Type: | Package |
Title: | Marine Benthic Ecosystem Analysis |
Description: | Preprocessing tools and biodiversity measures (species abundance, species richness, population heterogeneity and sensitivity) for analysing marine benthic data. See Van Loon et al. (2015) <doi:10.1016/j.seares.2015.05.002> for an application of these tools. |
Version: | 1.3-9 |
Date: | 2025-07-04 |
Depends: | R (≥ 3.6.0) |
Imports: | dplyr (≥ 0.7.0), lazyeval, readr, utils |
Suggests: | testthat (≥ 2.1.0), rmarkdown, knitr, ggplot2, tidyr |
VignetteBuilder: | knitr |
LazyData: | true |
Encoding: | UTF-8 |
License: | GPL (≥ 3) |
RoxygenNote: | 7.3.2 |
NeedsCompilation: | no |
Packaged: | 2025-07-04 08:15:22 UTC; dennis |
Author: | Dennis Walvoort [aut, cre, cph] |
Maintainer: | Dennis Walvoort <dennis.Walvoort@wur.nl> |
Repository: | CRAN |
Date/Publication: | 2025-07-04 08:30:02 UTC |
Marine Benthic Ecosystem Analysis
Description
benthos provides functions for facilitating the analysis of marine benthos data. Examples are indicators like species abundance, species richness, Margalef's index of diversity, Shannon's Entropy, AZTI's Marine Biotic Index, and the Infaunal Trophic Index (ITI). In addition functions for data pooling, genus-to-species conversion and validation and conversion of species names to those recommended by the World Register of Marine Species are provided.
Details
All functions are designed to work seamlessly with the dplyr-package which implements a grammar for structured data manipulation.
The benthos-package contains functions for estimating various species abundance, species richness, species heterogeneity and species sensitivity measures:
total abundance (
total_abundance
)abundance (
abundance
)species richness (
species_richness
)Margalef's index of diversity (
margalef
)Rygg's index of diversity (
rygg
)Hurlbert's Expected Number of Species (
hurlbert
)Simpson's measure of concentration (
simpson
)Hurlbert's probability of interspecific encounter (PIE) (
hpie
)Shannon's index or entropy (
shannon
)Hill's diversity number (
hill
)AZTI Marine Biotic Index (AMBI) (
ambi
)Infaunal Trophic Index (ITI) (
iti
)Bray-Curtis dissimilarity (
bray_curtis
)
In addition, functions are available for data preparation, e.g.:
data pooling (
pool
)genus to species conversion (
genus_to_species
)
For an overview of all the functions in the package click on the index link at the bottom of this page.
Author(s)
Dennis Walvoort dennis.walvoort@wur.nl
See Also
The BEQI2-package on CRAN, and the package vignettes.
Abundance
Description
The number of indiviuals in each taxon.
Usage
abundance(.data = NULL, taxon = NULL, count)
abundance_(.data = NULL, taxon = NULL, count)
Arguments
.data |
data in a |
taxon |
name of column in |
count |
name of column in |
Value
numeric
vector with abundance per taxon.
Functions
-
abundance_()
: version suitable for calling from a function (see package lazyeval).
Note
due to pooling, the abundance is not necessarily an integer
Examples
abundance(
taxon = c("Euspira pulchella", "Nephtys cirrosa"),
count = c(4, 6)
)
AZTI Marine Biotic Index (AMBI)
Description
AZTI Marine Biotic Index (AMBI) according to Borja et al. (2000)
Usage
ambi(.data = NULL, taxon, count, group = NULL)
ambi_(.data = NULL, taxon, count, group = NULL)
has_ambi(.data = NULL, taxon, group = NULL)
has_ambi_(.data = NULL, taxon, group = NULL)
Arguments
.data |
data in a |
taxon |
species names |
count |
counts of individuals ( |
group |
sensitivity groups I, II, III, IV, or V |
Details
The index is given by:
c_\mathrm{b} = \frac{3}{2} \sum_{i=2}^5 (i-1) p_i
where p_i
is the proportion of species in sensitivity group i
.
Value
numeric vector of length 1 containing the AMBI
Functions
-
ambi_()
: version suitable for calling from a function (see package lazyeval). -
has_ambi()
: tests if an AMBI sensitivity group is available fortaxon
(returnsTRUE
(available) orFALSE
(unavailable)) -
has_ambi_()
: version suitable for calling from a function (see package lazyeval).
