Abies delavayi (苍山冷杉) description

subsp. delavayi

var. fabri

subsp. fansipanensis

subsp. motuoensis

subsp. nukiangensis

Abies delavayi

(Van Tiegh.) Franchet (1899)

Common names

Delavay fir; 苍山冷杉 cang shan leng shan [Chinese]. Var. fabri is also called Yunnan fir (Cheng & Fu 1978), Faber fir (Farjon 1990); lianshan, gaoshancung (Cheng and Fu 1978), 冷杉 (lengshan), paoshan (Farjon 1990) [Chinese]. Subsp. fansipanensis is also called Vân sam phan xi păng or Lãnh sam hoàng liên sơn (Loc et al. 2017) [Vietnamese].

Taxonomic notes

A species with five infraspecific taxa:

A. delavayi subsp. delavayi.
Abies delavayi var. fabri (Mast.) D.R.Hunt (1967).
Abies delavayi subsp. fansipanensis (Q.P.Xiang, L.K.Fu & Nan Li) Rushforth (1999).
Abies delavayi var. motuoensis W.C.Cheng & L.K.Fu (1975).
Abies delavayi var. nukiangensis (W.C.Cheng & L.K.Fu) Farjon & Silba (Silba 1990).

A. delavayi was formerly something of a catch-all term for Chinese firs. A. beshanzuensis and A. ziyuanensis have been placed in synonymy by some authors but are here treated as distinct species. A. delavayi var. smithii is a synonym for what for what is here treated as A. forrestii. A. delavayi var. georgei is a synonym for what is here treated as A. forrestii var. georgei; it has also been called A. georgei. This suite of fir species are now for the most part allied with A. delavayi in Section Delavayi (Farjon 1990, 2010). There are also a plethora of synonyms for A. delavayi and its varieties; see POWO for the full list. Molecular methods finally brought some clarity by showing that the minor morphological differences between at least four taxa, A. delavayi (s.s.), A. fansipanensis, A. fabri, and A. nukiangensis, were also minor molecular differences, a product of range expansions and contractions related to late Pleistocene and Holocene climate variation (Shao et al. 2019); there is one other variety, motuoensis, maintained on morphological grounds.

Description

Trees to 40 m tall and 100 cm dbh, with a pyramidal crown, dome-shaped in very old trees. Bark gray to brown, rough, flaking or longitudinally furrowed; twigs initially yellow, light brown, red-brown or brown, darker in later years, puberulent or glabrous, rarely pubescent when young; winter buds globose, resinous. Leaves spirally arranged, radially spreading ± forward or pectinately arranged in 2 lateral sets, bright green, linear, often curved or "S"-shaped, flattened, 15-30 × 1.7-2.5 mm, stomatal lines abaxial in 2 white bands, resin canals 2, marginal, margin strongly revolute, apex emarginate or obtuse. Pollen cones borne in leaf axils of previous year’s branchlets. Seed cones erect, short-pedunculate, black at maturity, variably glaucous, cylindric or ovoid-cylindric, 6-11 × 3-4.5 cm. Seed scales flabellate-trapeziform, 13-20 × 14-24 mm. Bracts included or exserted; cuneate, obovate, oblong or spatulate; apex with a narrow, usually recurved cusp 3-5 mm. Seeds ellipsoid to obovate, 13-16 mm including the brown to black, cuneate wing. Pollination May, seed maturity October (Fu et al. 1999 [as A. delavayi & A. fabri], Loc et al. 2017).

Var. fabri has gray and flaky bark. Twigs puberulent or glabrous, light brown or gray-yellow, turning brown-gray in later years (Fu et al. 1999.

Subsp. fansipanensis has reddish-brown, glabrous twigs. Leaves linear, 18–22 mm long, bright green, margin strongly revolute, apex emarginate. Seed scales 16–19 × 21–24 mm; bracts included, obovate–cuneate, 2/3–3/4 as long as seed scales (Loc et al. 2017).

Var. motuoensis differs from the type in having paler, densely ferruginous pubescent young shoots and longer leaves (20-32 mm) that are less densely arranged (Farjon 1990).

Var. nukiangensis (Cheng et Fu) Farjon 1990 has "longer (but variable: 1.2-4.3 cm) and broader (1.5-2.8 mm) leaves, which ... are less revolute. The shoot is purplish-brown and glabrous. The cone is purplish-blue and has the same apically thickened, obtriangular-flabellate seed scales, but included bract scales with a short cusp, which may be barely visible in the lower part of the mature cone" (Farjon 1990).

