The MOVECLIM – AZORES project: Bryophytes from Pico Island along an elevation gradient

Abstract Background In September 2012, a comprehensive survey of Pico Island was conducted along an elevational transect, starting at Manhenha (10 m a.s.l.) and culminating at the Pico Mountain caldera (2200 m a.s.l.). The primary objective was to systematically inventory the bryophytes inhabiting the best-preserved areas of native vegetation environments. Twelve sites were selected, each spaced at 200 m elevation intervals. Within each site, two 10 m x 10 m plots were established in close proximity (10-15 m apart). Within these plots, three 2 m x 2 m quadrats were randomly selected and sampled for bryophytes using microplots measuring 10 cm x 5 cm, which were then collected into paper bags. Six substrates were surveyed in each quadrat: rock, soil, humus, organic matter, tree bark and leaves/fronds. Three replicates were obtained from all substrates available and colonised by bryophytes, resulting in a maximum of 18 microplots per quadrat, 54 microplots per plot, 108 microplots per site, and a total of 1296 microplots across the 12 sites on Pico Island. New information Two-thirds of the maximum expected number of microplots (n = 878; 67.75%) were successfully collected, yielding a total of 4896 specimens. The vast majority (n = 4869) were identified at the species/subspecies level. The study identified a total of 70 moss and 71 liverwort species or subspecies. Elevation levels between 600-1000 m a.s.l., particularly in the native forest plots, exhibited both a higher number of microplots and greater species richness. This research significantly enhanced our understanding of Azorean bryophyte diversity and distribution, contributing valuable insights at both local and regional scales. Notably, two new taxa for the Azores were documented during the MOVECLIM study, namely the pleurocarpous mosses Antitrichiacurtipendula and Isotheciuminterludens.


Introduction
Bryophytes are ancient terrestrial plants (Laenen et al. 2014), exhibiting different morphological and physiological adaptations that account for their evolutionary success.These plants are characterised by the dominance of the gametophyte over the sporophyte and lack of vascular tissues in the sporophyte.These organisms are taxonomically classified in three Divisions: Bryophyta (mosses), Marchantiophyta (liverworts) and Anthocerotophyta (hornworts) (Goffinet and Shaw 2009).Ecologically, bryophytes occupy a wide range of habitats, from the Poles to the Equator and from sea-level to high mountains, presenting higher diversity in the tropics (Goffinet and Shaw 2009).
As they are small and rootless, bryophytes are very dependent of their immediate context, responding to different environmental changes, namely, substrate composition and acidity, rainfall, temperature, salinity and pollution (e.g.Hodgetts et al. (2019)).Bryophytes maintain a number of ecosystems services, positively influencing the water cycle (Coelho et al. 2023a, Coelho et al. 2023b) and the decomposition of organic material, creating a favourable environment for the development of other non-pioneer organisms (Goffinet and Shaw 2009).
Globally, bryophytes represent the second largest group of plants -with over 20000 species: 13000 mosses, 8000 liverworts and 250 hornworts (Goffinet and Shaw 2009).In Europe, there are 1892 species of bryophytes (1390 mosses; 494 liverworts; 8 hornworts) (Hodgetts et al. 2020), while about a quarter of those are found in the Azores (308 mosses; 162 liverworts; 5 hornworts) (Gabriel et al. 2010), although this archipelago represents only 0.06% of the European territory (Borges et al. 2023).Bryophytes are, thus, one of the main biological groups for maintaining biodiversity (Sérgio et al. 2012), with different taxonomic groups responding differently to environmental pressure and gradients (e.g.Henriques et al. (2016)) and including a number of conservation concern species (Hodgetts et al. 2019).
The distribution of bryophyte species in the nine Azorean islands is uneven, but this fact is not completely explained by area or elevation.For instance, Pico Island, the highest and second largest (2350 m a.s.l.; 445 km ), has similar richness of bryophytes (283 species) to the much smaller Faial Island (1043 m a.s.l.; 173 km ) (286 species) (Forjaz 2004, Gabriel et al. 2010).This may be related to the sampling effort amongst different islands.Indeed, the work of many collectors and authors contributed to the current knowledge of the distribution of Azorean bryophytes.A list of publications mentioning bryophytes collected in Pico Island may be seen in Suppl.material 1.It comprises 96 references, published from 1862 to 2023, including mostly journal articles ( 65), but also other types of references, such as books and book chapters, theses and dissertations, scientific reports, Herbaria records and expert's documents.Erik Sjögren stands out as the major source of distribution information, with more than 3000 records on Pico Island; however, the publications of Herman Persson, Jan-Peter Frahm, Pierre and Valentine Allorge, Tutin and Warburg and Juana González-Mancebo, are also noteworthy, having added more than 100 records each to the bryoflora distribution of the Island.
Since 2012, an effort has been made to update the information regarding bryophytes in the Azores, namely under the 'MOVECLIM project -Montane Vegetation as Listening Posts for Climate Change' (Coelho et al. 2014a, Gabriel et al. 2014, Borges et al. 2018).One of the purposes of this project was to characterise the poorly known, but highly diverse, bryophyte flora of different archipelagos, including the Azores, the Canary Islands and the Mascarene Islands.In the Azores, it was possible to survey seven islands using an adaptation of the BRYOLAT protocol (Gabriel et al. 2014) The MOVECLIM -AZORES project: Bryophytes from Pico Island along an elevation g ...
2014 and Santa Maria Island in 2019.Graciosa and Corvo Islands, the smallest and devoid of native forest, were not surveyed under this protocol.
Thus, the objective of this study was to inventory bryophyte species in different altitudinal gradients (between 10 m and 2200 m a.s.l.) and substrates (rupicolous, terricolous, humicolous, lignicolous, epiphytic, epiphyllous) in the Island of Pico sampled in a stratified way.