References
Borja, A., J. Franco and V. Perez, 2000. A Marine Biotic Index to Establish the Ecological Quality of Soft-Bottom Benthos Within European Estuarine and Coastal Environments. Marine Pollution Bulletin 40:1100-1114
Examples
ambi(
taxon = c("Euspira pulchella", "Nephtys cirrosa"),
count = c(4, 6)
)
data(oosterschelde)
has_ambi(oosterschelde, TAXON)
Convert Taxon Names to Comply with WoRMS/TWN
Description
Taxon names are standardized according to the World Register of Marine Species (WoRMS) database. The conversion is case-insensitive. For this conversion, the TWN-list (Taxa Water management the Netherlands) is used, extended with species of the Southern North Sea. See references below for download locations.
Usage
as_accepted(taxon, taxa = NULL)
Arguments
taxon |
|
taxa |
an optional table usually created with |
Value
character vector with WoRMS/TWN compliant species names
References
https://www.marinespecies.org/
Bray-Curtis Dissimilarity
Description
Bray-Curtis Dissimilarity
Usage
bray_curtis(n1, n2)
Arguments
n1 |
abundances of species at site 1 |
n2 |
abundances of species at site 2 |
Value
Bray-Curtis dissimilarity (0..1, 0 = equal, 1 = different)
Note
species in n1 and n2 need to be aligned
Examples
n1 <- c(11, 0, 7, 8, 0)
n2 <- c(24, 37, 5, 18, 1)
bray_curtis(n1, n2)
Ecological Quality Ratio (EQR)
Description
The ecological quality ratio is the ratio beween a parameter value and its reference value:
EQR = \frac{x-bad}{ref-bad}
Depending on bad
and ref
, the EQR usually
(but not necessarily!) varies between 0 (bad ecological quality) and 1 (
ecological quality equals the reference status).
Usage
eqr(x, bad, ref)
Arguments
x |
numeric vector containing benthic indices |
bad |
the value for a bad status |
ref |
the value for a reference status |
Value
numeric vector with EQR-values: low values indicate bad ecological quality and high values indicate good ecological quality.
Genus to Species Conversion
Description
This algorithm reallocates the counts of taxa, that are only identified at the genus level to taxa in the same sampling unit and of the same genus but that are identified on the species level. The redistribution of counts is proportional to the number of counts at the species level.
Usage
genus_to_species(is_genus, count)
Arguments
is_genus |
|
count |
|
Value
numeric
vector with updated counts. The counts for the
taxon on the genus level have been set to zero.
Note
Parameters is_genus
and count
are of the same length and
correspond to the same taxon.
The resulting counts are not necessarily integers.
Examples
genus_to_species(is_genus = c(TRUE, FALSE, FALSE), count = c(3, 10, 20))
genus_to_species(is_genus = c(TRUE, FALSE, FALSE), count = c(1, 10, 20))
Get Supplementary AMBI Sensitivity Groups
Description
This function gets sensitivity groups that are supplementary to the AMBI of Borja et al., (2000)
Usage
get_ambi(which = "NL")
Arguments
which |
which AMBI supplement? Currently only the Dutch supplement is
available ( |
Value
a data frame with columns TAXON
containing taxa and
GROUP
containing Dutch AMBI-groups
References
Borja, A., J. Franco and V. Perez, 2000. A Marine Biotic Index to Establish the Ecological Quality of Soft-Bottom Benthos Within European Estuarine and Coastal Environments. Marine Pollution Bulletin 40:1100-1114
Get Infaunal Trophic Index
Description
This function gets the sensitivity groups to estimate the infaunal trophic index of Gittenberger et al., (2011)
Usage
get_iti()
Value
a data frame with columns TAXON
containing taxa and
GROUP
containing the ITI-groups of Gittenberger & Van Loon (2013).
References
Gittenberger A. and W. van Loon, 2013. Sensitivities of marine macrozoobenthos to environmental pressures in the Netherlands. Nederlandse Faunistische Mededelingen 41: 79-112.
Harmonize Case
Description
Convert text to the most occuring case. In case of ties, the first occurence in sorted order will be taken.
