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Are wildfires an adapted ecological cue breaking physical dormancy in the Mediterranean basin?

Published online by Cambridge University Press:  09 January 2015

Ganesh K. Jaganathan
Ganesh K. Jaganathan*
Affiliation:
Institute of Biothermal Technology, University of Shanghai for Science and Technology, Shanghai 200093, China
*
*Correspondence E-mail: jganeshcbe@gmail.com
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Abstract

Many studies have claimed that fire acts as the chief ecological factor cueing dormancy break in seeds with a water-impermeable seed coat, i.e. physical dormancy (PY), in Mediterranean ecosystems. However, a proposal is made that seasonal temperature changes must be viewed as more meaningful dormancy-breaking cues because: (1) fire is erratic and may break PY in seasons during which seedlings cannot complete their life cycle; (2) fire may not occur for long periods, thereby only providing an opportunity for dormancy break and germination once in every several years; and (3) if fire opens the specialized anatomical structures called ‘water gaps’, in seconds, their evolutionary role of detecting environmental conditions becomes irrational. Although fire breaks dormancy in a proportion of seeds, given the risk of seed mortality and the post-fire environment providing cues for dormancy break, it is suggested that fire might possibly be an exaptation.

Keywords

adaptationdry heatexaptationgermination timinghigh temperaturepost-fire environmentseasonal temperaturewater-impermeable seed coatwater gap

Information

Type
Research Opinion
Information
Seed Science Research , Volume 25 , Special Issue 2: Seed Dormancy , June 2015 , pp. 120 - 126
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Copyright © Cambridge University Press 2015 

