Kremer, Antoine. 2017. Adaptive and plastic responses of Quercus petraea populations to climate across Europe. Global Change Biology, 23 (7). 2831-2847. 10.1111/gcb.13576 Contact CEH NORA team at noraceh@ceh.ac.ukThe NERC and CEH trademarks and logos ('the Trademarks') are registered trademarks of NERC in the UK and other countries, and may not be used without the prior written consent of the Trademark owner. Accepted ArticleThis article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version of Record. Please cite this article as doi: 10.1111/gcb.13576 This article is protected by copyright. All rights reserved. Accepted ArticleThis article is protected by copyright. All rights reserved. Accepted ArticleThis article is protected by copyright. All rights reserved. †Corresponding author: E-mail: antoine.kremer@pierroton.inra.fr Phone: + (33) 5 5712- 2832.Keywords: Climatic change, Climatic transfer distance, Mixed model, Quercus petraea, Survival, Tree growth.Paper Type: Primary Research. AbstractHow temperate forests will respond to climate change is uncertain; projections range from severe decline to increased growth. We conducted field tests of sessile oak (Quercus petraea), a widespread keystone European forest tree species, including more than 150,000 trees sourced from 116 geographically diverse populations. The tests were planted on 23 field sites in six European countries, in order to expose them to a wide range of climates, including sites reflecting future warmer and drier climates. By assessing tree height and survival, our objectives were twofold: (1) to identify the source of differential population responses to climate (genetic differentiation due to past divergent climatic selection versus plastic responses to ongoing climate change), (2) to explore which climatic variables (temperature or precipitation) trigger the population responses. Tree growth and survival were modeled for contemporary climate and then projected using data from four regional climate models for years 2071-2100, using two greenhouse gas concentration trajectory scenarios each. Overall results indicated a moderate response of tree height and survival to climate variation, with changes in dryness (either annual or during the growing season) Accepted ArticleThis article is protected by copyright. All rights reserved.explaining the major part of the response. Whilst, on average, populations exhibited local adaptation, there was significant clinal population differentiation for height growth with winter temperature at the site of origin. The most moderate climate model (HIRHAM5-EC; rcp4.5) predicted minor decreases in height and survival, whilst the most extreme model (CCLM4-GEM2-ES; rcp8.5) predicted large decreases in survival and growth for southern and southeastern edge populations (Hungary and Turkey). Other non-marginal populations with continental climate...

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Summary -Clonal variation in flowering characteristics and cone production was investigated in a Scots pine (Pinus sylvestris L) clonal seed orchard consisting of 32 clones. At the time of observations, the orchard was 17-19 years old. It was found that on average, within a clone, female flowers were receptive about 1 day before the beginning of pollen shedding and there was a significant correlation between the ranks of clones according to their onset of flowering in 2 consecutive years. Male and female flowering periods were synchronized among the majority of clones and the index of phenological overlap was over 0.41. Significant variations among clones were found for male and female cone production as well as for some selected pollen-related characteristics. On average, individual clones in the orchard produced in total from 0.4 to 4.5 kg of pollen and from 900 to 6500 cones a year. It was found that 25% and 50% of clones produced 46% and 72% of pollen, respectively. Analogous numbers for cone production were 35% and 63%. Some patterns of sexual asymmetry among clones were detected; however, genetic correlations between pollen and cone productions were positive. Effective population sizes were generally high, but the estimate was lower for pollen (75.9%) than for cone production (95.9%). The expected outcrossing rate, based on effective population size calculated using both male and female contribution and background pollination, was high (0.977). The efficiency of the orchard and its potential use for reforestation purposes is discussed.

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The genetic variability of Scots pine was investigated in six populations from Poland representing two maternal populations and their natural and artificial progenies. Thirteen enzyme systems controlled by 2 allozyme loci were analyzed using starch gel electrophoresis. Progeny populations maintained a high and similar level of genetic variation to that observed in the maternal populations. As expected, much closer genetic relationships were observed between maternal populations and their respective progeny than between the two maternal populations themselves. Progeny populations had the same major alleles, but differed in the number of rare alleles. Therefore, probably not all rare alleles were transferred from the maternal stands to the progenies. In addition, new rare alleles appeared in the progeny populations, possibly as a result of external pollen flow into the maternal populations.

Precocious flowering provides opportunities to shorten a breeding cycle. A tree may flower for the first time when sufficient crown development has occurred and there are enough meristems to support both vegetative and reproductive buds. Precocious flowering can be promoted through the use of cultural techniques, such as photoperiod, accelerated growth, gibberellins and water stress. The length of the juvenile phase is dependent on genetic and environmental variables that affect achievement of a minimum size, and is positively correlated with the height of the plants within a family. Selection pressure can be applied successfully to the precocious flowering character, and crossed or inbred lines of precocious flowering progeny can be developed. Various levels and amounts of genetic control have been implicated in the control of precocious flowering.

Seedlings of three families of jack pine (Pinus banksiana Lamb.) were subjected to 16 combinations of photoperiod, growth environment (outdoors, greenhouse and biotron) and gibberellin (GA(4/7)) treatment. After 14 months, which included two dormancy induction periods, ovulate flowering was observed. There was a strong positive correlation between flowering and seedling height; female flower production was stimulated by both a declining photoperiod during bud development and GA(4/7) treatment; and there was an interaction between GA(4/7) treatment and family, such that the difference in flowering intensity between a late-flowering and an early-flowering family was eliminated by GA(4/7) treatment. The results suggest that the genetic control over the time of onset of flowering, and GA(4/7)-induction of flowering depend on a common mechanism.