Abstract
Background
In the scope of the MOVECLIM project, in 2013, we surveyed vascular plants and their ground cover in native or better-preserved vegetation patches, following an elevational transect, on four Azorean islands (São Miguel, Terceira, Pico and Flores). Using a standardised, plot-based protocol, permanent 10 m × 10 m plots were established at approximately 200 m elevation steps, each plot subdivided into four 5 m × 5 m subplots. All vascular taxa were recorded per subplot and cover was assigned using the Braun-Blanquet Ordinal Transform Value (OTV), a scale based on a geometric series, that assigns a numeric value (1–9) to each Braun–Blanquet category.
New information
We established 58 permanent plots across the four Azorean islands, resulting in 232 event records at the subplot level (eventID) and 2,539 occurrence records (occurrenceID), spanning 58 families, 92 genera, 109 species and five subspecies of vascular plants. Amongst these taxa, 44 are Azorean endemics, 40 are native non-endemic and 30 are introduced (of which 17 are invasive). This study provides a baseline for long-term monitoring of native vegetation, assessment of invasive species and evaluation of native communities' responses to such pressures across islands with contrasting elevation ranges and disturbance histories.
Keywords: Azores, biodiversity monitoring, islands, vascular plants, endemism, invasive species, occurrences, field survey, long-term monitoring, Wallacean shortfall
Introduction
Long-term ecological monitoring is essential to detect shifts in community composition, set conservation priorities and understand global-change impacts (Scheele et al. 2019, Lindenmayer et al. 2022). Elevational gradients are particularly informative in this regard, because they capture environmental variation over short spatial distances and can serve as early indicators of climate-driven shifts (Colwell and Lees 2000, Kluge et al. 2006).
Although several floristic and ecological studies have been conducted in the Azores, particularly in protected areas, systematic elevational surveys of vascular plant diversity remain relatively scarce. Here, we aim to fill this gap by presenting a multi-island, plot-based dataset, designed to support the long-term study of vascular plant diversity across the Azores.
General description
Purpose
To publish a standardised baseline of vascular plant occurrences and percentage cover along elevational gradients on four Azorean islands, enabling long-term monitoring and cross-island comparisons.
Project description
Title
MOVECLIM–AZORES: plot-based vascular plant cover across elevational gradients in Azorean native forests (2013)
Personnel
The vascular plant inventory and identification was carried out by Rui Bento Elias (RBE), with the participation of Fernando Pereira (FP). Databases were compiled by Rui Andrade (RA). Darwin-Core data were verified and managed in GBIF IPT by Paulo A.V. Borges.
Study area description
The Azores Archipelago (Portugal) comprises nine volcanic islands in the North Atlantic Ocean (36º55’–39º43’ N; 24º46’–31º16’ W), ranging in age from 0.3 to 8.1 million years (França et al. 2003) (see Fig. 1) and grouped into Western (Corvo, Flores), Central (Faial, Pico, Graciosa, São Jorge, Terceira) and Eastern (São Miguel, Santa Maria) groups. The Archipelago lies approximately 1,600 km west of mainland Portugal and has a total land area of 2,332.7 km² (Forjaz 2004).
Figure 1.
The Azores Archipelago is located in the middle North Atlantic (left panel). The Azorean Islands covered in this study, São Miguel, Terceira, Pico and Flores are highlighted in black.
The climate is temperate oceanic, with high humidity, regular and abundant rainfall, mild temperatures and frequent strong winds (Azevedo et al. 2004).
Design description
This research comprised four islands of the three main groups of the Azores Archipelago: São Miguel Island with 745 km2, the highest elevation being 1105 m a.s.l. with an estimated age of 0.79 MY (millions of years) (Sibrant et al. 2015); Terceira Island with 400 km2, a maximum elevation of 1023 m a.s.l. and 0.39 MY (Hildenbrand et al. 2014); Pico Island with an area of 447 km2, mostly occupied by volcanoes reaching an altitude of 2351 m a.s.l. and an approximate age of 0.27 MY (Demand et al. 1982); and Flores Island with an area of 143 km2, the highest elevation being 914 m a.s.l., with an estimated age of 2.2 MY (Azevedo and Ferreira 2006).
Following Elias et al. (2016), Azorean native vegetation is arranged in altitudinal belts. Our 200-m elevation transects deliberately cut across these belts, ensuring that plots capture the main vegetation types per island.
Centuries of land-use change and biological invasions have extensively transformed Azorean native vegetation (Dias 2007). Invasives exert marked pressure, particularly on São Miguel, where native remnants are often heavily encroached by species, such as Pittosporum undulatum, Clethra arborea and Hedychium gardnerianum (Moniz and Silva 2003, Hortal et al. 2010). The remaining native forest mosaics are thus most intact in the higher, wetter belts, characterised by cloud-forest conditions.
