Making ecosystems resilient to Invasive Alien Species

PROJECT DESCRIPTION

BACKGROUND

The combination of historical use and current management, exacerbated by human-induced environmental pressures, has rendered native ecosystems disturbed and species-poor. Such ecosystems are more vulnerable to Invasive Alien Species (IAS). They lack the functional mechanisms that well-developed ecosystems provide, such as competition and predation. Ecosystem resilience as a concept for IAS control is based on the observation that undisturbed species-rich communities are less prone to IAS invasion than disturbed species-poor ones. When native species fully exploit available resources, such as space, light and nutrients, it leaves little for invasive species to exploit and they are less likely to become dominant. This concept can be translated into the practical management of IAS. Improving ecosystem resilience to IAS constitutes a new approach to IAS management. It has been tested successfully on pilot scale for several IAS. However, the results are not yet widely known, and the importance of the conditions of the receiving ecosystem as a driver for invasions is not yet commonly recognised.

OBJECTIVES

The main project objective of LIFE RESILIAS is to demonstrate the effectiveness of IAS management based on improving ecosystem resilience within a relatively short time span, as compared to current practice that requires permanent IAS management. The project is designed on a scale that will convince stakeholders of its benefits and raise awareness of the importance of the conditions of the receiving ecosystems as a driving factor for invasions.

The project will demonstrate this ecosystem resilience approach on a selection of ecosystems for the reduction and control of selected invasive species, i.e. Fallopia sp. (Japanese knotweed), Prunus serotine (black cherry), Crassula helmsii (an aquatic stonecrop species) and Lepomis gibbosus (pumpkinseed, a freshwater fish). The aim is also to prevent subsequent new invasionsof these species, as well as other IAS. The broad applicability, and thus the replicability and transferability of the approach will be demonstrated by targeting:

Natural ecosystems and man-made habitats inside and outside of Natura 2000 sites;

Aquatic and terrestrial habitats;

Early and climax successional stages;

Four different IAS;

Flora and fauna;

A variety of interacting native species characteristic of the managed habitat;

Different functional interacting species (competition and predation);

Ecosystem scale.

The second project objective is to promote and replicate the application of the IAS ecosystem resilience approach at ecosystem scale, targeting the following audience: habitat owners, forest and nature managers, researchers, and policy development experts.

RESULTS

Expected results:

Increased native tree and scrub species populations and 156 ha of resilient forest ecosystems in which Prunus serotina and Fallopia sp. cease to threaten biodiversity. By the end of the project, replication is expected to have started on 1 200 ha of forest;

Decrease in the opportunities for the establishment of IAS such as Fallopia sp., by creating over 245 ha of wet soil conditions on the stream banks, lowering the light availability, and ensuring a higher abundance and diversity of native species;

Reduced abundance of IAS in the grassland demonstration sites, while increasing the abundance and diversity of native herbaceaous vegetation in 0.3 ha of high nature value grassland, leaving little space and nutrients for IAS to repopulate. Replication is expected to have started on 2 additional hectares by the end of the project;

Reduce the population of Lepomis gibbosus

in 4 ha of aquatic demonstration sites, which will subsequently be controlled by native predators, resulting in resilient aquatic ecosystems;

Reduce the cover of Crassula helmsii in 4 ha demonstration sites and subsequently replenish the population of native flora by planting competitive native species. This is expected to result in resilient wetland ecosystems. By the end of the project, replication is expected to have started on 40 ha of wetlands;

Policy recommendations taken up at regional, national and EU level;

Stakeholders commited to the application of the ecosystem resilience approach, including at least 50 habitat managers preparing plans to replicate the approach over 500 ha by the projects end;

50 researchers joining the ERA network.