Picea crassifolia (青海云杉) description

Conservation Status

Picea crassifolia

Kom. (1923)

Common names

Qinghai spruce; 青海云杉 Qinghai yunshan [Chinese] (Farjon 1990).

Taxonomic notes

Type: China, N. M. Przewalski s.n., Feb-1800; P. K. Kozlov s.n., May-1895 (syntypes LE). Syn: P. schrenkiana var. crassifolia (Kom.) Kom.; P. complanata var. crassifolia (Kom.) Gaussen (Farjon 1990). The species was commonly treated as a synonym of P. asperata, especially in the European and American literature, until late in the 20th century.

Molecular studies place these two taxa of the Tibetan Plateau as sister species (Feng et al. 2022, Liu et al. 2024). Other closely-related species include P. koreana and 4 other spruces: P. meyeri, P. neoveitchii, P. retroflexa, and P. wilsonii (Liu et al. 2024; all species shown on the map below); the group is often called the "Picea asperata complex" (see Christian 2025a for discussion). Within P. crassifolia there are clear and pronounced genetic differences between different populations, with the differences reflecting environmental variates of temperature and precipitation, rather than distance between populations (Feng et al. 2023).

Description

Trees up to 25 m tall and 60 cm dbh, generally with a single straight, round trunk and horizontal or upturned branches forming a conical crown that becomes open in old trees. Bark on mature trees rough and scaly, red-brown. Twigs short, firm, greenish yellow, with age turning pink or brownish yellow, often pruinose; later gray, with prominent ridges and deep grooves, glabrous or with some scattered pubescence; pulvini large, 2-2.5 mm long, erect or recurved. Vegetative buds ovoid-globose, more conical on leading shoots, up to 8-12 × 6-10 mm, not or slightly resinous; bud scales triangular, acute, keeled with erose margins, orange-brown, often pruinose, persistent, leaving wide collars of perular scales at the base of shoots. Leaves radially inserted, crowded above shoot, upper leaves directed forward and lower leaves curved upward, very stiff, curved or nearly straight, quadrangular in cross section, apex obtuse to acutish; amphistomatic, 12-22 × 1.5-2.5 mm, stomata in 5-7 lines above and 4-6 lines beneath the leaf; leaves bright green with two whitish stomatal bands. Pollen cones axillary, 10-15 mm long, yellowish pink. Seed cones terminal, erect at first, pendulous at maturity, sessile, ovoid-oblong or cylindrical, obtuse at apex, (5)7-11 × 2.5-3.5 cm with opened scales, purplish-red at first, maturing green, with purple margins on seed scales; fully ripe cones light or dark brown. Seed scales broadly obovate-flabellate, slightly convex, flattened when open, 15-20 x 10-17 mm at mid-cone; surface smooth, usually finely striate, or slightly wrinkled, glabrous; upper margin entire, slightly incurved, rounded; base cuneate. Bracts rudimentary, ligulate, 2 mm long, entirely included. Seeds ovoid-oblong, 3-3.5 mm long, brown, with a 10-13 mm orange-brown wing. Pollination Apr-May, seed maturity Sep-Oct (Wu and Raven 1999, Farjon 2010).

The bark of P. crassifolia forms irregular, small, thin plates, while that of P. asperata forms irregular, large, thick plates (Christian 2025b).

Distribution and Ecology

China: Gansu, Nei Mongol, Ningxia, Qinghai. The principal range is in the Qilian Shan, located on the northeastern edge of the Qinghai-Tibetan Plateau, bordered by the Tengger Desert and the Badain Jaran Desert in the north and the Qaidam Basin in the south (Gao et al. 2013). There is also a disjunct occurrence in the Helan Shan area on the Nei Mongol-Ningxia border (Shen et al. 2019), and a smaller disjunct occurrence even farther east in the Daqing Shan of Nei Mongol (Wu and Raven 1999, Bai et al. 2011). Within Qinghai, it is the predominant forest tree, covering about 93,333 ha which is 44% of the province's conifer forest area (Qinghai Provincial People's Congress Gazette 2015). P. crassifolia grows variously on calcareous or siliceous soils at 1600-3800 m elevation in high mountains, mainly on N-facing slopes, above steppe or desert. The climate is cold continental and dry. The tree mostly forms single-species stands, occasionally in forests with Betula albo-sinensis or groves of Populus tremula; at elevations below 2200 m in Ningxia it occurs with Pinus tabuliformis and Juniperus rigida (Farjon 1990, Wu and Raven 1999, Farjon 2010, Bai et al. 2011). This is the dominant tree species in the Qilian Shan, accounting for over 75% of the area's forest cover (Feng et al. 2020).

