Principal Investigators: Katherine Wynne, Dr. Lauren Sullivan
Institution and/or Affiliation: The University of Missouri, Division of Biological
Project Description:
Our primary research objective is to determine whether manipulating the timing and order of species arrival according to natural dispersal phenology influences the formation of tallgrass prairie plant communities. Manipulating seed additions may result in plant communities differing in diversity, composition, and function depending on which species are planted first (Martin & Wilsey 2012, Fukami 2005). Priority effects, or the impact on plant communities due to variations in species arrival, occur when early-arriving species either facilitate or limit the colonization of late-arriving species (Fukami 2015). For example, adding species that are otherwise poor competitors early, may allow these species to garner enough biomass or modify their environment before being excluded by strong competitors such as warm-season grasses (Fargione & Tilman 2005, Eddy & Van Auken 2019, Wilsey 2020). Therefore, giving temporal priority to target species may increase their establishment and persistence in reconstructions (Weidlich et al 2020, Wilsey 2020). Weidlich et al (2020) reviewed 43 studies that compared simultaneous vs. non-simultaneous plantings and found widespread evidence of priority effects; however, the strength and long-term consequences of these effects are likely system dependent. Because priority effects are system dependent, knowledge of local ecology and natural history is imperative for successfully manipulating the timing and order of seedings to create reconstructions that achieve restoration goals (Weidlich et al 2020). Our previous study
on seed dispersal patterns in Missouri tallgrass prairies provides us a unique opportunity to
experimentally test the influence of priority effects on creating diverse plant communities in connection to real-life dispersal patterns. We ask:
- Does manipulating species’ arrival result in long-lasting differences in species diversity and composition?
- Does adding hard-to-establish species before competitively dominant species increase the establishment and persistence of these conservative species?
- How temporally sensitive are these processes?
- Does manipulating seeding order result in ecosystem-level effects?
- Is incorporating multiple seed additions into restoration plans beneficial enough for managers to implement?
We hypothesize that if the timing and order of species’ arrival matters, then manipulating species
arrival via seed additions will result in multiple dissimilar plant communities, and species added with temporal priority will have higher diversity and establishment than late-arriving species. However, if competition-colonization mechanisms matter, then plant community composition will not differ between treatments; and, competitively dominant species will perform better than competitively inferior species regardless of when species are planted. Furthermore, if these processes are temporally sensitive, treatments that closely follow observed patterns of seed dispersal will significantly differ from treatments that conduct “lumped” species additions according to phenological dispersal guild.