mesophotic: Calculate the mesophotic community value for a given light...

In Jack-H-Laverick/MCE: Modelling Community Transitions Across Coral Reef Depth Gradients

Description

This function captures the preferred light environment of the mesophotic coral community.

Usage

mesophotic(light = seq(0.01, 100, length = 500), a = 1.54, b = 8.92)

Arguments

light	The percentage of surface irradiance (PAR) reaching a reef, positive and up to 100%.
a	The scale parameter of a Weibull distribution, defaults to (Tamir et al., 2019). a describes the spread of the data, or ‘the peakyness’. Larger numbers create a flatter, wider, curve. Varying a will simultaneously change the width of the preferred light environment of mesophotic taxa, and the maximum similarity a reef patch is expected to achieve in comparison to the idealised mesophotic community.
b	The shape parameter of a Weibull distribution, defaults to (Tamir et al., 2019). A value of 3 approximates a normal distribution. Values larger than 3 introduce a left-skew to the curve. This means mesophotic taxa can be light-limited, while keeping mesophotic communities in low-light environments. Varying b shifts the preferred light environment of mesophotic communities.

Details

A Weibull distribution is used to represent the relationship between mesophotic coral communities and light. We assume mesophotic community values (how similar a reef patch is to the idealised mesophotic community) center on a preferred light value, between light limitation and light-induced stress.

This relationship has been verified in the Red Sea (Tamir et al., 2019), but certainly needs more research!

Value

A mesophotic community indicator value, as discussed in (Laverick et al., 2017). When a single light value is provided, a single value is returned. You can pass a vector of light levels for a vector of depths.

References

(Tamir et al., 2019)

(Laverick et al., 2017)

See Also

Other Community relationships: shallow()

Examples

# Specifying a single light value
# returns a single community value.

   mesophotic(light = 10)


# Specifying a vector of light values
# returns a vector of community values.

   mesophotic(light = seq(0.0065, 100, length = 500))


# By default the function uses the shallow community
# light relationship from (Tamir et al., 2019) for a
# range of light values.

   mesophotic()


# You can specify your own community light relationship
# by setting parameters explicitly

   mesophotic(a = 1.2, b = 8)

Jack-H-Laverick/MCE documentation built on May 9, 2020, 3:58 p.m.