Seed germination, hydrothermal time models and the effects of global warming on a threatened high Andean tree species

Abstract Seed germination is a crucial event in a plant's life cycle. Because temperature and water availability are important regulators of seed germination, this process will likely be influenced by global warming. Insight into the germination process under global warming is thus crucial, and requires the study of a wide range of water availability and temperature conditions. As hydrothermal time (HTT) models evaluate seed germination for any combination of water potential and temperature, they can be suitable to predict global warming effects on seed germination. We studied the germination characteristics of the high Andean endemic tree species Polylepis besseri (Rosaceae), using HTT models. We were especially interested in the potential effects of global warming on seed germination. Assembly of HTT models for P. besseri was fairly straightforward due to the lack of a seed dormancy mechanism. The models allowed prediction of Polylepis germination under constant and alternating temperatures. Initially, a global warming induced increase in the field minimum and mean temperature will increase P. besseri germination, but as maximum temperatures rise above the optimum temperature for the species, seed germination will become jeopardized. Effects of global warming on seed germination are currently considerably underexplored. HTT models prove to be useful tools to study a plant species' general germination characteristics, and how they may become affected under global warming. For the endemic mountain tree species P. besseri, we predict an increase, followed by a decrease of seed germination under global warming.

[1]  Ken Thompson,et al.  Climate change and plant regeneration from seed , 2011 .

[2]  V. LeMay,et al.  Changes in high arctic tundra plant reproduction in response to long‐term experimental warming , 2011 .

[3]  M. Dainese.  Impact of land use intensity and temperature on the reproductive performance of Dactylis glomerata populations in the southeastern Alps , 2011, Plant Ecology.

[4]  D. Goldblum,et al.  Geographic Variation of Germination, Growth, and Mortality in Sugar Maple (Acer saccharum): Common Garden and Reciprocal Dispersal Experiments , 2011 .

[5]  Rafael Rubio de Casas,et al.  Germination, Postgermination Adaptation, and Species Ecological Ranges , 2010 .

[6]  K. Tielbörger,et al.  Evolvability of between-year seed dormancy in populations along an aridity gradient , 2010 .

[7]  J. Fjeldså,et al.  Polylepis woodland remnants as biodiversity islands in the Bolivian high Andes , 2010, Biodiversity and Conservation.

[8]  W. Landman.  Climate change 2007: the physical science basis , 2010 .

[9]  O. Eriksson,et al.  Significant effects of temperature on the reproductive output of the forest herb Anemone nemorosa L. , 2010 .

[10]  S. Meyer,et al.  Predicting seed dormancy loss and germination timing for Bromus tectorum in a semi-arid environment using hydrothermal time models , 2009, Seed Science Research.

[11]  F. Pugnaire,et al.  Response of a Mediterranean semiarid community to changing patterns of water supply , 2009 .

[12]  Y. Wei,et al.  Critical conditions for successful regeneration of an endangered annual plant, Cryptantha minima: A modeling approach , 2009 .

[13]  C. Fernández-Quintanilla,et al.  Germination Patterns in Naturally Chilled and Nonchilled Seeds of Fierce Thornapple (Datura Ferox) and Velvetleaf (Abutilon Theophrasti) , 2009, Weed Science.

[14]  M. Verdú,et al.  EARLY TO RISE MAKES A PLANT HEALTHY, WEALTHY, AND WISE. , 2008, Ecology.

[15]  A. Mackay.  Climate Change 2007: Impacts, Adaptation and Vulnerability. Contribution of Working Group II to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change , 2008 .

[16]  D. Renison,et al.  The performance of Polylepis australis trees along their entire altitudinal range: implications of climate change for their conservation , 2008 .

[17]  B. Graae,et al.  The impact of temperature regimes on development, dormancy breaking and germination of dwarf shrub seeds from arctic, alpine and boreal sites , 2008, Plant Ecology.

[18]  A. Fehér,et al.  The effect of drought and heat stress on reproductive processes in cereals. , 2007, Plant, cell & environment.

[19]  J. Peñuelas,et al.  European phenological response to climate change matches the warming pattern , 2006 .

[20]  W. Finch-Savage,et al.  Seed dormancy and the control of germination. , 2006, The New phytologist.

[21]  E. Zavaleta.  Shrub establishment under experimental global changes in a California grassland , 2006, Plant Ecology.

[22]  A. Valleriani,et al.  Can seeds predict their future? Germination strategies of density-regulated desert annuals , 2005 .

[23]  J. Porter.  Rising temperatures are likely to reduce crop yields , 2005, Nature.

[24]  Darach Watson,et al.  Mysterious disappearance of female investigators , 2005, Nature.

[25]  Julie R. Etterson,et al.  EVOLUTIONARY RESPONSES TO CHANGING CLIMATE , 2005 .

[26]  K. Bradford,et al.  Hydrothermal time analysis of seed dormancy in true (botanical) potato seeds , 2005, Seed Science Research.

