Juniperus canariensis (sabino canario) description

(as J. turbinata)

Juniperus canariensis

Guyot & Mathou (1942)

Common names

Sabino canario [Spanish], Canary juniper. These names are easily confused with the other native juniper of the Canaries, cedro canario/Canary Island juniper, Juniperus cedrus.

Taxonomic notes

Synonyms, Juniperus turbinata subsp. canariensis (Guyot & Mathou) Rivas Mart., Wildpret & P.Pérez (1993), J. phoenicea subsp. canariensis (Guyot & Mathou) D.Pav., Véla & Médail (2021).

Historically this was regarded as a variety or subspecies of Juniperus phoenicea or Juniperus turbinata, but over time many different lines of evidence have revealed strong and consistent division between the three taxa, with chemical, molecular, morphological, phenological and ecological differences warranting recognition at species rank; that this has not happened much earlier, is largely because the least conspicuous differences are morphological (Adams et al. 1996, 2002, 2009, 2013; Arista et al. 1997; Adams 2006; Boratyński et al. 2009; Mazur et al. 2016; Boratyński et al. 2024). These three species are sisters in a highly distinctive clade within Section Sabina, not particularly closely related to any other junipers. Mao et al. (2010) estimate the phoenicia-turbinata clade to be more than 30 million years old, while Mazur et al. (2016) estimate that the J. phoenicia and J. turbinata diverged within the last two million years. At some point in that time period, a population of J. phoenicia or J. turbinata must have become established in the Canary Islands, with subsequent differentiation to produce J. canariensis.

These three species, commonly called the J. phoenicea complex, are a good example of something we've seen a lot of since molecular taxonomy became popular: species that seldom or never hybridize, but that have almost identical morphology. There are minor morphology differences if you know what to look for, but they are subtle, certainly not of the prominence that is commonly used to draw a line between different species. However, they occupy distinct ecological niches, and they have a means of reproductive isolation: flowering at different times of the year.

Description

See Juniperus phoenicea for a description that applies to all three species in the J. phoenicea complex. The following description emphasizes characters that differ between J. canariensis, J. phoenicea, and J. turbinata:

Trees 4-7 m tall and 25-28 cm dbh at maturity (rarely it is a dense shrub); typically single-stemmed, the stem with a very irregular cross-section. Twigs 1 mm diameter, round, scaly, dark brown, often elongated and flexible, with a truncate apex. Leaves both whip and scale-like. Scale leaves on adult plants 0.7-1 mm long, ovate-rhombic, closely appressed, acute to acuminate with hard and prickly tips, with an oblong furrowed gland and a scarious border. Seed cones 8–12 × 7–11 mm, diameter less than or equal to length, ripening in the 2nd year, turbinate, changing from blackish to green or yellowish, sometimes slightly pruinose; dark red at maturity. Seeds 3-4 per cone, 5-7.5 mm long. 2n=22. Pollen shed October-November (Farjon 2005, Adams 2014, Boratyński et al. 2024). J. phoenicea cones average 8 seeds, while J. turbinata averages 5-6 seeds (Mazur et al. 2003). In habitat, even in sympatric populations, J. canariensis is usually on basalt substrates, J. turbinata on silicic coastal substrates such as sand, and J. phoenicia on carbonate substrates, particularly dolomite (Boratyński et al. 2024).

Distribution and Ecology

Portugal (Madeira and Porto Santa) and Spain (Canary Islands: El Hierro, Gran Canaria, La Gomera, La Palma, and Tenerife); this places it in the Macaronesian biogeographic realm. The trees usually grow on basalt-derived soils, at different elevations on windward and leeward slopes. To the windward, they grow between coastal scrub and laurel forest at 200-500 m, and to the leeward they grow between coastal scrub and Pinus canariensis forest at 300-900(-1100) m. The highest occurrences are on El Hierro. As a result of the different exposures there is a dry juniper forest on the leeward side and a humid juniper forest to the windward. The juniper woodlands (locally called sabinar, from the Spanish sabino = juniper) develop in flat areas with relatively deep soil, and in rocky areas with poor soil layers. In general, the oldest trees are found in steep areas difficult to access, which prevented them from being logged (Boratyński et al. 2024). The humid windward sabinar experiences lower temperatures, reduced evapotranspiration and slightly higher precipitation (300-450 mm/year), compared to the leeward dry sabinar, with precipitation of 200-300 mm/year. Associated species on windward sites include Argyranthemum spp., Echium strictum, Erica arborea, Erysimum bicolor, Heberdenia excelsa, Hypericum canariense, Marcetella moquiniana, Morella faya, Pericallis spp., Sideroxylon canariensis, Sonchus spp., and Visnea mocanera. Leeward sites are associated with Bupleurum salicifolium, Carlina salicifolia, C. canariensis, Cistus monspeliensis, C. symphytifolius, Convolvulus floridus, Echium aculeatum, Globularia salicina, Jasminum odoratissimum, Olea cerasiformis, Pistacia atlantica, Retama rhodorhizoides, and Rhamnus crenulata (Rota et al. 2021).

