The relevance of pelagic calcification in the global carbon budget of lakes and reservoirs

Calcite precipitation acts as a carbon sink in the sediments and a short-term source of carbon dioxide (CO2) to the atmosphere, as widely acknowledged in marine studies. However, pelagic calcite precipitation has received limited attention in lakes. Here we use the relationship between lake water al...

Full description

Bibliographic Details
Authors: Khan, Hares, Marcé, Rafael, Laas, Alo, Obrador Sala, Biel
Format: article
Status:Published version
Publication Date:2021
Country:España
Institution:Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
Repository:Recercat. Dipósit de la Recerca de Catalunya
OAI Identifier:oai:recercat.cat:2445/178698
Online Access:https://hdl.handle.net/2445/178698
Access Level:Open access
Keyword:Calcificació
Ecologia dels llacs
Cicle del carboni (Biogeoquímica)
Calcification
Lake ecology
Carbon cycle (Biogeochemistry)
Description
Summary:Calcite precipitation acts as a carbon sink in the sediments and a short-term source of carbon dioxide (CO2) to the atmosphere, as widely acknowledged in marine studies. However, pelagic calcite precipitation has received limited attention in lakes. Here we use the relationship between lake water alkalinity and reported calcification rates to provide the first global estimate of pelagic calcification in lakes. Global gross calcification rates amount to 0.03 Pg C yr-1 (0.01 - 0.07) comparable to rates of or­ganic carbon burial, whereas its related CO2 release is largely buffered by the carbonate equilibria. Calcification occurs at water alkalinity above 1 meq/L corresponding to 57 % of global lake and reservoir surface area. Pelagic calcification therefore is a prevalent process in lakes and reservoirs at the global scale, with a potentially relevant role as a sedimentary inorganic carbon sink, comparable in magnitude to the total calcite accumulation rates in ocean sediments.