Description
Data Records
The data in this occurrence resource has been published as a Darwin Core Archive (DwC-A), which is a standardized format for sharing biodiversity data as a set of one or more data tables. The core data table contains 460 records.
This IPT archives the data and thus serves as the data repository. The data and resource metadata are available for download in the downloads section. The versions table lists other versions of the resource that have been made publicly available and allows tracking changes made to the resource over time.
Versions
The table below shows only published versions of the resource that are publicly accessible.
How to cite
Researchers should cite this work as follows:
Floyd K, Myer B (2026). Tristan da Cunha: Alien Plant Observations 2023 and 2025. Version 1.6. Kaitiaki o te Ngahere. Occurrence dataset. https://ipt.gbif.org.nz/resource?r=tristan_observations&v=1.6
Rights
Researchers should respect the following rights statement:
The publisher and rights holder of this work is Kaitiaki o te Ngahere. To the extent possible under law, the publisher has waived all rights to these data and has dedicated them to the Public Domain (CC0 1.0). Users may copy, modify, distribute and use the work, including for commercial purposes, without restriction.
GBIF Registration
This resource has been registered with GBIF, and assigned the following GBIF UUID: b870725b-d0da-4dd4-9ca4-20bebb62c4d7. Kaitiaki o te Ngahere publishes this resource, and is itself registered in GBIF as a data publisher endorsed by GBIF New Zealand.
Keywords
Occurrence; Tristan da Cunha; alien; invasive; plants; Observation
Contacts
- Originator
- Originator ●
- Point Of Contact
- Point Of Contact
Geographic Coverage
Tristan da Cunha
| Bounding Coordinates | South West [-37.095, -12.334], North East [-37.064, -12.281] |
|---|
Taxonomic Coverage
Alien vascular plants from Tristan da Cunha
| Kingdom | Plantae |
|---|---|
| Phylum | Streptophyta |
| Class | Pinopsida, Magnoliopsida, Liliopsida |
| Order | Dipsacales, Geraniales, Cucurbitales, Asterales, Arecales, Ericales, Solanales, Alismatales, Poales, Malpighiales, Asparagales, Myrtales, Zingiberales, Lamiales, Caryophyllales, Rosales, Fabales, Saxifragales, Commelinales, Brassicales, Gentianales, Cornales, Pinales, Apiales |
| Family | Commelinaceae, Corynocarpaceae, Lamiaceae, Araliaceae, Pittosporaceae, Myrtaceae, Cannaceae, Rosaceae, Amaryllidaceae, Arecaceae, Solanaceae, Caryophyllaceae, Pinaceae, Iridaceae, Araceae, Polygonaceae, Onagraceae, Poaceae, Geraniaceae, Rubiaceae, Brassicaceae, Juncaceae, Fabaceae, Crassulaceae, Urticaceae, Caprifoliaceae, Asphodelaceae, Moraceae, Hydrangeaceae, Convolvulaceae, Primulaceae, Asteraceae, Salicaceae |
Project Data
Tristan da Cunha is the most remote inhabited island in the world. The community has a long history here, and the Settlement Plain has been transformed from a natural landscape into a productive area. The island’s steep and mountainous geography has limited broader landscape development. Tristan da Cunha hence supports significant populations of globally threatened birds and plants. Tristan da Cunha's unique biodiversity is of global importance due to its high levels of endemism. The island group’s flora includes roughly 50 native flowering plants and 35 native ferns, with nearly half of these vascular plants being endemic. The territory is also globally significant for its avifauna, supporting 86 native bird species, including 11 endemic species such as the Tristan Thrush. The ecosystem types are vertically zoned by elevation, ranging from coastal areas – where the original tussock grassland communities have largely been lost due to grazing – to Phylica arborea woodland and fernbush, to high-altitude mire and feldmark vegetation. A total of 170 non-native plant species have been recorded on Tristan da Cunha. While a small number of additional introduced species occur on the other islands in the archipelago, the primary source of plant introductions is Cape Town, South Africa, from which the majority of shipping originates. Weeds pose a serious threat to biodiversity by disrupting ecosystem processes and outcompeting native species. Once established, many invasive plants produce large quantities of long-lived seeds, making eradication challenging. Successful weed management depends on accuracy, persistence, and timing. A clear management strategy ensures stakeholders understand their roles, are adequately resourced, and can act effectively, thereby safeguarding both ecological integrity and prior conservation investments. Proactive management remains the most effective and cost-efficient approach for protecting biodiversity and achieving long-term conservation outcomes.
