Functional Traits

Abstract

Functional traits are morphological, biochemical, physiological, structural, phenological or behavioural characteristics of organisms that influence performance or fitness. Grouping species by functional characteristics is a long‐standing idea, but there has more recently been rapid development in the application of trait‐based approaches to diverse topics in ecology. Two common applications of functional traits are to characterise community responses to changes in the environment, including community assembly processes, and to quantify the influence of community shifts on ecosystem processes. Practical decisions include: What types of traits should be considered? How can traits be measured or inferred? Are traits correlated or traded‐off? Which, and how many, traits should be assessed? How should trait data be analysed? Functional trait approaches enhance ecological understanding by focusing on the mechanisms that govern interactions between organisms and their environments. Measuring and understanding traits increases our understanding of ecological processes, thus also informing conservation and restoration. Key Concepts Functional traits are morphological, biochemical, physiological, structural, phenological or behavioural characteristics that influence organism performance or fitness. Traits can be broadly classified either as having an effect on ecosystem properties and the services that human societies derive from them, or as characterising a response to environmental change or with respect to processes affecting community assembly. Common data types for traits include continuous, categorical, ordinal and binary variable formats. The data type has repercussions for subsequent data analyses. Methods for measuring traits vary from time‐consuming (hard traits) to rapid (soft traits), and in turn the information content of the resulting data also varies. Trait syndromes describe patterns of inter‐trait correlation that define differences and trade‐offs in ecological strategies. When choosing traits for calculating functional diversity it is important to consider which, and how many, traits are included, as well as what insights they will provide into the ecosystem processes, community structure or assembly processes under consideration. Functional traits are at the forefront of efforts to develop a mechanistic understanding of how species diversity influences ecosystem functioning, and the current ecological literature presents many indices by which functional diversity can be computed.

Unifying functional trait approaches to understand the assemblage of ecological communities: synthesizing taxonomic divides

“…Functional traits can be physiological, morphological or behavioral. Significant work throughout the literature discusses this dichotomy between response and effect traits (Díaz and Cabido 2001, Lavorel and Garnier 2002, Violle et al 2007, Díaz et al 2013, Nock et al 2016). However, it can be difficult to quantify traits that correspond with organismal performance (see discussion on performance currencies in McGill et al 2006) and many trait definitions do not include impacts on performance as a requisite for functionality (Table 1).…”

“…Discrepancies in trait definitions may be due in part to researcher focus on effect traits, which most often reflect ecosystem health and processes as opposed to fitness and performance (Lavorel andGarnier 2002, Díaz et al 2013). Significant work throughout the literature discusses this dichotomy between response and effect traits (Díaz and Cabido 2001, Lavorel and Garnier 2002, Violle et al 2007, Díaz et al 2013, Nock et al 2016). Since the hierarchical filtering of traits mediates the formation of ecological communities (Morin 2011, Aronson et al 2016, for cross-taxa comparisons we recommend the use of response traits that incorporate organismal performance and fitness relative to ecological filters and assembly processes.…”

Managing biological control services through multi‐trophic trait interactions: review and guidelines for implementation at local and landscape scales

“…Rather, functions are often inferred from easily measured characteristics (i.e. soft traits sensu Nock, Vogt & Beisner, 2016). Body size, for example, is a presently ambiguous arthropod trait.…”

Functional Response Trait Analysis Improves Climate Sensitivity Estimation in Beech Forests at a Trailing Edge

“…During the last three decades, the species-based trait concept has been generalized and interpreted at several levels ranging from populations to ecosystems [1][2][3]. This novel approach has been widely used in community and ecosystem ecology to define functional traits addressing the underlying concept that refers to [2][3][4][5][6]. In most cases, a trait is defined at the level of individuals, but the interpretation can be presented at any organizational level (e.g., community).…”