183
greater mechanistic understanding of the physiological and genomic responses of
these remarkable submerged vascular plants to the simultaneous impacts of ocean
acidification, climate warming, and eutrophication that are altering ecosystem function across the globe. In the case of seagrass systems, CO 2 appears to be a master
variable that can exert significant impacts on light requirements, temperature tolerance, and even reproductive success. However, even among those species exhibiting
initial positive responses to increased [CO 2 ], long-term effects can be difficult to
predict (Arp 1991; Woodward 2002). In terrestrial systems, higher rates of carbon
fixation can increase nutrient demand and/or dilute the nutritional quality of plant
biomass, producing a cascade of effects on rates of grazing and decomposition
(Field and Mooney 1986; Cotrufo et al. 2002). Further, ocean acidification resulting
from increased atmospheric CO 2 may produce significant impacts on organisms,
particularly calcareous species that presently serve to keep leaf epiphytes and algal
competitors in check (Hall-Spencer et al. 2008).
Clearly, seagrasses possess a number of characteristics that are consistent with
the paradigm of adaptation, yet CO 2 limitation of photosynthesis demonstrates that
they are less than perfectly adapted to a submerged aquatic existence. Like the panda’s thumb (Gould 1978), these less-than-perfect features may help reveal the constraint of evolutionary history on the optimization of systems-level performance in
this remarkable group of aquatic angiosperms that we are just beginning to
understand.
Acknowledgments Thanks to Manoj Kumar and Peter Ralph for inviting this contribution to this
book. Financial support was provided by the US National Science Foundation (Awards OCE1061823 and OCE-1635403).
References
Ackerman J (2006) Sexual reproduction of seagrasses: pollination in the marine context. In:
Larkum A, Orth R, Duarte C (eds) Seagrasses: biology, ecology and conservation. Springer,
Dordrecht
Al-Moghrabi S, Goiran C, Allemand D, Speziale N, Jaubert J (1996) Inorganic carbon uptake for
photosynthesis by the symbiotic coral-dinoflagellate association II. Mechanism for bicarbonate
uptake. J Exp Mar Biol Ecol 199:227–248
Arp W (1991) Effects of source-sink relations on photosynthetic acclimation to elevated CO 2 .
Plant Cell Environ 14:869–876
Backhausen J, Scheibe R (1999) Adaptation of tobacco plants to elevated CO 2 : influence of leaf
age on changes in physiology, redox states and NADP-malate dehydrogenase activity. J Exp
Bot 50:665–675
Bailey-Serres J, Voesenek LACJ (2008) Flooding stress: acclimations and genetic diversity. Annu
Rev Plant Biol 59:313–339
Batiuk R, Bergstrom P, Kemp M, Koch E, Murray L, Stevenson J, Bartleson R, Carter V, Rybicki
N, Landwehr J, Gallegos C, Karrh L, Naylor M, Wilcox D, Moore K, Ailstock S, Teichberg M
(2000) Chesapeake Bay submerged aquatic vegetation water quality and habitat-based requirements and restoration targets: a second synthesis. Chesapeake Bay Program Office, Annapolis,
MD
8 Systems Biology and the Seagrass Paradox…
greater mechanistic understanding of the physiological and genomic responses of
these remarkable submerged vascular plants to the simultaneous impacts of ocean
acidification, climate warming, and eutrophication that are altering ecosystem function across the globe. In the case of seagrass systems, CO 2 appears to be a master
variable that can exert significant impacts on light requirements, temperature tolerance, and even reproductive success. However, even among those species exhibiting
initial positive responses to increased [CO 2 ], long-term effects can be difficult to
predict (Arp 1991; Woodward 2002). In terrestrial systems, higher rates of carbon
fixation can increase nutrient demand and/or dilute the nutritional quality of plant
biomass, producing a cascade of effects on rates of grazing and decomposition
(Field and Mooney 1986; Cotrufo et al. 2002). Further, ocean acidification resulting
from increased atmospheric CO 2 may produce significant impacts on organisms,
particularly calcareous species that presently serve to keep leaf epiphytes and algal
competitors in check (Hall-Spencer et al. 2008).
Clearly, seagrasses possess a number of characteristics that are consistent with
the paradigm of adaptation, yet CO 2 limitation of photosynthesis demonstrates that
they are less than perfectly adapted to a submerged aquatic existence. Like the panda’s thumb (Gould 1978), these less-than-perfect features may help reveal the constraint of evolutionary history on the optimization of systems-level performance in
this remarkable group of aquatic angiosperms that we are just beginning to
understand.
Acknowledgments Thanks to Manoj Kumar and Peter Ralph for inviting this contribution to this
book. Financial support was provided by the US National Science Foundation (Awards OCE1061823 and OCE-1635403).
References
Ackerman J (2006) Sexual reproduction of seagrasses: pollination in the marine context. In:
Larkum A, Orth R, Duarte C (eds) Seagrasses: biology, ecology and conservation. Springer,
Dordrecht
Al-Moghrabi S, Goiran C, Allemand D, Speziale N, Jaubert J (1996) Inorganic carbon uptake for
photosynthesis by the symbiotic coral-dinoflagellate association II. Mechanism for bicarbonate
uptake. J Exp Mar Biol Ecol 199:227–248
Arp W (1991) Effects of source-sink relations on photosynthetic acclimation to elevated CO 2 .
Plant Cell Environ 14:869–876
Backhausen J, Scheibe R (1999) Adaptation of tobacco plants to elevated CO 2 : influence of leaf
age on changes in physiology, redox states and NADP-malate dehydrogenase activity. J Exp
Bot 50:665–675
Bailey-Serres J, Voesenek LACJ (2008) Flooding stress: acclimations and genetic diversity. Annu
Rev Plant Biol 59:313–339
Batiuk R, Bergstrom P, Kemp M, Koch E, Murray L, Stevenson J, Bartleson R, Carter V, Rybicki
N, Landwehr J, Gallegos C, Karrh L, Naylor M, Wilcox D, Moore K, Ailstock S, Teichberg M
(2000) Chesapeake Bay submerged aquatic vegetation water quality and habitat-based requirements and restoration targets: a second synthesis. Chesapeake Bay Program Office, Annapolis,
MD
8 Systems Biology and the Seagrass Paradox…