Ott, Jacqueline , Hartnett, David .
Bud bank dynamics of four perennial grasses of varying growth form and photosynthetic pathway in mixed-grass prairie.
Annual regeneration and sustainability of perennial grass populations rely heavily on the belowground bud bank. We quantified bud production and bud bank dynamics as they relate to aboveground tiller dynamics and belowground rhizome development in four grasses of varying photosynthetic pathway and growth form in mixed-grass prairie in South Dakota, USA. Bud bank dynamics of Stipa comata, Nassella viridula, Pascopyrum smithii, and Andropogon gerardii were monitored approximately every three weeks from late summer 2010 until winter 2011 at Wind Cave National Park. Based on our previous research on co-occurring grasses in tallgrass prairie, the C3 grasses would be expected to mainly recruit spring adult tillers from overwintering juvenile tillers but maintain overwintering buds in multiple developmental stages while the C4 grass would recruit adult tillers from over-wintering mature buds. In caespitose grasses (S. comata and N. viridula),bud bank production was predicted to be closely linked with their aboveground tiller growth phenology while rhizomatous grasses (P. smithii) may exhibit two pulses in bud production coinciding with tiller growth and rhizome elongation. The C4 A. gerardii recruited spring adult tillers from over-wintering mature buds while the C3 P. smithii and S. comata overwintered in multiple developmental bud stages and as juvenile tillers. Stipa comata also overwintered a large number of adult tillers which were recruited from two separate bud cohorts produced in the previous growing season. In the spring, adult tillers of P. smithii were recruited from juvenile tillers and began mature bud production. These adult tillers did not produce new rhizomes within the first two months of their growth indicating that increases in bud production via rhizomes came at a separate time than bud production via tillers. In the spring, overwintering adult tillers of S. comata continued photosynthesizing without much additional recruitment from juvenile tillers or the overwintering bud bank. Because these adult tillers had already produced buds in the fall, buds were not readily produced in the early spring. Knowledge of bud bank dynamics, as it offers insight into the control of grass population regeneration and regulation of aboveground vegetation production and composition, will be useful in understanding the underlying mechanisms by which management practices and environmental change can alter perennial grasslands.
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1 - Kansas State University, Division of Biology, 104 Ackert Hall, Manhattan, KS, 66506, USA
Presentation Type: Poster:Posters for Sections
Location: Battelle South/Convention Center
Date: Monday, July 9th, 2012
Time: 5:45 PM