DURING, HEINJO J. Dept. of Plant Ecology, Utrecht University, Went Building, P.O. Box 80084, NL-3508 TB Utrecht, The Netherlands. - On the role of branching patterns in the density-dependent growth of pleurocarpous chalk grassland mosses.
Density had both positive and negative effects on shoot growth of
pleurocarpous chalk grassland mosses. In an attempt to understand the
mechanisms involved, a simulation model of pleurocarp shoot growth was
built that included interaction for light and water along an explicit
vertical dimension. The model allowed coexistence of at least four
'species' differing in shoot angle and branch density. Density and
mass/area ratio of side branches with determinate growth strongly
affected biomass gain. From an experiment on the effects of light
quantity and quality on branching patterns of Ctenidium
molluscum and Calliergonella cuspidata we hope to derive
rules to allow incorporation of plasticity in branching patterns into
the model.
Key words: branching, bryophytes, competition, facilitation, simulation model