The Case for a Critical Zone Science Approach to Research on Estuarine and Coastal Wetlands in the Anthropocene

Abstract

As the focus of land-sea interactions, estuarine and coastal ecosystems perform numerous vital ecological service functions, although they are highly vulnerable to various kinds of disturbance, both directly and indirectly related to human activity, that have attracted much recent attention. Critical zone science (CZS) has emerged as a valuable conceptual framework that focuses on quantitative interactions between diverse components of the environment and is able to integrate anthropogenic disturbance with a view to predicting future trajectories of change. However, coastal and estuarine environments appear to have been overlooked in CZS and are notably under-represented, indeed not explicitly represented at all, in the global network of critical zone observatories (CZOs). Even in the wider network of environmental observatories globally, estuarine and coastal wetland ecosystems are only very rarely an explicit focus. Further strengthening of integrated research in coastal and estuarine environments is required, more especially given the threats these ecosystems face due to growing population at the coast and against the background of climate change and sea level rise. The establishment of one or more CZOs, or their functional equivalents, with a strong focus on estuarine and coastal wetlands, should be urgently attended to.

Sustainable Management of the Coastal Water pH of Pulau Tuba Using the Inverse Distance Weighted (IDW) Method

“…The lowering of pH in water in this area also could be a result of the decomposition of organic matter and humic acid water (Sammut et al, 1995). The estuarine ecosystem is important as the area is critical natural habitat (Carle, Benson, & Reinhardt, 2020) has significant economic value (Liu et al, 2020), performs environmental services (Carstensen et al, 2019) and acts as protective buffers (Pavoni et al, 2021). Anthropogenic activities would affect the natural balance of the estuarine ecosystem (Hillman et al, 2020) and impose increased pressure on vital natural resources (Serrao-Neumann et al, 2019).…”

The Importance of Groundwater in Critical Zone Science

“…Wetlands have high evapotranspiration (ET) rates, which thus affect surface water and energy balances. From a CZ perspective, some open questions around how the mixing of long residence-time groundwater and the shorter-term surface water affect wetland chemistry, including prediction of algal blooms (Brookfield et al 2021) as well as the role of wetlands in buffering sea level rise and storm surges (Liu et al 2021).…”

Substrate quality overrides soil salinity in mediating microbial respiration in coastal wetlands

“…Coastal wetlands are typical critical zones acting as pivotal interfaces across the continent and ocean (Liu et al, 2021). Although coastal wetlands make up only 4% of the earth's land area, they can provide numerous ecosystem services, such as pollution purification, support of fisheries, climate regulation, and carbon (C) sequestration (Deegan et al, 2012; Schuerch et al, 2018).…”

“…However, since the Anthropocene, human activity has dominated the regulation of environmental conditions (Sullivan et al, 2022). Coastal wetlands are increasingly threatened by human disturbances and facing widespread wetland loss because of sea‐level rise and land‐use change (Craft et al, 2009; Liu et al, 2021; Schuerch et al, 2018; Xia, Wang, et al, 2021). On this account, a considerable release of soil C occurs with the loss of vegetated coastal wetland through conversion to open water (Lovelock & Reef, 2020).…”