piecewise structural equation modeling (Ambystomatidae)

Knowledge graph centered on piecewise structural equation modeling (Ambystomatidae) with 25 nodes and 97 connections. Top connected: Lepidoptera, aquatic insects, Ambystoma, phenotypic plasticity, Ambystoma tigrinum.

Method synopsis

Used mixed-effects SEM framework to determine direct and indirect effects of climate and density-dependent variables on larval body size and morph outcome. Models incorporated random effects for cohort and correlation structures for temporal autocorrelation.

Synthesized from method descriptions across 1 paper using this protocol.

Procedure from a recent peer-reviewed implementation

Steps below were extracted from the most recent peer-reviewed implementation of this protocol in the corpus — Climate mediates the trade-offs associated with phenotypic plasticity in an amphibian polyphenism (2024), Journal of Animal Ecology. Implementations in other papers (listed below) may differ.

1. Body size measurement
   Measured relative snout-vent length (SVL) calculated as larva's absolute SVL relative to average SVL of all other larvae from that natal pond in given year. Relative SVL chosen over absolute SVL and body condition due to higher modelling performance and ability to account for between-pond variation in density-dependent effects.
   Quantities: Relative SVL measurements standardized within pond and year for all 717 individualsDuration: Measured at time of morph determination for each individualConditions: Measured relative to pond-specific and year-specific averages to control for environmental variation
   Equipment: SVL measurement tools, standardization calculations

Typical Equipment

• piecewiseSEM R package
• R statistical software

Output Measurements

• path coefficients
• direct effects
• indirect effects
• model fit statistics

Papers Using This Protocol (1)

Species Studied With This Protocol