Biodiversity Data Journal : Data Paper (Biosciences)
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Data Paper (Biosciences)
SLAM Project - Long Term Ecological Study of the Impacts of Climate Change in the Natural Forest of Azores: III - Testing the impact of edge effects in a native forest of Terceira Island
expand article infoPaulo A. V. Borges‡,§, Lucas Lamelas-López, Noelline Tsafack‡,|, Mário Boieiro‡,§, Alejandra Ros-Prieto, Rosalina Gabriel, Rui Nunes, Maria Teresa Ferreira|
‡ cE3c - Centre for Ecology, Evolution and Environmental Changes / Azorean Biodiversity Group & CHANGE – Global Change and Sustainability Institute, University of the Azores, Faculty of Agricultural Sciences and Environment, Rua Capitão João D` Ávila, São Pedro, 9700-042, Angra do Heroísmo, Azores, Portugal
§ IUCN SSC Mid-Atlantic Islands Specialist Group, Angra do Heroísmo, Azores, Portugal
| Regional Secretariat of Environment and Climate Change, Project LIFE BEETLES (LIFE 18 NAT/PT/000864), Rua do Galo n. 118, 9700-040, Angra do Heroísmo, Azores, Portugal
Open Access

Abstract

Background

The data we present are part of the long-term project “SLAM Project - Long Term Ecological Study of the Impacts of Climate Change in the Natural Forest of Azores” that started in 2012, aiming to understand the impact of biodiversity erosion drivers on Azorean native forests (Azores, Macaronesia, Portugal). The data for the current study consist in an inventory of arthropods collected in three locations of a native forest fragment at Terra-Brava protected area (Terceira, Azores, Portugal) aiming to test the impact of edge effects on Azorean arthropod communities. The three locations were: (i) the edge of the forest, closer to the pastures; (ii) an intermediate area (100 m from edge); and (iii) the deepest part of the native forest fragment (more than 300 m from edge). The study was carried out between June 2014 and December 2015. A total of nine passive flight interception SLAM (Sea, Land and Air Malaise) traps were deployed (three in each of the studied locations), during 18 consecutive months. This study provides the raw data to investigate temporal and edge effect variation for the Azorean arthropod communities.

New information

The collected arthropods belong to a wide diversity of taxonomic groups of Arachnida, Diplopoda, Chilopoda and Insecta classes. We collected a total of 13,516 specimens from which it was possible to identify to species level almost all specimens (13,504). These identified specimens belong to 15 orders, 58 families (plus three with only genus or family level identification) and 97 species of arthropods. A total of 35 species are considered introduced, 34 native non-endemic and 28 endemic. Additionally, a total of 10 taxa (12 specimens) were recorded at genus, family or order level. This dataset will allow researchers to test the impact of edge effect on arthropod biodiversity and to investigate seasonal changes in Azorean arthropod native forest communities.

Keywords

Arthropoda, Azores, edge effect, inventory, Macaronesia, temporal variation

Introduction

Arthropods are being affected by dramatic population declines and species extinctions worldwide (Sánchez-Bayo and Wyckhuys 2019, Cardoso et al. 2020, Harvey et al. 2020). One of the major causes for this biodiversity loss is the habitat destruction and degradation associated with replacement of native forest areas by other habitats, such as forest timber plantations, pasturelands etc. (e.g. Raven and Wagner 2021). These land use changes lead to habitat fragmentation by creating several isolated native forest patches of different size and morphology, thus leading to the exposure of forest-adapted biota to the conditions of the surrounding habitats, which is known as the “edge effect” (Murcia 1995). This interaction between two adjacent habitats (native forest and newly human-created habitat in this case) may have detrimental effects on the forest-adapted biotas due to changes in the biotic and abiotic conditions, mainly at the edges of the forest patches.

Oceanic islands have been especially affected by habitat degradation, as consequence of human colonisation (Triantis et al. 2010, Borges et al. 2019a, Borges et al. 2019b). In the Azores, the native habitats of the islands were strongly modified since Portuguese settlement starting in the 15th century, by replacing native and pristine forests with pasturelands, agricultural areas, exotic tree plantations (e.g. Cryptomeria japonica and Eucalyptus spp.) and urban areas. These major land-use changes actuated gradually in a gradient of elevation promoting the extinction of large-bodied beetle species (Terzopoulou et al. 2015) and the an ongoing process of extinction debt for many more (Triantis et al. 2010). Currently, the original forests comprise only about 5% of the total surface of the islands and are restricted to the most inaccessible areas (Gaspar et al. 2008, Triantis et al. 2010, Rego et al. 2015, Norder et al. 2020).

