Transboundary cooperation for the removal of an invasive river plant

Full Solution
Distribution of Himalayan Balsam plants along the River Thaya before eradication efforts (2001)
Podyjí National Park administration

Eradication of the neophyte Himalayan Balsam (Impatiens glandulifera) was a successful joint project of two bordering national parks Thayatal (AT) and Podyjí (CZ) that led to a significant decrease of Himalayan balsam plants in the river valley and return of native plants. The most important success factors were the common approach to river valley management, access to both river banks by Czech staff, change in management of river valley meadows, and ongoing joint monitoring in the river valley.

Last update: 27 Jul 2018
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Context
Challenges addressed
• Rapid spread of Himalayan Balsam, an aggressive neophyte that can quickly form monocultures and cause large changes to ecosystems that it invades while reducing biodiversity. • Contrasting scientific beliefs between two national parks regarding management effectiveness and handling of invasive species. • Lack of management of river valley meadows by landowners in Thayatal NP, favoring spread of Himalayan Balsam.
Beneficiaries
Protected area managers and authorities
Scale of implementation
Local
Multi-national
Ecosystems
Temperate deciduous forest
River, stream
Theme
Invasive alien species
Connectivity / transboundary conservation
Protected and conserved areas governance
Protected and conserved areas management planning
Outreach & communications
Location
Podyjí National Park, Podmolí, Czech Republic
East Europe
Process
Summary of the process
Monitoring of invasive neophytes (Building Block 1) and communication between the two national parks (BB 2) was essential to enable efficient removal efforts by both national parks (BB 3) and to ensure sustained suppression of the invasive plants. Coordinating the mowing of valley meadows by local landowners (BB 4) helped reduce the spread of the invasive plant. Together, then, these building blocks interacted to enable successful eradication of the Himalayan Balsam. Today, there exist only very few stocks of invasive species and both parks have developed procedures and practice to control them or face their potential increase. Also the landowners know about the potential dangers of the invasive species.
Building Blocks
Invasive plant monitoring
Podyjí National Park took sole responsibility for monitoring the river valley for infestations of the Himalayan Balsam and other invasive plants. The National Park staff used a boat to monitor the occurrence of the plant along the river banks, especially in areas that are hard to reach overland. Today, staff from Thayatal National Park is also part of the boat crew, and monitoring from the river is conducted once a year. The measures to eliminate invasive species are implemented several times during the year (2 to 6 times). The Himalayan Balsam occurs on both sides of the border, but Podyji National Park has greater capacity in implementing the measures. The participation on monitoring and management has thus been divided in accordance of capabilities of both national parks.
Enabling factors
Thayatal NP co-funded the purchase of a boat to be used for riverside monitoring by Podyjí NP staff. To be able to cross the border regularly for monitoring, the European Schengen system, i.e. in this case open borders for passenger traffic, was a facilitating condition.
Lesson learned
Initially, monitoring occurred at a small scale only on the Czech side. Eventually it became apparent that it was necessary to monitor Himalayan Balsam on both banks and on both sides of the border to get the necessary data to inform eradication efforts.
Transboundary protected areas staff communication
The two national park directors met 4-5 times per year to discuss among other issues the status of the invasive plant monitoring and removal. Jointly, they allowed the project to be funded and enabled the necessary actions. Furthermore, other staff from both parks met each other whenever needed to share information regarding the monitoring and removal efforts.
Enabling factors
There was usually at least one Podyjí NP staff member involved in the joint project that spoke German, otherwise English was spoken to overcome the language barrier.
Lesson learned
The project revealed the additional value of transboundary communication in the field of nature protection. Without the exchange and the mutual enriching cooperation between Thayatal and Podyjí National Park the project would not have been that successful. Both National parks took the experience with them for future challenges and projects that collaboration enables positive exchange and mutual learning.
Joint transboundary removal of an invasive plant
Invasive plants occurred on both sides of the Thaya River, which serves as the international boundary and the border between the two national parks. Plants were removed from both sides of the river by staff from the respective parks, and removal of plants took place following their detection by the monitoring effort. When the joint eradication project was originally proposed by Podyjí National Park, staff of Thayatal National Park were sceptical of the efficiency of the efforts to remove the invasive plant based on their knowledge of many unsuccessful eradication attempts in other areas. Thayatal National Park was therefore only willing to invest a small amount of resources initially to test whether the eradication efforts would work. After initial successes, Thayatal National Park contributed resources to conduct more substantial removal measures jointly with Podyjí National Park. As both parks are opposed to the use of pesticides, individual plants needed to be removed by hand and preferably during the adolescent life stages before seeds emerged. Otherwise, seeds could be spread during removal of the adult plants. Nevertheless, mowing measures proved very effective in places of larger stocks.  
Enabling factors
The removal process had been initiated by Podyjí before establishment of Thayatal National Park, which reduced the effort needed through the joint eradication. Second, geomorphology within the river valley section running through the parks is relatively unfavorable for rapid expansion of the plant. Third, removal of plants by Czech staff on Austrian soil became easier after Czech Republic joined the EU in 2004. Before, border police had to be informed every time staff crossed the border.
Lesson learned
A big lesson learned for both National Parks was the need to cooperate across the state border and between the two protected areas to jointly implement nature conservation measures. This especially applied to the removal of invasive species in a river valley that is situated on the border.
Coordinating meadow management with local landowners
Private lands occupy a significant portion of the river valley within inholdings of Thayatal NP, which are dominated by meadows. The economic benefits for farmers to cultivate these meadows are too low to warrant raising of crops there. To prevent the establishment and spread of neophytes in the meadow areas, however, Thayatal NP staff coordinated with farmers to regularly mow these meadows. In turn, farmers were compensated monetarily.
Enabling factors
The financial support of the mowing measures came from the Austrian government, who fosters environmentally friendly and extensive forms of agriculture protecting natural habitats in the frame of the ÖPUL-program.
Lesson learned
Some of the farmers turned out to be a great help for the maintenance of the meadows and thus the control of the Himalayan Balsam. The established cooperation and contacts can prove to be relevant also in forthcoming activities.
Impacts

