Response to experimental warming in northern eelgrass populations: comparison across a range of temperature adaptations

Transcription

1 The following supplement accompanies the article Response to experimental warming in northern eelgrass populations: comparison across a range of temperature adaptations P. Beca-Carretero*, B. Olesen, N. Marbà, D. Krause-Jensen *Corresponding author: pedropersiobk@hotmail.es Marine Ecology Progress Series 589: (2018) Table S1. Comparison of growth- and physiological responses of eelgrass from a cold-temperate population (Århus Bay, Aa), and two subarctic populations (Kapisilit, Ka, and Kobbe Fjord, Ko) measured at their respective in-situ summer temperatures of 20 C, 15 C and 10 C. Pleaf/Rleaf is the ratio between net photosynthesis and respiration of leaves. F-values of one-way ANOVA are shown along with significance levels (*P<0.05; **P<0.01) and information from Tukey HD test on which of the populations are significantly different. Degrees of freedom are Response variable F-value Differences Growth responses Leaf formation rate (shoot 1 d -1 ) 3.65 Aa,Ka,Ko Leaf elongation rate (cm shoot 1 d -1 ) 2,60 Aa,Ka,Ko Rhizome elongation rate (cm shoot 1 d -1 ) 2.87 Aa,Ka,Ko Relative growth rate (g g -1 d -1 ) Aa,Ka,Ko Physiological responses Net photosynthesis (µmol O2 g -1 DW h -1 ) 24.89*** Aa,>Ka,Ko Leaf respiration rate (µmol O2 g -1 DW h -1 ) 1.54 Aa,Ka,Ko Rhizome-root respiration (µmol O2 g -1 DW h -1 ) 4.12 Aa, Ka,Ko Pleaf / Rleaf 9.91*** Aa>Ka,Ko 1

2 Table S2. Comparison of differences in growth responses (left column) and physiological responses (right columns) between eelgrass populations (pop) exposed to the same temperature gradient (temp). One population was cold-temperate, collected in Århus Bay (Aa), Denmark, while two were subarctic, collected in Kapisilit (Ka) and Kobbe Fjord (Ko), Greenland. F-values of two-way ANOVA are shown along with significance levels (*P<0.05; **P<0.01; ***P<0.001) and Tukey HD test results on which of the populations are significantly different. Degrees of freedom are 7-8. Units are as shown in Figure 1 and Table S1. Response variable F-value Differences Response variable F-value Differences Leaf formation rate Net photosynthesis Pop 14.21*** Aa<Ka,Ko Pop 1.13 Aa,Ka,Ko Temp 20.85*** Temp 40.33*** Pop x Temp 1.67 Pop x Temp 2.77* Leaf elongation rate Leaf respiration Pop 28.25*** Aa<Ka,Ko Pop 27.09*** Aa,Ka<Ko Temp 25.47*** Temp 35.07*** Pop x Temp 1.09 Pop x Temp 5.08*** Rhizome elongation rate Rhizome-root respiration Pop 30.38*** Aa<Ka,Ko Pop 7.5** Aa,Ka<Ko Temp 7.54*** Temp 27.02*** Pop x Temp 2.57* Pop x Temp 2.38* Relative growth rate Pmax:Rleaf Pop 16.92*** Aa<Ka,Ko Pop 6.36** Aa,Ka; Aa>Ko Temp 5.69** Temp 13.68*** Pop x Temp 1.79 Pop x Temp 2.0 2

3 Table S3. Optimum temperature, coefficient of variation (CV), activation energy-rise (Ear), activation energy-fall (Eaf). The standard error of Ea, coefficient of determination (R 2 ), number of observations (N) and significance (p) of the rise and fall fits are indicated. ns: non significant Optimum T (ºC) CV (%) rise Ear (ev) SE R 2 N p Eaf (ev) SE R 2 N p Leaf formation rate (shoot 1 d -1 ) Århus ns ns Kobbe Fj Kapisillit Kapisillit low ns ns Leaves elongation rate (cm shoot 1 d -1 ) Århus Kobbe Fj ns Kapisillit ns Kapisillit low Rhizome elongation (cm shoot 1 d -1 ) Århus Kobbe Fj ns Kapisillit ns ns Kapisillit low Relative growth rate (g g -1 d -1 ) Århus ns ns Kobbe Fj Kapisillit ns Kapisillit low fall 3

