Objava Dwarf Cattail Monitor pojavila se prvi puta na Drava Life.

Objava Reintroduction of Dwarf Cattail pojavila se prvi puta na Drava Life.

However, Purger warned that human activity on the river, primarily the construction of hydroelectric power plants, excessive gravel and sand removal, and the construction of regulatory infrastructure, has resulted in major changes in hydromorphological dynamic processes and the ecological condition of the Drava River.

Purger notes that important indicators of negative changes include the disappearance of specific river habitats, gravel and sand banks, as well as the disappearance of key species that depend on these habitats. One of them is the dwarf cattail (Typha minima), which disappeared from the Croatian part of the Drava river in the last three decades. “The reintroduction of dwarf cattail in its natural habitat on the Drava River, implemented within the scope of the DRAVA LIFE project, has a practical and symbolic significance,” Purger said.

©WWF

©WWF

Dwarf cattail disappeared from this area more than 20 years ago. To be more precise, it was last recorded on gravel bars near Varaždin in 1994. Both the German tamarisk (Myricaria germanica) and the dwarf cattail (Typha minima) are pioneer species that grow on habitats such as sandbanks and river banks in freshwater ecosystems.

“Given that last year’s reintroduction of dwarf cattail was not completely successful due to extremely high water levels, we decided to reintroduce this extinct river plant once again, this time under the guidance of our expert associate Dragica Purger, PhD. We hope that we will have more luck this year and that the plants will grow well”, explained Branka Španiček from WWF Adria. Španiček added that the ultimate success of reintroduction and repopulation can only be ascertained once the seedlings are fully adapted to the new habitat and once they begin to reproduce.

©WWF

©WWF

“Successful reintroduction of this plant species will increase the biodiversity and improve the ecological function of river ecosystems, although the permanent establishment of these populations will depend on the implementation of river revitalization measures. It will also be an indicator of improving river conditions and increasing natural value of the Drava River”, concluded Purger. This year’s reintroduction wouldn’t be possible without help of DRAVA LIFE partners and associates from the Drava Federation (Hungary).

Objava World Water Day Marked by the Reintroduction of Dwarf Cattail on the Drava River pojavila se prvi puta na Drava Life.

As a part of the re-introduction activity, german tamarisk was moved from the gravel pit near Varaždin and Prelog to the pre-selected locations, while dwarf cattail was transported from Austria, where its population along Drava river is in good condition due to the reintroduction that was carried out throughout several projects.

Patuljasti rogoz na lokaciji Forjanov siget/Dwarf cattail at location Forjanov siget

German tamarisk at location Libanovec/Kebrač na lokaciji Libanovec

“Despite the unfavorable conditions and fear that high water levels will adversely affect plants, we are extremely happy that our first monitoring results showed that the first phase of repopulation and reintroduction was successful. Our expert associate, Dr. Dragica Purger has found separate seedlings on almost all sites where the activities were carried out. Unfortunately, not all plants have survived high water levels but we believe that the species that survived will continue to grow. The first year is crucial in such cases and we will closely monitor plants in the upcoming months. The ultimate success of reintroduction and repopulation can only be ascertained when seedlings are fully adapted to the new habitat conditions and are beginning to reproduce”, said Branka Španiček from WWF Adria.

Both the german tamarisk and dwarf cattail are indicators of healthy and natural rivers. German tamarisk was last recorded in 2013 at the gravel bars near Legrad, while dwarf cattail disappeared from this area more than 20 years ago, to be more precise, last time it was recorded on the gravel bars near Varaždin was in the year 1994.

Both plants are pioneer species that grow on new habitats such as sandbanks and river banks in freshwater ecosystems. They could be found on this kind of habitats along the Drava river in Croatia until the recent past but have become almost extinct from the area with the gradual decrease of such habitats and loss of river dynamics along with rapid and frequent changes in water levels due to hydropower operation. Factors that have contributed to the disappearance of these habitats are lack of sediment as well as decreases of natural river dynamics due to river regulation and hydropeaking.

Objava Successful first phase of re-introduction and repopulation of riverine plants along the Drava pojavila se prvi puta na Drava Life.

The reintroduction is a process of returning the plant species to the area in nature where those species disappeared, but the conditions for their survival are still remaining. Both the german tamarisk (Myricaria germanica) and the dwarf cattail (Typha minima) are pioneer species that grow on new habitats such as sandbanks and river banks in freshwater ecosystems. Both plants` could be found on this kind of habitats along the Drava river in Croatia until the recent past, but today they are almost extinct from the area due to river regulation activities from the past.

“Appropriate habitats for these two species on the Drava river are still here, but these species have disappeared from them due to various anthropogenic influences and changes in the morphodynamics of the river. These species are considered to be indicators of the river that has natural hydromorphological dynamics and a shape of the riverbed that changes. Drava river is still one of them”, said Branka Španiček, DRAVA LIFE project officer in WWF Adria.

The german tamarisk and dwarf cattail are considered to be one of the most important indicators of healthy and natural rivers. Human impacts on rivers (e.g. channelization, construction of hydropower plants as well as gravel and sand extraction) alter vital hydro-morphological processes, reduce river gravel dynamics and affect natural floods, all being essential features for these natural ecosystems to develop and persist. Gravel and sand bars as pioneer habitat types have become very rare in Europe and they are among the most endangered ecosystems. Therefore, they are declared as priority habitats within the European Habitat Directive in the European Union.

The german tamarisk until recently could be found on only two sites at the confluence of the Drava and Mura, on two gravel pits and along the drainage channel near the hydropower plant Donja Dubrava. It is a statutorily protected species in Croatia and listed by the IUCN as critically endangered. Only 26 seedlings found in two gravel pits of German tamarisk were repopulated to 3 previously chosen locations near Legrad in Koprivnica-Križevci county.

“Unfortunately just few young seedlings with well-developed root system have been found on those locations. Mostly adult plants of German tamarisk were dug out and planted on 3 different locations which are most suitable for their survival. Adult plants are still less susceptible to dryness and mechanical disruption than juvenile plants and therefore can be planted in various microhabitats. This method was chosen because it was verified and proven as the most successful method in the reintroduction of riverine plants in Austria, Germany and Switzerland”, said dr. Dragica Purger, a botanist and expert associate in the DRAVA LIFE project for the plants reintroduction and repopulation activity.

The dwarf cattail is on the European Bern Convention list for the Protection of Wild Species and Natural Habitats. The existence of dwarf cattail in Croatia could not been confirmed, and this species is unfortunately considered to be extinct from the territory of Croatia due to the human activities. Several hundreds of adult plants of dwarf cattail with developed roots system have been reintroducted to sand banks along the Drava river near Legrad as well. The plants were brought from Carinthia in Austria, from the Upper Drava ecosystem. Expert Dr. Gregory Egger has accompanied the removal and safe transport of the plants.

If the action turns out successful, German tamarisks and dwarf cattails will once again become indicators of an intact and healthy free flowing river and their reintroduction aims to directly improve the biodiversity of flora and fauna and the natural values ​​of Drava river’s ecosystem.

The event of reintroduction and repopulation of riverine plants was also supported by Ivan Sabolić, Mayor of Legrad and Marina Mihalec, Deputy Mayor of the Municipality of Đelekovec, who both helped plant a mother plant on an island in the Drava. Partners in the Drava life project from Croatian Waters, WWF, Public Institutions for the Management of Protected Areas of Nature in Koprivnica-Križevci County conducted the reintroduction together, with support from local fishermen and Rafting club Zeus.

Objava First reintroduction and repopulation of riverine plants in Croatia pojavila se prvi puta na Drava Life.