Funding
This study was originally financed by ERANET BIOME MOVECLIM ‘Montane vegetation as listening posts for climate change’ of the Regional Government of the Azores, grant number M2.1.2/F/04/2011/NET. RA received a Ph.D. Grant from FCT (UIDB/00329/2020-2024; DOI: 10.54499/UIDB/00329/2020), under Thematic Line 1 – Integrated ecological assessment of environmental change on biodiversity. While working on this publication, RBE, RG and PAVB were funded by FCT through national and European funds by UID/00329/2025 - Centre for Ecology, Evolution and Environmental Change (CE3C). This study is part of the Biodiversa+ project BioMonI – Biodiversity monitoring of island ecosystems, funded by FCT (BiodivMon/0003/2022), which also supported Open Access and provided funding to RG, RBE and PAVB.
Sampling methods
Sampling description
On each of the four islands, at each elevation level within areas dominated by native vegetation, two permanent 10 m × 10 m plots were established at approximately 200 m intervals, ranging from sea level to the highest summit. The two plots at each elevation were placed 10–15 m apart to minimise microhabitat overlap. Each plot was subdivided into four 5 m × 5 m subplots. All vascular plant species present were recorded within each subplot following an adapted BRYOLAT protocol (Ah-Peng et al. 2012, Gabriel et al. 2014), designed for standardised sampling across altitudinal gradients (Fig. 2) and presently known as the GIMS protocol (Borges et al. 2018).
Figure 2.
Altitudinal sampling model on all islands (adapted from Ah-Peng et al. (2012), Gabriel et al. (2014)): at 200 m elevation steps, two plots (black squares, 10 m × 10 m) were placed within 10 m to 15 m from each other; each plot is subdivided into four subplots of 5 m × 5 m (grey squares); all vascular plant species were recorded and their cover assigned to ordinal OTV classes (1-9).
For each species, cover was estimated using the OTV scale (van der Maarel 1979): 1 (≤ 0.5%), 2 (0.5–1.5%), 3 (1.5–3%), 4 (3–5%), 5 (5–12.5%), 6 (12.5–25%), 7 (25–50%), 8 (50–75%), 9 (≥ 75%).
The sampling locations and coordinates are listed in Table 1.
Table 1.
List of the 58 plots established in Flores (n = 10), Pico (n = 24), São Miguel (n = 12) and Terceira (n = 12) islands. Elevation in metres above sea level and coordinates in decimals (datum WGS84).
| Island | Plot_code | Municipality | Locality | Elevation (m a.s.l.) | Latitude | Longitude |
| Flores | FLO_0060_P1 | Santa Cruz | Ponta do Ilhéu | 75 | 39.506464 | -31.194688 |
| FLO_0060_P2 | 55 | 39.506187 | -31.194626 | |||
| FLO_0200_P1 | Ponta Delgada (200 m) | 248 | 39.506932 | -31.212854 | ||
| FLO_0200_P2 | 242 | 39.506609 | -31.212727 | |||
| FLO_0400_P1 | Ponta Delgada (400 m) | 379 | 39.501848 | -31.205639 | ||
| FLO_0400_P2 | 378 | 39.501847 | -31.205623 | |||
| FLO_0600_P1 | Cedros | 647 | 39.482888 | -31.190428 | ||
| FLO_0600_P2 | 643 | 39.482683 | -31.190348 | |||
| FLO_0800_P1 | Morro Alto | 828 | 39.463191 | -31.225955 | ||
| FLO_0800_P2 | 829 | 39.463200 | -31.225988 | |||
| Pico | PIC_0010_P1 | Lajes | Manhenha | 16 | 38.413700 | -28.02994 |
| PIC_0010_P2 | 16 | 38.413855 | -28.029837 | |||
| PIC_0200_P1 | Cabeço da Hera | 222 | 38.418127 | -28.053985 | ||
| PIC_0200_P2 | 218 | 38.418193 | -28.053614 | |||
| PIC_0400_P1 | Fetais | 356 | 38.425861 | -28.087491 | ||
| PIC_0400_P2 | 362 | 38.425918 | -28.087264 | |||
| PIC_0600_P1 | São Roque | Chão Verde | 624 | 38.479754 | -28.272413 | |
| PIC_0600_P2 | 629 | 38.479491 | -28.272322 | |||
| PIC_0800_P1 | Lajes | Caiado | 808 | 38.455640 | -28.257293 | |
| PIC_0800_P2 | 805 | 38.455504 | -28.257308 | |||
| PIC_1000_P1 | Caveiro | 955 | 38.437177 | -28.213032 | ||
| PIC_1000_P2 | 954 | 38.437170 | -28.212779 | |||
