Functional traits related to environmental divergence in combination with phylogenetic relationship of Picea species

Abstract

Background: Plants have adapted to fine-scale environmental heterogeneity through ecologically important traits, leading to new lineages. This suggests that differentiation of important traits has been beneficial to habitat partitioning among closely related species. However, the pattern of ecological divergences and differentiation of functional traits in combination with phylogenetic relationships have not been widely examined. Material and methods: To illustrate the pattern of ecological divergences of nine Picea species, spatial evolutionary and ecological vicariance analysis (seeva) was used to quantify and test the divergence between sister lineages. Five functional traits were measured in a common garden experiment. For all traits the quantitative convergence index (QVI) was determined. Furthermore, their relationships with divergent environmental variables were analyzed in the context of phylogenetic relationships. Results: Temperature variables (maximum temperature of warmest month and temperature annual range) split at basal nodes and precipitation variables (annual precipitation and precipitation of driest quarter) split at terminal nodes. Conservative traits were leaf mass per area (LMA) and net photosynthetic rate (Pn), which reflected selective retention when ancestors suffered cold environmental separation. Meanwhile, linear stomatal density (LSD), carbon-13 isotope ratio (δ 13 C) and water potential at 50% loss of hydraulic conductivity (P 50) were convergent between species, but only P 50 exhibited adaption to different precipitation conditions. The nine Picea species exhibit a distinct environmental divergence pattern. LMA and Pn were selectively retained when their ancestors were subjected to cold environmental separation. P 50 was an important trait with respect to adaptation to precipitation differences. This research provided a new way of expounding the correlation between environment, functional traits and phylogeny, deepening our understanding of environmental divergence, trait differentiation and speciation.

Stomatal density in Pinus sylvestris as an indicator of temperature rather than CO2: Evidence from a pan‐European transect

“…This effect of MAT as a positive driver of intraspecific SD in Scots pine is consistent with the previously reported latitudinal decline in SD between tropical and cool temperate forests, at both a species and community level (R. Wang et al, 2015). Notably, however, our provenance trial results contrast with the findings in nine Picea species, representing provenances with MAT ranging from 3.7°C to 9.5°C (M. Wang et al, 2018), nine provenances of Abies sachalinensis from diverse elevations with MAT ranging from 1.5°C to 6.5°C (Taneda et al, 2020), and five Populus provenances from sites between 1°C and 12°C (Gornal & Guy, 2007), all of which exhibited negative relationships between SD and MAT. These studies, however, did not report corresponding field data.…”

Does Cathaya argyrophylla, an ancient and threatened Pinaceae species endemic to China, show eco-physiological outliers to its Pinaceae relatives?

“…As such, not only morphological traits ( Nobis et al , 2012 ) but also the key physiological functions of hydraulic safety and photosynthetic capacity showed phylogenetic niche conservation (PNC) signals among Pinaceae species. On the other hand, Wang et al (2018 ) found that P n showed more PNC than P 50 among nine Picea species in mid-China, which is opposite to our finding. This is probably due to the ‘local scale effect’ ( Forrestel et al , 2017 ) or statistical ‘funnel effect’ caused by the insufficient species amount investigated ( Blomberg et al ., 2003 ; Wright et al , 2005 ).…”