Zeitschriftenartikel

Population momentum: implications for wildlife management

Koons, D. N., Rockwell, R. F., Grand, J. B.
Journal of Wildlife Management, 70:1, 19–26 (2006)

Abstract

Maintenance of sustainable wildlife populations is one of the primary purposes of wildlife management. Thus, it is important to monitor and manage population growth over time. Sensitivity analysis of the long-term (i.e., asymptotic) population growth rate to changes in the vital rates is commonly used in management to identify the vital rates that contribute most to population growth. Yet, dynamics associated with the long-term population growth rate only pertain to the special case when there is a stable age (or stage) distribution of individuals in the population. Frequently, this assumption is necessary because age structure is rarely estimated. However, management actions themselves have strong potential to change the age distribution of a population. For initially growing and declining populations, we instituted hypothetical management targeted at halting the growth or decline of the population, and measured the effects of a changing age structure on the population dynamics. When we changed vital rates, the age structure became unstable and population momentum caused populations to grow in a much different fashion than that predicted by the long-term population growth rate. Interestingly, changes in fertility actually reversed the direction of short-term population growth, leading to long-term population sizes that were actually smaller or larger than that when fertility was changed. Population momentum can significantly affect population dynamics, and will be important to consider in the use of population models for management.
Schlagwörter: age distribution, demography, population projections
Das Max-Planck-Institut für demografische Forschung (MPIDR) in Rostock ist eines der international führenden Zentren für Bevölkerungswissenschaft. Es gehört zur Max-Planck-Gesellschaft, einer der weltweit renommiertesten Forschungsgemeinschaften.