4 Pmax/Rleaf Århus ns Kobbe Fj Kapisillit Kapisillit low Net photosynthesis rate (µmol O2 g -1 DW h -1 ) Århus Kobbe Fj Kapisillit Kapisillit low Rhizome respiration rate (µmol O2 g -1 DW h -1 ) Århus > Kobbe Fj > Kapisillit > Kapisillit low > Leaf respiration rate (µmol O2 g -1 DW h -1 ) Århus > Kobbe Fj Kapisillit Kapisillit low

5 Table S4. Comparison of growth responses (left columns) and physiological responses (right columns) to temperature (temp) between eelgrass shoots collected in Kapisillit, Greenland and grown at high (H; 200 µmol photons m -2 s -1 ) and low (L; 50 µmol photons m -2 s -1 ) irradiance. F-values of two-way ANOVA are shown along with significance levels (*P<0.05; **P<0.01, ***P<0.001) and Tukey HD test results on which of the light treatments are significantly different. Degrees of freedom are 4. Units are as shown in Figure 2 and Table S1. Response variable F-value Differences Response variable F-value Differences Leaf formation rate Net photosynthesis Light 5.11* H>L Light 49.36*** H<L Temp 7.01*** Temp 41.04*** Light x Temp 2.75 Light x Temp 4.5** Leaf elongation rate Leaf respiration Light 0.13 H>L Light 1.73 H,L Temp 24.4*** Temp 6.84*** Light x Temp 1.54 Light x Temp 1.21 Rhizome elongation rate Rhizome-root respiration Light 4.96* H>L Light 2.28 H,L Temp 3.75* Temp 22.6*** Light x Temp 1.9 Light x Temp 3.65* Relative growth rate Pmax:Rleaf Light 33.93*** H>L Light 37.05*** H<L Temp 2.15 Temp 10.08*** Light x Temp 2.60 Light x Temp 2.28 Table S5. Comparison of whole plant photosynthetic light response and chlorophyll content between eelgrass shoots collected in Kapisillit, Greenland and grown at temperatures (Temp) between 10 o C and 28 C and high (H; 200 µmol photons m -2 s -1 ) and low (L; 50 µmol m -2 s 1 ) irradiance, respectively. F-values of two-way ANOVA are shown along with the significance levels (*P<0.05; P**<0.01; P***<0.001) and Tukey HD test results on significant differences between light treatments. Degrees of freedom are 4. Units are as shown in Figure 3. Response variable Factors F-value Difference Light use efficiency Light 2.10 H,L Temp 0.19 Light x Temp 1.30 Respiration Light 0.34 H,L Temp 7.36*** Light x Temp 1.04 Light compensation point Light 8.17** H>L Temp 10.86*** Light x Temp 0.79 Chlorophyll a+b Light 75.49*** H<L Temp 5.79** Light x Temp 4.9** 5

6 Fig. S1. Plant collection locations: two in Greenland at 64 ºN, Kobbe Fjord (KO) and Kapisilit (KA); and one in Denmark at 56 ºN, Århus (AR) Fig. S2. Simulation of the experimental design of one temperature treatment with shoots from the three populations. The 3 rows of cylinders left to right correspond to AR (Århus), KO (Kobbe) and KA (Kapisillit). The row of cylinders on the far right, KA L (Kapisillit Low), represents the low light treatment (50 µm photons m -2 s -1 ) 6

7 Fig. S3. The response of rhizome elongation (left) and respiration (right) of Zostera marina populations from Greenland (Kobbe Fjord, Kapisillit) and Denmark (Århus) to a range of experimental temperatures including the in situ temperature at the time of collection of each of populations, i.e. 10 C for Kobbe Fjord, 15 C for Kapisillit, and 20 C for Århus Fig. S4. The temperature response of rhizome elongation (left) and respiration (right) of Zostera marina from subarctic Greenland (Kapisillit) population grown under low (50 µmol photons m -2 s -1 ) and high light (200 µmol photons m -2 s -1 ). 7