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References

Auld, T.D. (1986) Population dynamics of the shrub Acacia suaveolens (Sm.) Willd.: fire and the transition to seedlings. Australian Journal of Ecology 11, 373–385.Google Scholar
Auld, T.D. and Denham, A.J. (2006) How much seed remains in the soil after a fire? Plant Ecology 187, 15–24.CrossRefGoogle Scholar
Auld, T.D. and O'Connell, M.A. (1991) Predicting patterns of post-fire germination in 35 eastern Australian Fabaceae. Australian Journal of Ecology 16, 53–70.Google Scholar
Baeza, M.J. and Roy, J. (2008) Germination of an obligate seeder (Ulex parviflorus) and consequences for wildfire management. Forest Ecology and Management 256, 685–693.Google Scholar
Baker, K.S., Steadman, K.J., Plummer, J.A., Merritt, D.J. and Dixon, K.W. (2005) Dormancy release in Australian fire ephemeral seeds during burial increases germination response to smoke water or heat. Seed Science Research 15, 339–348.Google Scholar
Baskin, C.C. and Baskin, J.M. (2014) Seeds: Ecology, biogeography, and evolution of dormancy and germination (2nd edition). New York, Elsevier.Google Scholar
Baskin, J. and Baskin, C. (1997) Methods of breaking seed dormancy in the endangered species Iliamna corei (Sherff) sherff (Malvaceae), with special attention to heating. Natural Areas Journal 17, 313–323.Google Scholar
Baskin, J.M. and Baskin, C.C. (2000) Evolutionary considerations of claims for physical dormancy-break by microbial action and abrasion by soil particles. Seed Science Research 10, 409–413.CrossRefGoogle Scholar
Baskin, J.M. and Baskin, C.C. (2004) A classification system for seed dormancy. Seed Science Research 14, 1–16.Google Scholar
Baskin, J.M., Baskin, C.C. and Li, X. (2000) Taxonomy, anatomy and evolution of physical dormancy in seeds. Plant Species Biology 15, 139–152.Google Scholar
Baskin, J.M., Davis, B.H., Baskin, C.C., Gleason, S.M. and Cordell, S. (2004) Physical dormancy in seeds of Dodonaea viscosa (Sapindales, Sapindaceae) from Hawaii. Seed Science Research 14, 81–90.CrossRefGoogle Scholar
Bradshaw, S.D., Dixon, K.W., Hopper, S.D., Lambers, H. and Turner, S.R. (2011) Little evidence for fire-adapted plant traits in Mediterranean climate regions. Trends in Plant Science 16, 69–76.Google Scholar
Bradstock, R. and Auld, T. (1995) Soil temperatures during experimental bushfires in relation to fire intensity: consequences for legume germination and fire management in south-eastern Australia. Journal of Applied Ecology 32, 76–84.Google Scholar
Buhk, C. and Hensen, I. (2006) ‘Fire seeders’ during early post-fire succession and their quantitative importance in south-eastern Spain. Journal of Arid Environments 66, 193–209.Google Scholar
Buhk, C., Meyn, A. and Jentsch, A. (2007) The challenge of plant regeneration after fire in the Mediterranean Basin: scientific gaps in our knowledge on plant strategies and evolution of traits. Plant Ecology 192, 1–19.CrossRefGoogle Scholar
Céspedes, B., Torres, I., Luna, B., Pérez, B. and Moreno, J.M. (2012) Soil seed bank, fire season, and temporal patterns of germination in a seeder-dominated Mediterranean shrubland. Plant Ecology 213, 383–393.Google Scholar
Céspedes, B., Luna, B., Pérez, B., Urbieta, I.R. and Moreno, J.M. (2014) Burning season effects on the short-term post-fire vegetation dynamics of a Mediterranean heathland. Applied Vegetation Science 17, 86–96.CrossRefGoogle Scholar
Chawan, D. (1971) Role of high temperature pretreatments on seed germination of desert species of Sida (Malvaceae). Oecologia 6, 343–349.CrossRefGoogle Scholar
Christensen, N.L. and Muller, C.H. (1975) Effects of fire on factors controlling plant growth in Adenostoma chaparral. Ecological Monographs 45, 29–55.Google Scholar
Cook, A., Turner, S., Baskin, J., Baskin, C., Steadman, K. and Dixon, K. (2008) Occurrence of physical dormancy in seeds of Australian Sapindaceae: a survey of 14 species in nine genera. Annals of Botany 101, 1349–1362.Google Scholar
Cushwa, C.T., Martin, R.E. and Miller, R.L. (1968) The effects of fire on seed germination. Journal of Range Management 21, 250–254.Google Scholar
De Lange, J. and Boucher, C. (1990) Autecological studies on Audouinia capitata (Bruniaceae). I. Plant-derived smoke as a seed germination cue. South African Journal of Botany 56, 700–703.Google Scholar
De Luis, M., Raventós, J., Wiegand, T. and Carlos González-Hidalgo, J. (2008) Temporal and spatial differentiation in seedling emergence may promote species coexistence in Mediterranean fire-prone ecosystems. Ecography 31, 620–629.Google Scholar
Dixon, K.W., Roche, S. and Pate, J.S. (1995) The promotive effect of smoke derived from burnt native vegetation on seed germination of Western Australian plants. Oecologia 101, 185–192.CrossRefGoogle ScholarPubMed
Doussi, M. and Thanos, C. (1994) Post-fire regeneration of hard-seeded plants: ecophysiology of seed germination. pp. 1035–1044 in Proceedings of the Second International Conference on Forest Fire Research, Coimbra, Vol. II.Google Scholar
Floyd, A. (1966) Effect of fire upon weed seeds in the wet sclerophyll forests of northern New South Wales. Australian Journal of Botany 14, 243–256.CrossRefGoogle Scholar
