- 1.5. Forest – Subtropical/tropical dry
The rapid formation of large areas of dry shrubland, especially of Mexican thorn has clearly already resulted in a loss of large areas of desert. It is possible that they will gradually encroach on these important bird breeding grounds, taking advantage of the undisturbed periods when the birds are at sea to establish. Were this to happen, it could constitute a serious threat to the viability of the colonies. Thorn scrub can be extremely dense in on the sandier soils around the foot of Green Mountain, with little understorey vegetation. Has the potential to provide habitat for alien invertebrate communities to develop and increases the fire risk across the lowlands. Socio-economic impacts: Thorn scrub can be extremely dense in on the sandier soils around the foot of Green Mountain, impeding human access. (Lambdon, P. & Darlow, A. (2008) Botanical Survey of Ascension Island and St. Helena 2008. RSPB);
The nutritious seed pods are much sought by donkeys and sheep, which probably help to spread the seed to remote corners of the island. Rats occasionally pith twigs of Mexican thorn in the lowlands and take their seed, have a potential role in seed dispersal. (Lambdon, P. & Darlow, A. (2008) Botanical Survey of Ascension Island and St. Helena 2008. RSPB);(Lambdon, P. & Darlow, A. (2008) Botanical Survey of Ascension Island and St. Helena 2008. RSPB);
Pagad S, Wong L J (2022). Global Register of Introduced and Invasive Species Ascension Island, Saint Helena, Ascension and Tristan da Cunha. Version 1.4. Invasive Species Specialist Group ISSG. Checklist dataset https://doi.org/10.15468/vijxee; Lambdon, P. & Darlow, A. (2008) Botanical Survey of Ascension Island and St. Helena 2008. RSPB;