Influence of Thermal Stratification on Seasonal Net Ecosystem Production and Dissolved Inorganic Carbon in a Shallow Subtropical Lake

Abstract

Small lakes (lake area < 0.1 km 2 ) occupy 25%-35% of the total area of all lakes in the world (Downing et al., 2006;Verpoorter et al., 2014). However, C emissions from small lakes are usually ignored when evaluating C fluxes (Cole et al., 2007;Raymond et al., 2013), resulting in an underestimation of CO 2 emissions on a global scale (Downing et al., 2006;Verpoorter et al., 2014). Lake size has also been revealed to be one of the most critical factors controlling CO 2 emissions, with small lakes having more considerable contributions from convection to gas transfer velocities (Read et al., 2012;Vachon & del Giorgio, 2014). Heavy rainfall, wind shear, and convective mixing are essential meteorological forces that cause vertical mixing in small lakes; in shallow lakes, stratification can cause internal waves, which in turn can cause mass transport (Kimura et al., 2012(Kimura et al., , 2014(Kimura et al., , 2017. Therefore, to accurately estimate C fluxes from small lakes, it is necessary to clarify the mechanisms of vertical mixing and the collapse of stratification.There are many mountainous shallow lakes in subtropical East Asia. For example, in Taiwan, previous studies have shown that seasonal and annual C fluxes are frequently influenced by typhoon and monsoon events, but C fluxes from subtropical lakes above an altitude of 1,500 m are not well understood (

Perceptions of practitioners on the importance and achievement of research and social implementation activities on marine and freshwater carbon

“…While studies on freshwater carbon are still limited, results indicating its potential have been revealed in recent years. For example, Lin et al (2021); Lin et al (2022) showed that pCO 2 partial pressure can be lower than that of the atmosphere throughout the year in freshwater lakes above mesotrophic levels, indicating the feasibility of freshwater carbon through the planting of water plants. Additionally, Gu et al (2020) revealed the high possibility of carbon capture and storage by Phragmites australis (common reed) in a St. Lawrence Estuary Marsh.…”

“…The target areas of BC research have mainly focused on marine and coastal ecosystems, with less attention paid to inland waters where dense submerged aquatic vegetation exists. However, Lin et al (2022) revealed that ecosystems, such as phytoplankton in a subtropical mountainous shallow lake, capture and accumulate carbon through photosynthesis even though terrestrial carbon is supplemented through inflows and autochthonous carbon is produced (Lin et al, 2021). Freshwater areas (5.0 million km 2 ) are larger than coastal areas (1.8 million km 2 ) and are expected to have greater potential for carbon sequestration (Downing et al, 2006;Verpoorter et al, 2014).…”

Methane and Nitrous Oxide Emissions From an Anthropogenically Transformed Lake (Lake Licheńskie, Poland)

“…a k -empirical parameter related to lake surface area A l (km 2 ) and N 2 -Brunt-Väisälä stability frequency [s −2 ] calculated from lake water density (ρ) for different depths in the water column (z) (Lin et al, 2021)…”

“…N 2 –Brunt‐Väisälä stability frequency [s −2 ] calculated from lake water density ( ρ ) for different depths in the water column ( z ) (Lin et al., 2021) $$${N}^{2}=-\frac{g}{\rho }\cdot \frac{\partial \rho }{\partial z}$$$ …”

A Spatially Integrated Dissolved Inorganic Carbon (SiDIC) Model for Aquatic Ecosystems Considering Submerged Vegetation

“…Previous studies have shown that SAV enhances the stratification of the water column (Nakayama, Sato, et al., 2020), suppressing vertical water exchange in shallow water areas (Ghisalberti & Nepf, 2006, 2009). When stratification occurs, large amounts of dissolved inorganic carbon (DIC) can accumulate in the deeper layers of an aquatic ecosystem because the dampening of vertical mixing prevents the flux of carbon between the upper and lower layers (Lin et al., 2021, 2022). Therefore, by suppressing vertical water exchange, SAV presence can limit the supply of carbon dioxide from bottom waters to the surface layer where it is subject to exchange with the atmosphere, and this effect will vary between different environments depending on the amount and form of the biomass.…”