The intertidal plant communities in north‐eastern Australia, their carbon stores and vulnerability to extreme climate events

Abstract

1. During the strong El Niño event of 2015-2016 large-scale dieback of mangrove forests was observed in the Gulf of Carpentaria region of northern Australia. These and other intertidal communities are also extensive along the 7,400 km coastline of northeastern Australia. Determination of their floristic composition, potential carbon (C) store and sequestration capacity, and vulnerability to climate extremes is required for their effective conservation management and was the aim of this study. 2. Standardized, statewide quantitative classification methods identified five mangrove forest and three saltmarsh communities covering 2,604 km 2 along this coastline. 3. Estuarine and oceanic mangrove forests were mapped separately. Carbon storage and sequestration capacity of the intertidal communities and their vulnerability to strong El Niño events were estimated using published data and GIS analyses. 4. An estimated potential 126.2 (± 27.3 SEM) Tg C and 8.3 (±0.4 SD) Tg C were stored in the mangrove forests and saltmarshes, respectively. Comparatively, the rainforests of the region stored an estimated equivalent amount of C but covered three times the area, and the most widespread woodlands (Eucalyptus tetrodonta) of the region stored an estimated 1.5 times the C but covered 16 times the area. The C stored in the intertidal communities was estimated as equivalent to 493.47

Current and future carbon stocks in coastal wetlands within the Great Barrier Reef catchments

“…Extreme weather patterns in the past few years have caused extensive areas of mangrove tidal wetland vegetation dieback in northern Australia (Addicott et al, 2020; Asbridge et al, 2019; Duke et al, 2017) with the nature of these events being attributed to a low sea level event that was also associated with El Niño conditions (Sippo et al, 2020). Similarly, in the austral summer of 2010/2011, a marine heatwave associated with El Niño resulted in the collapse of ~1300 km 2 of seagrass extent in Shark Bay, Western Australia (Arias‐Ortiz et al, 2018).…”

Aligning quantitative vegetation classification and landscape scale mapping: updating the classification approach of the Regional Ecosystem classification system used in Queensland

“…However, in contrast to this, in broad, often inaccessible parts of the country this two-tiered survey design shows how vegetation mapping and classification systems developed in conjunction can provide comprehensive capturing of environmental variability and b-diversity at a landscape scale (Addicott et al 2018a;Addicott 2020). When a vegetation classification system, underpinned by a quantitatively based classification approach, is combined with mapping their application becomes powerful in allowing possibilities of ecological comparisons on a national or global scale (Addicott et al 2020).…”