Some studies revealed a higher species richness and abundance of arthropods in the forest edges, which could have implications on the re-colonisation of adjacent altered habitats (Jokimäki et al. 1998, Magura 2002). Studies about Azorean arthropods have shown that the endemic species are mainly restricted to native forests and introduced species are more frequently detected in anthropogenic habitats, given their higher adaptability to the conditions of the newly-created habitat (Cardoso et al. 2009, Florencio et al. 2015, Florencio et al. 2016). The impact of invasive plants species is the major threat to endemic and native species in the native forest areas (Borges et al. 2019b) and their deleterious effects are probably more severe at the edges of the forests patches (Borges et al. 2006).

This publication is the seventh of a long-term monitoring project that started in the Azores in 2012 (SLAM Project - Long Term Ecological Study of the Impacts of Climate Change in the Natural Forest of Azores). The project was described in detail in Costa and Borges (2021) as a data-paper, but the first outputs were published earlier to test several ecological questions (see Borges et al. 2017, Matthews et al. 2018, Borges et al. 2020, de Vries et al. 2021). More recentlly, another data-paper was published investigating the occurrence of exotic and endemic arthropods in exotic and mixed forests and small disturbed remnants of native forests (Borges et al. 2022).

General description

Purpose: 

The current study is the third data-paper of the series and provides data from arthropod communities from Terra-Brava pristine native forest fragment (Terceira Island, Azores, Portugal) that will be useful to investigate: i) the impact of edge effects on biodiversity of arthropod communities from Terra-Brava pristine native forest and ii) seasonal changes in arthropod species richness and composition. In addition, the use of three replicate SLAM traps per (micro)habitat will be important to assess sampling completeness, perform sensitivity analyses and to support a cost-effective sampling design.

Additional information: 

The data we present are part of the long-term project “SLAM Project - Long Term Ecological Study of the Impacts of Climate Change in the Natural Forest of Azores” that started in 2012, aiming to understand the impact of biodiversity erosion drivers on Azorean native forests (Azores, Macaronesia, Portugal). The current study includes new sampling areas in the native forests of Terceira Island and contributes with novel data that will be of paramount importance to obtain information about the native communities of arthropods across gradients of temporal and edge effects variation. Additionally, the samples collected in the most pristine areas contributed to the publication of Matthews et al. (2018) in testing the capacity of one single trap to capture relevant ecological properties (e.g. species composition, distribution of abundance) of the sampled communities. In two previous data papers, the project was described in detail and spider data were provided for several plots in Terceira and Pico Islands (Costa and Borges 2021) and the occurrence of exotic and endemic arthropods in exotic and mixed forests and small disturbed remnants of native forests was also investigated (Borges et al. 2022).

Project description

Title: 

SLAM Project III - Testing the impact of edge effects in native forests

Personnel: 

The project was conceived and led by Paulo A.V. Borges.

Fieldwork: Paulo A. V. Borges, Rui Nunes.

Parataxonomists: Alejandra Ros-Prieto, David Rodilla Rivas, Juan Ignacio Pitarch Peréz, Laura Cáceres Sabater, Laura Gallardo, Marija Tomašić, Percy de Laminne de Bex, Rui Carvalho, William Razey.

Taxonomists: Paulo A. V. Borges.

Voucher specimen management was mainly undertaken by Alejandra Ros-Prieto and Paulo A. V. Borges.

Study area description: 

The study area comprises a fragment of the native forest “Terra-Brava” (Fig. 1) with an area of 180 ha located in the interior of Terceira Island (coordinates: 38°43'17"; -27°13'14") (Fig. 2), in the Azores Archipelago. The elevation ranges between 600 and 780 m a.s.l. This native forest fragment is pristine and covered by native vegetation, dominated by three endemic trees: Laurus azorica (Seub.) Franco (Laurales, Lauraceae), Ilex azorica Gand. (Aquifoliales, Aquifoliaceae) and Juniperus brevifolia (Hochst. ex Seub.) Antoine (Pinales, Cupressaceae). The forest type of this forest fragment was classified by Elias et al. (2016) as “Juniperus-Ilex montane forests” that, in addition to a dominance of J. brevifolia and I. azorica, are characterised also by the presence of L. azorica at high densities and a dense cover of bryophytes and ferns in all substrates (Fig. 3). The shrub layer is dominated by the endemic species Myrsine retusa Aiton (Ericales, Myrsinaceae) and Vaccinium cylindraceum Sm. (Ericales, Ericaceae).

Figure 1.  

Terra-Brava Forest fragment on Terceira Island (Azores, Portugal) (Credit: Paulo A. V. Borges).

Figure 2.  

Location of Terra-Brava within Terceira Island, Azores (Credit: Paulo A. V. Borges).

Figure 3.  

Terra-Brava dense carpet of bryophytes and ferns (Credit: Paulo A. V. Borges).

In general, the climate of the Archipelago is temperate oceanic, with frequent and abundant precipitation, high high relative humidity and persistent winds, mainly during the winter and autumn seasons.

