analysis, however, in years with anatomical features suggestive of growing season flooding, mean vessel area is not related to tree growth.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Masters

Discipline thesis:degree_discipline

Natural Resources(MU)

Grantor dc:publisher

University of Missouri--Columbia

Year dc:date.issued

2024

Author dc:creator

• Malone, Sarah Anne

Advisor dc:contributor.advisor

• Stambaugh, Michael C.

Language dc:language.iso

eng, English

DOI

https://doi.org/10.32469/10355/107873

OAI identifier oai:identifier

oai:mospace.umsystem.edu:10355/107873