Usage
harmonize(x)
Arguments
x |
character vector |
Value
character vector with harmonized names (i.e., same case)
Examples
x <- c("FOO", "Foo", "bar", "FOO", "bar", "FOO", "Bar")
y <- harmonize(x)
stopifnot(all.equal(y, c("FOO", "FOO", "bar", "FOO", "bar", "FOO", "bar")))
Hill's Diversity Numbers
Description
According to Hill (1973): "a diversity number is figuratively a
measure of how many species are present if we examine the sample down to a
certain depth among its rarities. If we examine superficially (e.g.,
by using N_2
) we shall see only the more abundant species. If we
look deeply (e.g., by using N_0
) we shall see all the
species present."
Hill's diversity numbers are given by:
N_a=\sum{i=1}^S (p_i^a)^{1/(1-a)}
Special cases are:
N_{-\infty}
reciprocal of the proportional abundance of the rarest species;
N_0
total number of species present;
N_1
exp(H), where H: Shannon's index (see also
shannon
);N_2
reciprocal of Simpson's index (see also
simpson
);N_{\infty}
reciprocal of the proportional abundance of the commonest species.
Usage
hill(.data = NULL, taxon, count, a = 0)
hill_(.data = NULL, taxon, count, a = 0)
hill0(.data = NULL, taxon, count)
hill0_(.data = NULL, taxon, count)
hill1(.data = NULL, taxon, count)
hill1_(.data = NULL, taxon, count)
hill2(.data = NULL, taxon, count)
hill2_(.data = NULL, taxon, count)
Arguments
.data |
data in a |
taxon |
name of column in |
count |
name of column in |
a |
exponent in Hill's diversity number (R, with special cases for
|
Value
numeric vector of Hill's numbers
Functions
-
hill_()
: version suitable for calling from a function (see package lazyeval). -
hill0()
:N_0
-
hill0_()
:N_0
, version suitable for calling from a function (see package lazyeval). -
hill1()
:N_1
-
hill1_()
:N_1
, version suitable for calling from a function (see package lazyeval). -
hill2()
:N_2
-
hill2_()
:N_2
, version suitable for calling from a function (see package lazyeval).
References
Hill, M.O., 1973. Diversity and Evenness: A Unifying Notation and Its Consequences. Ecology 54:427-432
See Also
species_richness
, shannon
,
simpson
Examples
hill(
taxon = c("Euspira pulchella", "Nephtys cirrosa"),
count = c(6, 12),
a = 0
)
hill0(
taxon = c("Euspira pulchella", "Nephtys cirrosa"),
count = c(6, 12)
)
Hurlbert's Probability of Interspecific Encounter (PIE)
Description
The probability that two individuals selected at random (without replacement) from a sample will belong to different species is given by (Hurlbert, 1971, p.579, Eq. 3):
\Delta_1 = \sum_{i=1}^S (\frac{N_i}{N})(\frac{N-N_i}{N-1}) =
(\frac{N}{N-1})\Delta_2
where \Delta_2
(Hurlbert, 1971, p.579, Eq. 4) is the
probability that two individuals selected at random (with
replacement) from a sample will belong to different species:
\Delta_2 = 1 - \sum_{i=1}^S \pi_i^2
where N_i
is the number of individuals of the ith
species in the community, N
is the total number of individuals in the
community, \pi_i = N_i/N
, and S
is the number of
species in the community.
Note that Hurlbert's PIE hpie
is the complement of
simpson
.
Usage
hpie(.data = NULL, taxon, count)
hpie_(.data = NULL, taxon, count)
Arguments
.data |
data in a |
taxon |
name of column in |
count |
name of column in |
Value
A numeric vector with the probability of interspecific encounter (PIE).
Functions
-
hpie_()
: suitable for calling from a function (see package lazyeval).
References
Hurlbert, S.H., 1971. The Nonconcept of Species Diversity: A Critique and Alternative Parameters. Ecology 52:577-586.
See Also
Examples
hpie(
taxon = c("Euspira pulchella", "Nephtys cirrosa"),
count = c(6, 12)
)
Hurlbert's Expected Number of Species
Description
The expected number of species in a sample of n
individuals:
Usage
hurlbert(.data = NULL, taxon, count, n = 100L)
hurlbert_(.data = NULL, taxon, count, n = 100L)
Arguments
.data |
data in a |
taxon |
name of column in |
count |
name of column in |
n |
number of individuals in a standard sample |
Value
expected number of species in a sample of n
individuals
Functions
-
hurlbert_()
: version suitable for calling from a function (see package lazyeval).