Design description: 

A total of nine SLAM (Sea, Land and Air Malaise) traps (Fig. 4) were deployed in the Terra-Brava native forest fragment: (i) three were set at the edge of the forest, closer to the pastures; (ii) three in an intermediate area (100 m from edge); and (iii) three in the deepest part of the native forest fragment (more than 300 m from edge) (Table 1). The trap samples were collected each month, during 18 consecutive months (from June 2014 to December 2015).

Table 1.

List of the nine sampled sites in the native forest fragment of “Terra-Brava”, in Terceira Island (Azores), between June 2014 and December 2015. Information is given about site location, site code, elevation (in metres) and decimal coordinates (Latitude and Longitude).

Site location Site code Elevation Latitude Longitude
Edge TER-NFTB-T-18_Edge-A 650 38.73276 -27.19681
Edge TER-NFTB-T-18_Edge-B 660 38.73232 -27.19657
Edge TER-NFTB-T-18_Edge-C 660 38.73243 -27.19576
100 m inside TER-NFTB-T-18_Original 670 38.73206 -27.1972
100 m inside TER-NFTB-T-18_Centre 680 38.73235 -27.19798
100 m inside TER-NFTB-T-18_Top 680 38.73272 -27.19827
300 m inside TER-NFTB-T-18_Deep-A 680 38.7327 -27.20035
300 m inside TER-NFTB-T-18_Deep-B 690 38.73227 -27.20012
300 m inside TER-NFTB-T-18_Deep-C 700 38.73189 -27.19981
Figure 4.  

SLAM Trap (Sea, Land and Air Malaise trap) (Credit: Paulo A. V. Borges).

Funding: 

A large number of students financed by the EU Programmes ERASMUS and EURODYSSÉE sorted the samples prior to species assignment. This manuscript was also partly financed by Portuguese FCT-NETBIOME –ISLANDBIODIV grant 0003/2011 (between 2012 and 2015), Portuguese National Funds, through FCT – Fundação para a Ciência e a Tecnologia, within the project UID/BIA/00329/2013-2020 and AZORESBIOPORTAL –PORBIOTA (ACORES-01-0145-FEDER-000072) (2019). The Natural Park of Terceira provided the necessary authorisation for arthropod sampling (Licence CCPI 006/2014). The database management and Open Access was funded by Fundação para a Ciência e a Tecnologia (FCT) through project “MACRISK-Trait-based prediction of extinction risk and invasiveness for Northern Macaronesian arthropods” - PTDC/BIA-CBI/0625/2021 (2022-2024).

Sampling methods

Sampling description: 

The data collection was performed using passive flight interception SLAM traps (Sea, Land and Air Malaise trap) (Fig. 4). Trap size is approximately 110 x 110 x 110 cm. The trap works on the principle that the intercepted arthropods crawl up the mesh and then fall inside the sampling recipient, which is filled with propylene glycol (pure 1,2-Propanodiol) (Borges et al. 2017). This sampling protocol is adequate to capture flying and non-flying arthropod species (Borges et al. 2017, Costa and Borges 2021) and it has been used to study diversity and abundance variations in the communities of arthropods on Azorean native areas (Matthews et al. 2018, Borges et al. 2020), to study patterns of diversity in a small elevation gradient (de Vries et al. 2021) and to investigate the role of exotic forests for the spread of exotic species and as a reservoir of relict populations of endemic species (Tsafack et al. 2021).

Quality control: 

All sampled individuals were first sorted by trained paratoxonomists (see list above). All specimens were allocated to a taxonomic species by Paulo A. V. Borges. Juveniles are also included in the data presented in this paper since the low species diversity in the Azores allowed a relatively precise identification of this life-stage.

Step description: 

At the laboratory, specimen sorting and arthropod identification followed standard procedures. A combination of somatic characters and reproductive structure was used for species identification. A reference collection was made for all collected specimens by assigning them a morphospecies code number and depositing them at the Dalberto Teixeira Pombo Insect Collection, University of Azores. Colonisation status for each identified species is based on Borges et al. (2010) (END -Endemic; NAT - native non-endemic; INT -introduced).

Geographic coverage

Description: 

Terra-Brava native forest fragment of Terceira Island, in the Azores Archipelago (Portugal).

Coordinates: 

38°44'0.47'' and 38°48'50.4'' Latitude; 27°11'0.99''W and 27°13'20.66'' Longitude.

Taxonomic coverage

Description: 

The following Arthropod Classes and Orders are covered:

Arachnida: Araneae; Opiliones; Pseudoscorpiones.

Chilopoda: Lithobiomorpha.

Diplopoda: Chordeumatida, Julida.

