Oral Presentation Society for Freshwater Science 2025 Annual Meeting

Increased moisture from beaver dam analogs prompts shift toward clonal reproductive strategies in riparian plant communities (117915)

Laurel F Martinez 1 , Katelyn P Driscoll 2 , Thomas F Turner 1
  1. Biology, University of New Mexico, Albuquerque, NM, United States
  2. Rocky Mountain Research Station, U.S. Forest Service, Albuquerque, NM, United States

Plants in riparian communities commonly reproduce using two strategies: seeds or below-ground bud banks. Recruitment from seeds involves sexual recombination to create potentially advantageous genotypes at the risk of seedling mortality. Bud bank recruitment occurs via vegetative propagules produced clonally from parent plants and allows investment in known successful genotypes. In restoration, seeding is typically used to drive recruitment in plant communities. Yet, in many ecosystems, most aboveground plant tissue is derived from clonal below-ground structures (Benson and Hartnett 2006). In New Mexico’s Jemez Mountains, beaver dam analogs (BDAs) are being used to restore degraded streams. Successful BDAs alter fluvial disturbance and the extent of anoxic conditions in floodplains. This could potentially impact riparian plant recruitment because use of belowground bud banks varies with disturbance frequency and severity (Clarke et al. 2015) as well as moisture gradients (Klimešová et al. 2023). We used a control-impact study to determine whether BDA treatments and associated changes in soil moisture affected riparian plant recruitment strategies and investments in belowground rhizomes. On the one hand, we investigated the number of flowering stems per 100cm2 as a proxy for investment in seed-based reproduction. We found that BDAs significantly increased plant investments in flowering stems compared to the control, however, at both sites the presence of hydric soil and increased water filled pore space decreased investments in flowering stems. On the other hand, we measured rhizome mass and length per 100 cm2 as a measure of clonal investments.  Here, we found that areas with higher water filled pore space had increased rhizome length and mass.  The restored stream also had significantly higher rhizome mass than the control. This suggests that disturbances and increased moisture following restoration treatments can impact plant recruitment by shifting to greater investment in belowground clonal structures, a finding which can inform restoration management goals.

  1. Benson, E. J., and D. C. Hartnett. 2006. The Role of Seed and Vegetative Reproduction in Plant Recruitment and Demography in Tallgrass Prairie. Plant Ecology 187:163–178.
  2. Clarke, P. J., D. M. Bell, M. J. Lawes, A. E. U. Berger, and E. S. Kalisz. 2015. Testing the Shifting Persistence Niche Concept: Plant Resprouting along Gradients of Disturbance. The American Naturalist 185:747–755.
  3. Klimešová, J., J. Martínková, A. Bartušková, and J. P. Ott. 2023. Belowground plant traits and their ecosystem functions along aridity gradients in grasslands. Plant and Soil 487:39–48.