[27]  A. Traveset,et al.  EARLY EMERGENCE ENHANCES PLANT FITNESS: A PHYLOGENETICALLY CONTROLLED META‐ANALYSIS , 2005 .

[28]  J. A. Molina,et al.  Classification of the high-Andean Polylepis forests in Bolivia , 2005, Plant Ecology.

[29]  Y. Bai,et al.  Effect of seed size and sub-zero imbibition-temperature on the thermal time model of winterfat (Eurotia lanata (Pursh) Moq.) , 2004 .

[30]  Marcelo Cabido,et al.  Regeneration of Polylepis australis Bitt. in the mountains of central Argentina , 2004 .

[31]  P. Allen.  When and how many? Hydrothermal models and the prediction of seed germination , 2003 .

[32]  Kent J. Bradford,et al.  A hydrothermal time model explains the cardinal temperatures for seed germination , 2002 .

[33]  Philip E. Hulme,et al.  Does temperature limit the invasion of Impatiens glandulifera and Heracleum mantegazzianum in the UK , 2002 .

[34]  Kent J. Bradford,et al.  Applications of hydrothermal time to quantifying and modeling seed germination and dormancy , 2002, Weed Science.

[35]  F. Forcella,et al.  Modeling seedling emergence , 2000 .

[36]  E. Kebreab,et al.  Modelling the effects of water stress and temperature on germination rate of Orobanche aegyptiaca seeds. , 1999 .

[37]  C. Swanton,et al.  Modeling germination and seedling elongation of common lambsquarters (Chenopodium album) , 1999, Weed Science.

[38]  C. Baskin,et al.  Seeds: Ecology, Biogeography, and, Evolution of Dormancy and Germination , 1998 .

[39]  D. T. Booth,et al.  Biophysical, physiological and biochemical processes regulating seed germination , 1998, Seed Science Research.

[40]  R. Ellis,et al.  Alternating Temperatures and Rate of Seed Germination in Lentil , 1994 .

[41]  K. Bradford,et al.  Hydrothermal time analysis of tomato seed germination at suboptimal temperature and reduced water potential , 1994, Seed Science Research.

[42]  K. Bradford,et al.  Effects of Priming and Endosperm Integrity on Seed Germination Rates of Tomato Genotypes I. GERMINATION AT SUBOPTIMAL TEMPERATURE , 1990 .

[43]  K. Bradford.  A water relations analysis of seed germination rates. , 1990, Plant physiology.

[44]  E. H. Roberts,et al.  The Influence of Temperature on Seed Germination Rate in Grain Legumes II. INTRASPECIFIC VARIATION IN CHICKPEA (Cicer arietinum L.) AT CONSTANT TEMPERATURES , 1986 .

[45]  E. H. Roberts,et al.  The Influence of Temperature on Seed Germination Rate in Grain Legumes I. A COMPARISON OF CHICKPEA, LENTIL, SOYABEAN AND COWPEA AT CONSTANT TEMPERATURES , 1986 .

[46]  R. J. Gummerson.  The Effect of Constant Temperatures and Osmotic Potentials on the Germination of Sugar Beet , 1986 .

[47]  B. E. Michel,et al.  Evaluation of the water potentials of solutions of polyethylene glycol 8000 both in the absence and presence of other solutes. , 1983, Plant physiology.

[48]  J. P. Grime,et al.  A COMPARATIVE STUDY OF GERMINATION RESPONSES TO DIURNALLY-FLUCTUATING TEMPERATURES , 1983 .

[49]  J. Harper.  Population Biology of Plants , 1979 .

[50]  J. P. Grime,et al.  Seed germination in response to diurnal fluctuations of temperature , 1977, Nature.

[51]  J. Wilmshurst,et al.  Spatial variation in temperature thresholds during seed germination of remnant Festuca hallii populations across the Canadian prairie , 2010 .

[52]  M. Herrero,et al.  Global warming and sexual plant reproduction. , 2009, Trends in plant science.

[53]  A. Fischlin,et al.  Ecosystems, their properties, goods and services , 2007 .

[54]  J. Palutikof,et al.  Climate change 2007: Impacts, Adaptation and Vulnerability. Contribution of Working Group II to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Summary for Policymakers. , 2007 .

[55]  O. E. Salab,et al.  Does drought control emergence and survival of grass seedlings in semi-arid rangelands? An example with a Patagonian species , 2007 .

[56]  D. Teketay.  Seed and regeneration ecology in dry Afromontane forests of Ethiopia: I. Seed production - population structures , 2005 .

[57]  M. Khan,et al.  Hydrothermal time as a tool in comparative germination studies. , 2000 .

[58]  K. Bradford,et al.  Hydrothermal time analysis of tomato seed germination responses to priming treatments , 1999 .

[59]  L. Conner.  Seed germination of five subalpine Acaena species , 1987 .

[60]  B. Simpson.  A Revision of the Genus Polylepis (Rosaceae: Sanguisorbeae) , 1979 .