Insecta: Archaeognatha; Blattodea; Coleoptera; Hemiptera; Neuroptera; Orthoptera; Psocodea; Thysanoptera; Trichoptera.

Taxa included:
Rank Scientific Name Common Name
phylum Arthropoda Arthropods

Temporal coverage

Data range: 
2014-6-11 - 2015-12-14.
Notes: 

Samples were taken monthly.

Collection data

Collection name: 
Entomoteca Dalberto Teixeira Pombo (DTP); University of Azores
Collection identifier: 
DTP
Specimen preservation method: 
All specimens were preserved in 96% ethanol.
Curatorial unit: 
Curator: Paulo A. V. Borges

Usage licence

Usage licence: 
Creative Commons Public Domain Waiver (CC-Zero)

Data resources

Data package title: 
Monthly monitoring of Azorean forest arthropods testing for edge effects (Terceira Island, Azores, Portugal)
Alternative identifiers: 
Number of data sets: 
2
Data set name: 
Event Table
Character set: 
UTF-8
Data format: 
Darwin Core Archive format
Data format version: 
Version 1.3
Description: 

The dataset was published in Global Biodiversity Information Facility platform, GBIF (Borges and Lamelas-López 2022). 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 158 records (eventID). This GBIF IPT (Integrated Publishing Toolkit, Version 2.5.6-rd6f172f) 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 (Borges and Lamelas-López 2022).

Column label Column description
eventID Identifier of the events, unique for the dataset.
stateProvince Name of the region of the sampling site.
islandGroup Name of archipelago.
island Name of the island.
country Country of the sampling site.
countryCode ISO code of the country of the sampling site.
municipality Municipality of the sampling site.
decimalLatitude The geographic latitude (in decimal degrees, using the spatial reference system given in geodeticDatum) of the geographic centre of a Location.
decimalLongitude The geographic longitude (in decimal degrees, using the spatial reference system given in geodeticDatum) of the geographic centre of a Location.
geodeticDatum The ellipsoid, geodetic datum or spatial reference system (SRS) upon which the geographic coordinates given in decimalLatitude and decimalLongitude are based.
coordinateUncertaintyInMetres Uncertainty of the coordinates of the centre of the sampling plot in metres.
coordinatePrecision A decimal representation of the precision of the coordinates given in the decimalLatitude and decimalLongitude.
georeferenceSources A list (concatenated and separated) of maps, gazetteers or other resources used to georeference the Location, described specifically enough to allow anyone in the future to use the same resources.
locationID Identifier of the location.
locality Name of the locality.
locationRemarks Additional information about the locality.
minimumElevationInMetres. The lower limit of the range of elevation (altitude, usually above sea level), in metres.
habitat The habitat of the sample.
year Year of the event.
sampleSizeUnit The unit of the sample size value.
eventDate Date or date range the record was collected.
sampleSizeValue The numeric amount of time spent in each sampling.
verbatimEventDate The verbatim original representation of the date and time information for an Event. In this case, we use the season and year.
samplingProtocol The sampling protocol used to capture the species.
Data set name: 
Occurrence Table
Character set: 
UTF-8
Data format: 
Darwin Core Archive format
Data format version: 
Version 1.3
Description: 

The dataset was published in Global Biodiversity Information Facility platform, GBIF (Borges and Lamelas-López 2022). 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 2779 records (occurrenceID). This GBIF IPT (Integrated Publishing Toolkit, Version 2.5.6-rd6f172f) 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 (Borges and Lamelas-López 2022).

Column label Column description
eventID Identifier of the events, unique for the dataset.
type Type of the record, as defined by the Public Core standard.
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.
collectionID The identity of the collection publishing the data.
collectionCode The code of the collection where the specimens are conserved.
basisOfRecord The nature of the data record.
occurrenceID Identifier of the record, coded as a global unique identifier.
recordedBy A list (concatenated and separated) of names of people, groups or organisations who performed the sampling in the field.
identifiedBy A list (concatenated and separated) of names of people, groups or organisations who performed the sampling in the field.
dateIdentified The date on which the subject was determined as representing the Taxon.
individualCount A number or enumeration value for the quantity of organisms.
organismQuantityType The type of quantification system used for the quantity of organisms.
lifeStage The life stage of the organisms captured.
sex The sex and quantity of the individuals captured.
scientificName Complete scientific name including author and year.
scientificNameAuthorship Name of the author of the lowest taxon rank included in the record.
kingdom Kingdom name.
phylum Phylum name.
class Class name.
order Order name.
family Family name.
genus Genus name.
specificEpithet Specific epithet.
infraspecificEpithet Infrapecific epithet.
taxonRank Lowest taxonomic rank of the record.
establishmentMeans The process of establishment of the species in the location, using a controlled vocabulary: in the GBIF database, we used the Borges et al. (2010) original classification: 'native', 'introduced', 'endemic'.
identificationRemarks Information about morphospecies identification (code in Dalberto Teixeira Pombo Collection).

