Thyme and ant gardens return to the wild horse reserve
This year, important species of herbs have appeared in a large herbivore reserve located in the former military training area of Milovice near Prague, which were either missing or very rare in the previous years. Biologists are particularly excited over thyme, grass pink, field cow-wheat and the strikingly yellow-flowering Irish fleabanes.
The main reason for establishing large herbivore grazing in the former training area was to restore diverse meadows featuring high numbers of plant species and maintaining them in a manner approximating natural processes. The underlying expectations of scientists have been fulfilled, and the project has resulted in the return of plants that either completely or, to a significant extent, disappeared from areas that had been overgrown for two decades.
The first two years of grazing – an activity which began in 2015 – have produced an overall change in vegetation. “The formation of a mosaic of grass stands of varied length was crucial, which is an important prerequisite for the biological diversity of meadow and steppe habitats,” notes Miloslav Jirku from the Biological Centre of the Academy of Sciences of the Czech Republic.
There is also a clear increase in the percentage of flowering plants, which means an increase in the presence of nectariferous herbs, which are very important for insects. On the contrary, aggressive grass species such as wood small reed and tall oat grass are on the decline.
While the first two years saw an increase in flowering species that had survived in small numbers at the site during the period the former military area became overgrown for two decades, this year marked the return of species that had been completely missing in the grazing areas. “The first pleasant surprise was field cow-wheat – an endangered, violet-yellow herb with an exotic appearance,” said Jirku.
The second flower whose return scientists have observed is large thyme. The nearest place where the herb grew to date was atop the hill overlooking the grazing land, hundreds of meters far away. The new occurrence was found by scientists in as many as three places in the Milovice area. “Thyme is an herb typical for warm and sparse grasslands. While these grasslands had formed as early as two years ago due to grazing, it took two years for the plant itself to reach the pasture,” adds Jirku. Thyme also produces high-quality nectar, so butterflies and bees were certainly happy with it.
Moreover, thyme became part of the first ant garden, since meadow ants seek out the seeds of the plant as well as those of other nectariferous herbs and sow them on their ant hills. “This is a phenomenon we know from, say, Carpathian and Balkan grazing land, and we hoped that it would appear in the Milovice pastures, too. It was like finding a coveted gift under the Christmas tree, because we have thus far only been discussing ant gardens as a typical phenomenon of grazing landscapes,” said Jirku.
“The return of new species of flowering herbs confirms the positive development seen in the reserve that began after the arrival of large hoofed mammals. Low-nutrient, high-grass stands have retreated. Instead, more diverse flowery grasslands of different types are emerging,” said Dalibor Dostal, director of the conservation organization European Wildlife.
Photo: Miloslav Jirku
