dynamics of bodícka brána forest vegetation

This article presents evaluation of long-term (1990–2004) stationary research on a forest phytocoenosis with the dominant tree species Populus × canadensis in the area affected by hydropower water structures Gabčíkovo on the Danube river. In the first three years of monitoring, where natural flooding occurred, species diversity was low, the structure and ecological proportion of a phytocoenosis were stabilized in an observed adult stand in rotation age. After clear-cutting and reforestation all the indicators changed (trends of parameters were statistically tested). An average of diversity increased 2.5 times, an intensive plants turnover was continuing during two years, and there was quantity of spreading of synanthrophyte, helipohyte, and nitrophilous herbs (species). After oscillating of ecological parameters (light, temperature, continentality, soil moisture, soil reaction, soil nitrogen), like forms and the species diversity were decreased in indicators, as well as a decline of heliophyte, synanthrophyte, and nitrophilous species. Formation of vegetation after 6 years of reforestation gradually tends to reach the state in the 90s. A tree layer was formed and herb understory was growing in mosaic.