0000000000034449
AUTHOR
Ligita Liepina
Age and spatial structure of natural Pinus sylvestris stands in Latvia
Abstract The age and spatial structure of six natural old growth Pinus sylvestris stands in Latvia were investigated, to attempt to identify retrospectively the past features of development. In each stand, one or two plots of size 200–900 m2 were established. Tree locations were mapped, stem diameter was measured, and tree age was determined from cores or by counting branch whorls. Tree distribution was assessed by Ripley's K function. A clumped spatial pattern was shown for P. sylvestris younger than 100 years. The temporal patterns of establishment could be partly linked to favourable climatic periods. The major disturbance affecting pine stands along the coast was windblown sand, which p…
Antibacterial Activity of Extracts from Some Bryophytes
The antimicrobial activity of aqueous and ethanolic extracts of 11 Bryophyta species and 9 Marchantiophyta species collected in Latvia was tested against Staphylococcus aureus, Escherichia coli and Bacillus cereus. The extract of Lophocolea heterophylla inhibited the growth of B. cereus, but none of the tested extracts inhibited the growth of E. coli. 70% of bryophyte species demonstrated certain activity in relation to S. aureus. In general, 73% of ethanolic extracts and 39% of aqueous extracts exhibited antibacterial activity against S. aureus. The highest degree of antibacterial activity against S. aureus was shown by the ethanolic extract of Dicranum scoparium and aqueous extracts of At…