General description
Purpose: The main objective of this work was to inventory the bryoflora present in the Pico Natural Park, including Municipalities of Lajes do Pico, São Roque do Pico and Madalena.Sampling was carried out on different altitudinal levels (between 10 m and 2200 m) and substrates (rupicolous, terricolous, humicolous, lignicolous, epiphytic, epiphyllous), with the aim of expanding the database of bryophyte species (mosses, liverworts, hornworts) known to Pico Island.

Project description
Title: Inventory of bryoflora present in different altitudinal gradients of Pico Island (Azores).

Personnel:
The bryoflora inventory of Pico Island was carried out during the month of September 2012, within the dates 5-10, under the responsibility of Rosalina Gabriel (RG) and Claudine Ah-Peng (CAP), with the participation of Márcia C.M. Coelho (MC), Débora Henriques (DH), Silvia Calvo Aranda (SCA) and Fernando Pereira (FP).Species growing on organic matter, tree trunks and leaves were identified by MC supervised by RG, while Helena Hespanhol (HH) identified species growing on rock and soil.Challenging specimens were confirmed by Cecília Sérgio (CS) and Manuela Sim-Sim (MSS).In 2023, the species of the genus Frullania were reviewed by Leila N. Morgado (LNM) and RG and were later confirmed by MSS.

