ABSTRACT
Variation in population sizes of indicator species on an annual scale is much more likely to be of significance for most studies of ecosystem recovery. This broader time scale encompasses the regularly occurring seasonal climatic cycles and the corresponding variation in population dynamics of most plants and animals. Variation toward the long-term end of the temporal continuum is certainly significant on an evolutionary time scale, but can probably be safely ignored with regard to the recovery of damaged ecosystems. In this chapter, the author presents the analyses of two sets of data: a Christmas bird count of Passer domesticus (house sparrow) from 1947 to 1984 in Wichita, Kansas, and counts of the number of flowers of Helianthella quinquenervis (aspen sunflower) from 1974 to 1985 at the Rocky Mountain Biological Laboratory. Both of these data sets are perhaps representative of the types of census data that might be collected by researchers monitoring the status of recovering ecosystems.
