Open AccessHighest rates of gross primary productivity maintained despite CO 2 depletion in a temperate river network
Author(s) -
Aho Kelly S.,
Hosen Jacob D.,
Logozzo Laura A.,
McGillis Wade R.,
Raymond Peter A.
Publication year - 2021
Publication title -
limnology and oceanography letters
Language(s) - English
Resource type - Journals
ISSN - 2378-2242
DOI - 10.1002/lol2.10195
Subject(s) - productivity , biogeochemistry , primary production , temperate climate , ecosystem , bicarbonate , environmental science , carbon dioxide , aquatic ecosystem , carbon cycle , primary producers , environmental chemistry , ecology , photosynthesis , drainage basin , chemistry , biology , botany , geography , nutrient , phytoplankton , cartography , organic chemistry , economics , macroeconomics
Abstract Aquatic primary productivity produces oxygen (O 2 ) and consumes carbon dioxide (CO 2 ) in a ratio of ~1.2. However, in aquatic ecosystems, dissolved CO 2 concentrations can be low, potentially limiting primary productivity. Here, results show that a large drainage basin maintains its highest levels of gross primary productivity (GPP) when dissolved CO 2 is diminished or undetectable due to photosynthetic uptake. Data show that, after CO 2 is depleted, bicarbonate, an ionized form of inorganic carbon, supports these high levels of productivity. In fact, outputs from a process‐based model suggest that bicarbonate can support up to ~58% of GPP under the most productive conditions. This is the first evidence that high levels of aquatic GPP are sustained in a riverine drainage network despite CO 2 depletion, which has implications for freshwater ecology, biogeochemistry, and isotopic analysis.