Measures and Approaches in Trait-Based Phytoplankton Community Ecology – From Freshwater to Marine Ecosystems

Abstract

Trait-based approaches to investigate (short-and long-term) phytoplankton dynamics and community assembly have become increasingly popular in freshwater and marine science. Although the nature of the pelagic habitat and the main phytoplankton taxa and ecology are relatively similar in both marine and freshwater systems, the lines of research have evolved, at least in part, separately. We compare and contrast the approaches adopted in marine and freshwater ecosystems with respect to phytoplankton functional traits. We note differences in study goals relating to functional trait use that assess community assembly and those that relate to ecosystem processes and biogeochemical cycling that affect the type of characteristics assigned as traits to phytoplankton taxa. Specific phytoplankton traits relevant for ecological function are examined in relation to herbivory, amplitude of environmental change and spatial and temporal scales of study. Major differences are identified, including the shorter time scale for regular environmental change in freshwater ecosystems compared to that in the open oceans as well as the type of sampling done by researchers based on site-accessibility. Overall, we encourage researchers to better motivate why they apply trait-based analyses to their studies and to make use of process-driven approaches, which are more common in marine studies. We further propose fully comparative trait studies conducted along the habitat gradient spanning freshwater to brackish to marine systems, or along geographic gradients. Such studies will benefit from the combined strength of both fields.

Quality–quantity trade‐offs drive functional trait evolution in a model microalgal ‘climate change winner’

“…To understand how the evolved strategies for growing in a persistent high pCO 2 environment can impact ecological function under environmental amelioration, we report our data as traits commonly used in aquatic ecosystem or biogeochemical models: cell size, biovolume (as a proxy for biomass) production per day and chlorophyll a production per day (Litchman & Klausmeier, ; Weithoff & Beisner, ). See Figs g and .…”

Quality-quantity tradeoffs drive functional trait evolution in a model microalgal “climate change winner”

“…The impact of Prodigal Son dynamics on projecting functional traits of future populations. To understand how the evolved strategies for growing in a persistent high pCO2 environment can impact ecological function under environmental amelioration, we report our data as traits commonly used in aquatic ecosystem or biogeochemical models: cell size, biovolume (as a proxy for biomass) production per day, chlorophyll a production per day (37,38). See Figures 1G and 3.…”

Decadal shifts of coastal microphytoplankton communities in a semi-enclosed bay of NW Mediterranean Sea subjected to multiple stresses

“…In application of the guild concept (Root, 1967), trait-based approaches using measurable properties from organisms (McGill et al, 2006) are nowadays currently used to summarize the functional diversity of phytoplankton communities. Cell size has been considered as a "master trait" (Weithoff and Beisner, 2019), as it conditioned many physiological and ecological functions such as metabolic rate (López-Urrutia et al, 2006), nutrient intakes (Grover, 1989;Marañón, 2015) or trophic interactions (Barton et al, 2013;Hansen et al, 1994). Early on, size-based approaches succeed to describe important succession and distribution patterns related to environment such as the classical diatoms to dinoflagellates phenological succession in temperate coastal systems (Margalef, 1978) or the description of community niches along environmental gradients Reynolds, 2003, 2001).…”