2020 ESA Annual Meeting (August 3 - 6)

LB 25 Abstract - Wiregrass phenology: Is local seed important?

Althea Hagan, Forestry and Environmental Conservation, Clemson University, Clemson, SC and Joan L. Walker, Southern Research Station, USDA Forest Service, Clemson, SC
Background/Question/Methods

One of the central tenets of restoration ecology is that local seed is best. However, for many ecosystems that have been severely impacted and exist in remnants it might be necessary to move quite far out before you find a viable seed source. This is true of longleaf pine forests which have been reduced to less than 5% of their historical 90-million-acre range. Fire is key to restoring these forests and without it, fire intolerant species invade. Wiregrass is the dominant grass species in this habitat and plays a key role in the reproduction and spread of longleaf pine as it helps to carry fire. Understanding the range of variation in wiregrass seed sources including responses to variations in fire is key to finding a seed source that will be successful in a specific restoration site. Wiregrass (Aristida stricta) from 5 northern populations and from 7 southern (Aristida beyrichiana) populations was grown in a common garden outside of Columbia, SC. Randomly selected plants were burned at different times between April and August 2018.

Results/Conclusions

Consistent with previous studies for both species we found that growing season burning resulted in higher biomass allocation to reproductive structures than not burning. We found that the inflorescence from plants grown from northern or stricta seed grew taller earlier in the season and peak flowering occurred about a month before flowering in plants grown from southern or beyrichiana seed. This provides further support for the idea that the two species of wiregrass are distinct and should not be used interchangeable in restorations.