Input - Genetic Diversity in Establishing Plant Populations: Founder Number and Geometry - page 27

not initiate reproduction until it is in its seventh “year” (i.e., episode of
population reproduction). During the years when it is not reproductive, that
individual still occupies a particular point, and newly generated offspring
cannot occupy that point: if new offspring land on a point already occupied
by an individual not scheduled to die after the current bout of mating, they
die (are removed from the output data set).
If the rate of offspring production per female is set to a number, say
3, then each female of a generation that is eligible to contribute offspring
to the next generation will produce three potential offspring for that
next generation (subject to user-defi ned input options described below).
NEWGARDEN does not operate by selecting one reproducing female at a
time and immediately generating its three offspring from that female with
three different matings, and then moving on to the next eligible reproducing
female in the list. Instead, given the total number of reproducing females
in a generation, there are three times as many matings. NEWGARDEN
selects one of the eligible zygote-offspring-producing parents at random,
selects an eligible microgamete contributor at random, and the zygote-
offspring is dispersed to an eligible grid point at random. The program then
randomly selects another eligible zygote-offspring-producing parent and
completes another mating, repeating this process until the total number of
matings scheduled is accomplished. In the current example, once an eligible
reproductive individual has generated three potential zygote-offspring, it
is removed from the zygote-offspring eligible list, although it is still eligible
as a potential microgamete contributor (but input options described below
can alter reproduction per eligible individual).
The procedure for generating offspring is implemented in the program
as follows. For each reproductive female, the number of offspring to be
produced and their genotypes are determined, and the offspring are
assigned to random preserve grid points. After all reproducing females
have been treated in that way, one offspring for each grid point is selected
at random for recruitment. As will be discussed below, the user can select
from a variety of procedures for determining the number of offspring
produced by each eligible maternal plant.
Reproductive Rate: Some Theoretical Considerations
The reproductive rate command sets the rate at which propagules (e.g., seeds)
are created by individuals in a bout of mating. As noted above, although an
individual may produce an offspring according to the reproductive value
input, that propagule may not become an established offspring in the next
cohort produced. In most discussions of NEWGARDEN analyses output
below, the term “offspring” does not refer to the total sexually produced
propagules (e.g., seeds, eggs) of an individual, nor to natality (e.g., the