-30.85

-24.478

41.344

36.457

2012-06-01

2016-09-26

Order

Anareae

Spiders

0000-0002-8448-7623

CONTENT_PROVIDER

Terceira Island (area: 400.6 km²; elevation: 1,021.14 m) is one of the nine islands from the Azores archipelago, located in the North Atlantic, roughly at 38°43′49″N 27°19′10″W. The climate in the Azores is temperate oceanic, with regular and abundant rainfall, with high levels of relative humidity and persistent winds, mainly during the winter and autumn seasons. Terceira Island is known for the presence of some very important pristine areas at high elevation (Gaspar et al. 2011). However, few natural areas still remain at lower elevations, notably in Praia da Vitória’s council.

At all plots we applied the optimised and standardised COBRA

(Conservation Oriented Biodiversity Rapid Assessment) sampling protocol for temperate

forests (Cardoso 2009). Different variants of the COBRA protocol for spiders have already

been applied in oceanic islands (Emerson et al. 2017) and tropical forests (Malumbres-

Olarte et al. 2016, Malumbres-Olarte et al. 2017). Although originally developed and

optimised for mainland habitats, COBRA has been recently proposed to be the standard

protocol for inventorying and monitoring island forest ecosystems (Borges et al. 2018b).

The COBRA protocol for temperate forest spiders consists of: 4 night aerial samples (1

hour/ sample), 2 day sweeping samples and 2 night sweeping samples (1 hour/ sample), 2

day beating samples and 2 night beating samples (1 hour/ sample) and 12 pitfall samples

(4 traps/ sample). For the island sampling additional samples were added to also cover

beetle diversity (Borges et al. 2018b): 2 diurnal active aerial searching under bark, lichens

and bryophytes (ABS) (1 hour/ sample) and 2 diurnal active aerial searching in decaying

trunks, dead wood on the ground, and under stones (GWS) (1 hour/ sample). The ABS

method consists in collecting mostly beetles, but also spiders, found under bark and lichen

using a small hoe to remove them when needed. The GWS method is similar to the aerial

method but directed towards beetles and spiders found below knee-level, including

species hidden below stones, inside hollow trunks or in dead wood.

The data has been published as a Darwin Core Archive (DwC-A), which is a standardised format for sharing biodiversity data as a set of one or more data tables. The core data table (events) contains 121 records and one data table extension also exists (occurrence), with 1639 records. The extension supplies extra information about the core record.

On each of the Azorean islands of Pico and Terceira, we established

respectively six and ten 50 m x 50 m plots along a 20 km long transect. In Pico, each plot

is located at increasing distances from the first plot: 0.1, 1, 5, 10 and 20 km. All plots were located in native forest dominated by Juniperus brevifolia, Laurus azorica

and Ilex perado subsp. azorica trees (see Borges et al. 2018C for more details).

At all plots we applied the optimised and standardised COBRA

(Conservation Oriented Biodiversity Rapid Assessment) sampling protocol for temperate

forests (Cardoso 2009). Different variants of the COBRA protocol for spiders have already

been applied in oceanic islands (Emerson et al. 2017) and tropical forests (Malumbres-

Olarte et al. 2016, Malumbres-Olarte et al. 2017). Although originally developed and

optimised for mainland habitats, COBRA has been recently proposed to be the standard

protocol for inventorying and monitoring island forest ecosystems (Borges et al. 2018b).

The COBRA protocol for temperate forest spiders consists of: 4 night aerial samples (1

hour/ sample), 2 day sweeping samples and 2 night sweeping samples (1 hour/ sample), 2

day beating samples and 2 night beating samples (1 hour/ sample) and 12 pitfall samples

(4 traps/ sample). For the island sampling additional samples were added to also cover

beetle diversity (Borges et al. 2018b): 2 diurnal active aerial searching under bark, lichens

and bryophytes (ABS) (1 hour/ sample) and 2 diurnal active aerial searching in decaying

trunks, dead wood on the ground, and under stones (GWS) (1 hour/ sample). The ABS

method consists in collecting mostly beetles, but also spiders, found under bark and lichen

using a small hoe to remove them when needed. The GWS method is similar to the aerial

method but directed towards beetles and spiders found below knee-level, including

species hidden below stones, inside hollow trunks or in dead wood.