Non‐native mangroves support carbon storage, sediment carbon burial, and accretion of coastal ecosystems

Abstract

Mangrove forests play an important role in climate change adaptation and mitigation by maintaining coastline elevations relative to sea level rise, protecting coastal infrastructure from storm damage, and storing substantial quantities of carbon (C) in live and detrital pools. Determining the efficacy of mangroves in achieving climate goals can be complicated by difficulty in quantifying C inputs (i.e., differentiating newer inputs from younger trees from older residual C pools), and mitigation assessments rarely consider potential offsets to CO 2 storage by methane (CH 4 ) production in mangrove sediments. The establishment of non-native Rhizophora mangle along Hawaiian coastlines over the last century offers an opportunity to examine the role mangroves play in climate mitigation and adaptation both globally and locally as novel ecosystems. We quantified total ecosystem C storage, sedimentation, accretion, sediment organic C burial and CH 4 emissions from ~70 year old R. mangle stands and adjacent uninvaded mudflats. Ecosystem C stocks of mangrove stands exceeded mudflats by 434 ± 33 Mg C/ha, and mangrove establishment increased average coastal accretion S U PP O RTI N G I N FO R M ATI O N Additional supporting information may be found online in the Supporting Information section at the end of the article. How to cite this article: Soper FM, MacKenzie RA, Sharma S, Cole TG, Litton CM, Sparks JP. Non-native mangroves support carbon storage, sediment carbon burial, and accretion of coastal ecosystems. Glob Change Biol. 2019;25:4315-4326. https ://doi.

Seagrass (Halophila stipulacea) invasion enhances carbon sequestration in the Mediterranean Sea

“…Vegetated coastal ecosystems, also known as Blue Carbon habitats, are intense carbon sinks (Duarte et al, 2013), due to their high primary productivity, efficiency in trapping suspended organic material and low rates of organic matter decomposition in their anoxic sediments (Fourqurean et al, 2012), and with their conservation and restoration help mitigate climate change. Marine exotic macrophytes may also contribute to climate regulation, as they can expand blue carbon habitats by (1) colonizing bare sediments, (2) enhancing carbon sequestration when invading native meadows and (3) colonizing historic carbon stores accreted by lost flora (Figueiredo da Silva et al, 2009; Gu et al, 2020; Salomidi et al, 2012; Soper et al, 2019). In a warming world where the arrival of exotic species is enhanced (Lenoir et al, 2020) and where organic carbon (C org ) sequestration should be prioritized to mitigate climate change (Gattuso et al, 2018), it is critical to understand the effect of the establishment of exotic macrophytes on C org cycling and storage by the resulting community.…”

Secondary Ecological Succession of Mangrove in the 2004 Tsunami Created Wetlands of South Andaman, India

“…However, very few studies were conducted to understand the dynamics of the ecological succession of mangroves after natural disasters like hurricanes and tsunamis [80]. The mangroves of the study area faced the double impact of mortality due to 26th December 2004 tsunami viz., (1) physical fury, and (2) prolonged submergence due to subsidence of land mass [38][39][40][41][42][43][44][45][46][47][48]. Zones of subsided landmass were waterlogged permanently resulting in (TCWs).…”

“…On the contrary, these natural factors are also partly responsible for the loss of mangrove forests [34]. However, Mangroves demonstrates the ability to be resilient to natural eventualities [18,[35][36][37][38][39][40] by following the fluvial influx [39,41].…”

Invasive mangroves produce unsuitable habitat for endemic goby and burrowing shrimp pairs in Kāneʻohe Bay, O‘ahu, Hawai‘i

“…Positive effects include protection of coral reefs by trapping land-derived sediments (D'iorio 2003) and provision of habitat to some native (and to non-native) fishes (MacKenzie and Kryss 2013, Goecke and Carstenn 2017), which many experience reduced risk of predation through prop root structural complexity (Nagelkerken 2009). Mangroves in Hawai'i also convert and store substantial amounts of atmospheric carbon in live tissues and detritus and accrete sediments along shores, both of which can serve to mitigate climate change impacts (Soper et al 2019). In contrast, negative effects include displacing endangered native bird habitat (Allen 1998) and altering nearshore invertebrate community composition and food web structure while facilitating numerous non-native invertebrate species (Demopoulos et al 2007, Demopoulos andSmith 2010).…”

“…Los efectos positivos incluyen la protección de los arrecifes de coral al atrapar sedimentos terrestres (D'iorio 2003) y la provisión de hábitat para algunos peces nativos (y no nativos) (MacKenzie y Kryss 2013, Goecke y Carstenn 2017), muchos de los cuales experimentan una reducción en el riesgo de depredación debido a la complejidad estructural de las raíces aéreas (Nagelkerken 2009). Los manglares de Hawai'i también convierten y almacenan cantidades sustanciales de carbono atmosférico en tejidos vivos y detritos y acumulan sedimentos a lo largo de las costas, lo que puede servir para mitigar los impactos del cambio climático (Soper et al 2019). Por el contrario, los efectos negativos incluyen el desplazamiento del hábitat de aves nativas en peligro de extinción (Allen 1998) y la alteración de la composición de la comunidad de invertebrados cercanos a la costa y la estructura de la red alimentaria mientras que se favorece el estabelecimiento de numerosas especies de invertebrados no nativos (Demopoulos et al 2007, Demopoulos y Smith 2010.…”