Effect of forest litter depth on seed germination efficacy of Rhododendron ponticum.

  • Edward Daly Waterford Institute of Technology, Cork Road, Waterford City.
  • Nick McCarthy Waterford Institute of Technology, Cork Road, Waterford City.
  • John O’Halloran School of Biological, Earth and Environmental Sciences, University College Cork.
  • Sandra Irwin School of Biological, Earth and Environmental Sciences, University College Cork.
  • Milo Ó Rathaille School of Biological, Earth and Environmental Sciences, University College Cork.
Keywords: Invasive species control, invasion dynamics, ground disturbance, woodland management.

Abstract

In Ireland one of the most serious invasive alien species which poses threats to local biodiversity is Rhododendron ponticum L. Once established on a susceptible site, R. ponticum can kill other plant species in the ground vegetation layer and prevent the regeneration of trees and shrubs, thereby also indirectly affecting the local fauna. Forest floor litter negatively impacts on the germination success of many plant species, and both the amount and distribution of forest litter can influence the establishment of invasive alien species. Many land management practices, particularly in forestry, disturb ground cover leading to soil exposure, which may increase the risk of R. ponticum invasion. In this study, the effect of forest floor litter on the germination of R. ponticum seeds in five different litter types was assessed. The treatments included bare soil; 1 cm, 3 cm and 5 cm depths of broadleaved litter; and 2 cm conifer litter depth. The results showed a clear relationship between litter type and seed germination success with seeds having poorer success rates in deeper forest litter. This study demonstrated that even small decreases in forest litter depth, sufficient to expose bare soil, facilitates R. ponticum seedling establishment. These findings will inform guidelines and standard operating procedures for future forest management plans, particularly in areas that are sensitive to R. ponticum invasion.
Published
2014-11-01
How to Cite
Daly, E., McCarthy, N., O’Halloran, J., Irwin, S., & Ó Rathaille, M. (2014). Effect of forest litter depth on seed germination efficacy of Rhododendron ponticum. Irish Forestry. Retrieved from https://journal.societyofirishforesters.ie/index.php/forestry/article/view/10133
Section
Articles