Included here are the Azores a group of nine volcanic islands situated in the North Atlantic. The three largest islands, São Miguel, Terceira and Pico represent about 69% of the total area of the archipelago.

Azorean Upland Calluna Heath

In the zones above 1500m Calluna vulgaris becomes the dominant heathland species although patches of the endemic Doboecia azorica (Ericaceae) may also occur, while the summit rocks include arctic-alpine bryophytes, particularly Gymnomitrium adustum and Racomitrium lanuginosum.

Azorean Erica woodland

Above about 600m the laurel forest peters out and is replaced by woodland mainly composed of the endemic Erica azorica (Ericaceae) which can grows to a height of about 6m. The endemic Juniper brevifolia (Cupressaceae) is also common in this zone. The shrub layer typically includes Hedera canariensis and Myrsine africana, while endemics such as Bellis azorica (Asteraceae) and Lysimachis azorica (Myrsinaceae) can be found in the field layer. In places, these woodlands have been converted to grazing pasture but surprisingly these areas can still support up to 14 endemics including Carex azorica (Cyperaceae) and Doboecia azorica (Ericaceae).

Azorean Acidic Shrublands

Shrublands are scattered throughout the islands and may be dense or open or in some cases have emergent trees. The shrubs can be low growing like Calluna vulgaris, Thymus caespititius and the endemic Daboecia azorica (Ericaceae) or semi-arborescent such as Myrica faya, Laurus azorica and Juniperus brevifolia. Several types have been described. Erica mixed shrubland occurs on acid gravel slopes and is dominated by the endemic Erica azorica (Ericaceae) together with the endemic Juniperus brevifolia (Cupressaceae). These are open communities interspersed with scattered grasslands with species such as the endemic Holcus rigidus and Festuca petraeae (Poaceae), together with Huperzia selago, Lycopodium cernuum and the endemic Tolpis azorica (Asteraceae). Euphorbia shrublands dominated by the endemic Euphorbia stygiana (Euphorbiaceae) are usually small, scattered communities often associated with some form of disturbance. They are mostly seen on mountain slopes or deposits associated with slopes. Lajido shrublands are associated with so-called lajido formations – a term used on Pico Island to describe flat basaltic compact lavas where root penetration is almost impossible. The species that manage to colonise these areas are mainly found in fissures and typically include Calluna vulgaris, Laurus azorica, Myrsine africana, Thymus caespititius and the endemic Erica azorica and Daboecia azorica (Ericaceae). Volcanic sand shrubland is also distinctive but mainly confined to just three locations – Graciosa (Pico Timão), Cabeco do Fogo (Faial) and the ‘sand mountain’ (Pico). Typical species include Thymus caespititius, the endemic Corema album subsp. azoricum (Empetraceae) and Daboecia azorica (Ericaceae), together with herbaceous taxa like Centaurium scilloides, the endemic orchid Plantanthera micrantha (Orchidaceae), and the moss Racomitrium lanuginosu.

References

Dias, E., Elias, Rui, B. & Nunes, V. 2004. Vegetation mapping and nature conservation: a case study in Terceira Island (Azores). Biodiversity and Conservation, 13: 1519-1539.

Dias, E., Mendes, C., Melio, C., Pereira, D. & Elias, R. 2005. Azores central Islands vegetation and flora guide. Quercetea, 7: 123-173.

Gabriel, R. & Bates, J. W. 2005. Bryophyte community composition and habitat specificity in the natural forests of Terceira, Azores. Plant Ecology, 177: 125-144.

Godman, F. D. C. 2005. Natural History of the Azores or Western Islands. An ubabridged facsimile of the edition published in 1870 by John van Voorst, London. Elibron Classics series.

Haggar, J. P., Westgarth-Smith, A. R. & Penman, D. 1989. Threatened flora and forest in the Azores. Oryx, 23: 155-160.

Humphries, C. J. 1979. Endemism and Evolution in Macaronesia. In: Plants and Islands. Ed. D, Bramwell. Academic Press.

Schäfer, H. 2005. Flora of the Azores. A Field Guide. Margraf Publishers.

Sunding, P. 1979. Origins of the Macaronesian Flora. In: Plants and Islands. Ed. D, Bramwell. Academic Press.

Tutin, T. G. 1953. The vegetation of the Azores. Journal of Ecology, 41: 53-61.

Tutin, T. G. & Warburg, E. F. 1932. Contributions from the University Herbarium Cambridge - notes on the flora of the Azores. The Journal of Botany, 70: 38-46.