effectOnResource: Per capita effect on resource population.

In dswdejonge/fwstability: Infer Food-Web Stability

Per capita effect on resource population.

Description

This function finds the per capita effect of a consumer on the growth of the resource population. It implements the functions from de Ruiter et al. (1995), Neutel et al. (2002) and Neutel & Thorne (2014). The flow from prey to predator is divided by the biomass of the consumer. The flow from consumer to detritus, plus the defecation of predators of the consumer into the detritus pool, minus the uptake of detritus, is divided by the biomass of the consumer.

Usage

effectOnResource(FMs, BM, AE, dead = NULL)

Arguments

FMs	(required) A list with two elements original and netMatrix, both containing a square flowmatrix, with source compartments as rows, sink compartments as columns. the list element original should contain the original flow matrix as can be obtained with the function getFlowMatrix, i.e. can contain a flow from A to B, and a flow from B to A. the list element netMatrix should contain an adjusted version of the original matrix with only net flows, which can be obtained with the function getNetMatrixFM, i.e. a netMatrix flow is the absolute result of flow A to B minus flow B to A in the correct direction. The net flow is only calculated for flows between live compartments, not for dead ones.
BM	(required) Numeric vector with biomasses of all compartments, must be in the same order as the flow matrix.
AE	(required) Numeric vector with assimilation efficiencies of all compartments, must be in the same order as the flow matrix.
dead	(optional) List with at most two elements named names and frac containing information on all dead compartments (like detritus and nutrients). The element names is required and contains a character vector with all names of dead compartments. The element frac is required if there is more than one detritus compartment. It is matrix the same size and order as the FM matrix, and contains the fraction of each flow that is defecation. If there are multiple defecation compartments, the Flowmatrix FM combined with frac is used to calculate the relative distribution of matter into defecation compartments.

Value

This function returns a matrix containing the effects of the consumers (rows) on the resources (columns).

References

• de Ruiter, P.C., Neutel, A.M., Moore, J.C., 1995. Energetics, Patterns of Interaction Strengths, and Stability in Real Ecosystems. Science. 269, 1257–1260. https://doi.org/10.1126/science.269.5228.1257

• Neutel, A.M., Heesterbeek, J.A.P., Ruiter, P.C. De, 2002. Stability in Real Food Webs: Weak Links in Long Loops. Science. 296, 1120–1123. https://doi.org/10.1126/science.1068326

• Neutel, A.M., Thorne, M.A.S., 2014. Interaction strengths in balanced carbon cycles and the absence of a relation between ecosystem complexity and stability. Ecol. Lett. 17, 651–661. https://doi.org/10.1111/ele.12266

• Moore, J. C., Berlow, E. L., Coleman, D. C., De Ruiter, P. C., Dong, Q., Hastings, A., … Wall, D. H. (2004). Detritus, trophic dynamics and biodiversity. Ecology Letters, 7(7), 584–600. https://doi.org/10.1111/j.1461-0248.2004.00606.x

dswdejonge/fwstability documentation built on Dec. 7, 2022, 7:24 p.m.