| Title | Building Capacity for Invasive Plant Management across Tristan’s Northern Islands |
|---|---|
| Identifier | DPLUS191 |
| Funding | This project is generously supported by Darwin Plus. DPLUS191 is a main sized project. https://darwinplus.org.uk/project/DPLUS191 |
| Study Area Description | The Tristan archipelago is one of the remotest in the world, home to 95+ unique species which have evolved in isolation. With the transport of people and goods across the globe, many plant species have been introduced into novel areas, with devastating and far-reaching consequences for the native biodiversity. |
| Design Description | Introduced species recorded on Tristan da Cunha were identified during November and December 2025 across the Settlement, the Pigbite, the 1961 lava flow, and the Potato Patches. Figure 2 illustrates the spatial distribution of survey and control efforts across the island. Due to time constraints and the limited accessibility of certain areas, it was not possible to locate and identify all species previously recorded by Gremmen and Halbertsma (2009) and Floyd (2023). In some cases, species recorded during earlier surveys may also have declined, been successfully removed, or persist at very low abundance, and were therefore not detected during the present assessment. |
| Project Award |
Enabling invasive plant eradications and long-term management in Tristan Darwin Plus (main) DPLUS191 https://darwinplus.org.uk/project/DPLUS191 |
The personnel involved in the project:
- Programmer
Sampling Methods
An extensive survey was conducted by Gremmen and Halbertsma, in 2007 - 2008. They spent 4 months on the island and identified 137 alien vascular plant species and documented the threats they pose to the island’s unique endemic biodiversity and agricultural production. Kelvin Floyd and Bradley Myer visited the island in 2023 and 2025 respectively. Their focus was re assessing the highest priority species based on the ecological impact of the alien invasive species. Alien species are primarily focused around the settlement of Edinburgh of the Seven Seas.
| Study Extent | Botanical documentation on Tristan da Cunha began in 1793, when Aubert du Petit-Thouars collected three plant species. By 1910, 44 alien plant species had been recorded. A major botanical survey was undertaken during the 1937–38 Norwegian Scientific Expedition by Christophersen and Mejland. Further extensive collections were made by Stableford in the 1950s, followed by Wace and Dickson. Knowledge of the flora was later consolidated by Groves (1981). A comprehensive study by Gremmen and Halbertsma in 2009 mapped 137 introduced plant species across the island. Currently, invasive plant management is being conducted under the Darwin Plus initiative (DPLUS191) through the Building Capacity for Invasive Plant Management across Tristan’s Northern Islands project. As part of this initiative, representatives from Indigena Biosecurity International visited the island in 2023 and 2025, documenting weed species and geolocating their distribution. |
|---|---|
| Quality Control | In 2023 and 2025 data was selected from dropdown lists, which included the species list from Gremmen and Halbertsma, in 2007 - 2008. There were fields for including adventive species. Plantnet was used to verify unknown species. |
Method step description:
- Data was recorded in the field then synced to the cloud and then aggregated with the other datasets.
Additional Metadata
Indigena Biosecurity International - www.indigena.co.nz
| Acknowledgements | |
|---|---|
| Introduction | |
| Getting Started | |
| Purpose | |
| Alternative Identifiers | b870725b-d0da-4dd4-9ca4-20bebb62c4d7 |
| https://ipt.gbif.org.nz/resource?r=tristan_observations |