Dynamiques temporelles de l'assemblage des communautés de plantes adventices : interactions entre pratiques agricoles et processus écologiques au cours des séquences culturales

Abstract : Understanding how farming practices affect weed community assembly in arable fields is a core challenge of agro-ecology. Weeds are supposed to share particular ecological characteristics that allow them to colonize arable fields despite environmental constrains exert by farming practices. In addition, interactions between ecological processes operating during a cropping season (eg: abiotic filtering) and at the scale of crop succession (eg: temporal dispersal) are supposed to drive weed community assembly in arable fields. These two hypotheses have been tested in my phD work.First, we compared a pool of weed species to a pool of non-weed herbaceous plants based on several functional traits to identify which functional traits and which strategies best characterized weeds. Our result brought evidences that weeds are a subset of non-weed herbaceous plant principally filtered out in arable fields by disturbances such as tillage. Second, I proposed different expected diversity patterns according to the influence of temporal dispersal and temporal variation of environmental conditions within temporal meta-community dynamics. Then I tested these predictions and quantified the respective contribution of contemporary and past ecological processes on weed community assembly. To do so, I used long term weed monitoring Biovigilance Flore dataset. Results showed that weed community assembly relies on complex interactions between temporal dispersal and contemporary environmental conditions. In addition, weed extinction risk seemed to increase for strong temporal variation of environmental conditions. However weed seed bank analyses are needed to confirm this hypothesis. Finally, my results confirmed that weed community assembly is largely unpredictable. I propose that patch dynamics and priority effects may explain this phenomenon.To conclude, the work presented here shade new lights on how farming practices interact with ecological processes across temporal and spatial scales to drive weed community assembly in arable fields.
Complete list of metadatas

Cited literature [438 references]  Display  Hide  Download

https://tel.archives-ouvertes.fr/tel-02305979
Contributor : Abes Star <>
Submitted on : Friday, October 4, 2019 - 4:57:12 PM
Last modification on : Wednesday, October 9, 2019 - 1:23:12 AM

File

78854_MAHAUT_2018_archivage.pd...
Version validated by the jury (STAR)

Identifiers

  • HAL Id : tel-02305979, version 1

Collections

Citation

Lucie Mahaut. Dynamiques temporelles de l'assemblage des communautés de plantes adventices : interactions entre pratiques agricoles et processus écologiques au cours des séquences culturales. Sciences agricoles. Université Bourgogne Franche-Comté, 2018. Français. ⟨NNT : 2018UBFCK004⟩. ⟨tel-02305979⟩

Share

Metrics

Record views

6

Files downloads

8