Distribution of all species in the Picea asperata complex; data from GBIF (2026). P. crassifolia shown in dark blue. Data have been edited to remove location duplicates, remove collections with coordinate uncertainty >10 km, and remove obvious extralimital occurrences. Specimens have not been checked and some may be misidentified. Click on any point for more info.

Describing a study site fully forested with Qinghai spruce in the Qilian Shan, Li et al (2013) report a mean elevation of 2,909 m, a NW exposure, and a temperate continental semi-humid mountain climate. The average annual temperature is 5.4°C with the coldest month (January) averaging -12.5°C and the hottest month (July) averaging 19.6°C. Annual precipitation ranges from 300 to 500 mm, mainly occurring from June to September. The parent material is calcareous rock. The stand structure features high canopy closure and is divided into tree, shrub, herb, and moss strata.

The growth of Qinghai spruce, at least within its occurrence between 2850–3230 m, is primarily influenced by precipitation (Gao et al. 2013). Indeed, genetic studies indicate that variation between populations is dominated by differing representation of genes for adaptation to drought stress (Feng et al. 2022). The species' ecology seems to have received little study, but silvicultural evidence indicates that in habitat its growth is best on NW to NE exposures at elevations of 2700-3300 m (He et al. 2018), suggesting that the species does best in such settings. A different study provided very similar results and also found that these environments have a mean annual temperature of about 0.6 to -2.7°C and annual precipitation of about 374 to 480 mm; in the study area, these forests were dominated by Qinghai spruce with secondary Juniperus przewalskii, Qilian juniper (Yang et al. 2017).

Hardy to Zone 5 (cold hardiness limit between -28.8°C and -23.3°C) (Bannister and Neuner 2001).

A demographic study in the Qilian Shan found an "inverted J" size class distribution, indicative of a fairly stable stand with ongoing natural regeneration (Feng et al. 2020). Citing Yang (2018), the authors contend that growth rates are very slow, with 5 cm dbh trees about 30 years old and 22.5 cm trees about 111 years old; anything larger is an uncommonly large tree, with maximum ages to about 400 years.

Noteworthy pests and pathogens include the dwarf mistletoe Arceuthobium sichuanense (Wang et al. 2016a) and a needle rust (Li and Bai 2024). The mistletoe affects a variety of Picea species and in some areas is a major cause of mortality, but the rust does not seem to pose a particular threat to the species.

A habitat model incorporating climate change forecasts for all standard scenarios through the year 2080 (IPCC 2013) generally predicts increases in suitable habitat for P. crassifolia (Gao et al. 2021). This is not necessarily good news since some areas of existing habitat will become unsuitable, the species has limited capacity to expand into suitable habitat except with human assistance, and due to a number of other reasons. Overall, though, the outlook is less gloomy than for many other conifers. Due to its large range with many distinct populations the IUCN has recently (in 2010) evaluated Qinghai spruce as of "Least Concern" for conservation, and evidence to date does not support a change in that designation.

Remarkable Specimens

No data as of 2026-10-14.

Ethnobotany

The bulk of Chinese studies of this species, published in the 2020's, suggest it is used for timber production and reforestation, with plantation silviculture performed widely in its native range. In the Helan Shan the species was formerly widely harvested for timber, though the area is currently protected in the 1570 km² Helan Shan Nature Preserve (Bai et al. 2011). In the Qilian Shan, Peng et al. (2013) assert "Qinghai spruce (Picea crassifolia) ... has in the past century undergone the most intensive and extensive deforestation due to economic gain from timber sale and land clearing for agriculture and grass lands ... the Qilian Mountains National Nature Reserve was [later] established, and various attempts have been made to reforest the nature reserve." China Green Times (2025) describes the species as being extensively used for afforestation of degraded lands in Qinghai E of Qinghai Lake, in the Muge Gobi Desert, the Gonghe Basin, and the Sanjiangyuan region; and also in the plateau region of Ningxia.

