Wiregrass (Aristida beyrichiana) survival after re-introducing fire in a long-unburned pine savanna

Cesar Zamora

Authors:  Cesar Zamora, Jennifer Fill, Carolina Baruzzi, Javier Salazar-Castro, Dr. Raelene Crandall

Faculty Mentor:  Dr. Raelene Crandall

College:   College of Agricultural and Life Sciences

Abstract

Wiregrass (Aristida beyrichiana) is a keystone species in longleaf pine (Pinus palustris) savannas of the southeastern USA. It fuels frequent, ground layer fires known to be essential for maintaining ecosystem function and diversity. Thus, an understanding of the factors that drive wiregrass survival should help explain community dynamics in pine savannas and inform restoration of long unburned sites. As time-since-fire increases in pine savannas, decomposing leaf litter (“duff”) begins to accumulate around plants and have been shown to increase soil heating and mortality of some species, including pines. We investigated whether duff accumulation and wiregrass size affected its survival by monitoring individuals after a prescribed fire in a fire-neglected research unit at Ordway-Swisher Biological Station near Hawthorne, FL. Individual plants were assigned to three treatments: low duff, high duff, and low duff with additional fuels added (3 pine cones). We found that plants had high survival unless they were small (<30 cm2 basal area) and had pine cones added. These results suggest that wiregrass can survive even when fuel loading and fire intensity are high. This is positive news for land managers concerned about grass mortality when reintroducing fire into long-unburned pine savanna sites.

Poster Pitch

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Poster

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15 Responses
  1. Pedro Celis

    Cesar this is great! Thank you for your thoughtful responses through Zoom, you really are an emerging talent in the industry!

  2. Rafael Hernandez

    Hello Cesar!

    I enjoyed your poster, and thought it was interesting to see how pine cones made the smaller plants more likely to die as opposed to the larger plants. I would’ve thought that more of the larger plants would die as well.

    Great work!
    – Rafael Hernandez

    1. Cesar Zamora

      Hello Rafael,

      It was actually a surprise for me and the whole team as well! I was actually expecting to find higher mortality throughout the sample but only a few group died. It turned out to be even better because now there is some proof that managers could re-introduce fire to fire-neglected systems in the southeastern US, which they need to be healthy ecosystems.

      Thank you for your comment

  3. Cesar Zamora

    Hello Rafael,

    It was actually a surprise for me and the whole team as well! I was actually expecting to find higher mortality throughout the sample but only a few group died. It turned out to be even better because now there is some proof that managers could re-introduce fire to fire-neglected systems in the southeastern US, which they need to be healthy ecosystems.

    Thank you for your comment

  4. Daniel Nunez

    Interesting poster Cesar! It’s always good to learn about interactions in our ecosystem.

  5. Maria Valentina Sansur

    cesar, why dis you focus on wiregrass? Just interested in the thought process behind the decision.

    1. Cesar Zamora

      Hey Maria Valentina

      Wiregrass is an understory plant, a grass specifically, which is a key species to the longleaf pine ecosystems throughout the Southeastern USA because it promotes the carry of fire by being very flammable. Fire is essential to these ecosystems because many plants depend on it for reproduction and animals needed because it promotes plants that they (or their preys) eat.

      Thank you for your comment.

  6. Andres Pulido

    Hi Cesar,
    Any thoughts on how land managers could increase the survival chance of small plants when there are pine cones on the ecosystem?
    Great work, congrats!

    1. Cesar E Zamora

      Hey Andres,

      If necessary to save very small plants for some reason (not that many large plants in the system, not enough money to replant some after a fire, etc), a simple raking around the plant to eliminate excess of fuel will suffice to ensure a great amount of small plants survival. No need to save them all, however. A population can bounce it self back with a few small plants if given enough time between fires to become bigger and withstand fires better. Theses survivors will reproduce and recruit more wiregrass plants to increase the population, creating a positive feedback loop with the seasonal fires.

      Thank you for your comment.

    1. Cesar E Zamora

      Hello Dr. Wysocki,

      I appreciate your encouraging words. Good communication of science is something I care about deeply, so it is refreshing to hear I am doing my part well.

      Thank you for your comment.