Additional information

We collected a total of 13,516 specimens 13,504 of which were identified to species (Table 2). These identified specimens belong to 15 orders, 58 families (plus three with only genus or family level identification) and 97 species of arthropods. A total of 35 species are considered introduced, 34 native non-endemic and 28 endemic (Table 2). Additionally, a total of 10 taxa (12 specimens) were recorded at genus, family or order level (see Table 2).

Table 2.

Inventory of arthropod species collected in the native forest fragment of “Terra-Brava”, in Terceira Island (Azores), between June 2014 and December 2015. The list includes individuals identified at species-level and also morphospecies. Class, order, family, scientific name, morphospecies code (MF), colonisation status (CS: END – endemic; NAT - native non-endemic; INT – introduced;) and abundance per forest depth (i.e. at the edge of the forest - Edge, in the most pristine area - Deep and in an intermediate area between both - Centre) are provided.

Class Order Family MF Scientific Name CS Edge Centre Deep Total
Arachnida Araneae Araneidae 134 Gibbaranea occidentalis Wunderlich, 1989 END 151 58 141 350
Arachnida Araneae Cheiracanthiidae 927 Cheiracanthium erraticum (Walckenaer, 1802) INT 1 0 2 3
Arachnida Araneae Clubionidae 516 Porrhoclubiona decora (Blackwall, 1859) NAT 0 2 0 2
Arachnida Araneae Dictynidae 117 Lathys dentichelis (Simon, 1883) NAT 96 72 92 260
Arachnida Araneae Dysderidae 28 Dysdera crocata C.L. Koch, 1838 INT 3 2 47 52
Arachnida Araneae Linyphiidae 2 Tenuiphantes miguelensis (Wunderlich, 1992) NAT 9 2 15 26
Arachnida Araneae Linyphiidae 4 Porrhomma borgesi Wunderlich, 2008 END 1 1 3 5
Arachnida Araneae Linyphiidae 21 Tenuiphantes tenuis (Blackwall, 1852) INT 28 2 12 42
Arachnida Araneae Linyphiidae 34 Erigone atra Blackwall, 1833 INT 0 0 1 1
Arachnida Araneae Linyphiidae 50 Canariphantes acoreensis (Wunderlich, 1992) END 6 0 3 9
Arachnida Araneae Linyphiidae 181 Savigniorrhipis acoreensis Wunderlich, 1992 END 213 211 598 1022
Arachnida Araneae Linyphiidae 233 Oedothorax fuscus (Blackwall, 1834) INT 2 0 0 2
Arachnida Araneae Linyphiidae 234 Erigone autumnalis Emerton, 1882 INT 1 0 0 1
Arachnida Araneae Linyphiidae 246 Erigone dentipalpis (Wider, 1834) INT 0 0 1 1
Arachnida Araneae Linyphiidae 312 Acorigone acoreensis (Wunderlich, 1992) END 29 70 56 155
Arachnida Araneae Linyphiidae 421 Walckenaeria grandis (Wunderlich, 1992) END 2 1 1 4
Arachnida Araneae Linyphiidae 442 Minicia floresensis Wunderlich, 1992 END 0 23 21 44
Arachnida Araneae Linyphiidae 697 Microlinyphia johnsoni (Blackwall, 1859) NAT 114 38 107 259
Arachnida Araneae Lycosidae 17 Pardosa acorensis Simon, 1883 END 1 0 0 1
Arachnida Araneae Mimetidae 140 Ero furcata (Villers, 1789) INT 47 76 84 207
Arachnida Araneae Pisauridae 39 Pisaura acoreensis Wunderlich, 1992 END 4 9 13 26
Arachnida Araneae Salticidae 198 Macaroeris cata (Blackwall, 1867) NAT 12 9 23 44
Arachnida Araneae Tetragnathidae 179 Sancus acoreensis (Wunderlich, 1992) END 80 24 64 168
Arachnida Araneae Theridiidae 5 Rugathodes acoreensis Wunderlich, 1992 END 114 519 464 1097
Arachnida Araneae Thomisidae 3 Xysticus cor Canestrini, 1873 NAT 0 4 1 5
Arachnida Opiliones Phalangiidae 6 Leiobunum blackwalli Meade, 1861 NAT 289 373 673 1335
