Plant Community Case Study: Vegetation Establishment after the Restoration of Southern Swedish Coastal Dunes Invaded by Rosa rugosa

Abstract

The main focus of this case study was to assess ecological succession and restoration success after the removal of Rosa rugosa. Plant species composition and moss presence, bare ground cover, and biodiversity indices were analysed to identify patterns and differences within and between the restored and an invaded adjacent area. The complete absence of R. rugosa in restored plots confirms the effectiveness of eradication efforts. Moreover, plant cover analysis showed significant differences across years, with the earliest restored plots resembling never-invaded reference sites, indicating progress toward undisturbed conditions. Diversity indices remained stable, further suggesting that restored communities are structurally similar to the original vegetation.

Secondly, the effect of R. rugosa abundance on biodiversity in control plots (in an invaded adjacent area) was assessed using linear regression. A negative relationship with Shannon index and Simpson’s D² indicates that higher R. rugosa cover reduces diversity and evenness. Although species richness showed no such trend, likely due to similar invasion levels, these patterns highlight the species’ disruptive impact on community structure.

Moss cover was higher in R. rugosa-invaded plots due to the shaded microhabitats created by the shrub, while removal plots showed more bare soil due to disturbance during eradication. These open conditions facilitated the establishment of early-successional species, which were more light-tolerant and typical of pioneer dune habitats. In comparison, species only found in invaded plots were shade-tolerant and nitrophilous, and species present in both plot types were cosmopolitan, indicating their adaptability to varying environmental conditions. A non-metric multidimensional scaling (NMDS) ordination visually supported these findings, although functional group identity (graminoids, herbaceous, woody) explained only a small portion of the total variation in species composition.

These results highlight the role of the R. rugosa as an ecosystem engineer, emphasising the need for active restoration through the removal of R. rugosa in areas where it is present, in order to recover the native flora and the ecosystem services that dune diversity offers.

Popular Abstract

Dunes N´ Roses: Native Dune Vegetation Strikes Back after Rosa rugosa removal

Plants in dune ecosystems are real fighters, managing to thrive in extreme conditions with barely any fresh water. These habitats are among the most disturbed by human activity, particularly due to tourism, urban development, and invasive species. In Sweden, Rosa rugosa is an invasive plant that has spread across dunes, altering native vegetation and ecosystem dynamics. Efforts have been made to eradicate this species from coastal areas and restore the affected habitats. But what happens to the vegetation once Rosa rugosa is removed? And how successful have these restoration efforts been? This study focused on Hittarp´s dunes and aimed to shed light on the ecological changes that follow the plant’s removal. After all, every rose has its thorn.

Coastal dune ecosystems are found all over the world and are rich in plant and animal species, some of which are rare. These habitats are very valuable—not only for their biodiversity but also because they provide important ecosystem services Dunes help prevent erosion, manage water, store carbon, and support wildlife. They also offer cultural and recreational value, making them important for both nature and people. However, coastal dunes are under serious threat from human activities such as tourism, urban development, and the spread of invasive plant species. One such invasive species is Rosa rugosa, a shrub originally from East Asia, which was introduced to Europe for ornamental use and erosion prevention. In places like Sweden, this plant has spread aggressively, forming dense patches that push out native vegetation and change the soil, making it harder for local plants to return, even after the shrub is removed.

This study focuses on southern Sweden, in an area that connects protected nature reserves. The main goal is to understand how removing Rosa rugosa affects the dune plant communities. The research looks at how native plants recover, how ground cover changes, and whether certain species play a key role in the restoration process. By comparing areas where Rosa rugosa has been removed in different years, areas that were never invaded, and areas where it is still present, the study aims to learn more about how these ecosystems respond to restoration. The results will help guide future conservation efforts to protect these unique environments and the biodiversity they support.

Methods
To conduct this project, two different areas were selected on Hittarp´s bay: a restored area and an adjacent area with Rosa rugosa. Random sampling points were predefined in both areas. Firstly, for the restored area, I divided it into sections using old aerial photos, in what is called “stratified random sampling”. This helped match each plot to the year the invasive plant was removed, so I could track how the vegetation changed over time. In each plot (a square metre marked with a wooden frame) of both areas, I recorded which plants were growing, how much space they covered, and whether there was bare ground or mosses. Photos were taken to help with plant identification, and some tricky specimens were collected for a more exhaustive review.

Results and discussion
The complete absence of Rosa rugosa in the restored plots showed that the removal efforts have been successful. When looking at plant cover over the years, clear differences were found. The plots that were restored earliest looked very similar to natural areas that had never been invaded, suggesting the environment is recovering well. Measures of plant diversity stayed stable, meaning the restored plant communities were quite similar in structure to the original vegetation.

The impact of Rosa rugosa on biodiversity in nearby, still-invaded plots was also studied. The results showed that areas with more Rosa rugosa had lower diversity and less balance between species. While the total number of species didn’t change much, probably because all the invaded plots were affected in similar ways, these patterns showed that Rosa rugosa disrupts the natural balance of plant communities.

In the invaded plots, mosses were more common due to the shade created by the shrub. In contrast, the removal plots had more bare soil as a result of the disturbance caused during the removal process. These open, sunnier conditions helped light-loving pioneer species, typical of early dune stages, take hold. On the other hand, species found only in the invaded plots preferred shady, nutrient-rich conditions. The species that appeared in both plot types were generalists, able to adapt to a range of conditions. A visual analysis supported these findings, although differences in plant types (such as grasses, herbs, or shrubs) explained only a small part of the variation in species composition.

Overall, the results show that Rosa rugosa acts as an “ecosystem engineer”, changing the environment around it. This highlights the importance of actively removing it from areas where it has spread, to help native plants return and to restore the ecological benefits that diverse dune habitats provide.




Master’s Degree Project in Conservation Biology 45 credits 2025
Department of Biology, Division of Biodiversity and Evolution,
Lund University

Advisor: Pål Axel Olsson
Department of Biology
Lund University

• author: Morán Escandón, Ana
• supervisor: Pål Axel Olsson
• organization: Degree Projects in Biology
• course: BION02 20231
• year: 2025
• type: H2 - Master's Degree (Two Years)
• subject: Biology and Life Sciences
• language: English
• id: 9212860
• date added to LUP: 2025-09-19 12:09:38
• date last changed: 2025-09-19 12:09:38