| PIC_1200_P1 | Madalena | Pico Mountain trail (1200 m) | 1268 | 38.470360 | -28.425126 | |
| PIC_1200_P2 | 1265 | 38.470683 | -28.424985 | |||
| PIC_1400_P1 | Pico Mountain trail (1400 m) | 1406 | 38.469385 | -28.421358 | ||
| PIC_1400_P2 | 1406 | 38.469292 | -28.421351 | |||
| PIC_1600_P1 | Pico Mountain trail (1600 m) | 1601 | 38.465878 | -28.416554 | ||
| PIC_1600_P2 | 1596 | 38.465353 | -28.416437 | |||
| PIC_1800_P1 | Pico Mountain trail (1800 m) | 1799 | 38.465962 | -28.412560 | ||
| PIC_1800_P2 | 1800 | 38.465901 | -28.412543 | |||
| PIC_2000_P1 | Pico Mountain trail (2000 m) | 2010 | 38.465647 | -28.408192 | ||
| PIC_2000_P2 | 2012 | 38.465489 | -28.408084 | |||
| PIC_2200_P1 | Pico Mountain trail (2200 m) | 2245 | 38.466337 | -28.399242 | ||
| PIC_2200_P2 | 2248 | 38.466756 | -28.399324 | |||
| São Miguel | SMG_0050_P1 | Nordeste | Lomba da Fazenda | 62 | 37.849901 | -25.150251 |
| SMG_0050_P2 | 62 | 37.849915 | -25.150426 | |||
| SMG_0200_P1 | Povoação | Ribeira Quente | 169 | 37.740682 | -25.303525 | |
| SMG_0200_P2 | 165 | 37.740648 | -25.303084 | |||
| SMG_0400_P1 | Lomba do Botão | 462 | 37.774053 | -25.275086 | ||
| SMG_0400_P2 | 460 | 37.773863 | -25.275239 | |||
| SMG_0600_P1 | Nordeste | Tronqueira | 591 | 37.799094 | -25.183596 | |
| SMG_0600_P2 | 587 | 37.799082 | -25.183441 | |||
| SMG_0800_P1 | Povoação | Salto do Cavalo | 765 | 37.787788 | -25.277236 | |
| SMG_0800_P2 | 743 | 37.787547 | -25.277206 | |||
| SMG_1000_P1 | Nordeste | Planalto dos Graminhais | 1023 | 37.809714 | -25.214029 | |
| SMG_1000_P2 | 1018 | 37.809691 | -25.214274 | |||
| Terceira | TER_0040_P1 | Angra do Heroísmo | Ponta do Queimado | 41 | 38.766448 | -27.375391 |
| TER_0040_P2 | 37 | 38.766525 | -27.375152 | |||
| TER_0200_P1 | Serreta | 241 | 38.759882 | -27.363701 | ||
| TER_0200_P2 | 243 | 38.760104 | -27.363874 | |||
| TER_0400_P1 | Pico do Carneiro | 384 | 38.764920 | -27.351604 | ||
| TER_0400_P2 | 378 | 38.765255 | -27.351658 | |||
| TER_0600_P1 | Pico da Lagoinha | 679 | 38.752462 | -27.331529 | ||
| TER_0600_P2 | 681 | 38.752538 | -27.331343 | |||
| TER_0800_P1 | Lagoa do Pinheiro trail | 833 | 38.750801 | -27.322126 | ||
| TER_0800_P2 | 833 | 38.750847 | -27.322056 | |||
| TER_1000_P1 | Serra de Santa Bárbara | 994 | 38.730496 | -27.322057 | ||
| TER_1000_P2 | 990 | 38.730633 | -27.321635 |
Quality control
In the field, identifications were checked with an Azorean flora guide (Schaefer 2005).
Taxonomic nomenclature follows the Azorean Biodiversity Portal vascular flora backbone (ABP 2025) together with regional checklists (Borges et al. 2010, Silva et al. 2010, Gabriel and Borges 2022, Silva et al. 2022).
The colonisation status of each species was determined, based on its biogeographical origin and degree of naturalisation in the Azores (Silva et al. 2008, Martín et al. 2008, ABP 2025).
Geographic coverage
Description
This study was carried out in São Miguel (Eastern group), Terceira and Pico (Central group) and Flores (Western group) islands of the Azorean Archipelago.
Coordinates
37.551908 and 39.650021 Latitude; -31.378349 and -24.822498 Longitude.
Taxonomic coverage
Description
Phylum: Tracheophyta
Classes: Selaginellopsida, Polypodiopsida, Pinopsida, Liliopsida, Magnoliopsida
Temporal coverage
Notes
Fieldwork was performed from 1 March to 29 September 2013.
Usage licence
Usage licence
Creative Commons Public Domain Waiver (CC-Zero)
Data resources
Data package title
The MOVECLIM – AZORES project: Vascular Plant Diversity and Ground Cover Across Elevation (São Miguel, Terceira, Pico & Flores)
Resource link
Alternative identifiers
https://ipt.gbif.pt/ipt/resource?r=plants_plots_moveclim; https://www.gbif.org/dataset/f92047fa-f2cb-445d-9a93-546d637b2820
Number of data sets
2
Data set 1.
