AZTI Marine Biotic Index

Borja et al. (2000) introduced the AZTI Marine Biotic Index (AMBI). It is a weighted linear combination of species sensitivity classes. The average percentage of the total abundance per sample without an AMBI classification is given below:

if (tibble::has_name(d_mmi, "AMBI_GROUP")) {
    d <- d_mmi %>% 
        group_by(OBJECTID, HABITAT, YEAR) %>%
        mutate(N = sum(VALUE)) %>%
        filter(has_ambi(taxon = TAXON, group = AMBI_GROUP)) %>%
        summarise(AMBI_MISSING = 100 * (1 - sum(VALUE) / unique(N)))
} else {
    d <- d_mmi %>% 
        group_by(OBJECTID, HABITAT, YEAR) %>%
        mutate(N = sum(VALUE)) %>%
        filter(has_ambi(taxon = TAXON)) %>%
        summarise(AMBI_MISSING = 100 * (1 - sum(VALUE) / unique(N)))
}

d %>% xtable %>%
    print(type = "html")

Note that in r sum(d$AMBI_MISSING > 20) cases, more than 20% of the total abundance does not have an AMBI classification.



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BENMMI documentation built on Oct. 23, 2020, 8:24 p.m.