Study area description:
The Azores Archipelago is a Portuguese autonomous region and comprises nine islands of volcanic origin.It is located in the North Atlantic Ocean (Fig. 1), about 1500 km from the western coast of mainland Europe and approximately 3900 km from the North America coasts.The shortest distance to European Portuguese coast is about 1400 km (Forjaz 2004).
Given its oceanic location, the Azores have a typically maritime climate, which translates into mild temperatures, with a small temperature range, high relative humidity (%) and high rainfall (mm) in autumn and winter.The average annual temperature varies between 12°C and 23°C, the average annual rainfall varies between 1000 and 1600 mm at sea level and the relative humidity is usually quite high, largely exceeding 80% in all seasons (Forjaz 2004, IPMA 2022).
The Laurissilva Forest of Macaronesia was recognised as a World Natural Heritage site by UNESCO in 1999(CONSLEG (1992L0043) 2014).Together with the Juniperus-Ilex montane cloud forests, these formations present the highest number of endemisms and other indigenous species (Nunes et al. 2015, Schäfer 2021, Elias et al. 2022).In fact, there are approximately 452 endemic species amongst land and freshwater organisms in the Azores (Borges et al. 2010) and vascular plants stand out with 73 Azorean endemic species and subspecies, a value surpassed only by phylum Arthropoda (266 taxa) (Borges et al. 2010).Native vegetation also includes a high number and cover of bryophytes ( Gabriel and Bates 2005, Homem and Gabriel 2008, Couto 2010, Gabriel et al. 2011, Elias et al. 2022), some of which rare and endangered (Esquivel et al. 2008, Hodgetts et al. 2019).Pico Island (38º33'57" and 38º33'44" N and 28º01'39" and 28º32'33" W), belongs to the central group of the Azores Archipelago (Portugal) in the North Atlantic Ocean.This Island is the second largest (445 km ), the highest (2350 m a.s.l.) and the youngest (0.27 MY) of the Azores (Forjaz 2004) and its forest incorporates the highest contribution of endemic (44%) and native (38%) taxa, compared to the Islands of São Miguel and Terceira (Borges Silva et al. 2022).
The sampling location and coordinates are listed in Table 1 and Fig Location and maximum elevation of each island of the Azores Archipelago.Source: Section of Management and Environmental Planning, University of the Azores; Elevation values follow Forjaz (2004).
The MOVECLIM -AZORES project: Bryophytes from Pico Island along an elevation g ... Design description: The sampling was performed in 2012, during 5-10 September, along a longitudinal elevational transect (east to west) in the Pico Natural Park, including the bestpreserved areas of native vegetation.The samples were collected in different altitudinal gradients (10 -2200 m) and substrates (rupicolous, terricolous, humicolous, lignicolous, epiphytic, epiphyllous).

Sampling methods
Description: Pico Island has the highest plant diversity compared to the other islands in the Archipelago, mainly due to a higher number of altitudinal vegetation areas (Dias et al. 2005).The soils are relatively young, mostly composed of basaltic rock debris (i.e.leptosols), presenting lower values of carbon accumulation (Borges Silva et al. 2022).This study was carried out in the Pico National Park (Azores), which has a large protected area (156 km -terrestrial, 79 km -maritime), including the mountain (the central volcanic formation that reaches 2351 m elevation), native forests and woodlands, lagoons and the coastal zones.

Sampling description:
The field study was carried out according to the BRYOLAT methodology (Ah-Peng et al. 2012), with some modifications according to the conditions and knowledge of the Azores flora (Gabriel et al. 2014).In each plot, three quadrats (2 m x 2 m) were randomly selected and bryophytes were sampled in a total of three microplots (5 The MOVECLIM -AZORES project: Bryophytes from Pico Island along an elevation g ... cm x 10 cm) in each different substrate (rupicolous, terricolous, humicolous, lignicolous, epiphytic, epiphyllous) and altitudinal gradients (between 10 m and 2200 m).This methodology consists of sampling the bryoflora according to the diagram (Fig. 3, Gabriel et al. (2014)).In the laboratory, the abundance and sociability of the bryophyte species were identified and estimated.
Quality control: FIELD: An initial visit of Pico Island was made by PAVB and RG in July 2012 to prospect the most suitable sampling sites.Plots were placed within homogeneous areas of representative native vegetation found at each sampled elevation.Sampling was made by experienced bryologists, who ensured the samples were properly collected, while avoiding the excessive removal of material.STORAGE: After the collection of the microplots in paper bags, these were left open and separated in a darkened room until complete dehydration.After identification, every sample was transferred to herbarium envelopes properly identified.All these envelopes were stored in the Herbarium of the University of the Azores (AZU), Section Bryophytes, under the name "MOVECLIM -AZORES project: Bryophytes from Pico Island (2012)".TAXONOMY: All efforts were made to achieve an accurate identification of the specimens: (i) the most updated keys and floras were used by/under the supervision of experienced bryologists; (ii) challenging samples were sent to specialists for confirmation/identification; (iii) identification of extremely small or etiolated specimens was not pursued to the species level.Mosses were identified mainly using the floras of Smith ( 2004) and Casas et al. (2006), whereas liverworts were identified mainly using the floras written by Paton (1999) and Casas et al. (2009)   (2019)) were also consulted, as well as the BBS Field Guide online pages, the Bildatlas der Moose Deutschlands for morphological and ecological data.Nomenclature follows Gabriel et al. (2010) and updates available on the Azorean Biodiversity Portal (Hodgetts et al. 2020, Borges et al. 2023).Species identification was performed by Márcia Catarina Mendes Coelho, under the supervision of Rosalina Gabriel and by Helena Hespanhol.In 2023, all the Frullania specimens were reviewed by Leila Nunes Morgado under the supervision of Rosalina Gabriel.The identification of some challenging specimens was performed by Manuela Sim-Sim and Cecília Sérgio.REPRESENTATION OF THE PICO BRYOFLORA: Species accumulation curves were generated, based on a presence-absence microplotscale matrix using Chao 2 estimator.Sampling completeness was high both for liverworts (87.5%) and mosses (94.5%) (Coelho et al. 2021).