The largest populations are on El Hierro and La Gomera. On the other islands, a history of timber exploitation and land conversion for agriculture has greatly reduced the species' abundance (see map right showing habitat loss on Tenerife). Only isolated individuals remain on Gran Canaria, where extensive populations once existed. On La Palma, the species grows at a few locations to the windward in Mazo and Las Breñas and to the leeward in El Charco. In Tenerife, a well preserved woodland of J. canariensis grows in the Anaga massif, around El Guincho, in Montaña de Tejina, in Ladera de Guímar, and in Arico. On El Hierro and on La Gomera, J. canariensis woodlands cover 1,142 and 2,820 ha, respectively. El Hierro is home to a humid forest of J. canariensis, and in Dehesa are the oldest individuals showing good regeneration. The highest-elevation occurrences are in the transition zone of J. canariensis and Pinus canariensis. On La Gomera, the largest juniper forest is in the northern part of the island in the Hermigua highlands and in Tamargada-Vallehermoso-Epina. The scattered occurrences in Madeira, on Pico Branco and the island of Porto Santo, have not been recorded recently and need to be confirmed (Boratyński et al. 2024).

The seeds of J. canariensis are mainly dispersed by lizards (Gallotia spp.) and by frugivorous birds such as the blackbird (Turdus merula cabrerae) and raven (Corvus corax canariensis). The seeds are also consumed by brown rats (Rattus rattus) and rabbits (Oryctolagus cuniculus), which both were introduced during the 15th Century. Establishment, regeneration, and growth following disturbance are typically slow, with J. canariensis acting as a typical late-successional species (Rota et al. 2021). Rota et al. (2021) provide a detailed account of an effort to restore a site on Tenerife to J. canariensis woodland.

The conservation status of this species has not been determined; IUCN conflates it with J. turbinata, and taken together, the two are "near threatened" due to habitat loss associated with coastal development (mainly due to tourism), and a small area of occupancy and very high level of population fragmentation, despite the very large area of occurrence. Rates of decline are not known; if ongoing decline were demonstrated, it may warrant "Vulnerable" status (Farjon 2020). That analysis is basically accurate for J. canariensis, except that it has a much smaller area of occurrence, particularly within its Portuguese range. It likely qualifies as "Vulnerable" under IUCN criteria, and "Endangered" or "Critically Endangered" within its Portuguese range.

Remarkable Specimens

No data as of 2024.01.02.

Ethnobotany

I have found no detailed references to use of this species, but recorded uses of "Canary Island juniper", which includes both J. cedrus and J. canariensis, include timber (e.g. furniture, paneling, posts, poles, fuel, and general carpentry) and as an ornamental plant. In addition, junipers in general are commonly used to flavor meat dishes and, due to their high essential oil content, for varied medicinal purposes. Such uses, along with land clearance for grazing, largely removed the species throughout most of its range, and it is now economically extinct (Ashmole and Ashmole 1989).

Observations

I haven't identified any specific locations, but there are a large number of observations of J. canariensis posted on iNaturalist, e.g. at the Parque Rural de Frontera and the Parque Rural de Anaga (both on Tenerife), or at El Sabinar in western El Hierro. Most of the posted locations will be accessible to members of the general public.

Remarks

The epithet refers to the primary area of occurrence, in the Canary Islands.

Citations

Adams, R. P. 2006. Geographic variation in Juniperus phoenicea from the Canary Islands, Morocco and Spain, based on RAPDs analysis. Phytologia 88(3):270–278.

Adams, R. P. 2014. Junipers of the World, 4th ed. Trafford, Bloomington, IN. 415 p.

