Description
This pack contains a workflow, a file and documentation (tutorial to run the workflow).
The Life Table Response Experiments year effect for multiple places workflow provides an environment to analyse two or more matrices (e.g., two or more matrices of different years of one place) of two or more different locations. The objective of this workflow is to determine the effects of the research years (2 or more) on λ. This workflow performs a fixed LTRE, one way design (Caswell 2001).
LTRE is a retrospective analysis (Caswell 1989), beginning with data on the vital rates and on λ under two or more sets of environmental conditions (in this case 2 or more years from different places) (Horvitz, Schemske and Caswell 1997). The goal of the analysis is to quantify the contribution of each of the vital rates to the variability in λ. (Caswell 1989, 1996, 2001 in Horvitz, Schemske and Caswell 1997).
Fixed Treatments: Decomposing Years Treatment Effects for multiple places
A fixed-effect analysis treats the matrices as representative of particular conditions, either experimental or natural (high vs. low nutrients in a one-way model, for example, or year and spatial location in a two-way model). The goal is to determine how much a treatment level (in this case year) on λ is contributed by each of the vital rates. The analysis uses a linear approximation in which the sensitivities appear as slopes. The effect of a treatment on λ depends on its effect on each matrix entry and on the sensitivity of λ to that entry. (Horvitz, Schemske and Caswell 1997).
For more details of the analysis see: Retrospective Analyses: Fixed Treatments (page 262 in Horvitz, Schemske and Caswell 1997) and Chapter 10 Life Table Response Experiments (page 258 in Caswell 2001).