Kathrin Holenstein

During my Master’s thesis at the Swiss Federal Institute of Aquatic Science and Technology, I looked at species-interactions and metapopulation dynamics in dendritic riverine ecosystems. My main interests focus on dispersal of species, changes in biodiversity and ecosystem functioning  e.g. as a consequence of the spread of invasive species and global changes. In my PhD project, I will investigate factors leading to permeability and variation of invasive species establishing in protected areas (PAs) in France and Europe. My research will aim to characterize the extent to which PAs are affected by invasive species and quantify the investment in management effort to prevent expansion or establishing of invasive species by interviewing managers of PAs. The results will contribute in order to predict how PAs will be affected by invasive species in the future and set management priorities.


PhD project: Permeability of European Protected Areas in the face of Invasive Alien Species

Invasive Alien Species (IAS), i.e. non-indigenous species that threaten native species, are widely acknowledged as a major threat to global biodiversity. Biological invasions has become one of the most challenging issues for both ecologists, who try to evaluate their ecological and evolutionary consequences, and conservationists, who try to prevent and control them.  In this context, it is highly relevant to evaluate the interaction between IAS and Protected Areas (PA), areas that are aimed at preserving biodiversity and ensuring ecosystems integrity. Given the importance of PAs as repositories of biodiversity, the impacts of IAS on global biodiversity could be particularly serious if they affect PAs. Protected areas thus need guidelines to strengthen their efforts in terms of control and management of IAS (Monaco & Genovesi 2014).

Cover of Monaco & Genovesi 2014.

Previous studies on IAS have highlighted several general patterns on biological invasions that would support the hypothesis that PA might be less permeable to IAS than non-protected areas:

  • PAs are generally remote from cities and from other areas of intense human activities, where numerous introductions of both flora and fauna occur, and that have been identified as major pathways of IAS.
  • Human disturbances (e.g. transport infrastructures, agriculture, logging), that are known as facilitator of biological invasions, are generally reduced in PAs.
  • PAs have financial and human resources to prevent biological invasions (early detection and eradication programs of IAS) that are generally not available outside PAs.
  • Considering that the resistance to invasion of a community is expected to be positively related with its species richness, it may be expected that PAs are more resistant than species-poorer areas.

However, very few assessments of the permeability of PAs to IAS have been carried out. A study in Florida found that small PAs are more invaded than large ones (Iacona et al. 2014), whereas another study carried out in Central Europe found no effect of PAs size on the number of IAS present (Braun et al. 2016).  In Greece, Dimitrakopoulos et al. (2017) found that native plant richness in PAs has a positive effect on the presence of IAS, a result in contradiction with the expected relationship between species richness and the resistance of communities to invasion. These preliminary results are obviously insufficient to provide PA managers with clear predictor variables of the permeability of PAs to IAS.

In this context, the objectives of the project will be:

  • To characterize the extent to which European PAs are affected by IAS;
  • To quantify the ongoing investment in management efforts to prevent the establishment or to control the expansion of IAS;
  • To understand the factors (environmental, economic, historical) affecting the permeability of European PAs to IAS in order to predict how European PAs will be affected in the future and guide future management priorities.

The project will focus on France as an intensive case-study, complemented by an extensive study of selected PAs across Europe. To meet the objectives, the project will involve the use of and contribution to existing databases on IAS (e.g. the IUCN Global Invasive Species Database), through a combination of data mining and questionnaires to/interviews with PA managers.

This dataset will be complemented by other relevant data, including on environmental variables, human occupation, socio-economic and historical data, both within PAs and more broadly at the regional and national level. Statistical models will then be used to test how different factors (ecological, economic, historical…) affect the threat posed by IAS on PAs.

The project will produce a spatially explicit database of IAS across European (and particularly French) PAs, as well as a quantification of the relationships between PA characteristics and their permeability to IAS. These results will inform recommendations on how to minimise the impacts of IAS on biodiversity in general, and PAs in particular.

Related references

  • Braun M, Schindler S, Essl F. 2016. Distribution and management of invasive alien plant species in protected areas in Central Europe. Journal for Nature Conservation 33:48–57.
  • Dimitrakopoulos PG, Koukoulas S, Galanidis A, Delipetrou P, Gounaridis D, Touloumi K, Arianoutsou M. 2017. Factors shaping alien plant species richness spatial patterns across Natura 2000 Special Areas of Conservation of Greece. Science of the Total Environment 601–602:461–468.
  • Iacona GD, Price FD, Armsworth PR. 2014. Predicting the invadedness of protected areas. Diversity and Distributions 20:430–439.
  • Monaco, A., Genovesi, P. 2014. European Guidelines on Protected Areas and Invasive Alien Species. Council of Europe, Strasbourg, Regional Parks Agency – Lazio Region, Rome.

The PDFs of these articles can be downloaded here.