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<br /> <br />1 <br /> <br /> <br />1 <br /> <br /> <br /> <br />1 <br /> <br /> <br /> <br /> <br />1 <br /> <br />1 <br /> <br />adults, 100 3-yr old fish, or 1000 2-yr-old fish,-etc, or some combination of those. The <br />specific age-class distribution is dependent on the specific carrying capacity variables <br />for each age class. It should be noted that the carrying capacity values primarily <br />represent intraspecific competitive effects as well as the amount of utilizable habitat. <br />In these models-carrying capacity has little effect on population dynamics due to the <br />low numbers of fish present. Instead, carrying capacity values affect the spatial <br />distribution of each particular species. For example, canyon species such as <br />humpback chub are limited to those geomorphic reaches where canyon habitat exists <br />by setting K to zero in alluvial valley reaches. <br />Initially, the stochasticity of the model is generated by randomly selecting values for <br />both the mean survivorship of each age class and the variation around the mean <br />(standard deviation) from the normal probability density function. The estimation and <br />uses of these values are discussed in detail below (parameter estimation section). ~- <br />schematic diagram of the model is depicted in Figure 1. <br />Following the initial review of the model, a number of reviewers {researchers) <br />suggested that rather than survivorship values from each age class being randomly <br />and independently drawn from a series of normal distributions. There should be a <br />correlation between `good' and `bad' survivorship within a year. Additionally, rather <br />than populations having an equal probability of `good' and 'bad' years, most years <br />should be at or below average, while only a few `good' recruitment years could exist <br /> <br /> <br />