Description Usage Arguments Details Value Author(s) References See Also Examples
This function calculates Hill's Species Dominance (N2) for j areas and i years.
hillN2(X, groups, species.table = NULL, metric = "ABUNDANCE", years)
A dataframe of fishery independent data derived from research vessel
survey data or model output, with columns
A vector indicating the species group(s) for which to calculate
the indicator. If
A table where the column names match the entries in
A character string indicating which column in
A vector of years for which to calculate indicator.
Hill's Species Dominance (HillN2):
HillN2 = 1/Σ p_i^2
p_i is the proportion of the total sample contributed by the i(th) species. HillN2 is the inverse of the Simpson's index. This index is sensitive to the evenness of the distribution of individuals between species (Hill, 1973).
Returns a dataframe with columns
YEAR, and a
HillDominance_group for each entry in
If there is no data for spatial scale j in year i, indicator values is assigned NA.
Danielle Dempsey Danielle.Dempsey@dfo-mpo.gc.ca, Adam Cook, Catalina Gomez, Alida Bundy
Bundy A, Gomez C, Cook AM. 2017. Guidance framework for the selection and evaluation of ecological indicators. Can. Tech. Rep. Fish. Aquat. Sci. 3232: xii + 212 p.
Greenstreet SP, Rogers SI. 2006. Indicators of the health of the North Sea fish community: identifying reference levels for an ecosystem approach to management. ICES J Mar Sci J du Cons 63:573-593
Hill MO. 1973. Diversity and evenness: a unifying notation and its consequences. Ecology 54: 427-431.
Other biodiversity indicators:
ID YEAR HillDominance_ALL 1 AREA1 2014 3.951117 2 AREA1 2015 3.903130 3 AREA1 2016 3.174042 4 AREA1 2017 4.679784 5 AREA1 2018 5.597405 6 AREA1 2019 2.447229 7 AREA2 2014 4.886472 8 AREA2 2015 3.987204 9 AREA2 2016 4.597779 10 AREA2 2017 4.387534 11 AREA2 2018 3.031386 12 AREA2 2019 3.118748
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