The BioBlitz held in 2017 at the SBP was organised in two different phases: (1) biodiversity data collation from research reports and education activities up to 60 years prior to the BioBlitz event and (2) species survey and abiotic parameters during 24 h on 18-19 July 2017, called the “SBP BioBlitz” (https://stationbioblitz.sciencesconf.org).

In total, 77 experts from 14 institutions, mainly from the EcoBio lab of the University of Rennes, but also from NGOs and nature conservatories (Suppl. material 1) were involved in the BioBlitz. The gathering of 60 years’ biodiversity data involved 6 experts from the EcoBio lab of the University of Rennes and the NGOs “Encyclopédie de Brocéliande”, “Groupe Mammalogique de Bretagne” and “GRETIA”. First, an inventory of study reports, PhD theses and survey data sheets was implemented. Historical data were mainly produced by the University of Rennes (France), the University Paris-Sud (France) and the University Liège (Belgium). After extraction, the data were verified, geo-localised and gathered in a common file under an occurrence format. Additionally, landscape photographs older than 60 years were provided by the NGO “Encyclopédie de Brocéliande” which collected old photographs and postcards from personal archives of inhabitants, territorial archives and libraries. During the BioBlitz, 120 citizens helped the experts to implement inventories; either they accompanied experts or explored a zone on their own to collect samples or photograph specimens. The non-expert participants were also invited to sort samples, label collected material and start taxon identifications. They were briefly trained for each task. Species identifications of non-experts were systematically verified by experts. All participants could enter records in a data template file, either their proper records or the data provided by field sheets or by people identifying species in the lab. The 12 European volunteers were involved in logistical organisation, habitat delimitation and communication.

The mission of the SBP is to preserve the ecological integrity of the area, while providing opportunities for scientific research, student field work and public education. Located on sedimentary rock (shale and sandstone), the climate is temperate oceanic with local specificities due to the topography (hilly landscape with the highest peak at 258 m) and mixed land-cover. The SBP study area covers a diversity of habitats including ponds and creeks, swamps, cliffs, meadows, moors, shrub thickets and forest (Fig. 1, Suppl. material 2). Due to this diversity of habitats, SBP has been the site of a variety of innovative research studies, including the ecology of mammals, birds and insects; fire ecology; phytosociology of bogs, cliffs and forest; landscape ecology; and soil biology. Moreover, the zones “Etang d’en haut” and “Les Pinçais” (Z1 and Z5, respectively, Fig. 1) are zones of ecological, faunistic and floristic interest (ZNIEFF) belonging to the national inventory of natural heritage sites.

Figure 1.  

Study area of the Biological Field Station of Paimpont and habitat codes used during the BioBlitz 2017 for different sites.

The study area of the SBP is composed by a diverse set of land parcels of different historical use in agriculture and local activity, purchased by the University of Rennes. In former times, today’s prairies were arable land, moor was grazed or regularly thinned, hedges represented firewood resource (i.e. trees were pruned), the pond served as a mill and fishing, pastoralism and hunting were practised in woodland. Current management of the study area includes rotating horse grazing on meadows and moor, mechanical thinning of creek and pond banks as well as of hedges and extensive mowing of grassland around the SBP buildings. A trail system across the study area is maintained through mowing, mechanical thinning and installation of board walks. Public access is restricted spatially to the trail around the pond and the area around the buildings of SBP and to public outreach events, such as the Science Festival, Open House and citizen science events, such as the BioBlitz.

Prior to the BioBlitz, in July 2017, the habitat zones were characterised, delimited and mapped. During the BioBlitz 2017, terrestrial sampling was performed in 42 different sites, aquatic sampling was performed in 4 different sites and the habitat map was adjusted and corrected after the BioBlitz using current biotic and abiotic observations (Fig. 1, Suppl. material 2).

The BioBlitz, held in 2017 at the SBP, aimed to implement a species inventory including records from 60 years of SBP research and education activities, to collect abiotic data from terrestrial and aquatic habitats and to integrate observations of landscape changes in relation to human activities that occurred during the last 100 years. Collection efforts focused on taxa historically recorded in all habitats of the 17 ha study area at the SBP (Fig. 1, Suppl. material 2). One broom moor site (Z5 La2, Fig. 1) could not be included in the inventory because horses owned by the SBP were kept there. All samplings were performed between 2 pm and ­8 pm (July 18th), 10 pm and 9 am (July 18th-19th) and 10 am­ and 2pm (July 19th). The pollinator observation was extended to July 20th because of unfavourable weather conditions on July 19th. Collembola sampling took place two weeks before the BioBlitz, because the expert could not participate on the chosen BioBlitz dates. Other data, opportunistically collected by participating experts during the year 2017, were also integrated into the dataset. Records were mostly visual and non-invasive observations, because the SBP puts a high priority on biodiversity conservation and protection. However, some biodiversity components were collected to allow identification at the lowest possible taxonomic rank. Sorting of collected samples and species identification mainly occurred on July 20th and 21th. Some identifications of species were conducted by experts up to three months after the BioBlitz. As a taxonomic reference, TaxRef V10.0 (Gargominy et al. 2016) was used for animals and Flora Europaea for plants (http://eunis.eea.europa.eu/references/1780/species).

