Tag: Azores

Biodiversity project in Azores delivers detailed abundance data for 286 arthropod species

In 1999, a long-term biodiversity project started at the Azores Islands (Portugal, Atlantic Ocean), the Biodiversity of Arthropods from the Laurisilva of the Azores (BALA) project (1999-2004). Its aim was to obtain detailed distributional and abundance data for a large fraction of arthropod fauna, living in all remaining native forests at seven of the Azores Islands.

After the first successful sampling of 100 sites at 18 native forest fragments over those five years, a second survey was accomplished in 2010-2011, where two sites per fragment were re-sampled. Now, Dr Paulo A.V. Borges and colleagues publish the complete list of the 286 species identified, including many species described as new to science in the open access journal Biodiversity Data Journal. They have also added detailed information on their distribution and abundance.

The resulting database has inspired the publication of many studies in the last ten years, including macroecological studies evaluating the abundance, spatial variance and occupancy of arthropods, the effects of disturbance and biotic integrity of the native forests on arthropod assemblages and the performance of species richness estimators.

image-2Moreover, these data allowed the ranking of conservation priorities for the fauna of the Azores, and allowed the estimation of extinction debt (the species likely to be wiped out because of past events) in the Azores. The present study has also inspired the development of the Azorean Biodiversity Portal and the Azores Island Lab.

The study stresses the need to expand the approaches applied in these projects to other habitats in the Azores, and, more importantly, to other less thoroughly surveyed taxonomic groups (e.g. Diptera and Hymenoptera).

“These steps are fundamental for getting a more accurate assessment of the biodiversity in the Azores archipelago, and we hope that can inspire similar biodiversity surveys at other islands,” say the authors.

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Original source:

Borges P, Gaspar C, Crespo L, Rigal F, Cardoso P, Pereira F, Rego C, Amorim I, Melo C, Aguiar C, André G, Mendonça E, Ribeiro S, Hortal J, Santos A, Barcelos L, Enghoff H, Mahnert V, Pita M, Ribes J, Baz A, Sousa A, Vieira V, Wunderlich J, Parmakelis A, Whittaker R, Quartau J, Serrano A, Triantis K (2016) New records and detailed distribution and abundance of selected arthropod species collected between 1999 and 2011 in Azorean native forests. Biodiversity Data Journal 4: e10948. https://doi.org/10.3897/BDJ.4.e10948

Species conservation profile of a critically endangered endemic for the Azores spider

Subject to continuing population decline due to a number of factors, an exclusively cave-dwelling (troglobitic) spider endemic to the Azores is considered as Critically Endangered according to the IUCN Red List criteria.

To provide a fast output, potentially benefiting the arachnid’s survival, scientists from the IUCN – Spider and Scorpion Specialist Group and the Azorean Biodiversity Group (cE3c) at University of Azores, where the main objective is to perform research that addresses societal challenges in ecology, evolution and the environment, also known as the three E’s from the centre’s name abbreviation, teamed up with colleagues from University of Barcelona, Spain, and the Finnish Museum of Natural History.

Together, they make use of a specialised novel publication type feature, called Species Conservation Profile, created by the open access journal Biodiversity Data Journal, to provide scholarly credit and citation for the IUCN Red List species page, as well as pinpoint the population trends and the reasons behind them.

The studied spider species (scientifically called Turinyphia cavernicola) is a pale creature with long legs, large eyes and a total size of merely 2 mm in length. These spiders never leave their underground habitats, which are strictly humid lava tubes and volcanic pits. There they build sheet webs in small holes and crevices on the walls of the caves.

The volcanic pit Algar do Carvão (Terceira, Azores), the main location of the species Turyniphia cavernicola.Not only is the species restricted to a single island within the Azorean archipelago (Portugal), but it is only found in three caves. Furthermore, out of the three, only one of them is home to a sustainable large population. These caves are under severe threat due to pasture intensification, road construction and tourist activities.

Although there is not much information about the species distribution through the years, with the spider having been discovered as recently as in 2008, the authors make the assumption that originally there have been significantly greater populations. Not only have they studied thoroughly another fifteen caves located on the island without finding any individuals, but they have identified increasing anthropogenic impact on the habitat.

“The species original distribution was potentially very large compared with the current,” the scientists explain. “Relatively intensive searches in and around the current caves where the species occurs have failed to find additional subpopulations.”

“The trend of decline is based on the assumption that this species can occur in all these caves and that the absence is due to anthropogenic disturbance on caves during the last 50 years,” they note.

 

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Original source:

Borges P, Crespo L, Cardoso P (2016) Species conservation profile of the cave spiderTurinyphia cavernicola (Araneae, Linyphiidae) from Terceira Island, Azores, Portugal.Biodiversity Data Journal 4: e10274. doi: 10.3897/BDJ.4.e10274