Data set name
Event Table
Data format
Darwin Core Archive format
Character set
UTF-8
Download URL
Data format version
Version 1.6
Description
The dataset was published on the Global Biodiversity Information Facility platform, GBIF (Andrade et al. 2025). The dataset submitted to GBIF is structured as a sample event dataset published as a Darwin Core Archive (DwCA), a standardised format for sharing biodiversity data as a set of one or more data tables. The core data file contains 232 records at the subplot level (eventID). This GBIF IPT (Integrated Publishing Toolkit, Version 2.5.6) archives the data and, thus, serves as the data repository. The data and resource metadata are available for download in the Portuguese GBIF Portal IPT (Andrade et al. 2025).
Data set 1.
| Column label | Column description |
|---|---|
| datasetName | The name identifying the dataset from which the record was derived. |
| eventID | Identifier of the events, unique for the dataset. |
| samplingProtocol | The sampling protocol used to record the species. |
| sampleSizeValue | The numeric amount of the sampling area. |
| sampleSizeUnit | The unit of the sample size value. |
| eventDate | Date of the sampling. |
| startDayOfYear | The earliest integer day of the year on which the event occurred. |
| day | The day in which the event occurred. |
| month | The month in which the event occurred. |
| year | The year in which the event occurred. |
| habitat | The habitat for an Event. |
| locationID | Identifier of the location. |
| islandGroup | Name of the archipelago. |
| island | Name of the island. |
| country | Country of the sampling site. |
| countryCode | The standard code for the country of the sampling site. |
| stateProvince | Name of the region of the sampling site. |
| municipality | Municipality of the sampling site. |
| locality | Name of the locality. |
| minimumElevationInMetres | The lower limit of the range of elevation (altitude, usually above sea level), in metres. |
| maximumElevationInMetres | The upper limit of the range of elevation (altitude, usually above sea level), in metres. |
| locationRemarks | Comments or notes about the Location. |
| decimalLatitude | Approximate centre point decimal latitude of the field site in GPS coordinates. |
| decimalLongitude | Approximate centre point decimal longitude of the field site in GPS coordinates. |
| geodeticDatum | The geodetic datum or spatial reference system (SRS), upon which the geographic coordinates given in decimalLatitude and decimalLongitude are based. |
| coordinateUncertaintyInMetres | The horizontal distance (in metres) from the given decimal Latitude and decimal Longitude describing the smallest circle containing the whole of the location. |
| verbatimCoordinates | Original coordinates recorded. |
| coordinatePrecision | Value in decimal degrees to a precision of five decimal places. |
| georeferenceSources | Method used to obtain coordinates. |
Data set 2.
Data set name
Occurrence Table
Data format
Darwin Core
Character set
UTF-8
Download URL
Data format version
Version 1.6
Description
The dataset was published on the Global Biodiversity Information Facility platform, GBIF (Andrade et al. 2025). The dataset submitted to GBIF is structured as an occurrence table and published as a Darwin Core Archive (DwCA), which is a standardised format for sharing biodiversity data as a set of one or more data tables. The core data file contains 2,538 records (occurrenceID). This GBIF IPT (Integrated Publishing Toolkit, Version 2.5.6) archives the data and, thus, serves as the data repository. The data and resource metadata are available for download in the Portuguese GBIF Portal IPT (Andrade et al. 2025). All taxa were identified to species/subspecies level, with the exception of Potentilla sp.
Data set 2.
| Column label | Column description |
|---|---|
| licence | Reference to the licence under which the record is published. |
| institutionID | The identity of the institution publishing the data. |
| institutionCode | The code of the institution publishing the data. |
| basisOfRecord | The nature of the data record. |
| occurrenceID | Identifier of the record, coded as a global unique identifier. |
| recordedBy | A list of names of the people who performed the sampling in the field. |
| organismQuantity | Estimated species percent cover. |
| organismQuantityType | The type of quantification system used for the measure of cover. |
| establishmentMeans | The process of establishment of the species in the location, using a controlled vocabulary: 'endemic', 'native', 'introduced'. |
| eventID | Identifier of the events, unique for the dataset. |
| identifiedBy | A list of names of people who assigned the Taxon to the subject. |
| dateIdentified | Date on which the record was identified. |
| scientificName | Complete scientific name including author. |
| kingdom | Kingdom name. |
| phylum | Phylum name. |
| class | Class name. |
| order | Order name. |
| family | Family name. |
| genus | Genus name. |
| specificEpithet | Specific epithet. |
| infraspecificEpithet | Infraspecific epithet, when available. |
| taxonRank | Lowest taxonomic rank of the record. |
| scientificNameAuthorship | Name of the author of the lowest taxon rank included in the record. |
Additional information
The 232 events across the four islands yielded 2,539 records, encompassing 114 vascular plant taxa, represented by 109 species and five subspecies. The majority of these taxa are indigenous (almost 39% endemic and 35% native), while 26% are non-indigenous (Table 2, Andrade et al. (2025)). Five categories were adopted, listed in order of increasing generality: Azorean endemics (END) — referring to species naturally occurring only in the Azores; native species (NAT) — which colonised the Azores via long-distance dispersal and are also present in other archipelagos or continents; introduced and naturalised species (INT NAT) — introduced through human action and capable of maintaining self-sustaining populations; invasive species (INV) — exotic species that establish themselves in natural or semi-natural ecosystems and cause measurable impacts or threats to native biodiversity.