References
Hurlbert, S.H., 1971. The Nonconcept of Species Diversity: A Critique and Alternative Parameters. Ecology 52:577-586.
Examples
hurlbert(
taxon = c("Euspira pulchella", "Nephtys cirrosa"),
count = c(4, 6),
n = 8
)
Test for Azoic Samples
Description
Case-insensitive test for taxa starting with 'azoi'
Usage
is_azoic(x)
Arguments
x |
character vector containing taxa |
Details
Azoic samples need special attention during data analysis. They should be marked as 'azoic', and taken care of during analysis. Note that an azoic sample is not the same as a record where a taxon has zero counts. The latter should be removed from further analysis, whereas the former provides important information.
Value
logical vector, with elements TRUE
for azoic samples,
and FALSE
otherwise.
Binomial Names
is_binomial
tests for valid binomial names,
generic_name
extracts the genus to which the species belongs,
specific_name
extracts the species within the genus.
Description
Binomial Names
is_binomial
tests for valid binomial names,
generic_name
extracts the genus to which the species belongs,
specific_name
extracts the species within the genus.
Usage
is_binomen(x)
generic_name(x)
specific_name(x)
strip_sp(x)
Arguments
x |
|
Value
character vector with either the generic name or the specific name of the species.
Functions
-
generic_name()
: extracts the genus to which the species belongs -
specific_name()
: extracts the species within the genus -
strip_sp()
: strips postfix sp. or spp. from a binomen
Examples
is_binomen("Venerupis corrugata") # TRUE
generic_name("Venerupis corrugata") # Venerupis
specific_name("Venerupis corrugata") # corrugata
generic_name("venerupis corrugata") # NA (genus part should be capitalized)
Infaunal Trophic Index (ITI)
Description
Computes the Infaunal Trophic Index (ITI) according to Gittenberger & van Loon (2013).
Usage
iti(.data = NULL, taxon, count, group = NULL)
iti_(.data = NULL, taxon, count, group = NULL)
has_iti(.data = NULL, taxon, group = NULL)
has_iti_(.data = NULL, taxon, group = NULL)
Arguments
.data |
data in a |
taxon |
species names |
count |
counts of individuals ( |
group |
sensitivity groups I, II, III, or IV |
Details
The Infaunal Trophic Index (ITI) is given by
\mathrm{ITI} = 100 \sum_{i=1}^3 \frac{(4-i)}{3} p_i
where p_i
is the proportion of species in class i
, where
group I are suspension feeders (highest quality);
group II are interface feeders
group III are surface deposit feeders and
group IV are subsurface deposit feeders (lowest quality).
Value
numeric vector of length 1 containing the ITI
Functions
-
iti_()
: version suitable for calling from a function (see package lazyeval). -
has_iti()
: tests if an ITI sensitivity group is available fortaxon
(returnsTRUE
(available) orFALSE
(unavailable)) -
has_iti_()
: version suitable for calling from a function (see package lazyeval).
References
Gittenberger A. and W. van Loon, 2013. Sensitivities of marine macrozoobenthos to environmental pressures in the Netherlands. Nederlandse Faunistische Mededelingen 41: 79-112.
Examples
iti(taxon = c("Euspira pulchella", "Nephtys cirrosa"), count = c(4, 6))
data(oosterschelde)
has_iti(oosterschelde, TAXON)
Margalef Index of Diversity
Description
Margalef Index of Diversity is given by
D = \frac{S-1}{\ln(N)}
For N=1
, the index is set to 0.
Usage
margalef(.data = NULL, taxon, count)
margalef_(.data = NULL, taxon, count)
Arguments
.data |
data in a |
taxon |
taxa names ( |
count |
counts ( |
Value
Margalef diversity index (numeric
vector
of length 1)
Functions
-
margalef_()
: version suitable for calling from a function (see package lazyeval).
Examples
margalef(
taxon = c("Euspira pulchella", "Nephtys cirrosa"),
count = c(4, 6)
)
MWTL North Sea Bentos Data
Description
MWTL North Sea Bentos Data
Usage
northsea
Format
An object of class tbl_df
(inherits from tbl
, data.frame
) with 24983 rows and 9 columns.
Oosterschelde Marine Benthos Data
Description
Oosterschelde data set. The Oosterschelde is located in the southwest of the Netherlands.
