Japanese rose impacts on sand dune vegetation and soil

Dona Paul

Swansea university Masters student Dona Paul shares her experience of undertaking fieldwork at Crymlyn Burrows investigating the influence of the invasive plant Japanese rose (Rosa rugosa) on native dune vegetation and the surrounding soil.

Heya! I am Dona Paul. I am an international masters student in Environmental Biology at Swansea University. To flaunt, this is my second masters where my initial course was environmental biotechnology. There I gained skills in the laboratory aspects of environmental studies, but I was passionate about working on field and conducting surveys. Hence, I chose this course that has huge potential in helping me to advance my field research skills. I chose to become a plant ecologist and the dissertation I recently completed at Swansea University in collaboration with the Dynamic Dunescapes project has played a huge factor in boosting my confidence in the subject.

My dissertation was looking into the impacts on biodiversity of sand dune habitats of Crymlyn burrows. Crymlyn Burrows is a designated SSSI site under the wildlife and countryside Act in 1987. These comprises of 244 Ha of sand dunes, salt marsh and beach between the river Neath and Swansea university on Swansea Bay (Swansea University, 2018). The sand dunes of Crymlyn burrows support a wide range of life forms specific to these habitats.

My study took place at sand dune habitats of Crymlyn Burrows during the summer of 2022. It was a basic project to give insight on the changes caused by the non-native invasive plant species called the Japanese rose (Rosa rugosa) through vegetation and soil survey. The study compared the differences between uninvaded, unmanaged sand dune habitat against Japanese rose invaded plot. The differences in plant species occurrence, species diversity, their life strategies, and the environmental characteristics are monitored. This was done through basic statistical analysis and multivariate analysis.

Top: area of dune taken over with rosa rugosa. Bottom: area of native dune plants

The biodiversity of the plots shows a clear difference in plant species occurrence as many sand dune specific species were more inclined towards the uninvaded plot. It also showed that all the quadrats of the invaded plot (in terms of species diversity and environmental characteristics) were similar in diversity with less variation. This suggests biotic homogenisation (Olden et al., 2016) of the sand dune habitat, a process where the habitat lose its biological uniqueness due to increased similarity of species over time and space.

The species diversity and soil characteristics of the two plots were also compared. The uninvaded plot has significantly higher evenness than invaded plot, where species evenness (e) explains how individuals split among species (Pielou, 1966). Low evenness would indicate, dominance of a single or few species whereas high evenness indicates relatively equal number of individuals belonging to each species. Other differences include higher moisture, higher pH, more competitive strategists, and less stress tolerant species in the invaded plot than the uninvaded plot. Moisture holding capacity of soil of the invaded plot maybe attributed by the roots and vegetative thickets of the Japanese rose and the other positively associated plant species. This is a significant impact as there is loss of sand dune habitat characteristics because sand dune soil does not possess water holding capacity. Japanese rose is not a competitive species, it facilitates the growth of other competitive species making the invaded community, a competitive one. This is a classic impact of invasional meltdown, a runaway process where invaders facilitate the invasion of other species. Loss of species diversity is also a concern (Simberloff and Von Holle, 1999). Though there is no species replacement in invaded plot, it experiences displacement of sand dune specific plant species. Alteration of the sand dune habitat to a less stress tolerant plant community maybe incompatible and disadvantageous to the sea front in the context of climate change. The sand dunes have a significant role in protecting the seas coasts. These were the major findings from my study and I am very hopeful that it will be helpful for future management of this conservational site.

A person crouches in a an area of dune scrub
A person collects a sample from an area of dune scrub

It was a delightful and insightful experience working at the Crymlyn burrows, as this independent study provided a lifetime experience to successfully undertake field work in the future as well. I gained new skills in conservation biology and learnt a lot about the sand dunes and its vegetation. As I spend almost 7 hours straight for 5-6 days, I appreciate the unique habitat of sand dunes. They are so close to the sea and there are different lifeforms supported by this habitat. The Dunescapes bursary helped me to overcome many additional expenses associated with the fieldwork.  This helped me to focus more on the study as I missed lot of my part time work time. I was able to network with many other conservation biologists through the project. I am very thankful to my supervisor Dr. Sophie Hocking, my university professors, volunteers of Crymlyn burrows, friends, and family. I will be ever thankful for the opportunity.


  1. Olden, J. D., Comte, L. & Giam, X. (2016) Biotic homogenisation. eLS, 1-8.
  2. Pielou, E. C. (1966) The measurement of diversity in different types of biological collections. Journal of theoretical biology, 13, 131-144.
  3. Simberloff, D. & Von Holle, B. (1999) Positive interactions of nonindigenous species: invasional meltdown? Biological invasions, 1, 21-32.
  4. Swansea University, S. (2018) Crymlyn Burrows SSSI Management Plan 2018-2023. Swansea.
  5. Tekiela, D. R. & Barney, J. N. (2017) Not all roads lead to Rome: a meta-analysis of invasive plant impact methodology. Invasive Plant Science and Management, 10, 304-312.
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