N₂-fixing tropical legume evolution: a contributor to enhanced weathering through the Cenozoic?

ABSTRACT: Fossil and phylogenetic evidence indicates legume-rich modern tropical forests replaced Late Cretaceous palm-dominated tropical forests across four continents during the early Cenozoic (58-42 Ma). Tropical legume trees can transform ecosystems via their ability to fix dinitrogen (N₂) and higher leaf N compared with non-legumes (35-65%), but it is unclear how their evolutionary rise contributed to silicate weathering, the long-term sink for atmospheric carbon dioxide (CO₂). Here we hypothesize that the increasing abundance of N₂-fixing legumes in tropical forests amplified silicate weathering rates by increased input of fixed nitrogen (N) to terrestrial ecosystems via interrelated mechanisms including increasing microbial respiration and soil acidification,

SUBMITTER: Epihov DZ 

PROVIDER: S-EPMC5563791 | biostudies-literature | 2017 Aug

REPOSITORIES: biostudies-literature