Rapid change in adaptive performance from one generation to the next in Picea abies—Central European trees in a Nordic environment

Abstract

Seedlings of open-pollinated Picea abies families from Norwegian and Central European parent trees standing at three sites in Norway were tested for timing of bud set at the end of the first growth season together with seedlings from control provenances producing seeds at their geographical origin. The parental origins were confirmed with a maternally inherited mitochondrial marker that distinguishes trees of the Northern European range from those of the Central European range. The seedlings from the families of Central European mother trees producing seeds in Norway had on average a bud set more similar to the families of local Norwegian origin producing seeds at the same site than the provenance of the same Central European origin. It is argued that the rapid change in this adaptive trait from one generation to the next can be explained by recent research results demonstrating that day length and temperature conditions during embryo formation and maturation can influence the phenotypic performance of seedlings in Norway spruce. This effect may influence the fitness of naturally regenerated plants produced in plantations of Central European trees in Norway.

Considering evolutionary processes in adaptive forestry

“…Not included into this predictive model, epigenetic effects, i.e. environmentally determined heritable modification of gene expression, can also contribute to adaptation to sudden changes (Bossdorf et al 2008;Skrøppa et al 2010). …”

“…Emblematic examples are the worldwide transfer of Pinus radiata (Yan et al 2006) and the south to north translocation of Picea abies (Skrøppa et al 2010). This adaptation was achieved in very few generations of trees, and it proceeds from plasticity and/or evolution.…”

Impacts of warming and changes in precipitation frequency on the regeneration of two Acer species

“…lower survival under warmer conditions). This is likely related to the environmental conditions experienced by the mother tree during seed production (Johnsen et al, 2005a,b;Skrøppa et al, 2010;Carón et al, 2014a). While we lack detailed information on environmental conditions experienced by all the mother trees, previous studies suggest that the observed pattern (different survival according to the seed provenance under changing environmental conditions) is likely related to the temperature experienced during seed production (Johnsen et al, 2005a,b;Carón et al, 2014a,b).…”

Epigenetic memory effects in forest trees: a victory of “Michurinian biology”?

“…In Scandinavia again, quite much Norway spruce originating from Central Europe (Germany, Austria, the Carpathians) was planted, and some plantations already reproduce. Offsprings from such plantations resemble the local indigenous plantations rather than the material translocated from identical Central-European source populations in terms of timing of budburst, budset, growth cessation and other adaptive traits, which means that in spite of unchanged genetic structures, the populations of Central-European origin changed their phenological behavior within a single generation (Skrøppa et al 2010).…”

“…We deliberately avoid using the term 'adaptation' in this context, as this term is commonly used for changes of allelic structures through natural selection in response to environmental pressures. The capacity of a population to adjust phenology (and potentially other adaptive traits) to local climate and photoperiod as described by Skrøppa et al (2010) is relevant in the context of climate change: even when the adult trees will be damaged by climatic stress, the offspring generation may already be able to cope with the new climate. Close-to-nature forestry, leaving the broadest space for natural processes, may thus be a viable complementary strategy to assisted migration in mitigation of climate-change effects.…”