Physiological characteristics of the seagrass Posidonia sinuosa along a depth-related gradient of light availability
Collier, Catherine J., Lavery, Paul S., Ralph, Peter J., and Masini, Raymond J. (2008) Physiological characteristics of the seagrass Posidonia sinuosa along a depth-related gradient of light availability. Marine Ecology Progress Series, 353 . pp. 65-79.
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View at Publisher Website: http://dx.doi.org/10.3354/meps07171
Physiological plasticity has the capacity to prolong seagrass survival under reduced light conditions. However, when light is attenuated across a depth gradient, the relative importance of this over other mechanisms for tolerating long-term light reduction (such as morphological adjustments and shoot loss) has been questioned. This study aimed to describe a number of the physiological characteristics of Posidonia sinuosa Cambridge et Kuo along a depth-related gradient of light availability (1.6 to 9.0 m depth) and infer how these characteristics are important for the long-term maintenance of the meadow. Rapid light curve-derived parameters, light harvesting pigments, photoprotective pigments and nutrient and carbohydrate concentrations exhibited few differences among depth strata, but showed some (albeit limited) adjustment between the seasons. It was inferred that some physiological plasticity is possible in P. sinuosa but that differences in the depth-related gradient of long-term light availability were not sufficient to induce physiological differences, even at the depth limit. Shoot density reductions, which reduce the effects of self-shading, possibly offset depth-related light reductions. Because the physiological characteristics we examined did not explain the adaptations by P. sinuosa to the long-term gradient of light availability, they may not be useful indicators of long-term light reduction.
|Item Type:||Article (Refereed Research - C1)|
|Keywords:||light reduction; depth gradient; photosynthetic responses; pigments; carbohydrates; self-shading|
|FoR Codes:||06 BIOLOGICAL SCIENCES > 0607 Plant Biology > 060701 Phycology (incl Marine Grasses) @ 80%|
05 ENVIRONMENTAL SCIENCES > 0502 Environmental Science and Management > 050206 Environmental Monitoring @ 20%
|SEO Codes:||96 ENVIRONMENT > 9605 Ecosystem Assessment and Management > 960502 Ecosystem Assessment and Management of Antarctic and Sub-Antarctic Environments @ 100%|
|Deposited On:||01 Mar 2010 11:05|
|Last Modified:||31 Dec 2012 01:38|
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