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Computation of Pastoral Value (PV)

Source: R/pastoral_value.R
pastoral_value.Rd

Computation of PV from a database with SRA, either SRA_fo or SRA_SC.fo.occ (see vegetation_abundance). See @details for theoretical information

Usage

pastoral_value(SRA_data, isq_data)

Arguments

SRA_data

database with SRA values, either 'SRA_fo' or 'SRA_SC.fo.occ' (see vegetation_abundance). Database class must be data.frame

isq_data

database with ISQ values. Species without an ISQ have to be specified with 999.Database class must be data.frame

Value

database with PV computed per each survey

Details

The forage productivity and quality can be expressed through the Pastoral Value (PV), which is a unique and synthetic index derived from sward botanical composition summarizing forage yield, quality, and palatability for livestock (Daget and Poissonet, 1969, Pittarello et al. 2018, 2020).

PV, which ranges from 0 to 100, is computed according to the following formula (Daget and Poissonet, 1971):

PV = (SRAi ISQi) 0.2

where:

  • ISQ: is an Index of specific quality attributed to each species which epends on the preference, morphology, structure, and productivity of the plant species. It ranges from 0 (low) to 5 (high) (Daget and Poissonet, 1971; Cavallero et al., 2007).

  • SRA: Species Relative Abundance for each species within a survey computed as either 'SRA_fo' or 'SRA_SC.fo.occ' (see vegetation_abundance) attributed each species an Index of specific quality (ISQ)

References

  • Cavallero, A., Aceto, P., Gorlier, A., Lombardi, G., Lonati, M., Martinasso, B., Tagliatori, C., (2007). I tipi pastorali delle Alpi piemontesi. (Pasture types of the Piedmontese Alps). Alberto Perdisa Editore. p. 467, Bologna.

  • Daget, P., Poissonet, J., 1969. Analyse phytologique des praries, Centre Nat. ed, Applications agronomiques. Montpellier - France

  • Daget, P., Poissonet, J., 1971. A method of plant analysis of pastures. Ann. Agron. 22, 5–41.

  • Pittarello, M., Lonati, M., Gorlier, A., Perotti, E., Probo, M., Lombardi, G., 2018. Plant diversity and pastoral value in alpine pastures are maximized at different nutrient indicator values. Ecol. Indic. 85, 518–524. https://doi.org/10.1016/j.ecolind.2017.10.064

  • Pittarello, M., Lonati, M., Ravetto Enri, S., Lombardi, G., 2020. Environmental factors and management intensity affect in different ways plant diversity and pastoral value of alpine pastures. Ecol. Indic. 115, 106429. https://doi.org/10.1016/j.ecolind.2020.106429

Examples