Global Register of Introduced and Invasive Species – Saint Helena, Saint Helena, Ascension and Tristan da Cunha

Study Extent

The geographic focus of this checklist is Saint Helena, an Overseas territory of the United Kingdom.

Sampling

This annotated checklist is focused on introduced (alien) and invasive species that are known to occur in Saint Helena, an Overseas territory of the United Kingdom. The International Union for Conservation of Nature, (IUCN) describes an Introduced/ Alien and Invasive alien species as follows:
An Introduced/ Alien species means a species, subspecies, or lower taxon occurring outside of its natural range (past or present) and dispersal potential (i.e. outside the range it occupies naturally or could not occupy without direct or indirect introduction or care by humans) and includes any part, gametes or propagule of such species that might survive and subsequently reproduce. An Invasive alien species means an alien species which becomes established in natural or semi-natural ecosystems or habitat, is an agent of change, and threatens native biological diversity. In GRIIS, species are recorded as having an impact (as 'yes' under 'isInvasive') if there is evidence of the species negatively impacting biodiversity, and including species that are widespread, spreading rapidly or present in high abundance (Pagad et al. 2018). This usage is relevant to the purpose of GRIIS, and consistent with the concept of impact as formulated by Parker et al. (1999) and now widely used (e.g. Didham et al. 2005, Strayer et al. 2006, McGeoch et al. 2010, 2012, Vila et al. 2011), where impact is a function not only of the per capita effect of an individual organism, but is a combined function of the effect, abundance and range size of a species. Impact can of course be defined in different ways, driven by different objectives, such as its usage in EICAT where it is defined as a measurable change to the properties of an ecosystem caused by an alien taxon (Hawkins et al. 2015). Pagad S, Genovesi P, Carnevali L, Schigel D, McGeoch MA (2018) Introducing the Global Register of Introduced and Invasive Species. Scientific Data, 5, 170202. https://www.nature.com/articles/sdata2017202 Parker I, Simberloff D, Lonsdale W. et al. (1999) Impact: Toward a Framework for Understanding the Ecological Effects of Invaders. Biological Invasions 1, 3–19 (1999). https://doi.org/10.1023/A:1010034312781 Didham RK, Tylianakis JM, Hutchison MA, Ewers RM, Gemmell NJ. (2005) Are invasive species the drivers of ecological change? Trends Ecol Evol. 2005 Sep;20(9):470-4. Epub 2005 Jul 21. Strayer DL, Eviner VT, Jeschke JM, Pace ML. (2006) Understanding the long-term effects of species invasions. Trends in Ecology & Evolution 21(11):645-51 McGeoch MA, Butchart SHM, Spear D, Marais E. Kleynhans EJ, Symes A, Chanson J, Hoffmann M. (2010) Global indicators of biological invasion: species numbers, biodiversity impact and policy responses. Diversity and Distributions Volume16, Issue1 January 2010 McGeoch, M.A., Spear, D., Kleynhans, E.J. & Marais, E. 2012. Uncertainty in invasive alien species listing. Ecological Applications 22, 959-971. 10.1890/11-1252.1 Vilà M, Espinar JL, Hejda M, Hulme PE, Jarošík V, Maron JL, Pergl J, Schaffner U, Sun Y, Pyšek P. (2011) Ecological impacts of invasive alien plants: a meta‐analysis of their effects on species, communities and ecosystems. Ecology Letters Volume14, Issue7 July 2011 Pages 702-708 Hawkins CL, Bacher S, Essl F, Hulme PE, Jeschke JM, Kühn I, Kumschick S, Nentwig W, Pergl J, Pyšek P, Rabitsch W, Richardson DM, Vilà M, Wilson JRU, Genovesi P, Blackburn TM. (2015) Framework and guidelines for implementing the proposed IUCN Environmental Impact Classification for Alien Taxa (EICAT) Diversity and Distributions Volume21, Issue11 November 2015 Pages 1360-1363

Quality Control

The draft checklist is compiled by collating data and information through a comprehensive literature overview. Additional steps implemented to control the quality of the data are described below. Taxonomic harmonization and normalization using the GBIF taxonomic backbone In order to harmonize all species names across countries, species lists are subjected to a normalization process in which taxon rank and taxonomic status are identified and assigned. Spelling and other errors in assigning species authorship are also corrected. Data validation The checklist compiler team completes a review and validates all the annotations especially those on provenance and 'invasiveness' status of the species based on evidence of impact. Data verification The checklist is submitted to a network of country editors for a review of both accuracy of records, annotations and identification of any significant gaps in the data. Data verification is an iterative process and the activity is declared completed on agreement of all relevant country editors. One of the key tenets of the GRIIS project has been engagement with country editors in the verification process and as custodians of their country checklists. While this has been possible in the majority of countries, the compilers have not been very successful in this engagement for a small number of countries. In these cases, the GRIIS compiler team has completed the validation of the species records while working on identifying country experts.

Method steps

1. Data collation and categorization Data filtering and categorization/ classification Taxonomic harmonization and normalization Data validation Data verification
2. The published methods underpinning GRIIS and each checklist are described in the following article: Pagad S, Genovesi P, Carnevali L, Schigel D, McGeoch MA (2018) Introducing the Global Register of Introduced and Invasive Species. Scientific Data, 5, 170202. https://www.nature.com/articles/sdata2017202

Animalia, Bacteria, Chromista, Fungi, Plantae, Protozoa, Viruses

1. Animalia
   rank: kingdom
2. Bacteria
   rank: kingdom
3. Chromista
   rank: kingdom
4. Fungi
   rank: kingdom
5. Plantae
   rank: kingdom
6. Protozoa
   rank: kingdom
7. Viruses
   rank: kingdom

Saint Helena, an Overseas territory of the United Kingdom