During this transdisciplinary BioBlitz, species presence was recorded in each habitat and some protocols also measured abundance or biomass. Abiotic parameters were measured in aquatic habitats, in the soil and in the air using the meteorological station on site. Socio-ecological observations included filming and photographing. The methods are described below:

Birds

Birds have been observed between 2 pm and 7 pm (18 July) and 7 am–12 pm + 1 pm-2 pm (19 July) using opportunistic prospecting on a total length of 6200 m in all habitat zones of the SBP study area (Fig. 1). They were visually and audially identified. Walking speed was 0.5 km.h^-1 and every 10 minutes, there was a stop of one minute for audio detection.

Mammals

Mammals inventory was carried out in all habitats of the SBP study area (Fig. 1). Species records are direct observations of animals or signs of recent presence (fresh dung, fresh track, fresh food scraps, deer smear, dens, other specific traces) which were collected along paths of least cost. In addition, five camera traps were installed in two sites, Z4_Bo, Z5_Fo and Z1_La (Suppl. material 3), two days before the BioBlitz to minimise disturbance by human smell.

Small mammal inventory was done by using live trapping (Perez et al. 2017). Thirteen trap lines were set in different habitats of the SBP including woodland, meadows, moors and wetlands (Suppl. material 3). Each trap line featured 34 INRA traps with baited dormitory boxes and were set on 18th of July and checked in the morning the next day. Trapping effort was equivalent to 442 trap nights.

Bats were trapped using mist nets in one site, Z2_Bo4 (Suppl. material 3) and recorded based on their echo-location signals captured with D-1000X Bat Detector (Pettersson Elektronik AB, Uppsala, Sweden).

Amphibians and Reptiles

Amphibians and reptiles have been observed using opportunistic prospecting in all habitat zones of the SBP study area (Fig. 1). This method includes searching under decaying logs and rocks, prospecting nesting sites and using nets in ponds.

Plants, lichen and mosses

Vascular plants, lichens and mosses were surveyed using opportunistic prospecting of all habitat zones of the SBP study area (Fig. 1). For identification of species, the Flore des Abbayes (DesAbbayes et al. 2012), Flora Gallica (Tison and Foucault 2014), Flore Forestière Française (Rameau et al. 1999) and Rothmaler (Jäger et al. 2017) were used.

Soil biota

Soil and litter dwelling invertebrates were sampled at 37 points (Suppl. material 3) evenly distributed over the SBP study area. At each point, three sampling methods were used on a 1 m² plot: (i) pitfall traps (Spence and Niemelä 2012), (ii) board traps (Boag 1982) and (iii) soil extraction (0-10 cm deep, 5 cm diameter), followed by the Tullgren funnel method (Berlese 1905) over a 7-day period. Additionally, a 10 min visual search was performed 10 m around the plot. Barber traps were made of plastic pots (10 cm deep, 12 cm diameter), filled with salted water (30% v/v) and detergent (3% v/v) and buried to the rim into the soil, five days before the BioBlitz. In sites where natural wood traps, such as decaying logs, were available, they were included in the survey. Otherwise, board traps were made of poplar wood (30-40 x 50-60 x 2-3 cm) and placed flat on the ground, five days before the BioBlitz beside the pitfall traps. Individuals, that could not be identified in the field, were stored in 95% ethanol for later identification using binocular loupes. Collembolans were identified to species rank (Gisin 1960, Hopkins 1997).

Bacteria were quantified using qPCR (Heid et al. 1996). Bioluminescent organisms were randomly searched for at night in the forested areas around the pond “Etang du Châtenay” (Z2_Ea, Fig. 1).

Insects (above-ground)

Invertebrates in trees and shrubs were surveyed using a beating sheet with vegetation shuffling and a sweep net in each habitat type (Fig. 1). Pollination insects were photographed individually during 20 min on individual flowering plants following the SPIPOLL protocol (Suivi Photographique des insects pollinisateurs - photographic survey of pollinators, www.spipoll.fr). The plant was identified and recorded as host for each pollinator.

