Scientific name: Juniperus cedrus P. Webb & Berthelot 1847

Synonyms: Juniperus cedrus subsp. maderensis (Menezes) Rivas Mart., Capelo, J.C.Costa, Lousã, Fontinha, R.Jardim & M.Seq., Juniperus grandifolius Link, Juniperus maderensis (Menezes) R.P.Adams, Juniperus oxycedrus subsp. maderensis Menezes, Juniperus webbii Carrière

Common names: Canary Islands juniper (English), Cedro Canario (Spanish)

Description

Tree to 15(-30) m tall, with trunk to 50(-100) cm in diameter, usually much smaller today in nature. Bark pinkish to purplish brown, weathering grayish brown, thin, shallowly ridged and furrowed, peeling in narrow strips. Crown narrowly conical, with slender, graceful branches from near the base bearing numerous drooping branchlets. Branchlets short, about 1 mm thick, six-angled, with a waxy coating. Adult leaves needlelike, standing out from and jointed to the twig, in alternating trios, 4-12(-20) mm long, with two stomatal bands above, dark green with a waxy coating at first beneath, the tip pointed but not prickly. Pollen and seed cones on separate plants. Pollen cones spherical, 3.5-5 mm long, with three to five alternating trios of pollen scales. Seed cones spherical, 8-12 mm long, reddish brown, with a bluish waxy coating, maturing in 1 year. Seed one (or three), 5-10 mm long, light brown, the paler attachment scar extending halfway or more up the seed.

Canary Islands (La Palma and Tenerife, formerly also on Gomera and Gran Canaria) and Madeira. Subalpine woodlands and upper ends of valleys; (450-)2,000-3,000 m

Conservation Status

Red List Category & Criteria: Endangered

The total area of occupancy (AOO) is calculated to be 29 km². The AOO is based on presence within 1 km² grid cells overlaid on 1:40,000 scale maps. Presence and absence records are derived from recent, extensive surveys carried out between 2004 and 2009 (Elliot 2009, B. Rumeu unpublished data 2010, Sequeira pers. comm. 2010). The total population (n = ca 600) consists of five subpopulations/ locations found on five islands (Gran Canaria (n =12), Gomera (n = 100), La Palma (n = 250), Tenerife (n = 200) and Madeira (n = ca 40)). Each subpopulation/location is more than 60 km from the next and no single subpopulation contains more than 50% of the total population. These subpopulations are regarded as severely fragmented. The total population is estimated to be less than 600 mature trees and no subpopulation contains more than 250 mature individuals. Regeneration in some subpopulations is poor or absent, possibly due to reduced seed set (Rumeu et al. 2009), the decline of avian dispersers (Nogales 1999, Rumeu 2009) and the effects of grazing. In some locations fires have led to the loss of mature individuals. Together, these factors contribute to a continuing decline in the quality of habitat and number of mature individuals. On the basis of these data, Juniperus cedrus meets the criteria for Endangered.

The population is estimated to be c.600 sexually mature individuals. Canary Islands - 572 individuals: Gran Canaria 12; La Palma 250; Tenerife 200; La Gomera 100. Madeira - one population with c.40 individuals.

In the Canary Islands this species has become adapted to different habitats. In Tenerife and La Palma, Juniperus cedrus occurs at the timberline (2,200 m), which characteristically has low precipitation and great diurnal temperature variation. Here the dominant vegetation is of shrubs Spartocytisus supranubius and Adenocarpus viscosus. In contrast, on La Gomera, which is lower in altitude, (1,150 m.) the habitat is Laurel forest which has high levels of humidity as a result of the north-east trade winds. In Gran Canaria it only occurs on Montaña del Cedro, where it grows at altitudes between 800-900 m, here the temperatures are relatively warmer. At some of the locations (La Gomera and one location on Tenerife) there is evidence of regeneration but generally recruitment appears to be relatively poor. One factor that may be related to this, is the decline in ravens (Corvus corax) that are thought to have played a significant role in seed dispersal. Recent research has revealed that winter visiting Ring Ouzels (Turdus torquatus) also play a key role in seed dispersal. Additional research has indicated that the Canary Islands subpopulations produce seed with relatively lower viability, possibly due to lower pollination rates resulting from fragmentation of stands.

The subpopulation on Madeira occurs on exposed rock faces above the laurel forest tree-line above 1,400 m in altitude. Here it belongs to the Polysticho falcinelli-Ericetum arboreae (Capelo et al. 2004). The main components include: Erica maderinicola, Ilex perado, Laurus novocanariensis, Polystichum falcinellum, Vaccinium padifolium & Sorbus maderensis. In Madeira there have not been any studies to establish whether or not there is any regeneration, however since the removal of goats in recent years the vegetation recovery rates are very encouraging.

Canary Islands - There are a variety of threats, the most severe of which is fire. In 2007 a fire on Tenerife (El Teide National Park) destroyed 30 old-growth trees. Other threats, which are detrimental to recruitment, include goats and the release of Barbary sheep (La Palma) and Muflón (Tenerife) for hunting purposes. Global warming could affect the amount of seasonal rainfall and moisture from coastal fog. Madeira - Historically over-grazing, cutting and burning have been significant threats to the population. Although these threats are less today, the fast expansion of Cytisus scoparius following grazing is certainly a potential threat as it greatly increases the fire risks.

Canary Islands - Historically the wood was exploited for its valuable, aromatic timber, and used by local people in carpentry for a various items of furniture, construction and for making boxes because of the wood's capacity to deter insect pests. Today, due to its rarity and protected status, Juniperus cedrus is not utilized. In Madeira the wood was also widely used. Even in the 15th century there were already concerns on the overcutting of this species. Restrictions on harvesting this species were ineffective; according to Silva and Menezes (1946) there were still some small woods of Juniperus cedrus by the end of the 19th century, but the tree had almost vanished by the first decades of the 20th century. Today the wood is no longer used, unless it is taken from cultivated sources. The plant is extensively cultivated as an ornamental and used by the forestry service particularly along the Laurissilva Levadas (manmade irrigation channels and pathways).

Juniperus cedrus is a protected species in the Canary Islands and occurs in three National Parks; Parque Nacional del Teide, Tenerife; Parque Nacional de Garajonay, La Gomera; Parque Nacional de la Caldera de Taburiente, La Palma. The area affected by fire in Parque Nacional del Teide is being restored by using local provenance material (seed). In Gran Canaria, the subpopulation in Montaña del Cedro is included within the Reserva Natural Especial de Güigüi. This sub-population is considered as 'in danger of extinction' in the Regional Catalogue of Threatened Species. On Madeira it is protected within the Parque Natural da Madeira (Natura 2000) where all goats have been removed above 1,400 m under the authority of Direcção Regional de Florestas. This has had a positive effect on the general vegetation, but as Juniperus cedrus is a slow growing tree, any benefits are unlikely to be seen for several years.

References

Farjon, A. (2010). A Handbook of the World's Conifers. Koninklijke Brill, Leiden.
Eckenwalder, J.E. (2009) Conifers of the World: The Complete Reference. Timber Press, Portland.
IUCN Red List of Threatened Species, International Union for Conservation of Nature and Natural Resources. Cambridge, UK /Gland, Switzerland