Vascular Plants Are Globally Significant Contributors to Marine Carbon Fluxes and Sinks
Simon M. Cragg
Daniel A. Friess
Lucy G. Gillis
Stacey M. Trevathan-Tackett
Oliver M. Terrett
Joy E.M. Watts
Daniel L. Distel
Paul Dupree
Abstract
More than two-thirds of global biomass consists of vascular plants. A portion of the detritus they generate is carried into the oceans from land and highly productive blue carbon ecosystems—salt marshes, mangrove forests, and seagrass meadows. This large detrital input receives scant attention in current models of the global carbon cycle, though for blue carbon ecosystems, increasingly well-constrained estimates of biomass, productivity, and carbon fluxes, reviewed in this article, are now available. We show that the fate of this detritus differs markedly from that of strictly marine origin, because the former contains lignocellulose—an energy-rich polymer complex of cellulose, hemicelluloses, and lignin that is resistant to enzymatic breakdown. This complex can be depolymerized for nutritional purposes by specialized marine prokaryotes, fungi, protists, and invertebrates using enzymes such as glycoside hydrolases and lytic polysaccharide monooxygenases to release sugar monomers. The lignin component, however, is less readily depolymerized, and detritus therefore becomes lignin enriched, particularly in anoxic sediments, and forms a major carbon sink in blue carbon ecosystems. Eventual lignin breakdown releases a wide variety of small molecules that may contribute significantly to the oceanic pool of recalcitrant dissolved organic carbon. Marine carbon fluxes and sinks dependent on lignocellulosic detritus are important ecosystem services that are vulnerable to human interventions. These services must be considered when protecting blue carbon ecosystems and planning initiatives aimed at mitigating anthropogenic carbon emissions.
Cragg S.M., Friess D.A., Gillis L.G., Trevathan-Tackett S.M., Terrett O.M., Watts J.E.M., Distel D.L. and Dupree P. (2020) Vascular Plants Are Globally Significant Contributors to Marine Carbon Fluxes and Sinks. Annual Review of Marine Science 12(1): 469-497. 10.1146/annurev-marine-010318-095333
@article{Cragg2020,
Title = {Vascular Plants Are Globally Significant Contributors to Marine Carbon Fluxes and Sinks},
Author = {Cragg, Simon M. and Friess, Daniel A. and Gillis, Lucy G. and Trevathan-Tackett, Stacey M. and Terrett, Oliver M. and Watts, Joy E.M. and Distel, Daniel L. and Dupree, Paul},
Editor = {},
Journal = {Annual Review of Marine Science},
Year = {2020},
Pages = {469-497},
Volume = {12},
Doi = {10.1146/annurev-marine-010318-095333},
Abstract = {More than two-thirds of global biomass consists of vascular plants. A portion of the detritus they generate is carried into the oceans from land and highly productive blue carbon ecosystems—salt marshes, mangrove forests, and seagrass meadows. This large detrital input receives scant attention in current models of the global carbon cycle, though for blue carbon ecosystems, increasingly well-constrained estimates of biomass, productivity, and carbon fluxes, reviewed in this article, are now available. We show that the fate of this detritus differs markedly from that of strictly marine origin, because the former contains lignocellulose—an energy-rich polymer complex of cellulose, hemicelluloses, and lignin that is resistant to enzymatic breakdown. This complex can be depolymerized for nutritional purposes by specialized marine prokaryotes, fungi, protists, and invertebrates using enzymes such as glycoside hydrolases and lytic polysaccharide monooxygenases to release sugar monomers. The lignin component, however, is less readily depolymerized, and detritus therefore becomes lignin enriched, particularly in anoxic sediments, and forms a major carbon sink in blue carbon ecosystems. Eventual lignin breakdown releases a wide variety of small molecules that may contribute significantly to the oceanic pool of recalcitrant dissolved organic carbon. Marine carbon fluxes and sinks dependent on lignocellulosic detritus are important ecosystem services that are vulnerable to human interventions. These services must be considered when protecting blue carbon ecosystems and planning initiatives aimed at mitigating anthropogenic carbon emissions.},
}
TY - JOUR
AU - Cragg, Simon M.
AU - Friess, Daniel A.
AU - Gillis, Lucy G.
AU - Trevathan-Tackett, Stacey M.
AU - Terrett, Oliver M.
AU - Watts, Joy E.M.
AU - Distel, Daniel L.
AU - Dupree, Paul
TI - Vascular Plants Are Globally Significant Contributors to Marine Carbon Fluxes and Sinks
T2 - Annual Review of Marine Science
PY - 2020
SP - 469-497
VL - 12
DO - 10.1146/annurev-marine-010318-095333
AB - More than two-thirds of global biomass consists of vascular plants. A portion of the detritus they generate is carried into the oceans from land and highly productive blue carbon ecosystems—salt marshes, mangrove forests, and seagrass meadows. This large detrital input receives scant attention in current models of the global carbon cycle, though for blue carbon ecosystems, increasingly well-constrained estimates of biomass, productivity, and carbon fluxes, reviewed in this article, are now available. We show that the fate of this detritus differs markedly from that of strictly marine origin, because the former contains lignocellulose—an energy-rich polymer complex of cellulose, hemicelluloses, and lignin that is resistant to enzymatic breakdown. This complex can be depolymerized for nutritional purposes by specialized marine prokaryotes, fungi, protists, and invertebrates using enzymes such as glycoside hydrolases and lytic polysaccharide monooxygenases to release sugar monomers. The lignin component, however, is less readily depolymerized, and detritus therefore becomes lignin enriched, particularly in anoxic sediments, and forms a major carbon sink in blue carbon ecosystems. Eventual lignin breakdown releases a wide variety of small molecules that may contribute significantly to the oceanic pool of recalcitrant dissolved organic carbon. Marine carbon fluxes and sinks dependent on lignocellulosic detritus are important ecosystem services that are vulnerable to human interventions. These services must be considered when protecting blue carbon ecosystems and planning initiatives aimed at mitigating anthropogenic carbon emissions.
ER -
