Phenology of perennial, native grass, belowground axillary buds in the northern mixed-grass prairie.

PREMISE OF THE STUDY

Vegetative reproduction from belowground bud banks is the primary driver of grassland systems. Despite the importance of bud banks, the timing of recruitment and the crucial link between formation and maintenance is unknown.

METHODS

We assessed patterns of belowground bud development, dormancy, and mortality associated with three perennial native grasses in the northern Great Plains. Temperature and soil moisture were measured below the soil surface to determine relationships with belowground bud development.

KEY RESULTS

Blue grama () generated more buds over winter that remained dormant; whereas, C species needle-and-thread () and western wheatgrass (), maintained limited dormant buds throughout winter. Soil temperature was a good predictor for C species bud production; whereas, soil moisture was a reliable predictor for C buds. Distinct differences existed between C species blue grama and C species needle-and-thread, whereas C species western wheatgrass () was intermediate, indicating there is likely a species-specific continuum between the C and C extremes rather than a stark difference.

CONCLUSIONS

The ability to predict belowground bud development is a novel insight to native perennial grasses. Native grass species' strategies and adaptability regarding belowground bud bank size and bud phenology are important factors optimizing tiller recruitment given the variable growing conditions. Patterns of bud dormancy and development will provide insight to the underlying mechanisms by which management practices and fluctuations in precipitation amount and growing season length can alter mixed-grass prairie plant community dynamics.