Usage
oosterschelde
Format
An object of class tbl_df
(inherits from tbl
, data.frame
) with 4269 rows and 8 columns.
Details
The Oosterschelde data contains the following columns:
ID sample identifier
HABITAT specification of the habitat
AREA sampled area
DATE sampling date (YYYY-MM-DD, ISO 8601)
TAXON standardized taxon code (see WoRMS-website https://www.marinespecies.org/)
COUNT number of individuals of 'TAXON'
Note
This is not the original data set, but a simplified version of it meant for didactic purposes only! For instance it only contains taxa identified at the species level. Other taxa have been removed.
Source
Rijkswaterstaat Water, Transport and Living Environment, Department of Information Management, Lelystad, The Netherlands (contact: servicedesk-data@rws.nl)
Pooling
Description
This function randomly assigns samples to pools of approximately equal area
Usage
pool(sample_id = 1:length(area), area, target_area, max_try = 100L)
.pool(sample_id = 1:length(area), area, target_area, max_try = 100L)
Arguments
sample_id |
sample identifier |
area |
sampling area of |
target_area |
vector of length 2 containing the lower and upper bound
of the pooled area (same units as |
max_try |
maximum number of unsuccessful pooling tries before the algorithm gives up. |
Value
vector with idenitifiers (integers) indicating the pool to which each sample belongs (NA for samples that could not be pooled)
Functions
-
.pool()
: internal function not supposed to be called directly.
Read and Validate AMBI Sensitivity Data
Description
This function reads and checks files with AMBI sensitivity data. The data should be stored in 'comma separated values' format (csv) consisting of two columns:
- TAXON
species name;
- GROUP
Roman numeral (I, II, III, IV, V) giving the sensitivity group
Usage
read_ambi(filename)
validate_ambi(.data)
Arguments
filename |
name of the AMBI sensitivity file (character) |
.data |
table in AMBI-format |
Details
The function performs the following tasks:
checks the existence of
filename
;checks availability of required columns (case insensitive);
removes redundant spaces;
removes duplicated records.
Functions
-
validate_ambi()
: validator for AMBI-format
References
Borja, A., J. Franco and V. Perez, 2000. A Marine Biotic Index to Establish the Ecological Quality of Soft-Bottom Benthos Within European Estuarine and Coastal Environments. Marine Pollution Bulletin 40:1100-1114
Read and Validate BEQI2 Input Files
Description
This function reads and checks BEQI2 input files. The format has been specified in Van Loon (2013) and is described in the vignette of the BENMMI-package.
Usage
read_beqi2(filename)
validate_beqi2(.data)
Arguments
filename |
name of BEQI2 input file ( |
.data |
table in BEQI2-format |
Details
The function performs the following tasks:
checks the existence of
filename
;checks availablitity of required columns (case insensitive);
make column names with aggregation data case-insensitive;
removes redundant spaces;
checks if DATE-field adheres to ISO 8601 (YYYY-mm-dd);
constructs a unique identifier
ID
by concatenating columnsOBJECTID
andDATE
;checks that each
ID
has a uniqueAREA
;checks azoic samples for VALUE=0;
removes records with VALUE=0, not belonging to azoic samples;
checks VALUE-field on missing values;
checks if VALUE-field is an integer;
Functions
-
validate_beqi2()
: validator for BEQI2-format
References
Willem van Loon, 2013. BEQI2 INPUT FORMAT. See the package-vignette of the BENMMI-package.
Read and Validate Infaunal Trophic Index Files
Description
This function reads and checks files containing Infaunal Trophic Index (ITI) data (Gittenberger & Van Loon, 2013)
Usage
read_iti(filename)
validate_iti(.data)
Arguments
filename |
name of the ITI file (character). |
.data |
table in ITI-format |
Details
The function performs the following tasks:
checks the existence of
filename
;checks availability of required columns (case insensitive), i.e., TAXON and GROUP;
removes redundant spaces;
removes duplicated records;
checks if all ITI classes are I, II, III, or IV
The column 'GROUP' contains the Roman numerals I, II, III, and IV, with the following meaning:
- I:
suspension feeders;
- II:
interface feeders;
- III:
surface deposit feeders;
- IV:
subsurface deposit feeders.
Value
A data frame with columns TAXON
containing taxa and
GROUP
containing user-defined ITI-groups
(see Gittenberger & Van Loon, 2013).
