English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

1. Sample size estimation through power analysis is a fundamental tool inplanning an ecological study, yet there are currently no well-establishedprocedures for when multivariate abundances are to be collected. A poweranalysis procedure would need to address three challenges: designing aparsimonious simulation model that captures key community data properties;measuring effect size in a realistic yet interpretable fashion; and ensuringcomputational feasibility when simulation is used both for power estimation andsignificance testing. 2. Here we propose a power analysis procedure thataddresses these three challenges by: using for simulation a Gaussian copulamodel with factor analytical structure, fitted to pilot data; assuming a commoneffect size across all taxa, but applied in different directions according toexpert opinion (to "increaser", "decreaser" or "no effect" taxa); using acritical value approach to estimate power, which reduces computation time by afactor of 500 with little loss of accuracy. 3. The procedure is demonstrated onpilot data from fish assemblages in a restoration study, where it was foundthat the planned study design would only be capable of detecting relativelylarge effects (change in abundance by a factor of 1.5 or more). 4. The methodsoutlined in this paper are available in accompanying R software (the ecopowerpackage), which allows researchers with pilot data to answer a wide range ofdesign questions to assist them in planning their studies.

How many sites? Methods to assist design decisions when collecting multivariate data in ecology