Transboundary cooperation for the removal of an invasive river plant

Podyjí National Park administration
Publicado: 18 Noviembre 2016
Última edición: 27 Julio 2018
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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.


Europa del Este
Escala de aplicación
Bosque templado caducifolio
Ecosistemas de agua dulce
Ecosistemas forestales
Río, corriente
Comunicación y divulgación
Conectividad / conservación transfronteriza
Especies exóticas invasoras
Gestión y planificación de áreas protegidas y conservadas
Gobernanza de las áreas protegidas y conservadas
Objectivos de Desarrollo Sostenible
ODS 15 - Vida de ecosistemas terrestres
Metas de Aichi
Meta 9: Especies exóticas invasoras prevenidas y controladas


Podyjí National Park, Podmolí, Czech Republic | Thayatal National Park (Austria)
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• 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.


Protected area managers and authorities

¿ Cómo interactúan los building blocks en la solución?

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.

Impactos positivos

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.


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.

Contribuido por

Lenka Reiterová Podyjí National Park

Contribuído por

Podyjí National Park
Thayatal National Park (former director)
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