For nocturnal insects, night sheets were installed on the dyke of the pond “Etang du Châtenay” (Z2-Za1, Fig. 1) and in the prairie (Z2-Pa1, Fig. 1) and sampling was implemented between 11 pm and 3 am (18-19 July). Additionally, a light trap was installed in the prairie near the weather station (Z3-Pa2, Fig. 1) between 10 pm and 5 pm (18-19 July).

Aquatic organisms

Aquatic meso-invertebrates were qualitatively sampled in the different freshwater habitats in four sampling sites (two in the stream upstream and downstream of the pond Etang du Châtenay and in the two ponds) using the kick-sampling method with a 0.25 mm mesh hand net. The net contents were placed into a shallow white tray with enough water to allow invertebrates to swim or crawl. Alive invertebrates were sorted directly in the field and preserved in 96° alcohol until their identification under a stereomicroscope SZX16 (Olympus).

For plankton analysis, water samples were taken in sub-surface (-10 to -20 cm) in the centre of the two water bodies (pond “Etang du Châtenay” Z2-Ea, pond “Etang d’en Haut” Z1-Ea, Fig. 1). In order to estimate the total phytoplankton biomass, the concentration of chlorophyll "a" was measured in situ, using a probe Ocean Seven 316+ probe (Idronaut, Brugherio, Italy), equipped with a Trilux multiparameter algae sensor (Chelsea, Surrey, United Kingdom). Then in the laboratory, the chlorophyll "a" measurement was used, according to the method of Lorenzen (2003). To determine the composition of the plankton community, 250 ml of water was fixed with lugol iodine acid solution (Throndsen and Sournia 1978) and stored at 4°C, until counting with an optical microscope after filtering with a bolting cloth of 60 µm mesh. A fresh sample was also observed within 24 hours of collection to identify the species present.

Fish were caught with a baited crawfish trap and released after identification.

Landscape photography

Out of a collection of historical photographs ranging from around 1900 to 2016, databased by the NGO “Encyclopédie de Brocéliande”, 32 viewpoints were chosen to reconduct. The diachronic observations were described and grouped into different categories that could best describe landscape changes within the study area of the SBP over time. The viewpoints of the four most representative photographs were mapped on two aerial photographs, one from 1950, prior to the construction of the SBP and one as of 2013 (Fig. 2).

Figure 2.  

Aerial photos of 1950 (left) and 2013 (right) with the study area of the Biological Field Station of Paimpont and localisation of landscape photographs (A: N48°00'22", W2°13'48"; B: N48°00'13", W2°13'47"23; C: N48°00'9", W2°13'46"20; D: N48°00'11", W2°13'48") with arrows for viewing direction.

Ecosemiotic interviews

Filmed interviews were implemented with BioBlitz participants to explore how humans perceive and translate or are affected by the exchange of signs with and amongst non-human organisms within the biosphere. In the search for a “systemic wisdom” (Bateson 1972), the film material presents human-non-human relationships beyond categorisations reified by our symbolic language.

Physico-chemical parameters

Historical data of abiotic parameters are available in various documents, but are not accessed yet. The weather station at the SBP recorded several parameters going back to 1958. These data can be communicated upon request. During the BioBlitz, soil, water and climatic parameters have been recorded using the following methods:

Soil parameters

Top soil sampling was performed on three different sites within the study area of the SBP: a gorse moor (Z2-La2), an oak forest (Z2-Bo5) and a meadow (Z2-Pa1, Fig. 1). One sample per site was sent to LABOCEA Comburg for standardised analyses (NF ISO or NFX norms) of total nitrogen and C/N (NF ISO 13878), granulometry (NFX 31107), organic matter (NF ISO 10694/14235), residual humidity (NF ISO 11465), cation exchange capacity (NF ISO 23470) and pH. In situ CO₂ and volatile organic compounds (VOCs) emissions from soil in these three sites were measured four times during the BioBlitz (on the 18th afternoon, twice during the night from the 18th to the 19th and once on the 19th July morning) using dynamic gas sampling in canisters and later analysis on a micro gas chromatography (µGC) and proton transfer reaction mass spectrometer (PTR-MS), respectively (Potard et al. 2017).