Table 2.
Species checklist, colonisation status and island records. Islands: SMG - São Miguel; TER - Terceira; PIC - Pico; FLO - Flores. Colonisation status (CS): END - Azorean endemic; NAT - native; INT NAT - introduced naturalised; INV - invasive. X - present, X* - new island record (not listed for that island in Silva et al. (2010)).
| Phylum | Class | Order | Family | Scientific Name | CS | SMG | TER | PIC | FLO |
| Tracheophyta | Selaginellopsida | Selaginellales | Selaginellaceae | Selaginella kraussiana (Kunze) A.Braun | NAT | X | X | X | X |
| Polypodiopsida | Cyatheales | Culcitaceae | Culcita macrocarpa C.Presl | NAT | X | X | X | X | |
| Cyatheaceae | Dicksonia antarctica Labill. | INV | X | ||||||
| Hymenophyllales | Hymenophyllaceae | Hymenophyllum tunbrigense (L.) Sm. | NAT | X | X | X | X | ||
| Hymenophyllum wilsonii Hook. | NAT | X | X | ||||||
| Vandenboschia speciosa (Willd.) G.Kunkel | NAT | X | |||||||
| Osmundales | Osmundaceae | Osmunda regalis L. | NAT | X | X | X | |||
| Polypodiales | Aspleniaceae | Asplenium hemionitis L. | NAT | X | |||||
| Asplenium marinum L. | NAT | X | |||||||
| Asplenium obovatum Viv. | NAT | X | X | ||||||
| Asplenium onopteris L. | NAT | X | |||||||
| Athyriaceae | Deparia petersenii (Kunze) M.Kato | INT NAT | X | ||||||
| Diplazium caudatum (Cav.) Jermy | NAT | X | |||||||
| Blechnaceae | Struthiopteris spicant (L.) Weis | NAT | X | X | X | X | |||
| Woodwardia radicans (L.) Sm. | NAT | X | X | ||||||
| Dennstaedtiaceae | Pteridium aquilinum (L.) Kuhn | NAT | X | X | X | X | |||
| Dryopteridaceae | Cyrtomium falcatum (L.f.) C.Presl | INV | X | X | X | ||||
| Dryopteris aemula (Aiton) Kuntze | NAT | X | X | X | X | ||||
| Dryopteris affinis (Lowe) Fraser-Jenk. | NAT | X | |||||||
| Dryopteris azorica (Christ) Alston | END | X | X | X | X | ||||
| Dryopteris crispifolia Rasbach, Reichst. & Vida | END | X | |||||||
| Elaphoglossum hirtum (Sw.) C.Chr. | NAT | X | X | X | X | ||||
| Polystichum setiferum (Forssk.) T.Moore ex Woynar | NAT | X | |||||||
| Polypodiaceae | Polypodium macaronesicum subsp. azoricum (Vasc.) Rumsey, Carine & Robba | END | X | X | X | X | |||
| Pteridaceae | Adiantum hispidulum Sw. | INV | X | ||||||
| Pteris incompleta Cav. | NAT | X | |||||||
| Thelypteridaceae | Christella dentata (Forssk.) Brownsey & Jermy | INT NAT | X | X | |||||
| Oreopteris limbosperma (All.) Holub | NAT | X | |||||||
| Pinopsida | Pinales | Cupressaceae | Cryptomeria japonica D.Don | INT NAT | X | X | |||
| Juniperus brevifolia (Hochst. ex Seub.) Antoine | END | X | X | X | X | ||||
| Magnoliopsida | Apiales | Apiaceae | Angelica lignescens Reduron & Danton | END | X | ||||
| Sanicula azorica Guthnick ex Seub. | END | X | |||||||
| Araliaceae | Hedera azorica Carrière | END | X | X | X | X | |||
| Pittosporaceae | Pittosporum undulatum Vent. | INV | X | X | X | X | |||
| Aquifoliales | Aquifoliaceae | Ilex azorica Gand. | END | X | X | X | X | ||
| Asterales | Asteraceae | Leontodon filii (Hochst. ex Seub.) Paiva & Ormonde | END | X | |||||
| Leontodon longirostris (Finch & P.D.Sell) Talavera | NAT | X | |||||||
| Leontodon rigens (Aiton) Paiva & Ormonde | END | X | |||||||
| Pericallis malvifolia (L’Hér.) B.Nord. | END | X | |||||||
| Solidago azorica Hochst. ex Seub. | END | X | |||||||
| Tolpis azorica (Nutt.) P.Silva | END | X | |||||||
| Boraginales | Boraginaceae | Myosotis maritima Hochst. ex Seub. | END | X | |||||
| Sagina maritima Don | NAT | X | |||||||
| Caryophyllales | Caryophyllaceae | Silene uniflora subsp. cratericola (Franco) Franco | END | X | |||||
| Phytolaccaceae | Phytolacca americana L. | INV | X | X | X | ||||
