Abstract
Backgrounds and aims
Germination timing strongly affects the probability of seedling survival and the conditions for subsequent plant growth and reproduction. For alpine species, timing of germination should be restricted to a period that ensures seedlings will attain a critical size during the short growing season and thus survive winter. Thus, we hypothesized that seeds of herbaceous alpine perennials germinate only at the beginning of the growing season in spring, when temperatures are low, and the seed dormancy mechanism helps synchronize the germination event to the beginning of the growing season.
Methods
Seed traits and effects of light, temperature, cold stratification and GA3 on germination of Primula alpicola and Pedicularis fletcheri were tested in the laboratory and germination responses to temperature of seeds buried in the field at 4500 m a.s.l. and exhumed over a 2-year period were investigated.
Results
Fresh seeds were dormant, and cold stratification and GA3 overcame dormancy in seeds of both species and the light requirement for germination of P. alpicola seeds. Buried seeds of both species exhibited an annual dormancy/nondormancy/dormancy cycle.
Conclusions
Seeds of P. alpicola and P. fletcheri have nondeep physiological dormancy and dormancy cycling. Dormancy cycling was coordinated with seasonal environmental conditions, and seeds germinated soon after snowmelt in late spring. This is the first comprehensive demonstration of regulation of germination timing by dormancy cycling in alpine plants.
Similar content being viewed by others
References
Baskin JM, Baskin CC (1980) Ecophysiology of secondary dormancy in seeds of Ambrosia artemisiifolia. Ecology 61:475–480
Baskin JM, Baskin CC (1981a) Seasonal changes in germination responses of buried seeds of Verbascum thapsus and V. blattaria and ecological implications. Can J Bot 59:1769–1775
Baskin JM, Baskin CC (1981b) Seasonal changes in the germination responses of buried Lamium amplexicaule seeds. Weed Res 21:299–306
Baskin JM, Baskin CC (1985a) The annual dormancy cycle in buried weed seeds: a continuum. Bioscience 35:492–498
Baskin JM, Baskin CC (1985b) Role of dispersal date and changes in physiological-responses in controlling timing of germination in achenes of Geum canadense. Can J Bot 63:1654–1658
Baskin CC, Baskin JM (1998) Ecology of seed dormancy and germination in grasses. In: Cheplick GP (ed) Population biology of grasses. Cambridge University Press, Cambridge, pp 30–83
Baskin CC, Baskin JM (2014) Seeds: ecology, biogeography, and evolution of dormancy and germination, 2nd edn. Elsevier/ Academic Press, San Diego
Billings WD, Bliss LC (1959) An alpine snowbank environment and its effects on vegetation, plant development, and productivity. Ecology 40:388–397
Cao D, Baskin CC, Baskin JM, Yang F, Huang Z (2012) Comparison of germination and seed bank dynamics of dimorphic seeds of the cold desert halophyte Suaeda corniculata subsp. mongolica. Ann Bot 110:1545–1558
Cao D, Baskin CC, Baskin JM, Yang F, Huang Z (2014) Dormancy cycling and persistence of seeds in soil of a cold desert halophyte shrub. Ann Bot 113:171–179
Chambers JC (1995) Disturbance, life history strategies, and seed fates in alpine herbfield communities. Am J Bot 82:421–433
Chambers JC, Macmahon JA, Brown RW (1987) Germination characteristics of alpine grasses and forbs - a comparison of early and late seral dominants with reclamation potential. Reclam Reveg Res 6:235–249
Crawley MJ (2012) The R book. John Wiley & Sons, West Sussex
Daneshvar A, Tigabu M, Karimidoost A, Oden PC (2016) Stimulation of germination in dormant seeds of Juniperus polycarpos by stratification and hormone treatments. New Forest 47:751–761
Donohue K, Rubio de Casas R, Burghardt L, Kovach K, Willis CG (2010) Germination, postgermination adaptation, and species ecological ranges. Annu Rev Ecol Evol Syst 41:293–319
Drescher M, Thomas SC (2013) Snow cover manipulations alter survival of early life stages of cold-temperate tree species. Oikos 122:541–554
Dubois J, Cheptou PO (2012) Competition/colonization syndrome mediated by early germination in non-dispersing achenes in the heteromorphic species Crepis sancta. Ann Bot 110:1245–1251
Fenner M, Thompson K (2005) The ecology of seeds. Cambridge University Press, New York
Finch-Savage WE, Leubner-Metzger G (2006) Seed dormancy and the control of germination. New Phytol 171:501–523
Gutterman Y (1993) Seed germination in desert plants. Springer-Verlag, Berlin
Hitchmough J, Innes S, Mitschunas N (2011) The effect of seed treatment and depth of sowing on seedling emergence in Primula species. Seed Sci Technol 39:539–551
Hong D, Hanbi Y, Cunli J, Holmgren NH (1998) Scrophulariaceae. In: E Board (ed) Flora of China. Revised edn. China Science Press, Beijing, vol. 18, pp 1-212
