Functional traits of marine macrophytes predict primary production

Abstract

Summary The relationship between community structure and the functioning of ecosystems is the subject of ongoing debate. Biological or functional trait‐based approaches that capture life strategy, morphology and behavioural characteristics have received far less attention than taxonomic diversity in this context, despite their more intuitive link to ecosystem functioning. Macrophyte primary production underpins aquatic food webs, regulates benthic and pelagic ecosystems and is a key aspect of the global carbon cycle. This study spans a range of aquatic biomes across Europe and aims to examine potential for predicting primary production of macrophyte communities based on the functional traits of species and identify the traits that are the most informative indicators of macrophyte production. Macrophyte primary production was assessed based on the oxygen production of the whole community, linked to biomasses of selected biological traits derived of its component species and analysed using the novel boosted regression trees modelling technique. Results showed that functional traits derived from macrophyte community data explained most of the variation in primary production of macrophyte communities without the need to incorporate environmental data on the habitats. Macrophyte primary production was influenced by a combination of tolerance, morphology and life habit traits; however tolerance traits contributed most of variability in macrophyte primary production when all traits were analysed jointly. This study also showed the existence of trait clustering as the studied trait categories were not fully independent; strong interlinkages between and within trait categories emerged. Our study suggests that functional trait analysis captures different aspects of ecosystem functioning and thereby enables assessing primary production of macrophyte communities over geographically distinct areas without extensive taxonomic and environmental data. This could result in a novel framework through which a simplification of the general procedure of production estimations and comparisons across environmental gradients can be achieved. A http://onlinelibrary.wiley.com/doi/10.1111/1365-2435.12798/suppinfo is available for this article.

Latitudinal variation in the competition‐colonisation trade‐off reveals rate‐mediated mechanisms of coexistence

“…It is also possible that trade‐offs for multiple traits exist, such as the classic C‐S‐R trait trade‐off triangle (Grime ), although it seems this specific mechanism is unlikely to apply to marine systems (Jänes et al . ). It is therefore important to recognise the context‐dependency of the mechanisms that support diversity and coexistence, which could vary in significance over time and across study systems.…”

Habitat variability in an underwater forest: Using a trait‐based approach to predict associated communities

“…For example, a variety of traits relating to life history, morphology and chemistry of terrestrial plants have been found to predict susceptibility to herbivory (Carmona, Lajeunesse, & Johnson, ). Similarly, the functional traits of macrophytes can be important predictors of primary production in marine systems (Jänes et al, ).…”

“…Similarly, the functional traits of macrophytes can be important predictors of primary production in marine systems (Jänes et al, 2017).…”

When form does not predict function: Empirical evidence violates functional form hypotheses for marine macroalgae

“…This framework was originally developed for terrestrial vegetation (Chapin, 1993; Eviner & Chapin, 2003; Grime, 1974; McGill et al., 2006; Voille et al., 2007; Wright et al., 2004) to understand mechanisms of community assembly and ecosystem functioning, but has been increasingly applied to other taxa such as marine phytoplankton (Edwards et al., 2013; Litchman & Klausmeier, 2008) and terrestrial fauna (García‐Llamas et al., 2019). There have been some promising recent efforts in this direction for marine macroalgae (Cappelatti et al., 2019; Jänes et al., 2017; Mauffrey et al., 2020; Stelling‐Wood et al., 2020), with functional traits successfully predicting in macroalgal productivity (Jänes et al., 2017) and associated community structure (Stelling‐Wood et al., 2020), as well as providing stronger links with macroalgal strategies and functions (Cappelatti et al., 2019; Mauffrey et al., 2020). However, more work is needed to understand which traits are most informative for macroalgal eco‐physiology and function.…”