Geographic coverage
Description: The study was carried out in Pico Island (Azores Archipelago, Portugal).The 12 sampling sites were distributed amongst the three municipalities of the island: Lajes do Pico, São Roque do Pico and Madalena; the coordinates range between the following values: Coordinates: 38.41375 and 38.47064 Latitude; -28.0298 and -28.42525Longitude.

Taxonomic coverage
Description: Bryophytes, including specimen from Division Bryophyta (mosses) and Division Marchantiophyta (liverworts).No elements from Division Anthocerotophyta were collected during this survey.

Temporal coverage
Notes: The sampling was performed in 2012, 5-10 September.

Usage licence
Usage licence: Creative Commons Public Domain Waiver (CC-Zero) IP rights notes: Additional information on this study may also be requested from the corresponding author.Description: The dataset was published in the Global Biodiversity Information Facility platform, GBIF (Gabriel et al. 2023).The following data table includes all the records for which a taxonomic identification of the species was possible.The dataset submitted to GBIF is structured as a sample event dataset that has been 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 878 records (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 (Gabriel et al. 2023).

Column label Column description
id Identifier of the events, unique for the dataset.Description: The dataset was published in the Global Biodiversity Information Facility platform, GBIF (Gabriel et al. 2023).The following data table includes all the records for which a taxonomic identification of the species was possible.The dataset submitted to GBIF is structured as an occurrence table that has been 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 4896 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 (Gabriel et al. 2023).

Column label
Column description eventID Identifier of the events, unique for the dataset.establishmentMeans The process of establishment of the species in the location, using a controlled vocabulary: 'native non-endemic', 'introduced', 'endemic'.
occurrenceRemarks Remarks on the occurrence substrate from where the specimens were captured.

Additional information
The 878 events yielded a grand total of 4896 specimens, with the majority (n = 4869; 99.45%) being successfully identified down to the species/subspecies level.Division Bryophyta is represented by 70 species, belonging to three classes (Bryopsida, Polytrichopsida and Sphagnopsida), 10 orders, 28 families and 45 genera, while Division Marchantiophyta is represented by 71 species, including three subspecies, organised in two classes (Jungermanniopsida and Marchantiopsida), six orders, 24 families and 43 genera (see Occurrence Table at Gabriel et al. (2023)).Both the number of species (Fig. 4) and the number of records (Fig. 5) show a peak from 600 m to 1000 m altitude, which correspond to the sites with more complex vegetation (Coelho et al. 2014a, Coelho et al. 2014b, Coelho et al. 2021).Campylopus flexuosus (Hedw.)Brid.
Figure 2. Map of Pico Island with indications of sampling points (yellow squares) (Source: Gil et al. 2017, with modifications).

