A population growth model with varying growth rates
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Date
2006
Authors
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Journal ISSN
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Publisher
CCSHAU
Abstract
The model of Lewis and Leslie (1945, 1948) has been
extensively used for the study of population growth in various
fields. However, complex growth structures require the use of
more general models. The model of Kapur (1979) allows
harvesting in the system is an initial step to move in this
direction. But the need is being felt to develop more general
models considering the effect of variable growth rates along with
harvesting on the reproductive structure of living organisms.
In the present work, and age-dependent population growth
model is proposed where birth, death and harvest rates are the
functions of three population groups viz. pre-reproductive,
more-reproductive and less-reproductive. The population
structure with varying growth rate has been obtained. The
condition for growth, extinction and stability for age-dependent
cattle population has been found. Further the model has been
illustrated by taking twelve year data on cattle growth. A harvest
policy to ensure the stable population structure is also given.
The population projections of cattle have been illustrated with
tables and graphs.