Distribution and Ecology

India: Arunachal Pradesh; Myanmar; Viet Nam; China: Yunnan and Tibet at 2400 to 4300 m elevation. In India it is only known from a pure stand atop Piri Mountain, Balipara Frontier Tract. In Myanmar and Viet Nam it occurs in the north, and its Chinese/Tibetan distribution is wide through the moist mountain forests of the Four Rivers country at 3000-4300 m. It thus includes NW Yunnan and SE Xizang/Tibet around the Lancang-Nukiang (Mekong-Salween) Divide. The climate is very wet (precipitation 1000-3000 mm), with cool summers and cold winters (snow on the ground from October to April). Soils are grey-brown mountain podzols. It is found on north-facing slopes forming pure (near treeline) or mixed stands with conifers such as Picea likiangensis and P. brachytyla var. brachytyla. At lower elevations it is sometimes mixed with Tsuga chinensis, T. dumosa, Juniperus formosana and broad-leaved trees such as Betula albosinensis, Betula platyphylla var. szechuanica and Quercus semicarpifolia (Liu 1971, Silba 1986, Farjon 1990, Fu et al. 1999). Hardy to Zone 7 (cold hardiness limit between -17.7°C and -12.2°C) (Bannister and Neuner 2001).

The type subspecies is found in China: SE Xizang, NW Yunnan; and N Myanmar at 3300-4300 m elevation (Luu and Thomas 2004). Due to its very wide distribution with many populations, it is assessed as "Least Concern" for conservation (Rushforth et al. 2011a).

Var. fabri is found in China (Sichuan), along the middle and lower reaches of the Dadu River, the Qingyi River valley, on Mount Emei, and in the Daliang Mountains, at 2000-3100(-3600) m elevation. It mainly forms pure stands or large mixed stands with Picea likiangensis, Tsuga chinensis, bamboo (Sinarundaria spp.), many different species of Rhododendron, and other shrubs. There are about 230,000 ha of natural forest, mainly in the Ebian, Mabian and Ya'an regions of Sichuan. Climate is cold and wet with an average annual temperature of 3-8°C and average annual precipitation >2000 mm. This species is very shade tolerant, but regeneration is best on sunny or semi-shaded slopes (Farjon 1990). In 2010, its conservation status was assessed as "Vulnerable" based on evidence of continuing population declines and highly fragmented populations. There are ongoing threats due to the impacts of over-exploitation and acid rain, which has particularly degraded the celebrated forests on Emei Shan (Xiang and Rushforth 2013).

Subsp. fansipanensis is found in Viet Nam and is only known from Mount Fansipan (elev. 3143 m), the highest peak in Viet Nam, in Lao Cai province. It experiences a monsoon climate with mean annual temperature 13-18°C and annual rainfall of 2000-3500 mm. It formerly grew in pure stands forming primary closed evergreen seasonal tropical subalpine forest on granite or gneiss slopes at 2600–3100 m elevation, but in the 1960s its habitat was widely affected by fires caused by visitors, and now only some old trees remain, scattered through woodlands with an understory of short bamboos; there are also Tsuga chinensis. The seedlings are not shade tolerant and disturbance appears to be necessary for their establishment; recent surveys have not found regeneration (Farjon 2002, Nguyen and Thomas 2005, Loc et al. 2017). Due to the small size of the population (200-400 trees) concentrated in an area of less than 1,000 ha and the lack of natural regeneration, this taxon was assessed in 2010 as critically endangered. The whole population is located within a reserve on Mt Fansipan and needs strict protection and regular monitoring. No active ex-situ conservation is currently occurring (Nguyen and Thomas 2005, Rushforth et al. 2011b).

Var. motuoensis is found in SE Xizang (Motuo Xian), at 3000-3800 m elevation. Due to its very wide distribution, it is assessed as "Least Concern" for conservation (Rushforth et al. 2011c).

Var. nukiangensis is found in China: NW Yunnan and Sichuan, NE India, and N Myanmar. It occurs at 2500-3100 m elevation (Fu et al. 1999, Luu and Thomas 2004). It is found in high mountains and on isolated peaks (such as Tama Bum in Myanmar) where it is the dominant species, occurring with Sorbus spp., Acer, Rhododendron and similar woody temperate plants, including bamboo. Its conservation status was assessed in 2010 as "Near Threatened" because of its extent of occurrence (about 20,000 km²) and severe habitat fragmentation. There has been an estimated decline of between 20-50% over the last three generations (150 years). In China, logging has been banned in most mountainous areas, but continuing decline due to ongoing logging is suspected in Myanmar (Rushforth et al. 2011d). This is a dated assessment and conditions may have further declined.

Remarkable Specimens

Heights to 40 m and dbh to 150 cm are reported by Liu (1971).

The oldest recorded tree provided 220 years of record (Bräuning 2006), for a tree growing on a young glacial moraine in eastern Tibet. This is a crossdated age on a tree that seems to have been alive when sampled.

Ethnobotany

The timber is used for construction, furniture, and wood pulp, and the bark yields tannin. Var. fabri has been used for construction, railway sleepers, telegraph poles, veneer, papermaking, matches and toothpicks. The gum extracted from its bark is regarded as an important adhesive for optical microscopy. It is also an important shelterbelt tree and is an important component of the Yangtze River watershed (Farjon 1990, Fu et al. 1999).

Observations

I have seen var. fabri on Emei Shan and in Hailuogou Glacier Park, both in Sichuan, both easily accessed with admirable forest stands. Subsp. fansipanensis is protected and accessible in Hoang Lien national park.

