The conservation and breeding of Eucalyptus urophylla: a case study to better protect important populations and improve productivity

Abstract

Eucalyptus urophylla is one of the most commercially important forest species in the world, primarily as a hybrid parent. However, the conservation status of the majority of the populations where it naturally occurs on seven islands in eastern Indonesia range from critically endangered to vulnerable. We examine the evolutionary forces that might have caused genetic variation within and between E. urophylla populations and link these findings to international provenance trial results and molecular marker studies. We demonstrate that one climatic type does not describe all E. urophylla populations. We suggest that volcanism played an important role in its distribution and levels of genetic diversity on the islands. We report significant provenance variation for survival and growth in trials established in Brazil, Colombia, Mexico, South Africa and Venezuela. Provenance differences for growth within a country are sometimes >50%. Based on these assessments, we develop an ex situ conservation strategy to protect populations that are most threatened but also show the greatest productivity across countries. We conclude that populations of E. urophylla will only be conserved ex situ if traditional and molecular tree breeders convince private industry of the economic importance to do so.