Abies nebrodensis (abete dei nebrodi) description

Abies nebrodensis

(Lojac.) Mattei 1908

Common names

Sicilian fir, Madonian fir, abete dei nebrodi (Italian).

Taxonomic notes

Syn: Abies pectinata Gilib. var. nebrodensis Lojac. 1904; A. alba Mill. var. nebrodensis (Lojac.) Svoboda 1964; A. alba Mill. subsp. nebrodensis (Lojac.) Nitz. 1968; A. pectinata Guss. 1844 non Gilib. (Farjon 1998). Both morphological and genetic studies provide evidence suggesting that the species may have arisen from A. alba or a similar progenitor, possibly through hybridization of different A. alba populations (Linares 2011 and sources therein); however, it is also regarded as a Tertiary relict in Sicily (which was beneath the seas until about 7 mya; Guarino and Pasta 2017), and thus may have been isolated from A. alba and its congeners through that time.

Description

Trees, 40-60 cm dbh and up to 15 m tall, with a single straight round trunk and a conical crown of horizontally-spreading branches. Bark smooth, light gray; with age becoming rough, scaly, fissured. Twigs stout, stiff, shiny, yellow-green turning gray, prominently ridged, glabrous (at first may be minutely pubescent), bearing circular leaf scars. Vegetative buds conical, 8-9 × 4-6 mm, slightly resinous, bearing light brown bud scales that persist for several years. Leaves (10-)15-20(-22) × 2-3.5 mm, twisted or curved at base, linear, flattened, bright green and longitudinally grooved above, with two greenish-white stomatal bands separated by a midrib below; may bear a few stomata on the upper side near the apex. Pollen cones lateral, crowded along the shoot, 15-20 mm long, greenish-yellow with purple microsporophylls. Seed cones lateral, erect, cylindrical with a conical point, 8-10 × 3-4 cm, greenish-brown when ripe. Seed scales wedge-shaped, average size 22 × 30 mm, smooth or slightly wrinkled with an undulate exposed margin; bracts linear, exserted, recurved, average 27 mm long. Seeds conical-oblong, 6-8 mm long with a light brown 10-15 mm wing (Farjon 2010).

Distribution and Ecology

Italy: the Madonie Mountains of Sicily, as solitary individuals, or in very small and scattered groves on the steep slopes and screes of Vallone Madonna degli Angeli, Mt. Scalone, Mt. Pene and Mt. Cavallo, at elevations of between 1350 and 1700 m, on bare soils derived from quartz sandstones (although the Madonie Mountains are primarily calcareous) (Farjon 2010, Pasta and Troia 2017). Climate is (of course) Mediterranean, with about 5 months of summer drought and annual preciptation of 600-700 mm. Nearly the entire extant population is found in the Vallone Madonna degli Angeli (approximate location 37.85°N, 14.04°E), where it benefits from precipitation enhancement due to frequent fogs (Guarino and Pasta 2017).

Distribution of Abies in the Mediterranean region. Data from Conifers of the World BRAHMS database, downloaded 2017.11.05. Taxa are color coded; see pull-out menu at left of map for details. Click on each occurrence for further information.

The fir is commonly in association with the deciduous trees Fagus sylvatica and Quercus petraea; habitat is mixed deciduous and coniferous woodland or temperate and Mediterranean-montane scrub (Farjon 2010, Pasta and Troia 2017). Ecologically, A. nebrodensis has declined partly due to competition with Fagus sylvatica, a relatively recent (Pleistocene) arrival on Sicily. Due to this competition, as well as anthropogenic disturbances in its habitat (logging, grazing), A. nebrodensis is typically early-successional, limited to stony places, where it grows together with Juniperus communis (Guarino and Pasta 2017).

