flow_t: Flow-T index

In alexology/biomonitoR: biomonitoring indices and metrics

Flow-T index

Description

This function calculates the Flow-T index.

Usage

flow_t(x, tax_lev = "Taxa", type = "ab", trans = NULL)

Arguments

x	Result of aggregate_taxa().
tax_lev	Taxonomic level at which the calculation has to be performed.
type	Presence only po or abundance ab.
trans	The function used to transform the abundances, by default log1p.

Details

This function calculates the Flow_T index developed by Laini et al. (2022). Flow-T is calculated using the current velocity preference categories for each sample using:

Flow-T= \frac{\sum_{i=1}^{n}\log(A_i + 1)(m_i + f_i)}{\sum_{i=1}^{n}\log(A_i + 1)}

Where n represents the number of taxa in a sample, A_i the abundance of the ith taxon, mi and fi the "moderate" and "fast" velocity preference classes of the ith taxon according to Tachet et al. (2010). The logarithm of the abundance can be replaced by 1 to obtain the presence-absence version of the Flow-T index.

References

Laini, A., Burgazzi, G., Chadd, R., England, J., Tziortzis, I., Ventrucci, M., Vezza, P., Viaroli, P., Wood, P.J. & Guareschi, S. (2022). Using invertebrate functional traits to improve flow variability assessment within European rivers. Science of The Total Environment, 832, 155047.

Tachet, H., Richoux, P., Bournaud, M., Usseglio-Polatera, P., (2010). Invertebres d'eau douce: Systematique, biologie, ecologie, edition revue et augmentee. CNRS EDITIONS, Paris.

See Also

as_biomonitor assign_traits

Examples

data(mi_prin)
data_bio <- as_biomonitor(mi_prin)
data_agr <- aggregate_taxa(data_bio)
data_ts <- assign_traits(data_agr)

alexology/biomonitoR documentation built on Oct. 10, 2024, 12:02 a.m.