Water parameters

Aquatic parameters have been measured at four sites, one site per pond and one site per creek downstream of each pond (Z1-Ea, Z2-Ea, Fig. 1) and at the dyke of pond “Etang du Châtenay” (Z2-Ea, Fig. 1), using the Ocean Seven 316+ probe (Idronaut, Brugherio, Italy), equipped with a subaquatic LI-190R Quantum sensor (LI-COR, Lincoln, USA) and a Trilux multiparameter algae sensor (Chelsea, Surrey, United Kingdom). In each pond, two profiles in three sites were obtained (6 profiles in total), except at the dyke and in the creeks where only stationary measurement was possible. Additionally, multiparametric water quality probes 6600-V2 and 6920 (YSI, Yellow Springs, USA) were used in the creeks.

In order to measure the concentrations of nutrients, a water sample was taken in the sub-surface (-10 to -20 cm) at the centre of the ponds. A volume of water was then filtered through Whatman GF/F filter (0.7 μm) for dissolved nutrients (nitrate and phosphate) and all samples were stored at -20°C. Measurements of nutrient concentrations were performed by colourimetric methods (Henriksen and Selmer-Olsen, 1970, Murphy and Riley, 1962) using a Bran and Luebbe Autoanalyzer 3 (Axflow, Norderstedt, Germany). Nitrate was measured after reduction to nitrite on a cadmium-copper column (Henriksen and Selmer-Olsen 1970). Phosphate was measured following the method of Murphy and Riley (1962). Total phosphorus (TP) and total nitrogen (TN) concentrations were analysed after a hot alkaline persulphate digestion (Aminot and Chaussepied 1983). Total dissolved organic carbon (DOC) was measured by chemical mineralisation using a carbon analyser (OI – Analytical).

Climatic parameters

Climatic parameters were obtained from the weather station of the SBP, located in Z3-Pa2 (Fig. 1). Automated measurements were performed every 2 seconds.

The Biological Field Station of Paimpont (Station Biologique de Paimpont, SBP, https://station-biologique-paimpont.univ-rennes1.fr) in the Brocéliande Forest in continental Brittany, North-West France (48.00 N, -2.22 W) is surrounded by a study area of 17 ha owned by the University Rennes.

47.993 and 48.011 Latitude; -2.2359 and -2.2019 Longitude.

During 60 years prior to the Bioblitz, 1176 species (Table 1) with 4270 occurrences were recorded (Fig. 3A). During the Bioblitz, 660 species, 5 kingdoms (following Ruggiero et al. 2015), 8 phyla, 21 classes, 90 orders and 247 families were covered, of which many species were already observed during the last 60 years; most occurrences were from the 1950s (Fig. 3A). However, 343 species were added to the historical list of species during the BioBlitz (Table 1), for instance, twelve new Coccinelidae insects were added. In total, there are 6089 occurrences including records identified to higher taxon ranks from 6 kingdoms and 12 phyla (Fig. 3 A, B). The most diverse groups were plants as well as arthropods, followed by vertebrates in the phylum Animalia (Fig. 3A, B). For arthropods, mainly insects were observed historically, while during the BioBlitz, eight other orders were additionally observed, mostly arachnids (Fig. 3C). In the vertebrate class, birds were the most often recorded historically, while amphibians and mammals received attention in the last decade prior to the BioBlitz and during the BioBlitz (Fig. 3D). The addition of 52 plant species, recorded during the BioBlitz (Table 1) to the botanical inventory at the SBP and the cartographical landscape observations (Fig. 1), led to an improved cartography of habitats (Fig. 1).

Figure 3.  

Number of occurrences per Kingdom (taxon rank) (A), per animal Phylum (B), per arthropod Class (C) and per vertebrate Class (D), within 10 years intervals since 1956, as well as within 2017 including the BioBlitz on July 18-20 at the Biological Field Station Paimpont, France. Note that the first interval is 11 years.

In total, our dataset includes 17 rare species ranging from near threatened to critically endangered on French, European or IUCN red lists (Table 1). Plants and arthropods comprise most red-listed species (Table 1). One arthropod species, found during the BioBlitz, was first recorded in Brittany in 2016 (coleoptera Lebia marginata Geoffroy in Fourcroy 1785). The moor plant Euphorbia esula Linneaus 1753 is rare in Brittany and was only recorded in two central Brittany sites, one of them at the SBP and seven coastal sites. Besides two endemic species (gastropod Elona quimperiana Blainville, 1821 and amphibian Triturus marmoratus Latreille, 1800), we also recorded 20 introduced species. During the BioBlitz, we also focused on kingdoms of microscopic species, such as Bacteria, Chromista and Protozoa (39 occurrences during the BioBlitz).