damageindex: Damage Index Calculator
In springpheno: Spring Phenological Indices

Description Usage Arguments Value Author(s) References

View source: R/springpheno_v0.4.R View source: R/springpheno_v0.5.R View source: R/springpheno_v0.3.R

This function calculates the damage index (Schwarz et al. 2006, Schwarz et al. 2013) given the first leaf index (FLI) and day of year for the last spring freeze. This is based on the calculation done in the original Matlab code base (Ault et al. 2015).

1	damageindex(leafidx, lastfreeze)

`leafidx`	Scalar - FLI value from the leafindex function. It's recommended to use the average, but one could also use the FLI for the individual plants.
`lastfreeze`	Scalar - day of year of the last spring freeze.

The output is a scalar with the value of the damage index. The damage index is effectively the difference between the FLI and the last freeze. Negative values are converted to zero as no damage occurs if the last freeze is before the first leaf.

Adrienne M. Wootten (University of Oklahoma)

Ault, T.R., R. Zurita-Miller and M. Schwarz, 2015: A Matlab© toolbox for calculating spring indices from daily meteorological data. Computers and Geosciences, 83, DOI: 10.1016/j.cageo.2015.06.015

Schwarz, M., R. Ahas and A. Aasa, 2006: Onset of spring starting earlier across the Northern Hemisphere, 12, DOI: 10.1111/j.1365-2486.2005.01097.x

Schwarz, M., T.R. Ault and J.L. Betancourt, 2013: Spring onset variations and trends in the continental United States: Past and regional assessment using temperature-based indices. International Journal of Climatology, 33, DOI: 10.1002/joc.3625

springpheno documentation built on Nov. 11, 2021, 9:06 a.m.