The most extreme version of this type of manipulation is to switch back and forth between u(t) = 0 (all extracted resources allocated to elevating the average quality of individuals in the population) and u(t) = 1 (all extracted resources allocated to increasing population abundance).
Research is sorely needed on whether the demographic advantages of increasing population abundance via captive breeding can outweigh the genetic disadvantages of losing fitness in captivity.
Fourth, because some degree of wild fitness may be unavoidably lost in captivity, I explore theoretical grounds for whether a demographic boost from increased population abundance can offset such fitness reductions.
Little research has also addressed under what conditions an increase in population abundance due to captive-rearing might offset fitness reductions induced in captivity.
Previous research indicated that planting switchgrass increased rodent population abundance but reduced recruitment and community diversity.
Regardless of individual distribution, the estimation precision becomes higher with increasing total population abundance and the sampled fraction.
Thus, an unresolved enigma in evaluating the likelihood that captive breeding programs can translate into self-sustaining salmonid populations, is whether, and how, increases to population abundance (N) provided by captive-rearing could offset reduced fitness in the wild of captive-reared fish and their progeny.
Controlled OMW spreading can increase the total soil microbial population, which can be accompanied by respective increase in the population abundance of spore-forming bacteria, Actinobacteria, and yeasts [ 59– 63].
As sample density declined, the probability of a survey availability event, defined as a survey yielding indices >125% or <75% of the true population abundance, increased and that increase was disproportionately biased towards underestimates.
A truncated age and size structure may have consequences for population dynamics, and has been shown to reduce reproductive potential (Marteinsdottir and Thorarinsson 1998; Murawski et al. 2001), increase variability in recruitment or population abundance (Longhurst 2002; Hsieh et al. 2006), and make a stock more vulnerable to environmental fluctuations (Ottersen et al. 2006; Hsieh et al. 2008).
