ABSTRACT
All of the examples given previously in this book have involved annuals. NEWGARDEN also permits input data regarding age-specifi ed schedules of mortality and rates of reproduction to model population growth and genetic diversity retention for a wide variety of perennials. For example, some species may have low mortality (say, 3%) in the fi rst 4 years of establishment followed by steeper losses for older individuals. In another species (or at another location for the same species), early mortality may be much higher. These differing mortality schedules will generate different rates and spatial patterns of population establishment that can have associated effects on population growth and genetic diversity. Likewise, the number of surviving offspring generated, as well as the chances of being a pollen donor, change with age for most perennials. Individuals that are 5 years old may contribute only 2% of the seed or pollen contributed by individuals that are 30 years old. As outlined in Chapter 4 (Input), these parameters can be specifi ed for developing populations via the NEWGARDEN input fi le. In the following sections, we examine, for perennials, some of the population genetic consequences that can stem from different patterns of introduction for populations or species that differ in life history characteristics such as mating system, seed or pollen dispersal patterns, age-specifi c production, or different schedules of age-specifi c rates of mortality.
