Drivers of carabid functional diversity: abiotic environment, plant functional traits, or plant functional diversity?

Abstract

Understanding how community assembly is controlled by the balance of abiotic drivers (environment or management) and biotic drivers (community composition of other groups) is important in predicting the response of ecosystems to environmental change. If there are strong links between plant assemblage structure and carabid beetle functional traits and functional diversity, then it is possible to predict the impact of environmental change propagating through different functional and trophic groups. Vegetation and pitfall trap beetle surveys were carried out across twenty four sites contrasting in land use, and hence productivity and disturbance regime. Plant functional traits were very successful at explaining the distribution of carabid functional traits across the habitats studied. Key carabid response traits appeared to be body length and wing type. Carabid functional richness was significantly smaller than expected, indicating strong environmental filtering, modulated by management, soil characteristics, and by plant response traits. Carabid functional divergence was negatively related to plant functional evenness, while carabid functional evenness was positively correlated to plant functional evenness and richness. The study shows that there are clear trait linkages between the plant and the carabid assemblage that act not only through the mean traits displayed, but also via their distribution in trait space; powerful evidence that both the mean and variance of traits in one trophic group structure the assemblage of another.

Revisiting the Holy Grail: using plant functional traits to understand ecological processes

“…Consequently, efforts which seek to expand upon our understanding of critical traits must consider abiotic and biotic context as fully as possible and seek to develop models which account for these interactions in a given system, especially across trophic levels (e.g. Lavorel et al, 2013;Pakeman & Stockan, 2014;Deraison et al, 2015). Once key traits are identified and specific hypotheses are generated regarding their links to responses and effects, other statistical approaches such as structural equation modelling can be applied to test how multiple traits ultimately drive community structure (see Section IV.2).…”

Handbook of protocols for standardized measurement of terrestrial invertebrate functional traits

“…; Moretti et al . ; Pakeman & Stockan ; Deraison et al . ), although the degree of overlap between the two types of traits will determine our ability to predict changes in key ecosystem processes under variable environmental conditions.…”

Seeking salt: herbivorous prairie insects can be co‐limited by macronutrients and sodium

“…It is also necessary for the control of some herbivore species that cause damage (Hulme 1994;Branson et al 2006) and to support those species that are important purveyors of ecosystem services (McNaughton et al 1997;Prather et al 2012). Several canonical factors are typically thought to largely regulate herbivore communities, including top-down consumers (Spiller & Schoener 1990;Dial & Roughgarden 1995) and bottom-up resources, typically characterised as plant biomass (Lawton 1983;McNaughton et al 1989;Lewinsohn et al 2005;Wimp et al 2010), plant diversity (Hutchinson 1959;May 1990;Siemann et al 1998;Pakeman & Stockan 2014), and plant nutritional quality (White 1984;Fagan et al 2002;Huberty & Denno 2006;Joern et al 2012). Although manipulations of any one these factors has usually resulted in some change to herbivore communities, our ability to explain herbivore abundance and diversity is still relatively weak.…”