Robustness of trait connections across environmental gradients and growth forms

Habacuc Flores-Moreno*, Farideh Fazayeli, Arindam Banerjee, Abhirup Datta, Jens Kattge, Ethan E. Butler, Owen K. Atkin, Kirk Wythers, Ming Chen, Madhur Anand, Michael Bahn, Chaeho Byun, J. Hans C. Cornelissen, Joseph Craine, Andres Gonzalez-Melo, Wesley N. Hattingh, Steven Jansen, Nathan J.B. Kraft, Koen Kramer, Daniel C. LaughlinVanessa Minden, Ülo Niinemets, Vladimir Onipchenko, Josep Peñuelas, Nadejda A. Soudzilovskaia, Rhiannon L. Dalrymple, Peter B. Reich

*Corresponding author for this work

Research output: Contribution to JournalArticle

Abstract

Aim: Plant trait databases often contain traits that are correlated, but for whom direct (undirected statistical dependency) and indirect (mediated by other traits) connections may be confounded. The confounding of correlation and connection hinders our understanding of plant strategies, and how these vary among growth forms and climate zones. We identified the direct and indirect connections across plant traits relevant to competition, resource acquisition and reproductive strategies using a global database and explored whether connections within and between traits from different tissue types vary across climates and growth forms. Location: Global. Major taxa studied: Plants. Time period: Present. Methods: We used probabilistic graphical models and a database of 10 plant traits (leaf area, specific leaf area, mass- and area-based leaf nitrogen and phosphorous content, leaf life span, plant height, stem specific density and seed mass) with 16,281 records to describe direct and indirect connections across woody and non-woody plants across tropical, temperate, arid, cold and polar regions. Results: Trait networks based on direct connections are sparser than those based on correlations. Land plants had high connectivity across traits within and between tissue types; leaf life span and stem specific density shared direct connections with all other traits. For both growth forms, two groups of traits form modules of more highly connected traits; one related to resource acquisition, the other to plant architecture and reproduction. Woody species had higher trait network modularity in polar compared to temperate and tropical climates, while non-woody species did not show significant differences in modularity across climate regions. Main conclusions: Plant traits are highly connected both within and across tissue types, yet traits segregate into persistent modules of traits. Variation in the modularity of trait networks suggests that trait connectivity is shaped by prevailing environmental conditions and demonstrates that plants of different growth forms use alternative strategies to cope with local conditions.

Original languageEnglish
Pages (from-to)1806-1826
Number of pages21
JournalGlobal Ecology and Biogeography
Volume28
Issue number12
Early online date1 Sep 2019
DOIs
Publication statusPublished - Dec 2019

Keywords

  • leaf traits
  • plant functional traits
  • plant strategy integration
  • seed traits
  • stem traits
  • trait interdependence
  • trait networks

Cite this

Flores-Moreno, H., Fazayeli, F., Banerjee, A., Datta, A., Kattge, J., Butler, E. E., ... Reich, P. B. (2019). Robustness of trait connections across environmental gradients and growth forms. Global Ecology and Biogeography, 28(12), 1806-1826. https://doi.org/10.1111/geb.12996