Differential seed germination responses to the ratio of red to far-red light in temperate and tropical species

Pimonrat Tiansawat, James W. Dalling

Research output: Contribution to journalArticlepeer-review


Variation in vegetation density creates a range of red to far-red ratios of irradiance (R:FR) potentially permitting fine-scale discrimination of light conditions for seed germination. However, remarkably few studies have explored whether R:FR responses of germination vary among species that differ in distribution and life-history traits. In this study, we explored the relationships between R:FR requirements and four species characteristics: seed mass, latitudinal distribution (tropical vs. temperate), seed dormancy (dormant vs. nondormant), and plant growth form (woody vs. nonwoody). We obtained data on germination response to R:FR of 62 species from published literature and added new data for ten species from aseasonal tropical forests in Borneo. First, we analyzed whether species characteristics influenced overall light dependency of germination using phylogenetic logistic regression. We found that seed mass had a strong negative effect on light dependency, but that the seed mass at which tropical taxa had a 50 % probability of light dependency was 40 times that of temperate taxa. For light-dependent species, we found that the threshold R:FR that stimulates 50 % of maximum germination (R:FR50) was also related to seed mass and latitudinal distribution. In agreement with an earlier study, we found that for temperate taxa, the R:FR50 was significantly negatively correlated with seed mass. In contrast, for 22 tropical taxa, we found a significant positive correlation. These opposing relationships suggest contrasting selection pressures on germination responses of tropical taxa (mostly trees) and temperate herbaceous plants, and which are likely related to differences in seed longevity, seed burial rates, and reproductive output.

Original languageEnglish (US)
Pages (from-to)751-764
Number of pages14
JournalPlant Ecology
Issue number5
StatePublished - May 2013


  • Lambir Hill National Park
  • Light dependence
  • Light quality
  • Regeneration niche
  • Seed mass

ASJC Scopus subject areas

  • Ecology
  • Plant Science


Dive into the research topics of 'Differential seed germination responses to the ratio of red to far-red light in temperate and tropical species'. Together they form a unique fingerprint.

Cite this