Pilot site for the management of Dwarf Serviceberry
It threatens a habitat of European importance: coastal wooded dunes, which are protected under EU nature conservation legislation.
The work is led by the project partner, Nature Conservation Agency of Latvia.
Removing dwarf serviceberry shrubs and roots using hand tools (19 ha).
Removing shrubs and roots using compact machinery (14 ha).
Cutting down shrubs and treating the stumps with plant protection products in a limited area (0.08 ha).
Repeated strimming of dwarf serviceberry (0.14 ha).
In the oldest and most biologically valuable part of the nature park, in Buļļuciems, the invasive alien species dwarf serviceberry (Amelanchier spicata) has spread across an area of 33 hectares. As it spreads rapidly and forms dense stands, it alters woodland structure, changes environmental conditions and affects soil composition. As a result, species characteristic of wooded coastal dunes disappear, and pine trees gradually lose their dominance. The open, light pine woodlands typical of coastal dunes may gradually develop into dense, overgrown stands that are difficult to walk through and have poor visibility.
To preserve the area’s unique natural values, the control of invasive alien species has been designated as a top-priority management measure in the approved Ragakāpa Nature Park Conservation Plan for 2019–2031.
Control work targeting dwarf serviceberry was carried out under the supervision of experts from Nature Conservation Agency of Latvia from September 2023 to February 2024. Experience shows that managing invasive alien species is challenging and cannot be achieved in a single year. Work was therefore continued during the autumn and winter months through to 2026, focusing on serviceberry stems that were previously missed and on regrowth from shoots. The results will be monitored and assessed through to 2027.
The work was organised to minimise the impact on the dunes. Compact machinery followed routes designated by experts. Piles of uprooted serviceberry shrubs remained in the dunes temporarily. The work was also exposed patches of sand where the shrubs have been uprooted. Although these exposed areas may look unusual, nature conservation experts emphasise that they provide habitats for rare species such as the pasqueflower (Pulsatilla patens) and sand pink (Dianthus arenarius), while also encouraging pine regeneration.
The effectiveness of management methods will be evaluated at the LatViaNature pilot sites, with the aim of developing science-based guidelines in 2027 for managing invasive alien species elsewhere in Latvia.
Visit www.invazivs.lv to learn more about dwarf serviceberry, including its introduction pathways, impacts, management methods and distribution in Latvia. Here>>>
Through the European Commission’s Green Assist initiative, LatViaNature engaged Dutch environmental economist Olaf Kooijmans for a detailed cost-efficiency and cost-benefit analysis of invasive alien species eradication methods in Latvia, including Amelanchier spicata.
O.Kooijmans compared the effectiveness of the tested eradication methods and the return on the funds invested. Data on the percentage cover of Amelanchier spicata before the eradication methods were applied (2022), together with annual monitoring results from the testing period (2024, 2025, 2026), were used to calculate the percentage reduction in the invasive species’ cover relative to the 2022 baseline. Implementation costs were also compiled and expressed per hectare, and a cost-efficiency ratio was calculated to show the cost of the reduction achieved.
The Cost-efficiency ratio (CER) was calculated to compare the relative effectiveness of each method per unit cost. The lowest ratio is the most cost-efficient (achieving highest reduction against lowest relative cost per unit reduction).
Updating the Green Assist data with 2025–2026 calculations showed the following average annual cover reductions in monitoring plots:
Brush-cutting value -126.67% indicates increased cover.
Chemical treatment was most effective and cost-efficient (CER 17.28). Manual uprooting had an average annual CER of 25.7; tractor uprooting, 26. Brush-cutting performed worst (CER −33.77): dividing costs by negative effectiveness produces a negative ratio, reflecting ineffective expenditure rather than better value.
Results remain preliminary; effectiveness assessment continues.
Seminars and volunteer work days have been held, in which the educational element plays a key role – experts on invasive species explain to participants the threats posed by invasive species to biodiversity, as well as the aims of the work and the results to be achieved.
participants
participants
