Dear all,
today we all know the problem that Molinia caerulea has spread massively in the fens and bogs as a result of drainage and the increase in nutrients. Molinia dominance is often observed in fens over peat, which are rich in bases. It is noteworthy, however, that Schoenus ferrugineus can also reach very large abundances in heavily drained fens. If you look at the peat below, it is very clear that it was not formed by the existing vegetation. The primary habitat of Schoenus ferrugineus in Austria is not very easy to identify. This species is native to spring fens in particular. Maybe also on the shores of lakes. All of these populations are mostly small and narrowly defined. I have the impression that Schoenus ferrugienus immigrated to drained fens or that the population has increased significantly. When drained, base-rich fens are abandoned, Molinia and Schoenus can form large, resilient hummocks that hardly provide a habitat for other species. There is absolutely no question that both Molinia and probably also Schoenus ferrugineus are very resistant and competitive species that get well with drainage. Some species of grass are generally very resistant to external influences. We also know this phenomenon from Trichophorum cespitosum in connection with intensive grazing. Further opinions from Europe would be very welcome.
all the best Christian
Also native plants could be invasiv due habitat degradation and are signals for ecological problems.
I guess you could classify species normally present in low levels that increase in abundance due to anthropogenic activity as invasive. However, if a forested area was deforested and all tree-related biomass was removed, and grassland species or shrubs instead appeared due to preferential growth conditions, would you call these species invasive? A change in conditions does not by necessity make them invasive, it just means that these species are more adapted to explore empty niches and/or utilize available resources more efficiently.
I think that I phrased my question a little bit incorrectly. The word invasive is in quotation marks. The question is actually another, it is about Schoenus ferrugineus a species of high nature conservation value. I think, however, that it has also benefited in part from drainage on the dens. Of course, many populations have been destroyed in the past.
Schoenus ferrugineus definitely benefited from drainage. As compared to other species occurring in spring mires etc., it has a rather low need in permanent water supply and thus can grow also in drained and/or managed fens. By forming a dense root system and only slowly decomposed leaf material, it somehow also forms its own site characteristics. However, since Schoenus occypies a newly created habitat type (drained and/or managed peatland) but does not invade into an existing, stable community, I would not classify it as invasive species. In my opinion it is an indicator of succession on abandoned peatland.
Hi Josef, I hope you are fine! Yes for this reason I put invasive under brackets. But Solidago canadensis also does the same thing in the end, only that it is not indigenous. In practice, a species is often referred to as invasive if it becomes a management requirement. This is the case with Molinia. This is not discussed at Schoenus, because it has a high nature conservation value.
Mmh... I still see a strong difference between Schoenus and such species as Solidago c. and Molinia c. – in particular because the latter two invade also into already existing, ± stable communities. Thus, they show the capacity to suppress other species and they can newly establish in dense vegetation. In contrast, Schoenus usually needs open conditions to establish (once established, it can of course hinder the establishment of other species). This is why I would not classify it as being invasive.
Yes that is right. I am of course exaggerating something. Schoenus is a little bit similar to Trichophorum cespitosum. In the latter case, nobody asks about the condition of the bog when you see these beautiful stands in autumn. It's all a succession. Nevertheless, there are former transition mires, where there was previously a Caricetum lasiocarpae and now a stray meadow with Molinia.
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