Functions
-
validate_iti()
: validator for ITI-format
References
Gittenberger A. and W. van Loon, 2013. Sensitivities of marine macrozoobenthos to environmental pressures in the Netherlands. Nederlandse Faunistische Mededelingen 41: 79-112.
Read and Validate Habitat References Files
Description
This function reads and checks files with reference values
Usage
read_ref(filename, indicators = c("S", "H", "AMBI"))
validate_ref(.data, indicators = c("S", "H", "AMBI"))
Arguments
filename |
name of the habitat reference file ( |
indicators |
indicators to be processed ( |
.data |
table in REF-format |
Details
The function performs the following tasks:
checks the existence of
filename
;checks availablitity of required columns (case insensitive);
removes redundant spaces
removes duplicated records
Argument indicators
is a character
vector of additional benthic
indicators to be checked for. For example, if indicators = "ITI"
, then
the habitat reference file should also contain columns ITIREF and ITIBAD.
Implemented indicators are N, LNN, S, D, SN, SNA, H, L, AMBI, ITI, PIE, N2 (see package vignette).
The format of the habitat reference file is documented in the BEQI2-package vignette.
Functions
-
validate_ref()
: validator for REF-format
References
Van Loon, W, 2013. Loon2013-BEQI2-Specs-Ecotopes-27nov.doc
Read and Validate Taxa Data
Description
This function reads files in the taxa format.
Usage
read_taxa(filename)
get_taxa()
validate_taxa(.data)
Arguments
filename |
name of taxa file |
.data |
table in taxa-format |
Details
Taxa files have the following format:
- group
taxonomic group
- provided
provided taxon name
- accepted
accepted taxon name
- level
taxonomic level
Other columns are allowed, but silently ingored.
Functions
-
get_taxa()
: get default taxa list (TWN list extended with species Southern North Sea) -
validate_taxa()
: validator for taxa-format
Read and Validate Taxa Waterbeheer Nederland (TWN) Data
Description
This function reads files in the Taxa Waterbeheer Nederland (TWN) format.
Usage
read_twn(filename)
get_worms()
validate_twn(.data)
Arguments
filename |
name of TWN file ( |
.data |
table in TWN-format |
Details
The function adds a new column taxon
. Its contents depending
on TWN-status:
- status = 10
taxonname
- status = 20
prefername
- status = 80
parentname
Value
a tibble
with four columns:
- GROUP
TWN/WoRMS taxon group
- LEVEL
TWN/WoRMS taxon level
- FROM
taxon name to convert from
- TO
taxon name to convert to
Functions
-
get_worms()
: get default WoRMS list (TWN list extended with species Southern North Sea) -
validate_twn()
: validator for TWN-format
References
Rygg's Index of Diversity
Description
Rygg's index of diversity is given by
SN = \frac{\ln(S)}{\ln(\ln(N))}
The adjusted version of Rygg's index which gives more consistent values
for smaller S=2, N=2, N=3
and S=3, N=3
is
SN = \frac{\ln(S)}{\ln(\ln(N+1)+1)}
Usage
rygg(.data = NULL, taxon, count, adjusted = FALSE)
rygg_(.data = NULL, taxon, count, adjusted = FALSE)
Arguments
.data |
data in a |
taxon |
taxa names ( |
count |
counts ( |
adjusted |
(defaults to |
Value
Rygg's index of diversity (numeric
vector
of length 1)
Functions
-
rygg_()
: version suitable for calling from a function (see package lazyeval).
Note
Rygg's index is not defined for N=exp(1)
. For
N \leq exp(1)
, rygg
returns
NA_real_
.
References
Rygg, B. (2006). Developing indices for quality-status classification of marine soft-bottom fauna in Norway. Norwegian Institute for Water Research, Oslo, Norway. NIVA Report SNO 5208-2006.
Examples
rygg(
taxon = c("Euspira pulchella", "Nephtys cirrosa"),
count = c(4, 6)
)
Shannon's Index or Entropy
Description
Compute entropy according to Shannon (1948)
Usage
shannon(.data = NULL, taxon, count, base = 2)
shannon_(.data = NULL, taxon, count, base = 2)
Arguments
.data |
data in a |
taxon |
taxa names ( |
count |
counts ( |
base |
the base with respect to which logarithms are computed. Defaults to 2 (unit: bits). |
Value
Shannon's entropy
Functions
-
shannon_()
: version suitable for calling from a function (see package lazyeval).
