The following examples of demographic models of two herbaceous plants, Campanula americana and Dipsacus sylvestris, and the loggerhead sea turtle, Caretta caretta, will be used to illustrate the value and limitations of loop analysis.
Demographic loop characteristics of Campanula americana.
biennial types of Campanula americana, the loops clearly reflect the alternative paths for individuals in the life history.
Campanula americana is endemic to eastern North America and occurs in partial shade in moist thickets and floodplain woods, along streams, roads, and in drier upland woods (Gleason and Cronquist, 1963).
Campanula americana seedlings require approximately 1,000 hr of 0 to 10 [degrees] C vernalization to bolt and flower (Baskin and Baskin, 1984), however, longer periods do not appear to have any deleterious effects, as the seedlings grow only slightly during the vernalization period.