Figure 3 .
Figure 3. Altitudinal sampling model on Pico Island (Ah-Peng et al. 2012 and Gabriel et al. 2014): (a) 200 m elevation steps, two plots (black squares, 10 m x 10 m) are placed within 10 m to 15 m from each other; (b) each plot is divided into 25 quadrats (grey squares, 2 m x 2 m), from which three are sampled; (c) and (d) -each quadrat is thoroughly examined for different substrata and three microplots (red rectangular shapes, 5 cm x 10 cm) are collected on every microhabitat, except on trees, where nine replicates are made, at three different height levels.(Source: Gabriel et al. (2014)).

type
Type of the record, as defined by the Dublin Core Standard.datasetName Name of the dataset that in current projects is "MOVECLIM-AZO-PIC_2012_Bryophytes from Pico Island".eventID Identifier of the events, unique for the dataset.samplingProtocol The sampling protocol used to capture the species.Detailed description of the sampling methodology in the field.Two plots of 10 m × 10 m (P1, P2), were set out at the best-preserved areas of native vegetation sites, every 200 m elevation, across an elevation gradient from coastal areas to Pico summit.Each plot was subdivided into 25 quadrats (2 m × 2 m), from which three were randomly selected for the collection of bryophyte species.Within each quadrat, bryophytes were collected in small sampling units (microplots of 10 cm × 5 cm), obtaining, whenever possible, three replicates per surveyed substrate (RU, rock, TE, soil, HU, humus, LI, dead wood, T, bark at three heights from the tree [a, 1-50 cm; b, 51-100 cm; c, 101-200 cm], LF, leaves/fronds).minimumElevationInMetres The lower limit of the range of elevation (altitude above sea level) of the Location.eventDate The date-time or interval during which an Event occurred.For occurrences, this is the date-time when the event was recorded.year Year the sample was collected (2012).habitat The habitat for an Event.continent The name of the continent in which the Location occurs (Europe).islandGroup The name of the island group in which the Location occurs (Azores).island The name of the island on or near which the Location occurs (Pico Island).country The name of the country or major administrative unit in which the Location occurs (Portugal).countryCode The standard code for the country in which the Location occurs (PT).municipality The full, unabbreviated name of the next smaller administrative region than county (city, municipality etc.) in which the Location occurs.locality The specific description of the place.verbatimCoordinates Original coordinates recorded.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 Standard Global Positioning System coordinate reference for the location of the sample collection points.coordinateUncertaintyInMetres Uncertain value of coordinate metrics.coordinatePrecision Value in decimal degrees to a precision of five decimal places.georeferenceSources Navigation system used to record the location of sample collections.Data set name: Occurrence Table Character set: UTF-8 Download URL: http://ipt.gbif.pt/ipt/resource?r=bryophytes_pico_2012Data format: Darwin Core Archive Data format version: 1.4

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.collectionCode The code of the collection where the specimens are conserved.datasetName Project reference.type Characteristics of the object of study.basisOfRecord The nature of the data record.dynamicProperties A list of additional measurements, facts, characteristics or assertions about the record, including IUCN categories (Endangered, Vulnerable, Near Threatened, Least Concern, Not Evaluated) and colonisation status of taxa following the standard notation used for bryophytes (Azorean endemic, Macaronesian endemic, Ibero-Macaronesian endemic, European endemic, non-endemic).occurrenceID Identifier of the record, coded as a global unique identifier.recordNumber An identifier given to the Occurrence at the time it was recorded.recordedBy A list (concatenated and separated) of names of people, groups or organisations responsible for recording the original Occurrence.identifiedBy A list (concatenated and separated) of names of people, who made the identification.

Figure 5 .
Figure 5.The number of presences in 50 cm microplots of species of mosses (Division Bryophyta) and liverworts (Division Marchantiophyta) along Pico Island's elevational gradient.2 : Pico and Terceira Islands were surveyed in 2012; Flores and São Miguel Islands in 2013; São Jorge and Faial Islands in