For four decades, cordgrass (Spartina alterniflora) has invaded salt marshes in the Yellow Sea, altering physical, biogeochemical, and biological processes. Here, we investigated the ecological effects of S. alterniflora invasion on benthic environments compared to native halophytes.
View Article and Find Full Text PDFGrapsoid crabs (Decapoda: Grapsoidea) inhabiting along the land-sea transition provided various amounts and quality of vascular plant carbon (e.g., fresh mangrove leaf, leaf litter, and mangrove-derived organic carbon) and perform differing levels of herbivory.
View Article and Find Full Text PDFSesarmid crabs modulate nutrient dynamics of tropical mangroves through their leaf-eating habit. How N enrichment may alter this regulatory role, and the implications for mangrove nutrient dynamics, remain unclear. Using a mesocosm experiment, we tested how N enrichment could change the microphytobenthos (MPB) communities, thus modifying the crabs' diet and their role in nutrient dynamics.
View Article and Find Full Text PDFSci Total Environ
January 2024
Mangroves are highly efficient in sequestering carbon from the atmosphere and can accumulate carbon in sediments for millennials. However, The fate of mangrove carbon has not been well constrained due to the lack of data on different pools of sediment carbon sinks and sources. This study examined the variation of carbon stocks and fluxes at the water-sediment-air interface in both estuarine mangroves (natural: Mai Po, restored: Gei Wai) and oceanic mangroves (Ting Kok).
View Article and Find Full Text PDFTropical estuaries support wetlands with high biodiversity value and provide essential ecosystem services. Many of these systems, however, are global hotspots for urbanization, particularly in Asia, where this process has resulted in rapid conversion, fragmentation, and degradation of 80 % of the wetlands along the East Asian-Australasian Flyway (EAAF) for migratory birds. However, the impact of such landscape scale changes on migratory birds at a key stopover site along the EAAF has not been evaluated.
View Article and Find Full Text PDFBlue carbon ecosystems (BCEs) are important nature-based solutions for climate change-mitigation. However, current debates question the reliability and contribution of BCEs under future climatic-scenarios. The answer to this question depends on ecosystem processes driving carbon-sequestration and -storage, such as primary production and decomposition, and their future rates.
View Article and Find Full Text PDFWe investigated the sediment carbon (C) stocks, sequestration and sources in tidal flats and their adjacent mangroves in two coastal wetlands in Hong Kong (the Mai Po Nature Reserve (MPNR) and Ting Kok (TK)), part of a megacity of ∼20 million. At both locations, the C stock of tidal flats was lower than that of mangroves. In MPNR, tidal flats indicated a higher C burial rate (75.
View Article and Find Full Text PDFGlobally dominant marine bacterioplankton lineages are often limited in metabolic versatility, owing to their extensive genome reductions, and thus cannot take advantage of transient nutrient patches. It is therefore perplexing how the nutrient-poor bulk seawater sustains the pelagic streamlined lineages, each containing numerous populations. Here, we sequenced the genomes of 33 isolates of the recently discovered CHUG lineage (~2.
View Article and Find Full Text PDFThere is an urgent need to halt and reverse loss of mangroves and seagrass to protect and increase the ecosystem services they provide to coastal communities, such as enhancing coastal resilience and contributing to climate stability. Ambitious targets for their recovery can inspire public and private investment in conservation, but the expected outcomes of different protection and restoration strategies are unclear. We estimated potential recovery of mangroves and seagrass through gains in ecosystem extent to the year 2070 under a range of protection and restoration strategies implemented until the year 2050.
View Article and Find Full Text PDFCoastal wetlands trap plastics from terrestrial and marine sources, but the stocks of plastics and their impacts on coastal wetlands are poorly known. We evaluated the stocks, fate, and biological and biogeochemical effects of plastics in coastal wetlands with plastic abundance data from 112 studies. The representative abundance of plastics that occurs in coastal wetland sediments and is ingested by marine animals reaches 156.
