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Biological systems are subject to a dramatic increase in invading species in the 21st century due to increasing globalization around the world. In the near future, these species will cause more extensive ecological as well as socio-economic damage. Biotic invasions will result not only in a reduction of the original biodiversity, but also total loss, particularly degradation of natural habitats – especially Natura 2000 habitats. This study aims to understand the processes of spread of invasive plant species, their way of life, adaptation to environmental changes and displacement of native species. Without the local level, it is not possible to understand these processes on the regional and continental dimensions and thus implement scientific facts and findings into the prediction of the development of global biosystems. The research was conducted during the vegetation period in the years 2017–2021 in the studied areas of non-forest and forest habitats in the central part of Slovakia. We recorded 242 localities in the area with the occurrence of invasive plant species in an area of 3.057 km2 out of the total mapped area of 169.024 km2. We recorded the highest number of localities and the most expansive distribution for the species Stenactis annua, Robinia pseudoacacia, Solidago canadensis, Impatiens glandulifera and Fallopia japonica.

In order to investigate the effects of tropical forest fragmentation, a comparative study on floristic composition, plant life forms and ecological species groups in a 13.9 ha remnant tropical rainforest was conducted over 48 years (1959/1960-2008) in southern Yunnan, China. A total of 258, 292 and 332 native seed plant species were present in the remnant in 1959/60, 1997 and 2008 respectively. A total of 407 species were recorded in the remnant from the three inventories, of which 188 species were common. Species diversity did not reduce with diminution and further isolation of the remnant. Species could condense with the limited natural habitats of the remnant with the loss of surrounding natural vegetation. There was a significant shift in floristic composition with 27.1% species of the original forest absent in the inventory in 2008 and 43.4% of the present species were new migrants. The species shift was greatly accelerated in the recent 10 years in the remnant with changes of surrounding vegetation into rubber plantations. There was a conspicuous shift in the relative representation of mature-forest and light-demanding species: the former decreased. However, plant life forms did not show significant change in the remnant over 48 years. Species loss was balanced by new migrants across life forms. Although species diversity was maintained and physiognomy (life forms) of the remnant did not change significantly, the floristic composition and ecological species groups were conspicuously changed through time. This implies that the essential flora of the tropical rainforest could not be actually maintained in the remnant. It is suggested that the flora of tropical rainforest cannot be protected from impoverishment even if the fragmented forests are conserved. [ABSTRACT FROM AUTHOR]