| Commelinales | Commelinaceae | Tradescantia fluminensis Vell. | INV | X | X | ||||
| Dipsacales | Adoxaceae | Viburnum treleasei Gand. | END | X | X | X | X | ||
| Caprifoliaceae | Leycesteria formosa Wall. | INV | X | ||||||
| Ericales | Clethraceae | Clethra arborea Aiton | INV | X | |||||
| Ericaceae | Calluna vulgaris (L.) Hull | NAT | X | X | X | X | |||
| Daboecia azorica Tutin & E.F.Warb. | END | X | |||||||
| Erica azorica Hochst. ex Seub. | END | X | X | X | X | ||||
| Vaccinium cylindraceum Sm. | END | X | X | X | X | ||||
| Myrsinaceae | Myrsine retusa Aiton | END | X | X | X | X | |||
| Primulaceae | Lysimachia azorica Hornem. ex Hook. | END | X | X | X | X | |||
| Fabales | Fabaceae | Acacia melanoxylon R.Br. | INV | X | |||||
| Lotus parviflorus Desf. | INT NAT | X | |||||||
| Fagales | Myricaceae | Morella faya (Aiton) Wilbur | NAT | X | X | X | X | ||
| Gentianales | Gentianaceae | Centaurium scilloides (L.f.) Samp. | END | X | X | ||||
| Rubiaceae | Rubia agostinhoi Dansereau & P.Silva | END | X | X | |||||
| Lamiales | Lamiaceae | Thymus caespititius Brot. | NAT | X | |||||
| Oleaceae | Picconia azorica (Tutin) Knobl. | END | X | X | X | X | |||
| Plantaginaceae | Plantago coronopus L. | NAT | X | ||||||
| Plantago lanceolata L. | INT NAT | X | |||||||
| Scrophulariaceae | Sibthorpia europaea L. | NAT | X | X | X | X | |||
| Laurales | Lauraceae | Laurus azorica (Seub.) Franco | END | X | X | X | X | ||
| Phoebe indica Pax | INT NAT | X | |||||||
| Malpighiales | Euphorbiaceae | Euphorbia azorica Hochst. ex Seub. | END | X | |||||
| Euphorbia stygiana H.C.Watson | END | X | |||||||
| Hypericaceae | Hypericum foliosum Aiton | END | X | X | X | X | |||
| Violaceae | Viola palustris subsp. juressi (Link ex Cout.) Cout. | NAT | X | X | |||||
| Malvales | Thymelaeaceae | Daphne laureola L. | NAT | X | |||||
| Myrtales | Myrtaceae | Metrosideros excelsa Gaertn. | INV | X* | |||||
| Psidium cattleyanum Sabine | INT NAT | X* | X | ||||||
| Ranunculales | Papaveraceae | Fumaria muralis W.D.J.Koch | INT NAT | X | |||||
| Rosales | Moraceae | Ficus carica L. | INT NAT | X | |||||
| Rhamnaceae | Frangula azorica Grubov | END | X | X | X | X | |||
| Rosaceae | Fragaria vesca L. | NAT | X | ||||||
| Potentilla anglica Laichard. | NAT | X | |||||||
| Potentilla erecta (L.) Raeusch. | NAT | X | |||||||
| Potentilla sp. | NAT | X | X | ||||||
| Prunus lusitanica subsp. azorica (Mouill.) Franco | END | X | |||||||
| Rubus hochstetterorum Seub. | END | X | X | ||||||
| Rubus ulmifolius Schott | INV | X | X | X | |||||
| Santalales | Santalaceae | Arceuthobium azoricum Wiens & Hawksw. | END | X | |||||
| Saxifragales | Crassulaceae | Umbilicus horizontalis (Guss.) DC. | NAT | X | X | ||||
| Umbilicus rupestris (Salisb.) Dandy | NAT | X | X | ||||||
| Solanales | Solanaceae | Physalis peruviana L. | INT NAT | X | |||||
| Salpichroa origanifolia (Lam.) Baill. | INV | X* | |||||||
| Solanum mauritianum Scop. | INV | X | |||||||
| Liliopsida | Alismatales | Araceae | Zantedeschia aethiopica Spreng. | INV | X | ||||
| Asparagales | Iridaceae | Iris foetidissima L. | INT NAT | X | |||||
| Orchidaceae | Platanthera pollostantha R.M.Bateman & M.Moura | END | X | X | X | ||||
| Liliales | Smilacaceae | Smilax azorica H.Schaef. & P.Schönfelder | END | X | X | ||||
| Poales | Cyperaceae | Carex echinata Murray | NAT | X | X | ||||
| Carex hochstetteriana J.Gay ex Seub. | END | X | X | X | X | ||||
| Carex leviosa Míguez, Jim.-Mejías, H. Schaef. & Martín-Bravo | END | X | |||||||
| Carex peregrina Link | NAT | X | X | ||||||
| Carex pilulifera subsp. azorica (J.Gay) Franco & Rocha Afonso | END | X | X | ||||||
| Carex vulcani Hochst. ex Seub. | END | X | X | ||||||
