Parietaria pensylvanicu Mühlenb. ex Willd. - potentialities of migration from park habitats to segetal communities

Abstract

Parietaria pensvlvanica Mühlenb ex. Willd is a species native to North America, whose occurrence in Poland was first reported in Bydgoszcz in 1991. Its biology and ecology has been researched since 1996. The present paper discusses measurements and phenological observations carried out on four selected populations during the vegetation season in 1997. The aim of the research was to determine potentialities of the migration of P. pensylvanica from park habitats to segetal communities, on the basis of a defined life strategy of the examined populations. The analysis focused on the dynamics of density and biomass as well as on the weight of 1000 nucules, against the habitat conditions. The findings demonstrated that the investigated species was characterised by a set of life strategy properties referred to as C-S-R or S-R, and was subject to the "r"-type selection. P. pensylvanica has become an integral part of the Bydgoszcz flora and is likely to expand into segetal communities of agricultural and vegetable crops.