Complexity vs linearity: relations between functional traits in a heterotrophic protist

BMC Ecology and Evolution

Research

Nils A. Svendsen¹  Virginie Thuillier¹  Nicolas Schtickzelle¹  Thibaut Morel-Journel²  Viktoriia Radchuk³ 

[1] Earth and Life Institute, Biodiversity Research Center, Université Catholique de Louvain, Louvain-La-Neuve, Belgium;Earth and Life Institute, Biodiversity Research Center, Université Catholique de Louvain, Louvain-La-Neuve, Belgium;Centre Interdisciplinaire de Recherche en Biologie (CIRB), Collège de France, PSL Research University, CNRS UMR 7241, Paris, France;Leibniz Institute for Zoo and Wildlife Research (IZW), Alfred-Kowalke-Straße 17, 10315, Berlin, Germany;

关键词: Functional traits;    Linearity assumption;    Soft/hard traits framework;    Tetrahymena thermophila;    Trait relations;   

DOI  :  10.1186/s12862-022-02102-w

 received in 2022-06-09, accepted in 2022-12-26,  发布年份 2022

来源: Springer

【 摘 要 】

BackgroundFunctional traits are phenotypic traits that affect an organism’s performance and shape ecosystem-level processes. The main challenge when using functional traits to quantify biodiversity is to choose which ones to measure since effort and money are limited. As one way of dealing with this, Hodgson et al. (Oikos 85:282, 1999) introduced the idea of two types of traits, with soft traits that are easy and quick to quantify, and hard traits that are directly linked to ecosystem functioning but difficult to measure. If a link exists between the two types of traits, then one could use soft traits as a proxy for hard traits for a quick but meaningful assessment of biodiversity. However, this framework is based on two assumptions: (1) hard and soft traits must be tightly connected to allow reliable prediction of one using the other; (2) the relationship between traits must be monotonic and linear to be detected by the most common statistical techniques (e.g. linear model, PCA).ResultsHere we addressed those two assumptions by focusing on six functional traits of the protist species Tetrahymena thermophila, which vary both in their measurement difficulty and functional meaningfulness. They were classified as: easy traits (morphological traits), intermediate traits (movement traits) and hard traits (oxygen consumption and population growth rate). We detected a high number (> 60%) of non-linear relations between the traits, which can explain the low number of significant relations found using linear models and PCA analysis. Overall, these analyses did not detect any relationship strong enough to predict one trait using another, but that does not imply there are none.ConclusionsOur results highlighted the need to critically assess the relations among the functional traits used as proxies and those functional traits which they aim to reflect. A thorough assessment of whether such relations exist across species and communities is a necessary next step to evaluate whether it is possible to take a shortcut in quantifying functional diversity by collecting the data on easily measurable traits.

【 授权许可】

CC BY   
© The Author(s) 2023

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