Use Accumulation Slope Segment when you need to compute the species accumulation rate for one survey segment as new species divided by units of sampling effort. Enter Species before, Species after, and Sampling effort using the definitions and units below so the result can be reproduced.

Species before

An integer count or setting greater than or equal to 0.

Species after

An integer count or setting greater than or equal to 0.

Sampling effort

A finite measured or assumed value, expressed in units.

The published tool contract uses this rule: Compute the species accumulation rate for one survey segment as new species divided by units of sampling effort.

New species per unit effort

The calculated new species per unit effort in species/unit.

A ratio or percentage can conceal the scale of its numerator and denominator and becomes sensitive to measurement error when the denominator is small.

Retain the original Species before, Species after, and Sampling effort values and their units alongside the result. Rarefied Species Curve Point is useful when you instead need to estimate a rarefied species count with a documented half-saturation form: species total times sample over sample plus half-saturation, where the half-saturation defaults to the total individual count rounded up to its half. Chao1 Bias Corrected provides another view by helping you compute the documented bias-corrected Chao1 estimate as observed species plus singletons times singletons minus one divided by two times doubletons plus one.

• Rarefied Species Curve Point

  Estimate a rarefied species count with a documented half-saturation form: species total times sample over sample plus half-saturation, where the half-saturation defaults to the total individual count rounded up to its half.

• Chao1 Bias Corrected

  Compute the documented bias-corrected Chao1 estimate as observed species plus singletons times singletons minus one divided by two times doubletons plus one.

• Rarefied Richness

  Estimate rarefied species richness with the documented linear form sTotal x m / n for a subsample of m individuals drawn from n.