Establishing a Wild, Ex Situ Population of a Critically Endangered Shade-Tolerant Rainforest Conifer: A Translocation Experiment

PLoS One. 2016 Jul 12;11(7):e0157559. doi: 10.1371/journal.pone.0157559. eCollection 2016.

Abstract

Translocation can reduce extinction risk by increasing population size and geographic range, and is increasingly being used in the management of rare and threatened plant species. A critical determinant of successful plant establishment is light environment. Wollemia nobilis (Wollemi pine) is a critically endangered conifer, with a wild population of 83 mature trees and a highly restricted distribution of less than 10 km2. We used under-planting to establish a population of W. nobilis in a new rainforest site. Because its optimal establishment conditions were unknown, we conducted an experimental translocation, planting in a range of different light conditions from deeply shaded to high light gaps. Two years after the experimental translocation, 85% of plants had survived. There were two distinct responses: very high survival (94%) but very low growth, and lower survival (69%) and higher growth, associated with initial plant condition. Overall survival of translocated W. nobilis was strongly increased in planting sites with higher light, in contrast to previous studies demonstrating long-term survival of wild W. nobilis juveniles in deep shade. Translocation by under-planting may be useful in establishing new populations of shade-tolerant plant species, not least by utilizing the range of light conditions that occur in forest understories.

MeSH terms

  • Conservation of Natural Resources / methods*
  • Endangered Species*
  • Extinction, Biological
  • Plant Stems / growth & development
  • Plant Stems / radiation effects
  • Rainforest*
  • Risk
  • Sunlight*
  • Tracheophyta / growth & development*
  • Tracheophyta / physiology
  • Tracheophyta / radiation effects*

Grants and funding

PJB was supported by an Australian Research Council Future Fellowship (FT120100715). HCZ’s doctoral research is funded by an Australian Postgraduate Award and the Wollemi Pine Recovery Team. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.