Effects of connectivity on carbon and nitrogen stocks in mangrove and seagrass ecosystems
Daniel Saavedra-Hortua
Ivan Nagelkerken
Lina M. Estupinan-Suarez
Lucy Gwen Gillis
Abstract
Seascape connectivity increases carbon and nitrogen exchange across coastal ecosystems through flow of particulate organic matter (POM). However, there are still critical gaps in knowledge about the drivers that mediate these processes, especially at regional seascape scales. The aim of this study was to associate three seascape-level drivers which could influence carbon and nitrogen stocks in intertidal coastal seascape: connectivity between ecosystems, ecosystem surface area, and standing vegetation biomass of ecosystems. Firstly, we compared whether connected mangrove and seagrass ecosystems contain larger carbon and nitrogen storage than isolated mangrove and seagrass ecosystems. Secondly, we compared autochthonous and allochthonous POM in mangrove patches and seagrass beds, simultaneously estimating the area and biomass relative contribution to POM of the different coastal vegetated ecosystem. Connected vs isolated mangrove and seagrass ecosystems were studied at six locations in a temperate seascape, and their carbon and nitrogen content in the standing vegetation biomass and sediments were measured. POM contributions of these and surrounding ecosystems were determined using stable isotopic tracers. In connected mangrove-seagrass seascapes, mangroves occupied 3 % of total coastal ecosystem surface area, however, their standing biomass carbon content and nitrogen per unit area was 9–12 times higher than seagrasses and twice as high as macroalgal beds (both in connected and isolated seascapes). Additionally in connected mangrove-seagrass seascapes, the largest contributors to POM were mangroves (10–50 %) and macroalgal beds (20–50 %). In isolated seagrasses, seagrass (37–77 %) and macroalgal thalli (9–43 %) contributed the most, whilst in the isolated mangrove, salt marshes were the main contributor (17–47 %). Seagrass connectivity enhances mangrove carbon sequestration per unit area, whilst internal attributes enhance seagrass carbon sequestration. Mangroves and macroalgal beds are potential critical contributors of nitrogen and carbon to other ecosystems. Considering all ecosystems as a continuing system with seascape-level connectivity will support management and improve knowledge of critical ecosystem services.
Saavedra-Hortua D., Nagelkerken I., Estupinan-Suarez L.M. and Gillis L.G. (2023) Effects of connectivity on carbon and nitrogen stocks in mangrove and seagrass ecosystems. 896: 164829. 10.1016/j.scitotenv.2023.164829
@article{Saavedra-Hortua2023,
Title = {Effects of connectivity on carbon and nitrogen stocks in mangrove and seagrass ecosystems},
Author = {Saavedra-Hortua, Daniel and Nagelkerken, Ivan and Estupinan-Suarez, Lina M. and Gillis, Lucy Gwen},
Editor = {},
Year = {2023},
Pages = {164829},
Volume = {896},
Doi = {10.1016/j.scitotenv.2023.164829},
Abstract = {Seascape connectivity increases carbon and nitrogen exchange across coastal ecosystems through flow of particulate organic matter (POM). However, there are still critical gaps in knowledge about the drivers that mediate these processes, especially at regional seascape scales. The aim of this study was to associate three seascape-level drivers which could influence carbon and nitrogen stocks in intertidal coastal seascape: connectivity between ecosystems, ecosystem surface area, and standing vegetation biomass of ecosystems. Firstly, we compared whether connected mangrove and seagrass ecosystems contain larger carbon and nitrogen storage than isolated mangrove and seagrass ecosystems. Secondly, we compared autochthonous and allochthonous POM in mangrove patches and seagrass beds, simultaneously estimating the area and biomass relative contribution to POM of the different coastal vegetated ecosystem. Connected vs isolated mangrove and seagrass ecosystems were studied at six locations in a temperate seascape, and their carbon and nitrogen content in the standing vegetation biomass and sediments were measured. POM contributions of these and surrounding ecosystems were determined using stable isotopic tracers. In connected mangrove-seagrass seascapes, mangroves occupied 3 % of total coastal ecosystem surface area, however, their standing biomass carbon content and nitrogen per unit area was 9–12 times higher than seagrasses and twice as high as macroalgal beds (both in connected and isolated seascapes). Additionally in connected mangrove-seagrass seascapes, the largest contributors to POM were mangroves (10–50 %) and macroalgal beds (20–50 %). In isolated seagrasses, seagrass (37–77 %) and macroalgal thalli (9–43 %) contributed the most, whilst in the isolated mangrove, salt marshes were the main contributor (17–47 %). Seagrass connectivity enhances mangrove carbon sequestration per unit area, whilst internal attributes enhance seagrass carbon sequestration. Mangroves and macroalgal beds are potential critical contributors of nitrogen and carbon to other ecosystems. Considering all ecosystems as a continuing system with seascape-level connectivity will support management and improve knowledge of critical ecosystem services.},
}
TY - JOUR
AU - Saavedra-Hortua, Daniel
AU - Nagelkerken, Ivan
AU - Estupinan-Suarez, Lina M.
AU - Gillis, Lucy Gwen
TI - Effects of connectivity on carbon and nitrogen stocks in mangrove and seagrass ecosystems
PY - 2023
SP - 164829
VL - 896
DO - 10.1016/j.scitotenv.2023.164829
AB - Seascape connectivity increases carbon and nitrogen exchange across coastal ecosystems through flow of particulate organic matter (POM). However, there are still critical gaps in knowledge about the drivers that mediate these processes, especially at regional seascape scales. The aim of this study was to associate three seascape-level drivers which could influence carbon and nitrogen stocks in intertidal coastal seascape: connectivity between ecosystems, ecosystem surface area, and standing vegetation biomass of ecosystems. Firstly, we compared whether connected mangrove and seagrass ecosystems contain larger carbon and nitrogen storage than isolated mangrove and seagrass ecosystems. Secondly, we compared autochthonous and allochthonous POM in mangrove patches and seagrass beds, simultaneously estimating the area and biomass relative contribution to POM of the different coastal vegetated ecosystem. Connected vs isolated mangrove and seagrass ecosystems were studied at six locations in a temperate seascape, and their carbon and nitrogen content in the standing vegetation biomass and sediments were measured. POM contributions of these and surrounding ecosystems were determined using stable isotopic tracers. In connected mangrove-seagrass seascapes, mangroves occupied 3 % of total coastal ecosystem surface area, however, their standing biomass carbon content and nitrogen per unit area was 9–12 times higher than seagrasses and twice as high as macroalgal beds (both in connected and isolated seascapes). Additionally in connected mangrove-seagrass seascapes, the largest contributors to POM were mangroves (10–50 %) and macroalgal beds (20–50 %). In isolated seagrasses, seagrass (37–77 %) and macroalgal thalli (9–43 %) contributed the most, whilst in the isolated mangrove, salt marshes were the main contributor (17–47 %). Seagrass connectivity enhances mangrove carbon sequestration per unit area, whilst internal attributes enhance seagrass carbon sequestration. Mangroves and macroalgal beds are potential critical contributors of nitrogen and carbon to other ecosystems. Considering all ecosystems as a continuing system with seascape-level connectivity will support management and improve knowledge of critical ecosystem services.
ER -