Adams, R. P., A. F. Barrero, and A. Lara. 1996. Comparisons of the leaf essential oils of Juniperus phoenicea, J. phoenicea subsp. eu-mediterranea Lehr. & Thiv. and J. phoenicea var. turbinata (Guss.) Parl. Journal of Essential Oil Research 8:367–371.

Adams, R. P., R. N. Pandey, S. Rezzi, and J. Casanova. 2002. Geographic variation in the Random Amplified Polymorphic DNAs (RAPDs) of Juniperus phoenicea, J. p. var. canariensis, J. p. subsp. eu-mediterranea, and J. p. var. turbinata. Biochemical Systematics and Ecology 30(3):223–229.

Adams, R. P., B. Rumeu, M. Nogales, and S. S. Fontinha. 2009. Geographic variation and systematics of Juniperus phoenicea L. from Madeira and the Canary Islands: Analyses of leaf volatile oils. Phytologia 91(1):40–53.

Adams, R. P., A. Boratynski, M. Arista, A. E. Schwarzbach, H. Leschner, Z. Liber, P. Minissale, T. Mataraci, and A. Manolis. 2013. Analysis of Juniperus phoenicea from throughout its range in the Mediterranean using DNA sequence data from nrDNA and petN-psbM: The case for the recognition of J. turbinata Guss. Phytologia 95(2):202-209.

Arista, M., P. L. Ortiz, and S. Talavera. 1997. Reproductive isolation of two sympatric subspecies of Juniperus phoenicea (Cupressaceae) in southern Spain. Plant Systematics and Evolution 208:225–237.

Ashmole, M. and P. Ashmole 1989. Natural history excursions in Tenerife. Peebles: Kidston Mill Press.

Boratyński, A., A. Lewandowski, K. Boratyńska, J. M. Montserrat, and A. Romo. 2009. High level of genetic differentiation of Juniperus phoenicea (Cupressaceae) in the Mediterranean region: geographic implications. Plant Syst Evol. 277:163–172.

Boratyński, Adam , Montserrat Salvà-Catarineu, Katarzyna Marcysiak, Małgorzata Mazur, Ángel Romo, Pietro Minissale, Kit Tan, Grzegorz Iszkuło, Radosław Witkowski, and Andrzej Mazur. 2024. Biology and ecology of the Juniperus phoenicea – J. turbinata – J. canariensis complex I. Taxonomy, structure and distribution. Dendrobiology 92:1–31. https://doi.org/10.12657/denbio.092.001.

Farjon, Aljos. 2020. Juniperus turbinata (amended version of 2013 assessment). The IUCN Red List of Threatened Species 2020: e.T16349692A168119952. https://dx.doi.org/10.2305/IUCN.UK.2020-1.RLTS.T16349692A168119952.en. Downloaded on 19 May 2020.

Guyot, A. P. and T. Mathou. 1942. Le genévrier des Iles Canaries Juniperus canariensis Guyot. Travaux du Laboratoire Forestier de Toulouse 1(3):17-24.

Mao, K., G. Hao, J. Liu, R. P. Adams, and R. I. Milne. 2010. Diversification and biogeography of Juniperus (Cupressaceae): variable diversification rates and multiple intercontinental dispersals. New Phytologist 188(1):254–272.

Mazur, M., K. Boratynska, K. Marcysiak, D. Gomez, D. Tomaszewski, J. Didukh and A. Boratynski. 2003. Morphological variability of Juniperus phoenicea (Cupressaceae) from three distant localities on the Iberian peninsula. Act. Soc. Bot. Poloniae 72:71-78.

Mazur, M., P. Minissale, S. Sciandrello, and A. Boratyński. 2016. Morphological and ecological comparison of populations of Juniperus turbinata Guss. and J. phoenicea L. from the Mediterranean region. Plant Biosystems - An International Journal Dealing with all Aspects of Plant Biology 150(2):313–322.

D.Pav., Véla & Médail. 2021. Ecol. Medit. 46: 93.

Rivas Mart., Wildpret, and P.Pérez. 1993. Itin. Geobot. 7:511.

Rota, Francesco, Mercedes Vidal-Rodríguez, Alessandro Chiarucci, José María Fernández-Palacios, and Robert J. Whittaker. 2021. Monitoring a thermophilous woodland reforestation project in Tenerife, Canary Islands. Revista Scientia Insularum 4:27-43. https://doi.org/10.25145/j.SI.2021.04.02.