| Eleocharis multicaulis (Sm.) Desv. | NAT | X | |||||||
| Juncaceae | Juncus effusus L. | NAT | X | ||||||
| Luzula purpureosplendens Seub. | END | X | X | X | X | ||||
| Poaceae | Agrostis congestiflora Tutin & E.F.Warb. | END | X | X | |||||
| Anthoxanthum odoratum L. | INT NAT | X | |||||||
| Arundo donax L. | INV | X | |||||||
| Brachypodium sylvaticum (Huds.) P.Beauv. | NAT | X | |||||||
| Deschampsia foliosa Hack. | END | X | X | X | X | ||||
| Festuca francoi Fern.Prieto, C.Aguiar, E.Días & M.I.Gut | END | X | X | ||||||
| Festuca petraea Guthnick ex Seub. | END | X | X | X | |||||
| Holcus lanatus L. | INV | X | |||||||
| Holcus rigidus Hochst. ex Seub. | END | X | X | X | X | ||||
| Hordeum murinum L. | INT NAT | X* | |||||||
| Zingiberales | Zingiberaceae | Hedychium gardnerianum Sheppard ex Ker-Gawl. | INV | X | X | X | X |
Across the four islands, the richness of indigenous species increases from low elevations to a peak around 600 m, followed by a decline towards higher elevations. Introduced species are concentrated at low elevations (0–400 m) and become rare or absent above 600–800 m, a pattern consistent across all islands (Fig. 3).
Figure 3.
Number of taxa (species and subspecies) along the elevational gradient on Flores (maximum altitude 914 m a.s.l.), Terceira (max. alt. 1,021 m a.s.l.), Pico (max. alt. 2,351 m a.s.l.) and São Miguel (max. alt. 1,103 m a.s.l.) islands, recorded using the MOVECLIM Protocol in 2013, by colonisation status.
The recorded species were distributed in five classes, 58 families and 92 genera. The most species-rich families were: Poaceae (10 taxa); Dryopteridaceae, Cyperaceae and Rosaceae (seven taxa each); and Asteraceae (six taxa). Suppl. material 1 provides a per-family list of genera and infrageneric taxa for all recorded vascular plants on the islands covered in this study.
Conservation and Management
According to the IUCN Red List (IUCN 2025), six species are considered to be of conservation concern: one is Critically Endangered (CR), three are Endangered (EN) and two are Vulnerable (VU). Amongst the remaining indigenous vascular plant taxa, 29 are considered as Least Concern (LC) and two are considered Near Threatened (NT). When comparing our checklist of indigenous species to the regional legislation for species conservation (DLR15 2012), 29.5% of the species are covered by protection and conservation measures and 21% are considered prioritary for conservation (Suppl. material 2).
Regarding the 17 invasive alien species reported in the dataset (cf. Suppl. material 3, ABP (2025)), 10 are included in DLR15 (2012), five are considered priority for control or eradication, while six are thought to pose ecological risks. Furthermore, if we compare our list with the Top 100 invasive species in the Azores (Silva et al. 2008), five of the 17 are in the top 25 (Q1), five in the second quartile (Q2) and one in the third quartile (Q3). Of these 11 species, only Acacia melanoxylon R.Br. (Q2), Adiantum hispidulum Sw. (Q2) and Cyrtomium falcatum (L.f.) C.Presl (Q1) are not included in the DLR15 (2012).
Supplementary Material
List of genera and infrageneric taxa recorded, by families.
Andrade, R
Data type
List of taxa occurrences
Brief description
Number of genera and of infrageneric taxa per family, of all vascular plants recorded, on four Azorean Islands (São Miguel, Terceira, Pico and Flores). Numbers within brackets represent the number of genera shared between indigenous (IND - endemic and native) and introduced (INT - introduced naturalised, casual or invasive) taxa.
File: oo_1459842.csv
Conservation and management species list
Andrade, R.
