Foundation Conservation Carpathia warns of the increasing threat posed by invasive alien plant species to both the environment and human activities. Around 400 invasive alien plant species have been identified in Romania, eight of which are widespread in the southeastern Făgăraș Mountains. The Foundation advises the public to limit and prevent the spread of these plants, starting with cultivating native decorative plant species in gardens and managing plant debris carefully to avoid disposal in natural environments, particularly along river banks.
In recent years, invasive alien (or non-native) plant species have become a significant global issue. These species are not native to the ecosystems they invade, often arriving accidentally or through human activity. Also known as alien, exotic, or non-native species, their spread is facilitated by the intensification and globalization of human activities, tourism, and climate change, leading to ecological imbalances. These plants spread rapidly, disrupt ecological balance, and negatively impact agriculture, food production and human health.
“The introduction of alien species often occurs intentionally, without knowledge of their impact on local ecosystems,” said Dr Oliviu Grigore Pop, biologist at Foundation Conservation Carpathia. “A common example is Japanese knotweed (Reynoutria japonica), which has ‘escaped’ from gardens and spread, replacing native species vital for maintaining a natural balance. The alder corridors, essential for for bank stabilisation and natural disaster prevention, are particularly vulnerable to invasion by alien species. Therefore, we have initiated removal activities along rivers. In invaded areas, these plants gradually eliminate native species, reducing biodiversity and causing ecological imbalances.”
Invasive species identified
Foundation Conservation Carpathia has identified eight invasive alien plant species in the project area, located in the southeastern Făgăraș Mountains. This area spans more than 170 km along the Dâmbovița Valley, Târgului River, Vâlsanului Valley, Doamnei Valley, and two tributaries of Vidraru Lake. The identified plants include Japanese knotweed, eastern daisy fleabane, Himalayan balsam, Jerusalem artichoke, cutleaf coneflower, Canadian goldenrod (solidago), Impatiens, and orange lily.
Control measures
Since 2020, the Foundation’s teams have undertaken actions to eliminate invasive alien species along 157 km of river valleys using environmentally friendly methods such as mowing, uprooting, and cutting invasive plants without the use of chemicals.
For a detailed analysis, Dr Oliviu Grigore Pop coordinated a scientific study over 164 km along the main valleys in the Făgăraș Mountains area. This study is part of the LIFE Carpathia project ‘Creating a Wilderness Area in the Southern Carpathian Mountains, Romania’. Based on the study’s results, the Foundation developed an action plan to control and limit invasive species, aiming to reduce their spread by at least 50%.
Impact of invasive species
Invasive alien plant species, often introduced deliberately for ornamental purposes, can cause significant damage. “The vegetation zones along the Dâmbovița and Argeș rivers are severely affected by logging, overgrazing, and climate change,” explained Dr Oliviu Grigore Pop, “which facilitate the invasion of alien plants. These plants grow rapidly and replace species valuable to the ecosystem. Practices such as irregular mowing of lawns, leaving soil bare, and discarding plant debris containing invasive plants exacerbate the problem. For instance, Japanese knotweed can grow through asphalt or cement due to its hardy rhizomes. Human intervention is essential to control and limit their impact since these plants have no natural enemies and spread rapidly.”
What can we do?
To prevent and control the spread of invasive alien plants, the following actions are recommended:
- Avoid introducing potentially invasive alien species into gardens and nature. Opt for native or non-invasive ornamental species (e.g., cornflowers, hawthorn, elder).
- Limit the spread of already established invasive species.
- Educate yourself about the potential of these plant species and control measures if they are already in your garden. Properly dispose of garden waste to prevent spreading invasive plants.
- To date, 396 invasive or potentially invasive alien plant species have been identified in Romania.
