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Sensitivity analysis of equilibrium in density‐dependent matrix population models
Author(s) -
Caswell Hal,
Takada Takenori,
Hunter Christine M.
Publication year - 2004
Publication title -
ecology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.852
H-Index - 265
eISSN - 1461-0248
pISSN - 1461-023X
DOI - 10.1111/j.1461-0248.2004.00595.x
Subject(s) - sensitivity (control systems) , eigenvalues and eigenvectors , density dependence , population , statistical physics , measure (data warehouse) , exponent , projection (relational algebra) , matrix (chemical analysis) , population density , mathematics , statistics , physics , chemistry , computer science , linguistics , philosophy , demography , algorithm , quantum mechanics , database , electronic engineering , chromatography , sociology , engineering
We consider the effects of parameter perturbations on a density‐dependent population at equilibrium. Such perturbations change the dominant eigenvalue λ of the projection matrix evaluated at the equilibrium as well as the equilibrium itself. We show that, regardless of the functional form of density dependence, the sensitivity of λ is equal to the sensitivity of an effective equilibrium density , which is a weighted combination of the equilibrium stage densities. The weights measure the contributions of each stage to density dependence and their effects on demography. Thus, is in general more relevant than total density, which simply adds all stages regardless of their ecological properties. As log λ is the invasion exponent, our results show that successful invasion will increase , and that an evolutionary stable strategy will maximize . Our results imply that eigenvalue sensitivity analysis of a population projection matrix that is evaluated near equilibrium can give useful information about the sensitivity of the equilibrium population, even if no data on density dependence are available.