Chapter 11
Life-History Responses to the Altitudinal
Gradient
Paola Laiolo and José Ramón Obeso
Abstract We review life-history variation along elevation in animals and plants
and illustrate its drivers, mechanisms and constraints. Elevation shapes life histories
into suites of correlated traits that are often remarkably convergent among organisms facing the same environmental challenges. Much of the variation observed
along elevation is the result of direct physiological sensitivity to temperature and
nutrient supply. As a general rule, alpine populations adopt ‘slow’ life cycles,
involving long lifespan, delayed maturity, slow reproductive rates and strong
inversions in parental care to enhance the chance of recruitment. Exceptions in both
animals and plants are often rooted in evolutionary legacies (e.g. constraints to
prolonging cycles in obligatory univoltine taxa) or biogeographic history (e.g.
location near trailing or leading edges). Predicting evolutionary trajectories into the
future must take into account genetic variability, gene flow and selection strength,
which define the potential for local adaptation, as well as the rate of anthropogenic
environmental change and species’ idiosyncratic reaction norms. Shifts up and
down elevation in the past helped maintain genetic differentiation in alpine populations, with slow life cycles contributing to the accumulation of genetic diversity
during upward migrations. Gene flow is facilitated by the proximity of neighbouring populations, and global warming is likely to move fast genotypes upwards
and reduce some of those constraints dominating alpine life. Demographic buffering
or compensation may protect local alpine populations against trends in environmental conditions, but such mechanisms may not last indefinitely if evolutionary
trajectories cannot keep pace with rapid changes.
Keywords Bet hedging Á Centre-periphery hypothesis Á Local adaptation Á
Ontogeny Á Phenotypic plasticity Á Reproductive allocation Á Slow-fast life-history
continuum Á Survival
P. Laiolo (&) Á J.R. Obeso
Research Unit of Biodiversity, Spanish National Research Council,
Principado de Asturias, Oviedo University, Campus de Mieres, 33600 Mieres, Spain
e-mail: paola.laiolo@csic.es
© The Author(s) 2017
J. Catalan et al. (eds.), High Mountain Conservation in a Changing World,
Advances in Global Change Research 62, DOI 10.1007/978-3-319-55982-7_11
253
Life-History Responses to the Altitudinal
Gradient
Paola Laiolo and José Ramón Obeso
Abstract We review life-history variation along elevation in animals and plants
and illustrate its drivers, mechanisms and constraints. Elevation shapes life histories
into suites of correlated traits that are often remarkably convergent among organisms facing the same environmental challenges. Much of the variation observed
along elevation is the result of direct physiological sensitivity to temperature and
nutrient supply. As a general rule, alpine populations adopt ‘slow’ life cycles,
involving long lifespan, delayed maturity, slow reproductive rates and strong
inversions in parental care to enhance the chance of recruitment. Exceptions in both
animals and plants are often rooted in evolutionary legacies (e.g. constraints to
prolonging cycles in obligatory univoltine taxa) or biogeographic history (e.g.
location near trailing or leading edges). Predicting evolutionary trajectories into the
future must take into account genetic variability, gene flow and selection strength,
which define the potential for local adaptation, as well as the rate of anthropogenic
environmental change and species’ idiosyncratic reaction norms. Shifts up and
down elevation in the past helped maintain genetic differentiation in alpine populations, with slow life cycles contributing to the accumulation of genetic diversity
during upward migrations. Gene flow is facilitated by the proximity of neighbouring populations, and global warming is likely to move fast genotypes upwards
and reduce some of those constraints dominating alpine life. Demographic buffering
or compensation may protect local alpine populations against trends in environmental conditions, but such mechanisms may not last indefinitely if evolutionary
trajectories cannot keep pace with rapid changes.
Keywords Bet hedging Á Centre-periphery hypothesis Á Local adaptation Á
Ontogeny Á Phenotypic plasticity Á Reproductive allocation Á Slow-fast life-history
continuum Á Survival
P. Laiolo (&) Á J.R. Obeso
Research Unit of Biodiversity, Spanish National Research Council,
Principado de Asturias, Oviedo University, Campus de Mieres, 33600 Mieres, Spain
e-mail: paola.laiolo@csic.es
© The Author(s) 2017
J. Catalan et al. (eds.), High Mountain Conservation in a Changing World,
Advances in Global Change Research 62, DOI 10.1007/978-3-319-55982-7_11
253