Remarks

The epithet honors Father I. M. Delavay who collected it at 3500-4000 m on Cangshan near Dali in Yunnan, April 1887 (Liu 1971). The epithet of var. fabri honors botanist Ernst Faber (1839-1899), who collected the type specimen. The other epithets designate type locations: Fansipan is a mountain in extreme NW Viet Nam; Motuo is a region in Tibet; and the Nujiang is a river in Yunnan.

E.H. Wilson (1913) describes the silver fir forests on Emei Shan: "At 6200 feet the Cunninghamia gives up the fight, having struggled nobly until reduced to the dimensions of an insignificant shrub. A Silver Fir (Abies delavayi) next assumes the sway, and right royally does it deserve the sceptre, for no more handsome Conifer exists in all the Far East; its large, erect, symmetrical cones are violet-black in colour and are usually borne in greatest profusion on the topmost branches. The temples on the higher parts of the mountain are constructed almost entirely of the timber of this tree. It is first met with on Mount Omei, at 6000 feet, at which altitude it is of no great size and unattractive in appearance; at 6500 feet it is a handsome tree. It is, however, between 8500 and 10,000 feet that this Silver Fir reaches its maximum size. In this belt hundreds of trees 80 to 100 feet tall, with a girth of 10 to 12 feet, can be found."

Citations

Bräuning, Achim. 2006. Tree-ring evidence of ‘Little Ice Age’ glacier advances in southern Tibet. The Holocene 16(3):369-380.

Cheng, W.C. and L. K. Fu. 1975. Species novae in Gymnospermae Sinicae. Acta Phytotaxonomica Sinica 13(4):83.

Farjon, Aljos. 1990. Pinaceae: drawings and descriptions of the genera Abies, Cedrus, Pseudolarix, Keteleeria, Nothotsuga, Tsuga, Cathaya, Pseudotsuga, Larix and Picea. Königstein: Koeltz Scientific Books.

Farjon, Aljos. 2002. Rare and Possibly Threatened Conifers in Vietnam. Report to the Fauna & Flora International Vietnam Programme.

Franchet, A. 1899. Plantarum sinensium ecloge tertia. Journal de Botanique 13:255. Available: Biodiversity Heritage Library, accessed 2020.11.26.

Hunt, D. R. 1967. Journal of the Royal Horticultural Society of London 92:263.

Loc, Phan Ke, Phan Vam Te, Phan Ke Long, J. Regalado, and Leonid V. Averyanov. 2017. Native Conifers of Vietnam – a Review. Pakistan Journal of Botany 49(5):2037–68.

Nguyễn, Đức Tố Lưu, and Philip Ian Thomas. 2005. Conifers of Vietnam. Hà Nội, Vietnam: Nhà xuất bản Thế giới.

Rushforth, Keith. 1999. International Dendrological Society Year Book 1998, p.62.

Rushforth, K., Q. Xiang, and G. Carter. 2011a. Abies delavayi var. delavayi. The IUCN Red List of Threatened Species 2011: e.T191553A8844552. dx.doi.org/10.2305/IUCN.UK.2011-2.RLTS.T191553A8844552.en, accessed 2025.01.18.

Rushforth, K., Q. Xiang, and G. Carter. 2011b. Abies delavayi subsp. fansipanensis. The IUCN Red List of Threatened Species 2011: e.T44724A10943353. dx.doi.org/10.2305/IUCN.UK.2011-2.RLTS.T44724A10943353.en, accessed 2025.01.18.

Rushforth, K., Q. Xiang, and G. Carter. 2011c. Abies delavayi var. motuoensis. The IUCN Red List of Threatened Species 2011: e.T191554A8844700. dx.doi.org/10.2305/IUCN.UK.2011-2.RLTS.T191554A8844700.en, accessed 2025.01.18.

Rushforth, K., Q. Xiang, and G. Carter. 2011d. Abies delavayi var. nukiangensis. The IUCN Red List of Threatened Species 2011: e.T191555A8844839. dx.doi.org/10.2305/IUCN.UK.2011-2.RLTS.T191555A8844839.en, accessed 2025.01.18.

Shao, Y.-Z., Chen, Y., Zhang, X.-C. and Xiang, Q.-P. 2020. Species delimitation and phylogeography of Abies delavayi complex: Inferred from morphological, molecular, and climatic data. J. Syst. Evol. 58: 234-246. doi.org/10.1111/jse.12500.

Silba, John. 1990. A supplement to the international census of the Coniferae, II. Phytologia 68(1):13. Available: Biodiversity Heritage Library, accessed 2025.01.17.

Wilson, E. H. 1913. A naturalist in western China. London: Methuen & Co. (p. 225).

Xiang, Q. and K. Rushforth. 2013. Abies fabri. The IUCN Red List of Threatened Species 2013: e.T42280A2969319. dx.doi.org/10.2305/IUCN.UK.2013-1.RLTS.T42280A2969319.en, accessed 2025.01.18.