@article{fdi:010060709,
  title = {{E}missions of nitrous oxide from casts of tropical earthworms belonging to different ecological categories},
  author = {{M}ajeed, {M}. {Z}. and {M}iambi, {E}. and {B}arois, {I}. and {B}lanchart, {E}ric and {B}rauman, {A}lain},
  editor = {},
  language = {{ENG}},
  abstract = {{W}hile earthworms' feeding behavior has been shown to be a key driver of greenhouse gas like nitrous oxide ({N}2{O}) emissions for temperate species, this assessment remains to be demonstrated for tropical ones. {T}his study constitutes a comparative assessment of the impact of different feeding strategies of tropical earthworms on their cast emissions of {N}2{O} and the characterization of microbial communities associated with these emission dynamics. {N}2{O} flux was determined in vitro from casts of 2 epigeic ({D}ichogaster annae and {E}isenia andrei) and 4 endogeic/epiendogeic ({M}etaphire houlleti, {O}ctolasion tyrtaeum, {P}ontoscolex corethrurus and {A}mynthas corticis) earthworm species in the presence or absence of acetylene. {C}asts of epigeic earthworms, fed on fresh coffee pulp, emitted about 392-fold higher amounts of {N}2{O} than those of endogeic ones, fed on a tropical soil. {A}cetylene exposure significantly increased the cast emission rates indicating that (i) apart from {N}2{O}, dinitrogen ({N}-2) is also emitted by earthworm casts, particularly by the epigeic guild (45%) and (ii) denitrification is the major microbial process responsible for these {N}-gas emissions from casts. {T}otal bacteria were 10-fold higher in epigeic casts than endogeic but the relative abundance of nitrifier ({AOB}) and denitrifiers (nir{K} and nir{S}) was many times higher in endogeic casts than epigeic ones. {T}he relative gene density of nos{Z} to (nir{K} + nir{S}) was 4-fold higher in epigeic casts than endogeic ones. {M}oreover, bacterial amo{A} gene abundance was higher in casts of all species than for their archaeal counterparts. {C}ast {N}2{O} emission was positively correlated with nitrifier as well as denitrifier gene abundance, while it was positively correlated with epigeic nitrate and negatively with endogeic nitrate contents. {A}mmonium contents did not show any relationship with cast emissions. {M}ean ammonium and nitrate contents were many times higher in casts than food substrates except nitrate in endogeic casts which was 4-fold less than parent food substrate.},
  keywords = {{N}2{O} emissions ; {E}arthworm feeding behavior ; {F}unctional genes ; {D}enitrification ; {N}itrification ; {ZONE} {TROPICALE}},
  booktitle = {},
  journal = {{P}edobiologia},
  volume = {56},
  numero = {1},
  pages = {49--58},
  ISSN = {0031-4056},
  year = {2013},
  DOI = {10.1016/j.pedobi.2012.10.003},
  URL = {https://www.documentation.ird.fr/hor/fdi:010060709},
}