Arachnida Pseudoscorpiones Chthoniidae 38 Chthonius ischnocheles (Hermann, 1804) INT 0 0 2 2
Arachnida Pseudoscorpiones Neobisiidae 296 Neobisium maroccanum Beier, 1930 INT 0 3 1 4
Chilopoda Lithobiomorpha Lithobiidae 27 Lithobius pilicornis pilicornis Newport, 1844 NAT 7 23 12 42
Diplopoda Chordeumatida Haplobainosomatidae 468 Haplobainosoma lusitanum Verhoeff, 1900 INT 10 14 0 24
Diplopoda Julida Julidae 9 Ommatoiulus moreletii (Lucas, 1860) INT 25 3 29 57
Insecta Archaeognatha Machilidae 144 Trigoniophthalmus borgesi Mendes, Gaju, Bach & Molero, 2000 END 209 375 462 1046
Insecta Blattodea Corydiidae 59 Zetha simonyi (Krauss, 1892) NAT 46 110 151 307
Insecta Coleoptera Carabidae 45 Anisodactylus binotatus (Fabricius, 1787) INT 1 0 0 1
Insecta Coleoptera Cerambycidae 147 Crotchiella brachyptera Israelson, 1985 END 3 1 1 5
Insecta Coleoptera Chrysomelidae 266 Chaetocnema hortensis (Fourcroy, 1785) INT 1 0 0 1
Insecta Coleoptera Chrysomelidae 395 Psylliodes marcida (Illiger, 1807) NAT 1 0 2 3
Insecta Coleoptera Chrysomelidae 679 Chrysomelidae ?? 0 1 1
Insecta Coleoptera Chrysomelidae 1246 Phylotreta INT 1 0 0 1
Insecta Coleoptera Ciidae 107 Atlantocis gillerforsi Israelson, 1985 END 10 0 2 12
Insecta Coleoptera Corylophidae 65 Sericoderus lateralis (Gyllenhal, 1827) INT 0 0 1 1
Insecta Coleoptera Cryptophagidae 145 Cryptophagus INT 0 0 2 2
Insecta Coleoptera Curculionidae 46 Drouetius borgesi borgesi (Machado, 2009) END 1 6 20 27
Insecta Coleoptera Curculionidae 102 Pseudophloeophagus tenax borgesi Stüben, 2022 NAT 21 20 65 106
Insecta Coleoptera Curculionidae 141 Calacalles subcarinatus (Israelson, 1984) END 16 10 47 73
Insecta Coleoptera Curculionidae 237 Xyleborinus alni Nijima, 1909 INT 2 0 0 2
Insecta Coleoptera Curculionidae 344 Sitona discoideus Gyllenhal, 1834 INT 0 2 1 3
Insecta Coleoptera Curculionidae 568 Phloeosinus gillerforsi Bright, 1987 END 0 1 0 1
Insecta Coleoptera Curculionidae 673 Mecinus pascuorum (Gyllenhal, 1813) INT 0 1 0 1
Insecta Coleoptera Dryopidae 286 Dryops algiricus (Lucas, 1846) NAT 0 1 0 1
Insecta Coleoptera Elateridae 244 Alestrus dolosus (Crotch, 1867) END 0 1 1 2
Insecta Coleoptera Hydrophilidae 40 Cercyon haemorrhoidalis (Fabricius, 1775) INT 6 2 2 10
Insecta Coleoptera Hydrophilidae 342 Cercyon INT 1 0 0 1
Insecta Coleoptera Laemophloeidae 98 Placonotus NAT 0 0 1 1
Insecta Coleoptera Laemophloeidae 110 Cryptolestes NAT 0 1 0 1
Insecta Coleoptera Laemophloeidae 705 Laemophloeidae INT 0 1 0 1
Insecta Coleoptera Latridiidae 710 Cartodere nodifer (Westwood, 1839) INT 2 0 1 3
Insecta Coleoptera Latridiidae 733 Cartodere bifasciata (Reitter, 1877) INT 0 0 1 1
Insecta Coleoptera Leiodidae 257 Catops coracinus Kellner, 1846 NAT 6 3 25 34
Insecta Coleoptera Monotomidae 708 Monotoma INT 0 0 2 2
Insecta Coleoptera Ptiliidae 72 Ptenidium pusillum (Gyllenhal, 1808) INT 1 0 0 1
Insecta Coleoptera Scraptiidae 78 Anaspis proteus Wollaston, 1854 NAT 21 32 20 73
Insecta Coleoptera Staphylinidae 16 Atheta fungi (Gravenhorst, 1806) INT 2 0 0 2
Insecta Coleoptera Staphylinidae 41 Ocypus aethiops (Waltl, 1835) NAT 1 2 12 15
Insecta Coleoptera Staphylinidae 52 Cordalia obscura (Gravenhorst, 1802) INT 1 0 0 1
Insecta Coleoptera Staphylinidae 57 Atheta aeneicollis (Sharp, 1869) INT 38 6 10 54
Insecta Coleoptera Staphylinidae 79 Quedius curtipennis Bernhauer, 1908 NAT 0 0 3 3
Insecta Coleoptera Staphylinidae 82 Proteinus atomarius Erichson, 1840 NAT 0 1 2 3
