Sunlight and red to far-red ratio impact germination of tropical montane cloud forest species

• DOI: 10.1071/bt22126
• Publication Date: 2023-04-21T06:49:46Z
• Authors: Gemma L. Hoyle; Amelia V. Stevens; Lydia K. Guja; Karen D. Sommerville; Stuart Worboys; Darren M. Crayn
• Keywords: Cloud forest; Far-red; Endemism

Context Australia’s tropical montane cloud forests (TMCF) exhibit exceptional species richness and endemism. Determinants of regeneration via seed these are next to unknown, limiting our ability quantify project their vulnerability climate change. The ratio red far-red light (R:FR) has been shown influence germination many species. Aims We investigated six previously unstudied TMCF in relation the presence or absence (light/dark) quality (R:FR). hypothesised that increased R:FR would lead small-seeded be more likely have a requirement less sensitive compared larger-seeded Methods Sunlight polyester filters were used create gradient ranging from 0.1 1.14. Seeds also sown constant darkness. Key results Across we saw varying responses. Three four smallest-seeded exhibited an absolute for did not discriminate between different R:FR. Germination endemic Dracophyllum exponentially with increasing largest-seeded was inhibited by both low high R:FR, higher darkness than diurnal light/dark. All able germinate at remarkably values. Conclusions Light affects plant variety ways. Implications findings this study provide insights into recruitment situ, acclimation potential under reduced predicted future.