Mikko Anttonen. Finnish Forest Research Institute

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1 Mikko Anttonen Finnish Forest Research Institute

2 Global warming is expected: Change temperature and precipitation Extreme weather events Effects on forest trees in Finland Increased winter temperatures and heat spells during growing season More precipitation in winter and uneven during summer Waterlogging, nutrient leaching but also drought and heat stress How will trees be able to adapt to these changes?

3 Genetic variation and phenotypic plasticity are key factors for species survival Trees maintain high genetic variation within population Increase the understanding of genetic variation in adaptability of silver birch to changing climate 1. Level of variation within a naturally regenerated birch stand (Punkaharju, Finland) 2. Variation in relation to adaptability to elevated temperature and different soil moisture levels (controlled pot experiment)

4 In the common garden experiment established in 1998 half of the trees were harvested in 28 for aboveground biomass measurements Large variation between genotypes Biomass accumulation provides a clue about the adaptation of individuals to current and future conditions DW, kg Fast Intermediate Slow

5 Controlled experiment with 11 genotypes Ambient and Ambient + 1 temperatures Limiting, optimal and excess water

6 Suonenjoki, Finland Temperature 1. Ambient 2. Heated (Amb + 1) Pot water content 1. Low 2-3% 2. Normal (optimal) 4-5% 3. Excess >6% All combinations in 3 replicates 2 year experiment Heating by IR (Kuopio and Joensuu) Watering controlled manually

7 Temperature difference between heated and ambient plots (daily average) /17/211 6/6/211 6/26/211 7/16/211 8/5/211 8/25/211 9/14/211 1/4/211 1/24/ Pot water contents, %Pot 5. Ambient daily av temp AL AV AN AV AE AV HL AV HN AV HE AV. 17/5/211 6/6/211 26/6/211 16/7/211 5/8/211 25/8/211 14/9/211 4/1/211 24/1/

8 Temperature treatment from the beginning From the beginning of July (growing month) slowly developing dry and wet condition Measurements during 4 campaigns (gas exchange, leaf morphology and leaf constituent, short shoot and long shoot leaves) C1: level C2: Early events (1-2 weeks) C3: Tolerance phase (5 th week) C4: Recovery (2 weeks after finishing) Continuous measurements (conductance, chlorophyll, fluorescence) Biomass harvest at the end of growing season 211 Heat C1 C2 VOC C3 VOC C4 week Jun 23 Jun 24 Jun 25 Jun 26 Jul 27 Jul 28 Jul 29 Jul 3 Aug 31 Aug 32 Aug 33 Aug 34 Aug

9 Biomass accumulation to above ground (stem, branches and leaves) parts was defined at the end of the growing season 211 All parameters were affected by the genotype (p <.1) Total DW range was from 86 to 12 g Genotypes 2, 4 and 23 invested slightly more on stem than leaves 12 1 Total DW, g Slow Medium Fast

10 All measured parameter and genotypes (no interactions) followed basically the same trend In ambient temperature conditions watering did not have strong effect and in heated conditions normal watering led to higher biomass Water Temp W x T Total DW * (N > L = E) ns *** Stem DW ns ns *** Branch DW * (N > L = E) ns *** Leaf DW * (N > L = E) * (H > A) ***

11 Total DW, g Ambient Heated Stem DW, g Ambient Heated Low Normal Excess Low Normal Excess Branch DW, g Ambient Heated Low Normal Excess Leaves DW, g Ambient Heated Low Normal Excess

12 Results in line with biomass parameters Height important in competition for light Higher leaf area supports higher production Area, cm2 Ambient Heated Height, cm Ambient Heated Low Normal Excess Low Normal Excess

13 Several parameters were measured during the treatments -level, initial phase, tolerance and recovery Tolerance campaign 3 after 4 weeks of watering

14 Categhory Parameter Min Max Max/Min Photosynthesis Pn Ambien CO Pn Saturating CO Pn Amb / Pn Sat Fluorescence Yield Water Leaf water potential Conductance WUE Leaf water content Morphology Single leaf area Single leaf DW Single leaf FW SLA Stomata Trichomes lower Trichomes upper Leaf thickness Growth Diameter Height Stress Ascorbic acid Lipid peroxidation

15 Net photosynthesis in ambient or saturating CO2 conditions or fluorescence yield parameter were not affected by the treatments Total chlorophyll measurements show an interesting trend which will be further investigated Total chlorophyll - genotype AL AN AE HL HN HE 1. 6/26/211 7/16/211 8/5/211 8/25/211 9/14/

16 WUE Low > Normal = Excess, P <.1, L/N = 1.55 Heated > Ambient, P <.5, H/A = 1.12 Conductance Ambient > Heated, P <.1, H/A= 1.11 Normal > Excess > Low, P <.1, N/E = 1.11, N/L = 1.55 Leaf water potential Pressure bomb Temperature * Water P <.1 Normal plants had highest leaf WC WUE WP, MPa Ambient Ambient Heated Low Normal Excess Heated Low keeps up with biomass production with efficicent water control.4.2 Low Normal Excess

17 Single leaf area Normal watering and heating led to largest leaves Temperature, P <.5, H/A = 1.6 Water, P <.1, N/E = 1.8, N/L = Single leaf DW.35 Limited water led to lowest DW.3.25 Heating emphasised the difference.2 between L and other treatments.15 SLA.1 L < N=E, P <.1, L/N = Low watering leads to smaller leaves = less evaration DW, g Ambient Heated Low Normal Excess

18 Many parameters were unaffected by the treatments Leaf thickness Stomata number Trichome desity

19 Lipid peroxidation methodology was used to evaluate oxidative damage No differences were seen betwen treatments Similarly, no differences were found in the contents of oxidized and reduced forms of ascorbic acid Other indicators might be needed

20 Pending analyses 211 VOC, metabolites, chlorophyll, roots Statistics The experiment will be repeated in 212 Spring phenology Mychorriza communities Heating started before bud burst Longer water treatment 211 C1 C2 VOC C3 VOC C4 week Jun 24 Jun 25 Jun 26 Jul 27 Jul 28 Jul 29 Jul 3 Aug 31 Aug 32 Aug 33 Aug 34 Aug 35 Sep C1 C2 VOC C3 VOC C

21 Genotype affected everything No interactions between genotype and treatments Plants were able to grow well in optimal conditions but they are also able to adapt and perform well in stressfull conditions Smaller leaves and efficeint use of water connecetd with stress tolerance

22 METLA Elina Vapaavuori Mikko Anttonen Boy Possen Matti Rousi Juha Heiskanen Katri Kärkkäinen UEF Elina Oksanen Sari Kontunen-Soppela Markku Keinänen Toini Holopainen Katariina Koikkalainen EMU Ülo Niinemetz Lucian Copolovici Astrid Kännaste

23 Water Temp W x T Total DW * (N > L = E) ns *** Stem DW ns ns *** Branch DW * (N > L = E) ns *** Leaf DW * (N > L = E) * (H > A) ***