Practice question

Net reproductive rate R0 is the mean number of offspring produced per individual over a generation, often counted as daughters per female in age-structured demography. When R0 exceeds one, each generation more than replaces itself and the population grows under the assumed vital rates. R0 equal to one indicates replacement, whereas a value below one indicates decline. Distinguishing per-capita growth from total growth prevents a common error. In the logistic model, per-capita growth r(1 - N/K) declines linearly with density, but total growth rN(1 - N/K) forms a dome because the number of potential reproducers initially rises. Both quantities reach zero or their maximum at different densities. Reading the terms biologically, rather than memorizing labels, shows how individual survival and reproduction scale up to population change. Ecological predictions remain conditional on the stated environment, because changing resources, mortality, or interactions can alter the observed demographic pattern. This interpretation connects individual-level processes with measurable changes in survival, reproduction, recruitment, or abundance across the population.