Change in spatial distribution patterns of a biennial plant between growth stages and generations in a patchy habitat

The aim of the study was to evaluate factors causing change in spatial distribution patterns of plants between growth stages and generations for a monocarpic biennial plant, Lysimachia rubida. It was assumed that habitat heterogeneity was a primary factor determining spatial patterns of plants, and a randomization procedure was developed for testing the null hypothesis that only spatial association with ground surface conditions determined spatial patterns of plants.

A 5-year demographic census was conducted on an open dry habitat that was heterogeneous with regard to the ground surface conditions.

There was significant habitat association in that plants at vegetative and reproductive stages were denser in areas with smaller gravel than with larger gravel. Point process analyses rejected the null hypothesis of the spatial association with ground surface conditions.

The results suggest that other factors, such as patchy seed dispersal, secondary dispersal of the seeds and life-history variation at various spatial scales, also affected spatial patterns of individuals in a population of L. rubida. Spatial structures and dynamics of a local population in a patchy habitat represent various performances of plants within patches and seed dispersal within a patch and beyond the patch.