Handbook of protocols for standardized measurement of terrestrial invertebrate functional traits

Abstract

Summary 1.Trait-based approaches are increasingly being used to test mechanisms underlying species assemblages and biotic interactions across a wide range of organisms including terrestrial arthropods and to investigate consequences for ecosystem processes. Such an approach relies on the standardized measurement of functional traits that can be applied across taxa and regions. Currently, however, unified methods of trait measurements are lacking for terrestrial arthropods and related macroinvertebrates (terrestrial invertebrates hereafter). 2. Here, we present a comprehensive review and detailed protocol for a set of 29 traits known to be sensitive to global stressors and to affect ecosystem processes and services. We give recommendations how to measure these traits under standardized conditions across various terrestrial invertebrate taxonomic groups. 3. We provide considerations and approaches that apply to almost all traits described, such as the selection of species and individuals needed for the measurements, the importance of intraspecific trait variability, how many populations or communities to sample and over which spatial scales. 4. The approaches outlined here provide a means to improve the reliability and predictive power of functional traits to explain community assembly, species diversity patterns and ecosystem processes and services within and across taxa and trophic levels, allowing comparison of studies and running meta-analyses across regions and ecosystems. Ecology 2017Ecology , 31, 558-567 doi: 10.1111Ecology /1365Ecology -2435 5. This handbook is a crucial first step towards standardizing trait methodology across the most studied terrestrial invertebrate groups, and the protocols are aimed to balance general applicability and requirements for special cases or particular taxa. Therefore, we envision this handbook as a common platform to which researchers can further provide methodological input for additional special cases.

Combining functional traits and phylogeny to disentangling Amazonian butterfly assemblages on anthropogenic gradients

“…Among them, butterflies are a group known to respond rapidly to environmental changes, and because of their relatively wellknown taxonomy represent an ideal study system for assessing the effects of disturbances in forests (Bonebrake et al 2010). Moreover, standardized functional traits for several insect groups have been proposed as important predictors of community structuring (Moretti et al 2017). This includes quantifiable morphological, physiological, and behavioral traits, which reflect different adaptation and survival strategies in heterogeneous environments (Violle et al 2007).…”

“…However, based on the natural history knowledge about butterflies, and testable protocols existing for other arthropod groups (Fountain-Jones et al 2015, Moretti et al 2017, the understanding of functional composition in butterflies along forest gradients requires an analysis of four major functional categories: flight performance, defense strategies, ecophysiological characteristics, and habitat perception. However, based on the natural history knowledge about butterflies, and testable protocols existing for other arthropod groups (Fountain-Jones et al 2015, Moretti et al 2017, the understanding of functional composition in butterflies along forest gradients requires an analysis of four major functional categories: flight performance, defense strategies, ecophysiological characteristics, and habitat perception.…”

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

“…For example, when investigating how plant and animal traits change along an elevation gradient, the study should target traits that specifically influence or respond to changes in elevation. However, height -or rather, body size -in terrestrial invertebrates may correspond more strongly to fecundity (Fountain-Jones et al 2015) or resource use (Moretti et al 2017) than competitive ability. Similarly, studies may only include a few traits that are easy to measure without describing how these traits directly correspond to the research question or ecological processes (see Discussion in Brousseau et al 2018).…”

Shifts in mollusc traits following floodplain reconnection: Testing the response of functional diversity components

“…Functional traits and their diversity are powerful tools indicating both the mechanisms driving community compositions after environmental changes and their subsequent effects on ecosystem processes Moretti et al, 2017). Response traits (i.e.…”