Skip to main content
2023 ESA Annual Meeting Main banner
Icon Legend
This session is not in your schedule.
This session is in your schedule. Click again to remove it.
Back

Latebreaking Poster

Session: Grasslands/Steppe (Latebreaking)

LB 24-209 - Recovery of tallgrass prairie function, but not plant community composition responses five years after cessation of nutrient additions and invertebrate removals

Thursday, August 10, 2023
5:00 PM – 6:30 PM PDT
Location: ESA Exhibit Hall

    Presenting Author(s)

  • RB

    Rachael Renae Brenneman

    PhD Student
    University of North Carolina in Greensboro
    Greensboro, North Carolina, United States

    • Coauthor(s)

  • KK

    Kimberly Komatsu, Ph.D.

    Associate Professor of Biology
    UNC - Greensboro
    Greensboro, North Carolina, United States

Nutrient pollution and the loss of insect herbivores as global change factors are important for understanding the structure and function of grassland ecosystems. These drivers can lead to changes in plant communities with alterations in species composition, identity, and overall health of the system. Grasslands systems are particularly susceptible to damage from global change drivers, with the potential to radically change plant community composition. However, we have relatively little understanding of how grassland systems might recover from these global change drivers. We examined five years of recovery in tallgrass prairie following ten years of experimental treatments testing plant community and productivity changes in the face of insect removal and chronic nutrient addition. The initial experiment (2008-2017) applied 10g/m2/year of nitrogen (N), phosphorus (P), and potassium (K) along with bi-weekly removal of invertebrate herbivores by insecticide from May-August. Plant species composition was measured twice per growing season (late May and late August), with biomass measurements in August. During treatment years, the NPK treatment alone led to the domination of the plant community by forbs rather than typically dominant C3 and C4 grasses. This trend was exacerbated by the removal of insects in addition to NPK additions. NPK also led to a general increase in grass biomass production. However, when NPK and insects were manipulated together, forb biomass increased. In 2018, all treatments ceased and species composition and biomass continued to be monitored through 2022. During the recovery years, biomass production returned to control levels with no lingering effect of NPK and insecticide remaining as of 2020 for forb biomass and 2021 for grass biomass. However, plant community composition has not recovered over these five years. Forb dominant communities remain in both the NPK and insecticide alone treatments, as well as the NPK/insecticide plots. This result suggests that plant communities experiencing chronic nutrient addition and loss of invertebrate herbivores will struggle to recover even if their disrupting drivers have been removed. Our results have meaningful consequences for grassland community recovery and restoration after degradation, with an indication that more active restoration strategies will be required to return tallgrass prairie plant communities to their natural state following disturbance.