The stage in which an ecosystem rapidly gains biomass through the introduction of plants with woody stems is called?

The answer is Aggregation.

During plant succession new community gets established at an area which had been uninhabited. The community which gets established at the site is called climax community. The aggregation is the stage during which there is increase in population of the species which has become established in the area. The shrubs replace the small herbs. This adds up biomass by introduction of more plants with woody stem. This also proves as a source of food for future inhabitants.

cells spend most of their time in interphase