Insecta Coleoptera Staphylinidae 89 Tachyporus nitidulus (Fabricius, 1781) INT 2 2 7 11
Insecta Coleoptera Staphylinidae 142 Tachyporus chrysomelinus (Linnaeus, 1758) INT 1 1 2 4
Insecta Coleoptera Staphylinidae 247 Aleochara bipustulata (Linnaeus, 1760) INT 2 1 1 4
Insecta Coleoptera Staphylinidae 265 Xantholinus longiventris Heer, 1839 INT 1 2 1 4
Insecta Coleoptera Staphylinidae 439 Notothecta dryochares (Israelson, 1985) END 27 22 213 262
Insecta Coleoptera Staphylinidae 825 Atheta atramentaria (Gyllenhal, 1810) INT 23 0 3 26
Insecta Hemiptera Anthocoridae 521 Brachysteles parvicornis (A. Costa, 1847) NAT 0 0 1 1
Insecta Hemiptera Aphididae 60 Rhopalosiphoninus latysiphon (Davidson, 1912) INT 3 1 0 4
Insecta Hemiptera Cicadellidae 8 Aphrodes hamiltoni Quartau & Borges, 2003 END 0 0 1 1
Insecta Hemiptera Cicadellidae 465 Eupteryx azorica Ribaut, 1941 END 7 1 1 9
Insecta Hemiptera Cicadellidae 1019 Eupteryx filicum (Newman, 1853) NAT 1 1 0 2
Insecta Hemiptera Cicadellidae 1021 Cicadellidae 1 0 0 1
Insecta Hemiptera Cixiidae 7 Cixius azoterceirae Remane & Asche, 1979 END 469 663 1143 2275
Insecta Hemiptera Corixidae 1039 Corixa affinis Leach, 1817 NAT 0 0 1 1
Insecta Hemiptera Delphacidae 254 Megamelodes quadrimaculatus (Signoret, 1865) NAT 0 0 7 7
Insecta Hemiptera Delphacidae 321 Kelisia ribauti Wagner, 1938 NAT 0 1 0 1
Insecta Hemiptera Delphacidae 1252 Delphacidae INT 0 0 1 1
Insecta Hemiptera Flatidae 124 Cyphopterum adcendens (Herrich-Schäffer, 1835) NAT 187 135 365 687
Insecta Hemiptera Lachnidae 44 Cinara juniperi (De Geer, 1773) NAT 164 75 476 715
Insecta Hemiptera Lygaeidae 167 Kleidocerys ericae (Horváth, 1908) NAT 1 5 12 18
Insecta Hemiptera Miridae 137 Pinalitus oromii J. Ribes, 1992 END 81 186 296 563
Insecta Hemiptera Miridae 476 Monalocoris filicis (Linnaeus, 1758) NAT 18 0 2 20
Insecta Hemiptera Miridae 1137 Trigonotylus caelestialium (Kirkaldy, 1902) NAT 0 1 0 1
Insecta Hemiptera Nabidae 230 Nabis pseudoferus ibericus Remane, 1962 NAT 1 1 6 8
Insecta Hemiptera Psyllidae 557 Strophingia harteni Hodkinson, 1981 END 10 25 10 45
Insecta Hemiptera Psyllidae 662 Acizzia uncatoides (Ferris & Klyver, 1932) INT 5 1 2 8
Insecta Hemiptera Triozidae 195 Trioza laurisilvae Hodkinson, 1990 NAT 261 74 174 509
Insecta Neuroptera Hemerobiidae 200 Hemerobius azoricus Tjeder, 1948 END 33 33 85 151
Insecta Orthoptera Gryllidae 245 Eumodicogryllus bordigalensis (Latreille, 1804) INT 1 0 0 1
Insecta Psocodea Caeciliusidae 191 Valenzuela flavidus (Stephens, 1836) NAT 41 46 80 167
Insecta Psocodea Caeciliusidae 625 Valenzuela burmeisteri (Brauer, 1876) NAT 1 0 0 1
Insecta Psocodea Ectopsocidae 121 Ectopsocus briggsi McLachlan, 1899 INT 9 8 18 35
Insecta Psocodea Elipsocidae 184 Elipsocus azoricus Meinander, 1975 END 53 3 21 77
Insecta Psocodea Elipsocidae 370 Elipsocus brincki Badonnel, 1963 END 224 147 224 595
Insecta Psocodea Epipsocidae 374 Bertkauia lucifuga (Rambur, 1842) NAT 50 15 42 107
Insecta Psocodea Trichopsocidae 478 Trichopsocus clarus (Banks, 1908) NAT 28 8 16 52
Insecta Thysanoptera Phlaeothripidae 13 Hoplothrips corticis (De Geer, 1773) NAT 7 6 75 88
Insecta Thysanoptera Thripidae 280 Hercinothrips bicinctus (Bagnall, 1919) INT 0 0 1 1
Insecta Trichoptera Limnephilidae 432 Limnephilus atlanticus Nybom, 1948 END 1 0 0 1
Grand Total 3349 3579 6588 13516