Data type
Species checklist
Brief description
Colonisation status according to PBA (2025): END - Azorean endemic; NAT - native. Conservation status according to IUCN (2025): CR - Critically Endangered; EN - Endangered; VU - Vulnerable; NT - Near Threatened; LC - Least Concern. Taxa included on (“X” indicates presence on the indicated list): DLR15/2012/A (regional legislation for species conservation); H (Habitats Directive - Natura 2000 Network); B (Berne Convention); T100 (list of 100 priority threatened species for management in the European biogeographical region of Macaronesia); CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora); R4 (protected by regional interest); P (priority for conservation).
File: oo_1459843.csv
Invasive species list
Andrade, Rui
Data type
Species checklist
Brief description
Colonisation status according to PBA (2025): INT NAT - introduced naturalised; INV - invasive. Taxa included on (“X” indicates presence on the indicated list): DLR15/2012/A (regional legislation for species conservation), P (priority for control or eradication), R (with ecological risks). The Top 100 (T100) invasive species in Macaronesia (Silva et al. 2008) are represented in quartiles (Q1 (Top 25); Q2 (26-50); Q3 (51-75); Q4 (76-100)).
File: oo_1511619.csv
Acknowledgements
This study was originally financed by ERANET BIOME MOVECLIM – ‘Montane vegetation as listening posts for climate change’ of the regional government of the Azores, grant number M2.1.2/F/04/2011/NET. R.A. received a Ph.D. Grant from FCT (UIDB/00329/2020-2024; DOI: 10.54499/UIDB/00329/2020), under Thematic Line 1 – Integrated ecological assessment of environmental change on biodiversity. While working on this publication, RBE, RG and PAVB were funded by FCT through national and European funds by UID/00329/2025 - Centre for Ecology, Evolution and Environmental Change (CE3C). This study is part of the Biodiversa+ project BioMonI – Biodiversity monitoring of island ecosystems, funded by FCT (BiodivMon/0003/2022), which also supported Open Access and provided funding to RG, RBE and PAVB. The project AZORES BIOPORTAL supported the availability of data for the general public.
Funding Statement
This study was originally financed by ERANET BIOME MOVECLIM – ‘Montane vegetation as listening posts for climate change’ of the regional government of the Azores, grant number M2.1.2/F/04/2011/NET. R.A. received a Ph.D. Grant from FCT (UIDB/00329/2020-2024; DOI: 10.54499/UIDB/00329/2020), under Thematic Line 1 – Integrated ecological assessment of environmental change on biodiversity. While working on this publication, R.B.E., R.G. and P.A.V.B. were funded by FCT through national and European funds by UID/00329/2025 - Centre for Ecology, Evolution and Environmental Change (CE3C).This study is part of the Biodiversa+ project BioMonI – Biodiversity monitoring of island ecosystems, funded by FCT (BiodivMon/0003/2022), which also supported Open Access and provided funding to RG, RE and PAVB.
Author contributions
RA: Manuscript writing; Formal analysis and interpretation; Research.
RG: Conceptualisation; Methodology; Resources; text revision.
PAVB: Darwin Core dataset revision, GBIF IPT management; text revision.
RBE: Conceptualisation; Methodology; Resources; text revision; Research (fieldwork); text revision.
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Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Supplementary Materials
List of genera and infrageneric taxa recorded, by families.
Andrade, R
Data type
List of taxa occurrences
Brief description
Number of genera and of infrageneric taxa per family, of all vascular plants recorded, on four Azorean Islands (São Miguel, Terceira, Pico and Flores). Numbers within brackets represent the number of genera shared between indigenous (IND - endemic and native) and introduced (INT - introduced naturalised, casual or invasive) taxa.
File: oo_1459842.csv
Conservation and management species list
Andrade, R.
Data type
Species checklist
Brief description
Colonisation status according to PBA (2025): END - Azorean endemic; NAT - native. Conservation status according to IUCN (2025): CR - Critically Endangered; EN - Endangered; VU - Vulnerable; NT - Near Threatened; LC - Least Concern. Taxa included on (“X” indicates presence on the indicated list): DLR15/2012/A (regional legislation for species conservation); H (Habitats Directive - Natura 2000 Network); B (Berne Convention); T100 (list of 100 priority threatened species for management in the European biogeographical region of Macaronesia); CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora); R4 (protected by regional interest); P (priority for conservation).
File: oo_1459843.csv
Invasive species list
Andrade, Rui
Data type
Species checklist
Brief description
Colonisation status according to PBA (2025): INT NAT - introduced naturalised; INV - invasive. Taxa included on (“X” indicates presence on the indicated list): DLR15/2012/A (regional legislation for species conservation), P (priority for control or eradication), R (with ecological risks). The Top 100 (T100) invasive species in Macaronesia (Silva et al. 2008) are represented in quartiles (Q1 (Top 25); Q2 (26-50); Q3 (51-75); Q4 (76-100)).
File: oo_1511619.csv