Figures
Fig. 1 A) Map of source and recipient transplant sites across the Mediterranean Sea. Colours indicate the source and direction of transplants in Catalunya (blue), Mallorca (yellow and orange) and Cyprus (red). B) Illustrated example of a transplant fragment, characterised by an apical shoot and multiple vertical shoots. C) Daily temperature anomalies experienced by P. oceanica transplants, with respect to the maximum annual temperature recorded in the site of origin (averaged between 1981-2019). Dashed vertical line, highlights switch between positive (stress) and negative (recovery) thermal anomalies. Maximum annual temperatures recorded in Catalunya = 25ºC, Mallorca = 29.1ºC and Cyprus = 29.3ºC. Daily temperatures experienced by transplants relative to their thermal regimes of origin in D) Catalunya, E) Mallorca and F) Cyprus. Shaded areas represent daily temperatures above thermal regime of origin. Different shades of blue, yellow, orange and red within D, E and F, illustrate temperature profiles in the different recipient sites. Grey line represents the long-term daily temperature, averaged between 1981-2019.
Fig. 2 Patterns of shoot length and nutritional quality of seagrasses over time in response to herbivory. A) Effects of a selective feeding event in August 2018 in Cyprus where herbivores selectively overgrazed cool-edge transplants (marked by asterisk). B) Carbon:Nitrogen ratios of P. oceanica leaves in the different treatments throughout the course of the experiment. C:N ratios in cool-cool plants (blue dashed line) were only measured in July 2018 and April 2019. C) Differences in herbivory on cool-warm transplants, compared to adjacent centre-warm and warm-warm transplants.
Fig. 3 Patterns of transplant survivorship (A) and transplant shoot survival (B) over the course of the experiment. Transplant fragment survival is represented as the proportion of transplants remaining at the end of each growth period, relative to the expected number of transplants (i.e. initial conditions minus fragments removed for growth measurements). Shoot survivorship is the change in the number of shoots per transplant, relative to initial conditions. Blue points and lines represent the fragments from Catalunya (cool edge), orange lines and points represent fragments from Mallorca (central) and red represents fragments from Cyprus (warm edge).
Fig. 4 Thermal performance of Posidonia oceanicatransplants across the Mediterranean Sea. Rows represent performance metrics of new leaf production (top), shoot elongation (middle) and total leaf length (bottom). Columns represent temperature metrics of absolute maximum temperature (left), maximum thermal stress anomaly (middle) and a comparison between heat stress period (July-Oct 2018, left, grey) and recovery periods (Nov – June 2019, white, right). Points represent mean ± SE rates per treatment. Shape of point illustrates the time-period measurements were recorded in. Colour of point represents the different transplant treatments and procedural controls as per previous Figures.