0000000001082839
AUTHOR
Päivi M. Tikka
showing 3 related works from this author
The role of competition and rarity in the restoration of a dry grassland in Finland
2001
Semi-natural grasslands have become scarce throughout Europe. Preservation of their plant species requires either the maintenance of the existing grasslands or the creation of new ones. To study the establishment and regeneration ability of plant species typical of dry grasslands we laid out an experiment on a former arable field in central Finland. We compared the success of 13 grassland species both in a theoretical situation with minimal competition and in competition with weeds. More than half of the species used were regionally rare. As a group, grassland plants reached the highest cover in the experimental plots in which outside competition was minimised by weeding. However, the total…
Population Persistence and Offspring Fitness in the Rare Bellflower Campanula Cervicaria in Relation to Population Size and Habitat Quality
2000
Data from several animal species and a few plant species indicate that small populations face an elevated risk of extinction. Plants are still underrepresented in these studies concerning the relation between population size and persistence. We studied the effect of population size on persistence among natural popu- lations of the rare bellflower Campanula cervicaria in Finland. We monitored 52 bellflower populations for 8 years and found that the mean population size decreased from 24 to 14 during this period. Small popula- tions with # 5 individuals were more prone to losing all fertile plants than were larger ones. Reduction in population size was nevertheless unrelated to the degree of …
Can grassland plant communities be preserved on road and railway verges?
2000
Semi-natural grasslands are a threatened biotope type in many countries. Typical grassland plant species are adapted to continuous grazing or mowing that keeps the envi- ronment open. With the decline in grassland area, these spe- cies are ever more reliant on alternative habitats such as road verges. To find out whether plant communities comparable to those of semi-natural grasslands can be maintained on modern road and railway sides, the vegetation of 92 grasslands and 90 road and railway verges was studied. These biotope types were compared with each other according to their community structure, total number of species, number of grassland species and restricted-range diversity. Further …