Hu C, Kelso S (1996) Primulaceae. In: E Board (ed) Flora of China. Revised edn. China Science Press, Beijing, vol. 15, pp 39-189
John F, Sanford W (2011) An R companion to applied regression, 2nd edn. Sage, CA, Thousand Oaks
Kelly MG, Levin DA (1997) Fitness consequences and heritability aspects of emergence date in Phlox drummondii. J Ecol 85:755–766
Körner C (2003) Alpine plant life: functional plant ecology of high mountain ecosystems, 2nd edn. Springer-Verlag, Berlin
Li A, Guan K, Probert R (2007) Effects of light, scarification, and gibberellic acid on seed germination of eight Pedicularis species from Yunnan, China. Hortscience 42:1259–1262
Liang E, Wang Y, Eckstein D, Luo T (2011) Little change in the fir tree-line position on the southeastern Tibetan plateau after 200 years of warming. New Phytol 190:760–769
Liu B, Liang E, Zhu L (2011a) Microclimatic conditions for Juniperus saltuaria treeline in the Sygera Mountains, southeastern Tibetan plateau. Mtn Res Dev 31:45–53
Liu K, Baskin JM, Baskin CC, Bu H, Liu M, Liu W, Du G (2011b) Effect of storage conditions on germination of seeds of 489 species from high elevation grasslands of the eastern Tibet plateau and some implications for climate change. Am J Bot 98:12–19
Liu K, Baskin JM, Baskin CC, Bu H, Du G, Ma M (2013) Effect of diurnal fluctuating versus constant temperatures on germination of 445 species from the eastern Tibet plateau. PLoS One 8:e69364
Lubzens E, Cerda J, Clark M (2010) Dormancy and resistance in harsh environments. Springer, Berlin
Marcante S, Sierra-Almeida A, Spindelböck JP, Erschbamer B, Neuner G (2012) Frost as a limiting factor for recruitment and establishment of early development stages in an alpine glacier foreland? J Veg Sci 23:858–868
Maruta E (1983) Growth and survival of current-year seedlings of Polygonum cuspidatum at the upper distribution limit on Mt. Fuji Oecologia 60:316–320
Mercer KL, Alexander HM, Snow AA (2011) Selection on seedling emergence timing and size in an annual plant, Helianthus annuus (common sunflower, Asteraceae). Am J Bot 98:975–985
Milberg P (1994) Annual dark domancy cycle in buried seeds of Lychnis flos-cuculi. Ann Bot Fenn 31:163–167
Milberg P, Andersson L, Thompson K (2000) Large-seeded species are less dependent on light for germination than small-seeded ones. Seed Sci Res 10:99–104
Mondoni A, Pedrini S, Bernareggi G, Rossi G, Abeli T, Probert RJ, Ghitti M, Bonomi C, Orsenigo S (2015) Climate warming could increase recruitment success in glacier foreland plants. Am J Bot 116:907–916
Onipchenko VG, Semenova GV, van der Maarel E (1998) Population strategies in severe environments: alpine plants in the northwestern Caucasus. J Veg Sci 9:27–40
Pons TL (2000) Seed responses to light. In: Fenner M (ed) Seeds: the ecology of regeneration in plant communities, 2nd edn. CABI Publishing, Wallingford
Rawlins JK, Roundy BA, Davis SM, Egget D (2012) Predicting germination in semi-arid wildland seedbeds. I. Thermal germination models. Environ Exp Bot 76:60–67
Ross MA, Harper JL (1972) Occupation of biological space during seedling establishment. J Ecol 60:77–88
Schütz W (2002) Dormancy characteristics and germination timing in two alpine Carex species. Basic Appl Ecol 3:125–134
Schwienbacher E, Navarro-Cano JA, Neuner G, Erschbamer B (2011) Seed dormancy in alpine species. Flora 206:845–856
Shimono Y, Kudo G (2005) Comparisons of germination traits of alpine plants between fellfield and snowbed habitats. Ecol Res 2:189–197
Stöcklin J, Bäumler E (1996) Seed rain, seedling establishment and clonal growth strategies on a glacier foreland. J Veg Sci 7:45–56
Wu X, Liao JX, Gan QL, Gang WU (2011) Influence of environmental factors on seed germination and seedling formation of Primula filchnerae. Plant Sci J 29:212–217
Yang Y, Fang J, Ji C, Ma W, Su S, Tang Z (2010) Soil inorganic carbon stock in the Tibetan alpine grasslands. Global Biogeochem Cycl 24:GB4022
Acknowledgements
Sincerely thanks are given to Prof. Jian Luo, Prof. Zhen Xing, and students including Xiaoyan Yao, Qionghua Jiang and Yifeng Wang from Tibet Agricultural and Animal Husbandry College, for the help in field works. We also thank Linzhi National Forest Ecosystem Observation & Research Station for providing meteorological data for the study site. This work was financially supported by the National Natural Science Foundation of P. R. China (31570416, 31370705, 31560153).
Author information
Authors and Affiliations
Corresponding authors
Additional information
Responsible Editor: Harry Olde Venterink.
Rights and permissions
About this article
Cite this article
Wang, G., Baskin, C.C., Baskin, J.M. et al. Timing of seed germination in two alpine herbs on the southeastern Tibetan plateau: the role of seed dormancy and annual dormancy cycling in soil. Plant Soil 421, 465–476 (2017). https://doi.org/10.1007/s11104-017-3400-0
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11104-017-3400-0