Year-end Sale % OFF 
Abstract
Organisms from all domains of life can have highly variable morphologies, with this plasticity suggested to increase fitness and survivability under stressful conditions. Predicting how organisms will adapt to environmental change requires an understanding of how variable morphologies perform under environmental stress. Morphological plasticity has been documented within marine macroalgae inhabiting environmental gradients, however the functional consequences of this variation has been rarely tested. In this study, form-function was assessed in the habitat-forming, intertidal macroalga Hormosira banksii. Morphological variation was quantified on two spatial scales (tidal gradient versus latitudinal gradient) and the performance tested (relative water content and photosynthetic efficiency) of morphological variants during heat and desiccation stress. At regional scales, individuals at the warm distributional edge were overall smaller in size, and had smaller vesicles (higher surface area to volume ratio; SA:VOL) than those from central populations. At local scales, individuals high on the shore were generally shorter and had larger vesicles than those low on the shore. Vesicle morphology (SA:VOL) was found to predict relative water content and photosynthetic performance during desiccation and rehydration. Differences in SA:VOL of vesicles between heights on the shore may reflect water requirements needed to maintain tissue hydration for photosynthesis during low tide. Warm-edge populations showed increased thermal sensitivity as indicated by decreased photosynthetic yield of PSII and delays in recovery after desiccation. Sensitivities to higher temperatures amongst warm-edge populations are potentially due to smaller fluctuations in regional temperatures as well as their morphology. This study provides a mechanistic understanding of the morphological variation among H. banksii populations. It suggests that H. banksii has a high degree of morphological plasticity reflecting local climate, topography and environmental conditions, with this morphological variation having functional consequences. Morphological variation across local and regional scales will be important for resilience of this species to future climate warming.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