The joint invasive-species monitoring and eradication project of the two parks was a great success. The Himalayan balsam has disappeared from both national parks with the exception of a few single stocks. That way, problematic impacts on the Thaya River’s ecosystem due to the rapid spreading of the neophyte were prevented. Targeted removal of Himalayan balsam started in 1995 on the Czech side and in 2001 on the Austrian side following establishment of Thayatal National Park in 2000. The population of Himalayan balsam then decreased rapidly. The surprising positive effect was enhanced by big floods in 2002, which also prevented Himalayan balsam from massive spreading. Since that time, the plant has practically disappeared from the river valley. The joint monitoring and removal of Himalayan balsam and other invasive neophytes in the river valley along with mowing of river meadows by local landowners occurs every year. These annual measures are still necessary to control the Himalayan balsam in the valley The experience of a successful cooperation through joint invasive-species eradication and monitoring efforts provided added value that encourages and facilitates future transboundary collaboration.

Sustainable Development Goals
SDG 15 – Life on land
Story
When Podyji National Park biologist Lenka Reiterová went on a random hike near the river bank in mid of 1990s, she noticed that Himalayan Balsam was slowly taking ground. Until that time, no measures had been taken to gain control over it. Following this, initial attempts to remove it were very ineffective, and staff of the national park started to develop better methods to eliminate the plant. “Soon after that, we realized that a big part of the problem was that we were only able to work on the Czech side of the river banks. The population of the Himalayan Balsam was still growing at that time,” Reiterová recalls. The big change came in 2000, when Thayatal National Park was established and became a partner of Podyji National Park in the elimination of the invasive species on the Austrian side of the border. A challenge to plant removal at the beginning – before the Czech Republic joined the European Union in 2004 – was that the border police had to be informed every time that Podyjí National Park staff crossed over to Austria. Following 2004, the population of Himalayan Balsam started to decrease notably. An unexpected but important change in Himalayan Balsam occurrence came in 2002, when big floods stroke Podyji. “At first we feared, that this natural disaster would help invasive species to spread, but the effect was completely opposite,” Reiterová describes. Following the flood, presence of Himalayan Balsam dramatically decreased. Since that time, there have only been isolated occurrences of the plant on both banks of the river, which are monitored annually. When plants are detected, they are removed by park staffs. “The visible effect of our first cooperation on management of the area with our colleagues from Austria has helped us support and create other common projects in coming years”, Reiterová thinks. Common monitoring and eradication of Himalayan Balsam continues today.
Connect with contributors
Other contributors
Lenka Reiterová
Podyjí National Park
Robert Brunner
Thayatal National Park (former director)
Christian Uebl
Thayatal National Park
Sophia Fettinger, solution coauthor
Institute of Silviculture, University of Natural Resources & Life Sciences, Vienna
Brady J. Mattsson, solution coauthor
Institute of Silviculture, University of Natural Resources & Life Sciences, Vienna