Microcosms were started in June 1991 and a period of 2 months was designated for the stabilization of seedlings and the development of a small ecosystem in the container. Figure 7.2 shows the average addition to height of seedlings over the 16 months of growth starting in August 1991. Both cypress and gum are deciduous, dropping leaves in November and replacing them in April. Thus, there was about 2 months growth before the leaves fell. Growth stopped for about 4 months, resuming after the leaves returned.