The diversity of traits associated with plant regeneration is often shaped by functional trade-offs where plants typically do not excel at every function because resources allocated to one function cannot be allocated to another. By analyzing correlations among seed traits, empirical studies have shown that there is a trade-off between seedling development and the occupation of new habitats, although only a small range of taxa have been tested; whether such trade-off exists in a biodiverse and complex landscape remains unclear.

Research group lead by Prof. LI Dezhu from Kunming Institute of Botany, Chinese Academy of Sciences (KIB/CAS) is focused on the taxonomy, systematics and seed ecology, and has recently conducted a study of the functional trade-offs of seeds.

This study amassed seed trait data of 1,119 species from a biodiversity hotspot of the Mountains of Southwest China and analyzed the relationship between seed mass and the number of seeds and between seed mass and time to germination.

The research results showed that seed mass was negatively correlated with seed number but positively correlated with time to germination (Figure 1). The same trend was found regardless of variation in life-form and phylogenetic conservatism.

Furthermore, the relationship between seed mass and other seed traits was randomly dispersed across the phylogeny at both the order and family levels (Figure 2).

This study suggests that there is a functional trade-off between seedling development and new habitat occupation for seed plants in the Mountains of Southwest China. Larger seeds tend to produce fewer seedlings but with greater fitness compared to those produced by smaller seeds, whereas smaller seeds tend to have a larger number of seeds that germinate faster compared to large-seeded species.

This study provides a mechanistic explanation for the relatively high levels of plant diversity currently found in a heterogeneous region of the Mountains of Southwest China.

The research finding has been published in Ecology and Evolution entitled “ Functional trade-offs and the phylogenetic dispersion of seed traits in a biodiversity hotspot of the Mountains of Southwest China'.

This study was supported by the Conservation Center in Germplasm Bank of Wild Species, the National Key Basic Research Program of China (2014CB954100), the Program of Science and Technology Talents Training of Yunnan Province (2017HA014), and the Applied Fundamental Research Foundation of Yunnan Province (2014GA003).