Research studies have primarily focused on understanding the P. crassifolia genome with a view to improving its utility in silviculture, and dendrochronological studies of the climate-growth response, also seemingly focused on silvicultural uses although often performed in naturally regenerated stands (Feng et al. 2022, 2023; Gao et al. 2013; Li et al. 2025; Liu et al. 2024; Lv et al. 2026; Wang et al. 2016b; Yang et al. 2017; Xu et al. 2013, 2014). Using collections from north of the Qilian Shan, the species has also been used to develop a long reconstruction of temperature, extending back to 1831 (Liu et al. 2016).

Observations

Several published studies (e.g. Bai et al. [2011] for the Helan Shan and Li et al. [2013] for the Qilian Shan) provide locations of stands within protected areas. iNaturalist also documents a variety of collections, e.g. within Datong Yaozigou National Forest Park. Such locations often are within areas that are accessible and open for access.

Remarks

The epithet means "having thick leaves."

This is the provincial tree of Qinghai; it "symbolizes the plateau spirit of the Qinghai people" (Qinghai Provincial People's Congress Gazette 2015).

Citations

Bai, X.-L., D.-P. Zhao, B. C. Tan, et al. 2011. Mosses of Picea crassifolia forest in Helanshan (Ningxia, China). Arctoa 20:81–86.

China Green Times. 2025. Legendary Trees | Spruce: The "Army" Protecting the Ecology of the Three-North Shelterbelt Region. https://www.forestry.gov.cn/c/www/lcdt/610054.jhtml, accessed 2026.10.12.

Christian, Tom. 2025a. Trees and Shrubs Online: Picea asperata aggregate. https://www.treesandshrubsonline.org/articles/picea/picea-asperata-aggregate/, accessed 2026.10.14.

Christian, Tom. 2025b. Trees and Shrubs Online: Picea crassifolia. https://www.treesandshrubsonline.org/articles/picea/picea-crassifolia/, accessed 2026.10.12.

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.

Feng, T. A., Xian-De Liu, Run-Hong Liu, et al. 2020. Spatial distribution patterns and association of Picea crassifolia population in Dayekou Basin of Qilian Mountains, northwestern China. Chinese Journal of Plant Ecology 44(11):1172-1183. https://dx.doi.org/10.17521/cjpe.2020.0177.

Feng, Shuo, Wei Wan, Yang Li, et al. 2022. Transcriptome‐based analyses of adaptive divergence between two closely related spruce species on the Qinghai–Tibet plateau and adjacent regions. Molecular Ecology 32(2):476-491. https://doi.org/10.1111/mec.16758.

Feng, Shuo, Erning Xi, Wei Wan, and Dafu Ru. 2023. Genomic signals of local adaptation in Picea crassifolia. BMC Plant Biology 23(1): 534. https://doi.org/10.1186/s12870-023-04539-7.

Gao, L., X. Gou, Y. Deng et al. 2013. Dendroclimatic response of Picea crassifolia along an altitudinal gradient in the eastern Qilian Mountains, Northwest China. Arctic, Antarctic and Alpine Research 45(4):491–499. https://doi.org/10.1657/1938-4246-45.4.491.

Gao, Y., Z. He, X. Zhu, et al. 2021. Potential distribution and habitat suitability of Picea crassifolia with climate change scenarios. Canadian Journal of Forest Research 51:1903–1915.

He, Z., S. Fang, L. Chen, et al. 2018. Spatial patterns in natural Picea crassifolia forests of northwestern China, as basis for close-to-nature forestry. Journal of Mountain Science 15:1909–1919.

IPCC. 2013. Climate change 2013: the physical science basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. Edited by T.F. Stocker, D. Qin, G.-K. Plattner, M. Tignor, S.K. Allen, J. Boschung, et al. Cambridge University Press, Cambridge, UK, and New York, NY.