Gama-Arachchige, N., Baskin, J., Geneve, R. and Baskin, C. (2012) The autumn effect: timing of physical dormancy break in seeds of two winter annual species of Geraniaceae by a stepwise process. Annals of Botany 110, 637–651.CrossRefGoogle ScholarPubMed
Gashaw, M. and Michelsen, A. (2002) Influence of heat shock on seed germination of plants from regularly burnt savanna woodlands and grasslands in Ethiopia. Plant Ecology 159, 83–93.CrossRefGoogle Scholar
Hagon, M. (1971) The action of temperature fluctuations on hard seeds of subterranean clover. Animal Production Science 11, 440–443.Google Scholar
Herranz, J.M., Ferrandis, P. and Martínez-Sánchez, J.J. (1998) Influence of heat on seed germination of seven Mediterranean Leguminosae species. Plant Ecology 136, 95–103.CrossRefGoogle Scholar
Herranz, J.M., Ferrandis, P. and Martínez-Sánchez, J.J. (2000) Influence of heat on seed germination of nine woody Cistaceae species. International Journal of Wildland Fire 9, 173–182.Google Scholar
Hodgkinson, K. and Oxley, R. (1990) Influence of fire and edaphic factors on germination of the arid zone shrubs Acacia aneura, Cassia nemophila and Dodonaea viscosa . Australian Journal of Botany 38, 269–279.CrossRefGoogle Scholar
Hu, X.W., Wu, Y.P. and Wang, Y.R. (2009) Different requirements for physical dormancy release in two populations of Sophora alopecuroides in relation to burial depth. Ecological Research 24, 1051–1056.Google Scholar
Jaganathan, G.K. and Liu, B. (2014a) Role of seed sowing time and microclimate on germination and seedling establishment of Dodonaea viscosa (Sapindaceae) in a seasonal dry tropical environment – a special insight into restoration efforts. Botany, doi:10.1139/cjb-2014-0159.Google Scholar
Jaganathan, G.K. and Liu, B. (2014b) Seasonal influence on dormancy alleviation in Dodonaea viscosa (Sapindaceae) seeds. Seed Science Research 24, 229–237.Google Scholar
Jayasuriya, K., Baskin, J. and Baskin, C. (2008) Cycling of sensitivity to physical dormancy-break in seeds of Ipomoea lacunosa (Convolvulaceae) and ecological significance. Annals of Botany 101, 341–352.Google Scholar
Jayasuriya, K.G., Baskin, J.M., Geneve, R.L. and Baskin, C.C. (2009) Sensitivity cycling and mechanism of physical dormancy break in seeds of Ipomoea hederacea (Convolvulaceae). International Journal of Plant Sciences 170, 429–443.Google Scholar
Keeley, J.E. (1991) Seed germination and life history syndromes in the California chaparral. Botanical Review 57, 81–116.Google Scholar
Keeley, J.E. and Fotheringham, C. (2000) Role of fire in regeneration from seed. pp. 311–330 in Fenner, M. (Ed.) Seeds: The ecology of regeneration in plant communities. Wallingford, UK, CAB International.Google Scholar
Keeley, J.E., Fotheringham, C. and Morais, M. (1999) Reexamining fire suppression impacts on brushland fire regimes. Science 284, 1829–1832.Google Scholar
Keeley, J.E., Bond, W.J., Bradstock, R.A., Pausas, J.G. and Rundel, P.W. (2011a) Fire in Mediterranean ecosystems: ecology, evolution and management. Cambridge, Cambridge University Press.CrossRefGoogle Scholar
Keeley, J.E., Pausas, J.G., Rundel, P.W., Bond, W.J. and Bradstock, R.A. (2011b) Fire as an evolutionary pressure shaping plant traits. Trends in Plant Science 16, 406–411.Google Scholar
Lloret, F., Pausas, J.G. and Vilà, M. (2003) Responses of Mediterranean plant species to different fire frequencies in Garraf Natural Park (Catalonia, Spain): field observations and modelling predictions. Plant Ecology 167, 223–235.Google Scholar
Lodge, G., Murison, R. and Heap, E.W. (1990) The effect of temperature on the hardseed content of some annual legumes grown on the northern slopes of New South Wales. Crop and Pasture Science 41, 941–955.Google Scholar
Loi, A., Cocks, P., Howieson, J. and Carr, S. (1999) Hardseededness and the pattern of softening in Biserrula pelecinus L., Ornithopus compressus L., and Trifolium subterraneum L. seeds. Crop and Pasture Science 50, 1073–1082.Google Scholar
Luna, B., Moreno, J., Cruz, A. and Fernández-González, F. (2007) Heat-shock and seed germination of a group of Mediterranean plant species growing in a burned area: an approach based on plant functional types. Environmental and Experimental Botany 60, 324–333.Google Scholar
Mallik, A. and Gimingham, C. (1985) Ecological effects of heather burning: II. Effects on seed germination and vegetative regeneration. Journal of Ecology 73, 633–644.CrossRefGoogle Scholar
Martin, R.E., Miller, R.L. and Cushwa, C.T. (1975) Germination response of legume seeds subjected to moist and dry heat. Ecology 56, 1441–1445.Google Scholar
McKeon, G. and Brook, K. (1983) Establishment of Stylosanthes species: changes in hardseededness and potential speed of germination at Katherine, NT. Crop and Pasture Science 34, 491–504.CrossRefGoogle Scholar
McKeon, G. and Mott, J. (1982) The effect of temperature on the field softening of hard seed of Stylosanthes humilis and S. hamata in a dry monsoonal climate. Crop and Pasture Science 33, 75–85.Google Scholar
Michael, P.J., Steadman, K.J. and Plummer, J.A. (2006) Climatic regulation of seed dormancy and emergence of diverse Malva parviflora populations from a Mediterranean-type environment. Seed Science Research 16, 273–281.Google Scholar
Moreira, B. and Pausas, J.G. (2012) Tanned or burned: the role of fire in shaping physical seed dormancy. PLoS ONE 7, e51523.Google Scholar