View Article and Find Full Text PDFDeforestation results in habitat fragmentation, decreasing diversity, and functional degradation. For mangroves, no data are available on the impact of deforestation on the diversity and functionality of the specialized invertebrate fauna, critical for their functioning. We compiled a global dataset of mangrove invertebrate fauna comprising 364 species from 16 locations, classified into 64 functional entities (FEs).
View Article and Find Full Text PDFIntertidal benthos link tertiary predators and primary producers in marine food webs as well as directly contribute to sediment CO emission. However, current methods for studying food sources of marine benthos are time-consuming and does not allow direct estimates on feeding regime-related (including different diets, active versus dormant) CO production. We examined the food sources of mangrove crabs and gastropods as well as their corresponding CO production using cavity-ring down spectroscopy to measure the δC-CO respiration for consumers, considering the effects of feeding regime, benthos taxa, and dominant feeding habit.
View Article and Find Full Text PDFBackground: The fast-growing introduced mangrove Sonneratia apetala is widely used for mangrove afforestation and reforestation in China. Some studies suggested that this exotic species outperforms native species in terms of carbon sequestration potential. This study tested the hypothesis that multi-species mangrove plantations might have higher carbon sequestration potential than S.
View Article and Find Full Text PDFCyclone disturbance results in mangrove foliage loss, tree mortality and other changes in ecosystem processes. However, the impact of cyclones on mangrove sediment nutrient density, sediment-air CO and CH fluxes and their isotopes remains largely unknown. Super-typhoon Mangkhut (maximum gust 256 km h) hit Hong Kong in September 2018.
View Article and Find Full Text PDFSmall-scale mangroves serve ecological functions similar to large-scale mangroves regarding biological conservation, environmental purification, and supporting biogeochemical processes. The rising aquaculture neighboring mangroves results in their serving as an important sink for massive nutrients and pollutants from aquaculture effluent. We assessed how long-term aquaculture effluent discharge influenced the soil properties of a mangrove-tidal flat continuum using field survey and geostatistics.
View Article and Find Full Text PDFThe paradigm that mangrove carbon supports secondary production in mangrove and adjacent habitats has been debated in recent years. Fatty acids (FA) are one of the classic biomarkers that have been frequently applied to track mangrove carbon pathways and assess trophic relationships. However, most previous studies did not evaluate the validity, potential and limitations of FA as biomarkers.
View Article and Find Full Text PDFFriess et al. discuss the results of conservation efforts for mangrove forests in recent years.
View Article and Find Full Text PDFThe ecological role of intertidal microphytobenthos (MPB) is increasingly recognized in coastal production systems. MPB primary production (PP) measured in coastal wetlands of Korea, Cambodia, and Australia confirmed large variability at the global scale. Surprisingly, MPB biomass in mangrove forests almost doubled those measured in nearby bare tidal flats.
View Article and Find Full Text PDFDespite carbon sequestration being an important service of mangrove ecosystems, many mangrove reforestation projects have little consideration of the carbon sequestration capacity of species to be planted. Species selection is mostly based on growth rate and convenience in planting. In this study, to compare the quantity and quality of carbon stored in soil, four habitats were selected in Haijiang River Estuary, southern China to assess the contribution by different mangrove species to sediment carbon pool.
View Article and Find Full Text PDFTidal wetlands are global hotspots of carbon storage but errors exist with current estimates on their carbon density due to the use of factors estimated from other habitats for converting loss-on-ignition (LOI) to organic carbon (OC); and the omission of certain significant carbon pools. Here we show that the widely used conversion factor (LOI/OC = 1.724) is significantly lower than our measurements for saltmarsh sediments (1.
View Article and Find Full Text PDFCoastal wetlands are increasingly recognised for their pivotal role in mitigating the growing threats from cyclones (including hurricanes) in a changing climate. There is, however, insufficient information about the economic value of coastal wetlands for cyclone mitigation, particularly at regional scales. Analysis of data from 1990-2012 shows that the variation of cyclone frequencies is related to EI Niño strength in the Pacific Ocean adjacent to Australia, but not China.
View Article and Find Full Text PDF