Most species (S = 81) and specimens (n = 6588) were found in the traps located at greater distances from the edge (Table 2). Many species were also found in the edge areas (S = 77), including several exclusive (mostly introduced), but overall abundance was much lower in these areas.

The most abundant endemic species were the planthopper Cixius azoterceirae Remane & Asche, 1979 (n = 2275), the spider Rugathodes acoreensis Wunderlich, 1992 (n = 1097) and the Archaeognatha jumping bristletail Trigoniophthalmus borgesi Mendes, Gaju, Bach & Molero, 2000 (n = 1046) (Table 2). The most abundant native non-endemic species were the harvestmen Leiobunum blackwalli Meade, 1861 (n = 1335), the aphid Cinara juniperi (De Geer, 1773) (n = 715) and the flatid planthopper Cyphopterum adcendens (Herrich-Schäffer, 1835) (n = 687) (Table 2). The most abundant introduced species were the spider Ero furcata (Villers, 1789) (n = 207), the millipede Ommatoiulus moreletii (Lucas, 1860) (n = 57) and the rove-beetle Atheta aeneicollis (Sharp, 1869) (n = 54) (Table 2).

Spiders (Araneae) and bugs (Hemiptera) dominate overall and endemic species abundance while Opiliones and Hemiptera include the most abundant non-endemic taxa (Fig. 5). Araneae and Coleoptera had the highest number of introduced specimens (Fig. 5).

Figure 5.  

Proportional abundance of arthropods specimens (per order) sampled in the native forest fragment. Allsp = all arthropod species; END = endemic; NAT = native non-endemic; and INT = introduced.

Proportionally, the most species-rich taxa are the beetles (Coleoptera), but spiders (Araneae) and bugs (Hemiptera) follow closely (Fig. 6). The same pattern applies when considering just the endemic and native non-endemic species, but Coleoptera are proportionally the most dominant taxon in the introduced species group (Fig. 6).

Figure 6.  

Proportional species richness of arthropods (per order) sampled in the native forest fragment. Allsp = all arthropod species; END = endemic; NAT = native non-endemic; and INT = introduced.

There are striking differences in specimen abundance and species richness throughout the sampling period (Figs 7, 8). The overall abundance of arthropod specimens presents a peak during July-October (unimodal) and this same pattern was found for endemic, native non-endemic and introduced groups of taxa (Fig. 7). Endemic arthropods were particularly abundant during July and August.

Figure 7.  

Boxplots of overall monthly variations of abundance for: (A) all species and separately for (B) endemic species, (C) native non-endemic species and (D) introduced species.

Figure 8.  

Boxplots of overall monthly variations of species richness for: (A) all species and separately for (B) endemic species, (C) native non-endemic species and (D) introduced species.

The variation in overall species richness also peaked during the summer months. The species richness patterns of the three groups of species (endemic, native-non-endemic and introduced) show a similar seasonal variation with very few species being active during winter and early spring (Fig. 8).

With this data, we are opening the possibility to investigate deeply the impact of edge effects in the Azorean hyper-humid native forests, which will be more accurately investigated in a classical research publication elsewhere. The scientific community interested in the use of SLAM traps for monitoring island forests have here also raw data to compare with other island systems (see also Borges et al. (2018) for best practices in monitoring island forest arthropods).

Acknowledgements

Trap acquisition and fieldwork were funded by the project Portuguese National Funds, through FCT – Fundação para a Ciência e a Tecnologia, within the project UID/BIA/00329/2013-2023. The database management and Open Access was funded by the project “MACRISK-Trait-based prediction of extinction risk and invasiveness for Northern Macaronesian arthropods” Fundação para a Ciência e a Tecnologia (FCT) - PTDC/BIA-CBI/0625/2021 (2022-2024). MB was supported by FCT - DL57/2016/CP1375/CT0001. NT and MTF were supported by the project LIFE-BETTLES (LIFE18 NAT_PT_000864). PAVB and RG were additionally supported by FCT-UIDP/00329/2020-2024 (Thematic Line 1--Integrated ecological assessment of environmental change on biodiversity) and MACRISK -- PTDC/BIA-CBI/0625/2021, through the FCT - Fundação para a Ciência e a Tecnologia.

Author contributions

PAVB and RG contributed to study conceptualisation. PAVB, ARP and RN performed the fieldwork. PAVB, RN and ARP performed the species sorting and identification. PAVB, ARP and LLL contributed to dataset preparation. PAVB, LLL and NT performed data analysis. All authors contributed to manuscript writing.

References