Moreira, B., Tormo, J., Estrelles, E. and Pausas, J. (2010) Disentangling the role of heat and smoke as germination cues in Mediterranean Basin flora. Annals of Botany 105, 627–635.Google Scholar
Moreno-Casasola, P., Grime, J.P. and Martinez, M.L. (1994) A comparative study of the effects of fluctuations in temperature and moisture supply on hard coat dormancy in seeds of coastal tropical legumes in Mexico. Journal of Tropical Ecology 10, 67–86.Google Scholar
Moreno, J., Zuazua, E., Pérez, B., Luna, B., Velasco, A. and Resco de Dios, V. (2011) Rainfall patterns after fire differentially affect the recruitment of three Mediterranean shrubs. Biogeosciences 8, 3721–3732.Google Scholar
Mouillot, F., Ratte, J.-P., Joffre, R., Moreno, J.M. and Rambal, S. (2003) Some determinants of the spatio-temporal fire cycle in a Mediterranean landscape (Corsica, France). Landscape Ecology 18, 665–674.Google Scholar
Mucunguzi, P. and Oryem-Origa, H. (1996) Effects of heat and fire on the germination of Acacia sieberiana DC and Acacia gerrardii Benth. in Uganda. Journal of Tropical Ecology 12, 1–10.Google Scholar
Ooi, M.K. (2012) Seed bank persistence and climate change. Seed Science Research 22, S53–S60.Google Scholar
Ooi, M.K., Denham, A.J., Santana, V.M. and Auld, T.D. (2014) Temperature thresholds of physically dormant seeds and plant functional response to fire: variation among species and relative impact of climate change. Ecology and Evolution 4, 656–671.Google Scholar
Probert, R.J. (2000) The role of temperature in the regulation of seed dormancy and germination. pp. 261–292 in Fenner, M. (Ed.) Seeds: The ecology of regeneration in plant communities. Wallingford, UK, CAB International.Google Scholar
Quinlivan, B. (1961) The effect of constant and fluctuating temperatures on the permeability of the hard seeds of some legume species. Crop and Pasture Science 12, 1009–1022.Google Scholar
Quinlivan, B. (1966) The relationship between temperature fluctuations and the softening of hard seeds of some legume species. Crop and Pasture Science 17, 625–631.Google Scholar
Quinlivan, B. (1968) Seed coat impermeability in the common annual legume pasture species of Western Australia. Animal Production Science 8, 695–701.Google Scholar
Quinlivan, B. and Millington, A. (1962) The effect of a Mediterranean summer environment on the permeability of hard seeds of subterranean clover. Crop and Pasture Science 13, 377–387.CrossRefGoogle Scholar
Rincker, C.M. (1954) Effect of heat on impermeable seeds of alfalfa, sweet clover, and red clover. Agronomy Journal 46, 247–250.CrossRefGoogle Scholar
Rivas, M., Reyes, O. and Casal, M. (2006) Influence of heat and smoke treatments on the germination of six leguminous shrubby species. International Journal of Wildland Fire 15, 73–80.Google Scholar
Rolston, M.P. (1978) Water impermeable seed dormancy. Botanical Review 44, 365–396.Google Scholar
Santana, V.M., Baeza, M.J. and Blanes, M.C. (2012) Clarifying the role of fire heat and daily temperature fluctuations as germination cues for Mediterranean Basin obligate seeders. Annals of Botany 111, 127–134.Google Scholar
Staden, J.V., Brown, N.A., Jäger, A.K. and Johnson, T.A. (2000) Smoke as a germination cue. Plant Species Biology 15, 167–178.CrossRefGoogle Scholar
Tarrega, R., Calvo, L. and Trabaud, L. (1992) Effect of high temperatures on seed germination of two woody Leguminosae. Vegetatio 102, 139–147.CrossRefGoogle Scholar
Taylor, G. (1981) Effect of constant temperature treatments followed by fluctuating temperatures on the softening of hard seeds of Trifolium subterraneum L. Functional Plant Biology 8, 547–558.CrossRefGoogle Scholar
Taylor, G. and Revell, C. (1999) Effect of pod burial, light, and temperature on seed softening in yellow serradella. Crop and Pasture Science 50, 1203–1209.Google Scholar
Taylor, G. and Revell, C. (2002) Seed softening, imbibition time, and seedling establishmentin yellow serradella. Crop and Pasture Science 53, 1011–1018.Google Scholar
Thanos, C. and Georghiou, K. (1988) Ecophysiology of fire-stimulated seed germination in Cistus incanus ssp. creticus (L.) Heywood and C. salvifolius L. Plant, Cell & Environment 11, 841–849.Google Scholar
Van Assche, J.A. and Vandelook, F.E. (2006) Germination ecology of eleven species of Geraniaceae and Malvaceae, with special reference to the effects of drying seeds. Seed Science Research 16, 283–290.Google Scholar
Van Assche, J.A., Debucquoy, K.L. and Rommens, W.A. (2003) Seasonal cycles in the germination capacity of buried seeds of some Leguminosae (Fabaceae). New Phytologist 158, 315–323.Google Scholar
Walters, M., Midgley, J.J. and Somers, M.J. (2004) Effects of fire and fire intensity on the germination and establishment of Acacia karroo, Acacia nilotica, Acacia luederitzii and Dichrostachys cinerea in the field. BMC Ecology 4, 3.Google Scholar
Warcup, J. (1980) Effect of heat treatment of forest soil on germination of buried seed. Australian Journal of Botany 28, 567–571.Google Scholar
Williams, P.R., Congdon, R.A., Grice, A.C. and Clarke, P.J. (2003) Fire-related cues break seed dormancy of six legumes of tropical eucalypt savannas in north-eastern Australia. Austral Ecology 28, 507–514.CrossRefGoogle Scholar