References
Shannon, C. E., 1948. A Mathematical Theory of Communication. Bell System Technical Journal 27: 379-423.
Examples
shannon(
taxon = c("Euspira pulchella", "Nephtys cirrosa"),
count = c(4, 6)
)
Simpson's Measure of Concentration
Description
The probability that two individuals selected at random (with replacement, Hurlbert, 1971, p.579) from a sample will belong to the same species. For an infinite sample Simpson's Index is given by (Peet, 1974):
\lambda = \sum_{i=1}^S p_i^2
For a finite sample by:
L = \sum_{i=1}^S \frac{n_i (n_i-1)}{N (N-1)}
where p_i
the proportion of the individuals in species i
,
n_i
the number of individuals in species
i
(relative abundance
), and N
the total number
of individuals (total_abundance
). The finite sample case
has been implemented in function simpson
(and simpson_
).
Usage
simpson(.data = NULL, taxon, count)
simpson_(.data = NULL, taxon, count)
Arguments
.data |
data in a |
taxon |
name of column in |
count |
name of column in |
Value
The probability that two individuals selected at random from a sample will belong to the same species.
Functions
-
simpson_()
: version suitable for calling from a function (see package lazyeval).
References
Peet, R. K. 1974, The Measurement of Species Diversity. Annual Review of Ecology and Systematics 5:285-307.
See Also
Examples
simpson(
taxon = c("Euspira pulchella", "Nephtys cirrosa"),
count = c(6, 12)
)
Species Richness
Description
Species richness (S
) is defined as the number of taxa
(lowest identification level possible) per sampling unit
(data pool or box core sample).
Usage
species_richness(.data = NULL, taxon, count = NULL)
species_richness_(.data = NULL, taxon, count = NULL)
Arguments
.data |
data in a |
taxon |
taxa names ( |
count |
number of individuals for each taxon ( |
Value
species richness (integer
vector of length 1)
Functions
-
species_richness_()
: version suitable for calling from a function (see package lazyeval).
Examples
species_richness(
taxon = c("Euspira pulchella", "Nephtys cirrosa"),
count = c(4, 6)
)
Remove Redundant Spaces
Description
This function removes redundant spaces from character vectors
Usage
strip_spaces(x)
Arguments
x |
character vector |
Value
character vector without trailing or multiple spaces
Convert Taxon Names to Comply with WoRMS
Description
Taxon names are standardized according to the World Register of Marine Species (WoRMS) database. The conversion is case-insensitive. For this conversion, the TWN-list (Taxa Water management the Netherlands) is used, extended with species of the Southern North Sea. See references below for download locations.
Usage
to_worms(taxon, worms = NULL)
is_worms(.data = NULL, taxon)
is_worms_(.data, taxon)
is_accepted(.data = NULL, taxon)
is_accepted_(.data, taxon)
Arguments
taxon |
|
worms |
an optional table usually created with |
.data |
data in a |
Value
character vector with WoRMS compliant species names
TRUE
for WoRMS compliant species names,
FALSE
otherwise.
TRUE
for WoRMS/TWN compliant species names,
FALSE
otherwise.
Functions
-
is_worms()
: check if a taxon complies with WoRMS -
is_worms_()
: asis_worms
but suitable for calling from a function (see package lazyeval). -
is_accepted()
: check if a taxon complies with WoRMS/TWN -
is_accepted_()
: asis_accepted
but suitable for calling from a function (see package lazyeval).
References
https://www.marinespecies.org/
Total Abundance
Description
The total number of individuals.
Usage
total_abundance(.data = NULL, count, na.rm = FALSE)
total_abundance_(.data = NULL, count, na.rm = FALSE)
lnn(.data = NULL, count, na.rm = FALSE)
lnn_(.data = NULL, count, na.rm = FALSE)
Arguments
.data |
data in a |
count |
counts ( |
na.rm |
Should missing values (including |
Value
total number of individuals (integer
)
Functions
-
total_abundance_()
: version suitable for calling from a function (see package lazyeval). -
lnn()
: natural log of total abundance + 1 (see package lazyeval). -
lnn_()
: version of lnn suitable for calling from a function (see package lazyeval).
Examples
total_abundance(count = c(4, 6))