Komarov, V. L. 1923. De Gymnospermis nonnullis Asiaticis I. Bot. Mater. Gerb. Glavn. Bot. Sada RSFSR 4: 177.

Li, X. X., X. D. Liu, and W. J. Zhao. 2013. Community structure of a dynamical plot of Picea crassifolia forest in Qilian Mountains, China. Journal of Desert Research 33:94-100. https://doi.org/10.7522/j.issn.1000-694X.2013.00013.

Li, H., and L. Bai. 2024. Transcriptome analysis of Picea crassifolia in response to rust infestation. Journal of Fungi 10:313. https://doi.org/10.3390/jof10050313

Li, Q., L. Jiao, Y. Qin et al. 2025. Species and elevation differences in climate responses of two conifers at the southern edge of the Tengger desert: insights from tree-ring width and δ18o analyses. Journal of Plant Ecology 18(3):rtaf041. https://doi.org/10.1093/jpe/rtaf041.

Liu, Y., C. Sun, Q. Li, and Q. Cai. 2016. A Picea crassifolia tree-ring width-based temperature reconstruction for the Mt. Dongda Region, northwest China, and its relationship to large-scale climate forcing. PLOS ONE 11:e0160963.

Liu, Y., W. Xiao, F. Wang, et al. 2024. Species divergence and environmental adaptation of Picea asperata complex at the whole genome level. Ecology and Evolution 14:e70126. https://doi.org/10.1002/ece3.70126.

Lv, Dong, Erwen Xu, Yanxia Wang, et al. 2026. Genome-wide association analysis of ecologically essential traits in Picea crassifolia. Tree Genetics & Genomes 22(2): 7.

Peng, S., C. Zhao, Z. Xu, and M. W. Ashiq. 2016. Restoration and conservation potential of destroyed Qinghai spruce (Picea crassifolia) forests in the Qilian Mountains of northwest China. Mitigation and Adaptation Strategies for Global Change 21:153–165.

Qinghai Provincial People's Congress Gazette. 2015. Explanation of the "Draft Decision on Designating Qinghai Spruce as the Provincial Tree". https://www.qhrd.gov.cn/zyfb/cwhgb_4710/lncwhgb/2015n_4719/201510/t20151014_53572.html, accessed 2026.10.12.

Shen, T.-T., J.-H. Ran, and X.-Q. Wang. 2019. Phylogenomics disentangles the evolutionary history of spruces (Picea) in the Qinghai-Tibetan Plateau: Implications for the design of population genetic studies and species delimitation of conifers. Molecular Phylogenetics and Evolution 141:106612. https://doi.org/10.1016/j.ympev.2019.106612.

Wang, Y., X. Li, W. Zhou, T. Li, and C. Tian. 2016a. De novo assembly and transcriptome characterization of spruce dwarf mistletoe Arceuthobium sichuanense uncovers gene expression profiling associated with plant development. BMC Genomics 17:771. https://doi.org/10.1186/s12864-016-3127-y.

Wang, B., T. Chen, G. Wu et al. 2016b. Qinghai spruce (Picea crassifolia) growth–climate response between lower and upper elevation gradient limits: a case study along a consistent slope in the mid-Qilian Mountains region. Environ Earth Sci 75(3):236.

Yang, W., Y. Wang, S. Wang, et al. 2017. Spatial distribution of Qinghai spruce forests and the thresholds of influencing factors in a small catchment, Qilian Mountains, northwest China. Scientific Reports 7:5561.

Xu, J., J. Lu, F. Bao et al. 2013. Climate response of cell characteristics in tree rings of Picea crassifolia. Holzforschung 67(2):217–225.

Xu, J., J. Lu, R. Evans, and G. M. Downes. 2014. Relationship between ring width and tracheid characteristics in Picea crassifolia: implication in dendroclimatology. BioResources 9. 10.15376/biores.9.2.2203-2213.

Yang, Wenjuan. 2018. Spatial Distribution, Structural Characteristics and Evapotranspiration of Qinghai Spruce Forests in the Qilian Mountains, Northwest China. PhD dissertation, Chinese Academy of Forestry, Beijing.