@article{fdi:010078834,
  title = {{Y}ear-to-year crop shifts promote weed diversity in tropical permanent rainfed cultivation [plus {S}upplementary information]},
  author = {{N}eyret, {M}. and {D}e {R}ouw, {A}nneke and {C}olbach, {N}. and {R}obain, {H}enri and {S}oulileuth, {B}. and {V}alentin, {C}hristian},
  editor = {},
  language = {{ENG}},
  abstract = {{I}n the past decades, the expansion and modernisation of agriculture in the mountainous areas of {S}outheast {A}sia has had severe impacts on biodiversity, as the once species-rich forests were turned into homogeneous fields receiving ample external inputs. {A} common feature of permanent cropping with annual crops is the frequent change of crop choice, depending on market opportunities or other motives. {H}owever, the precise effect of crop shifts on weeds in tropical areas is largely unknown. {I}n this study, we investigated the short-term effect of crop sequences on the diversity of weed communities in smallholder fields of {N}orthern {T}hailand. {C}rop choices were upland rice, maize, fallow and young tree plantations with or without intercrop. {W}e counted the number of crop shifts and the number of crops involved during a 3-years period preceding weed sampling. {W}e showed that the number of crop shifts did not affect weed density and biomass. {H}owever, herbaceous species number and diversity (measured as {S}hannon index) increased by 36% and 46% respectively, while herbaceous species dominance decreased by 38%,  in fields with yearly crop shifts compared to fields with no shifts in the previous three years. {T}he effect of a particular crop on diversity, or the effect of intercropping with young trees, was weaker. {I}t was likely due to the more variable resources (especially light) in fields with two crop shifts, allowing species with different niches to co-exist. {C}rop type and frequent crop shifts did not affect shrub and tree species number,diversity or dominance. {S}ome species were strongly associated with fields with no crop shift in the sequence (e.g. the tree {A}ntidesma velutinosum) or to fields with two crop shifts in the sequence (e.g. the herb {C}entella asiatica, the {C}4 grass {D}igitaria radicosa). {O}verall, this study showed that in this agronomical system, maintaining yearly crop shifts does not significantly affect weed abundance, but supports in-field plant species diversity, which is likely to impact the services provisioned by tropical mountainous agro-ecosystems.},
  keywords = {{THAILANDE} {NORD} ; {CHIANG} {RAI} {PROVINCE}},
  booktitle = {},
  journal = {{A}griculture {E}cosystems and {E}nvironment},
  volume = {301},
  numero = {},
  pages = {art. 107023 [11  + 9 p.]},
  ISSN = {0167-8809},
  year = {2020},
  DOI = {10.1016/j.agee.2020.107023},
  URL = {https://www.documentation.ird.fr/hor/fdi:010078834},
}