Habitat loss and logging had nearly extirpated this species when it was discovered to botany growing in a nearby village at the beginning of the 20th Century (Farjon 2010). The IUCN has classified this species as Critically Endangered due to its extremely small population, currently (2017) numbering only 30 adult trees within an extremely limited range of less than 1.5 km². Seedlings and saplings grown in nurseries display poor health, attributed to a genetic bottleneck effect (Parducci et al. 2001). Habitat degradation and hybridization with non-native firs (A. alba, A. cephalonica and A. nordmanniana) are currently the primary threats to this species; also, global climate change likely contributes to increased risk of extreme events (e.g. drought) and wildfire (Pasta and Troia 2017, Schicchi et al. 2013). See Pasta and Troia (2017) for discussion of past and ongoing in situ and ex situ conservation measures, as well as prospective needs for the species' conservation. Foremost among these are control of herbivores and of other Abies species, but Farjon (2010) concludes that in view of the severe habitat degradation that has occurred to date, likely full restoration of the forest ecosystem will be needed to ensure this species' survival.

Hardy to Zone 7 (cold hardiness limit between -17.7°C and -12.2°C) (Bannister and Neuner 2001).

Remarkable Specimens

The Holden Arboretum has a specimen, planted in 1956, that was 18.9 m tall and 75.4 cm DBH in 2014 (Johnson 2015). I have no other data.

Ethnobotany

Apart from historical logging that occurred even before the species was described, Abies nebrodensis seems to only be used as an ornamental conifer. Note that this is not a viable form of ex situ conservation due to the ease with which this species hybridizes with other firs in section Abies, all of which are also reasonably popular ornamentals (Farjon 2010).

Observations

The species is reasonably common in temperate zone arboreta. It can also readily be found in habitat; see Guarino and Pasta (2017) and Parducci et al. (2001) for helpful guidance if you intend a field excursion.

Remarks

The Madonie Mtns. were once called the ‘Nebrodes.’ The epithet nebrodensis recalls this name. There is also a range in northeast Sicily called the Nebrodi Mountains, but this species has not been recorded there (Pasta and Troia 2017).

Citations

Atlas Florae Europaeae. 1998. Computer program formerly available for download at http://www.fmnh.helsinki.fi/english/botany/afe/index.htm, accessed 2009.04.17, now defunct.

Guarino and S. Pasta. 2017. Botanical Excursions in Central and Western Sicily: Field Guide for the 60th IAVS Symposium, Palermo, 20-24 June 2017. Available https://www.unipapress.it/UPP/Data/Books/Admin20170619184100/Escursioni.pdf, accessed 2017.11.04, now defunct.

Linares, J. C. 2011. Biogeography and evolution of Abies (Pinaceae) in the Mediterranean Basin: the roles of long-term climatic change and glacial refugia. Journal of Biogeography 38(4):619-630.

Mattei. 1908. Boll. Reale Orto Bot. Palermo 7:64.

Parducci, L., A. E. Szmidt, A. Madaghiele, M. Anzidei, and G. G. Vendramin. 2001. Genetic variation at chloroplast microsatellites (cpSSRs) in Abies nebrodensis (Lojac.) Mattei and three neighboring Abies species. Theoretical and Applied Genetics 102:733-740.

Pasta, S. and A. Troia. 2017. Abies nebrodensis, in S. Pasta, A. Perez-Graber, L. Fazan and B. de Montmollin (eds.), The Top 50 Mediterranean Island Plants UPDATE 2017. IUCN/SSC/Mediterranean Plant Specialist Group. Neuchâtel (Switzerland). E-book and online. 141 pp. Available: http://top50.iucn-mpsg.org/book, accessed 2017.11.03.

Schicchi, R., F. M. Raimondo, P. Mazzola, and G. Bazan. 2013. Results of efforts made for in situ and ex situ conservation of Abies nebrodensis (Pinaceae) in Sicily. In: Abstracts XIV OPTIMA MEETING: 144. Orto Botanico and Herbarium Mediterraneum, Università degli Studi di Palermo. https://core.ac.uk/download/pdf/53286568.pdf, accessed 2017.11.03.