The consequences of plant invasions depend on the individual species
Invasive alien plants have a major impact on native plant communities and have a negative impact on overall biodiversity. A team of botanists, led by Margherita Gioria from the Botanical Institute of the Academy of Sciences, took a closer look at how two of the most successful invasive plants affect the surrounding environment. Petr Pyšek from the same institute and the Department of Ecology at the Faculty of Science, Charles University also contributed significantly to this research.
Invasive plant species, i.e. fast-spreading non-native species, only arrived in new areas with human activity. They are now one of the negative consequences of global change and are also contributing to biodiversity loss. They are often aggressive in new environments and their impact on some native plant species can be devastating. Among the plants that are listed as species of Union concern are the Gunnera tinctoria and Impatiens glandulifera. These two species have become the target of scientists studying their impact on the surrounding environment and vegetation.
Source: Flickr.com, Photo: Svenn Sivertssen.
These plant species share invasion potential, large growth, and high biomass production, but differ in life cycle, reproductive strategy, and environmental requirements. While the Gunnera tinctoria needs high rainfall conditions for its growth, the Impatiens glandulifera grows mainly in riparian habitats across North America and Europe.
The researchers used three sites in Ireland representing different ecosystems. At each site, they compared areas invaded by the invasive species with uninvaded ones. They compared various characteristics, in particular the soil seed bank, which assesses seed species composition and seed viability, but they also looked at soil chemistry.
The coastal and riparian grasslands invaded by the above-mentioned invasive species have experienced a significant decrease in species richness and functional diversity, as well as a change in the phylogenetic composition of the vegetation. The results of the study thus highlighted the considerable sensitivity of these communities to phylogenetically distant invasive species. The composition of the seed bank, on the other hand, showed a certain degree of resilience to invasions; no significant differences were found in its species richness between both species. However, differences were found for other environmental factors and local plant communities. Changes in ecosystem characteristics induced by the invasion of Gunnera tinctoria were more long-lasting than those of the Impatiens glandulifera, particularly in terms of nutrient cycling. This could facilitate its persistence in the invasion site and negatively affect the diversity of native species.
The results of research on these two successful invasive plant species have shown that despite some common characteristics that enabled their invasion, they have different effects on the surrounding environment. Scientists point out that control and restoration measures need to be designed with specific invasive species in mind.
Kateřina Fraindová
Published:
Feb 12, 2024 07:35 PM
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