Database Report

Socotra Vegetation Database

Fabio Attorre & Michele De Sanctis

GIVD Database ID: AS-YE-001	Last update: 2019-12-11
Socotra Vegetation Database	Web address:
Database manager(s): Fabio Attorre (fabio.attorre@uniroma1.it); Michele De Sanctis (michele.desanctis@uniroma1.it)
Owner: Michele De Sanctis
Scope: In the framework of the Socotra Conservation and Development Programme funded by GEF-UNDP, the DGCS (Italian Development Cooperation) and the Government of Yemen the study of the vegetation of Socotra Island has been carried out. The Socotra vegetation database contains 396 relevés (including 500 species). Phytosociological investigation was performed according to the Zurich-Montpellier methods. The location of the relevé was selected in relation to the homogeneity of physical features, vegetation structure and species dominance. According to these criteria forest, woodland, shrubland, grassland and halophytic communities along the whole altitudinal gradient and all the different geological substrata of the Island were sampled. Plot sizes ranged from 200m2 to 4m2 depending on the plant community. Cover/abundance data for all vascular plants were recorded in the field using the Braun-Blanquet scale. The database was created in TURBOVEG. A classification analysis was performed to identify the main vegetation communities of the Islands and the results are included in the database.
Abstract: The Socotra archipelago is located 380 km south of the Arabian Peninsula (Yemen), and 230 km east of Horn of Africa (Somalia), in the Indian Ocean. It is of continental origin its long (15-30 Myr ago) geographical isolation is responsible for the high level of endemism: Socotra archipelago hosts 837 species of vascular plants, of which 308 (37%) are endemic. Socotra is characterized by an undulating plateau, with altitude ranging from 300 to 900 m a.s.l. This plateau is composed of thin strata of limestone overlying igneous and metamorphic basement, which is exposed in three areas. The most scenic of these are the peaks of the Haghier Mountains, which rise up to 1500 m, the summit of the island. On the coastal plains and in the inner depressions, Quaternary and recent deposits of marine, fluvial and continental origin overlie the older substrata. The island lies on the margin of the sub-equatorial and northern tropical climate belts. The local climate is influenced by the seasonally reversing monsoon: the NE (winter) monsoon, and the SW (Indian or summer) monsoon. In the framework of the Socotra Conservation and Development Programme funded by GEF-UNDP, the DGCS (Italian Development Cooperation) and the Government of Yemen the study of the vegetation of Socotra Island has been carried out. The Socotra vegetation database contains 396 relevés (including 500 species). Ten percent of the relevés comes from the scientific literature; the remaining 90% have been collected by the authors during several field campaigns carried out between 2007 and 2010. Phytosociological investigation was performed according to the Zurich-Montpellier methods. The location of the relevé was selected in relation to the homogeneity of physical features, vegetation structure and species dominance. According to these criteria forest, woodland, shrubland, grassland and halophytic communities were sampled. Plot sizes ranged from 200m2 to 4m2 depending on the plant community. Cover/abundance data for all vascular plants were recorded in the field using the Braun-Blanquet scale. The database was created in TURBOVEG. A classification analysis was performed to identify the main vegetation communities of the Islands and the results are included in the database.
Availability: according to a specific agreement	Online upload: no	Online search: no
Database format(s): TURBOVEG	Export format(s): TURBOVEG, MS Access, Excel
Plot type(s): normal plots	Plot-size range (m²): 2 to 200
Non-overlapping plots: 396	Estimate of existing plots: 396	Completeness: 100%	Status: finished
Total no. of plot observations: 396	Number of sources (biblioreferences, data collectors): 1	Valid taxa: 753
Countries (%): YE: 100
Formations: Forest: 21% = Terrestrial: 21% // Non Forest: 79% = Terrestrial: 79% (Non arctic-alpin: 79% [Natural: 11%; Semi-natural: 67%])
Guilds: all vascular plants: 100%
Plot size categories (%): < 1 m2: 0%; 1-10 m2: 5%; 10-100 m2: 17%; 100-1000 m2: 70%; 1000-10000 m2: 0%; >= 10000 m2: 0%; unknowmn: 8%;
Environmental data (%): altitude: 80; slope aspect: 52; slope inclination: 52; surface cover other than plants (open soil, litter, bare rock etc.): 65
Performance measure(s): cover: 100%
Geographic localisation: GPS coordinates (precision 25 m or less): 75%; point coordinates less precise than GPS, up to 1 km: 25%
Sampling periods: 2000-2009: 85%; 2010-2019: 10%
Information as of 2026-06-04; further details and future updates available from http://www.givd.info/ID/AS-YE-001

Fabio Attorre* (fabio.attorre@uniroma1.it)
Environment Biology, Sapienza University of Rome, P.le Aldo Moro, 5, 00185 Rome, ITALY
Michele De Sanctis (michele.desanctis@uniroma1.it)
Environment Biology, Sapienza University of Rome, Via Cesare Fracassini 10, 00196 Roma, ITALY
* corresponding author