Biology subjects

Bretagnolle, F.

Publications and source records attributed to Bretagnolle, F..

3 recordsLinked to original sources

bioRxiv2022

Uncovering the hologenomic basis of an extraordinary plant invasion

While invasive species are a key driver of the global biodiversity crisis, the drivers of invasiveness remain debated. To investigate the genomic basis of invasiveness in plants, we use the invasive weed Ambrosia artemisiifolia, introduced to Europe in the late 19th century, resequencing 655 ragweed genomes, including 308 herbarium specimens collected up to 190 years ago. In introduced European populations, we report selection signatures in defense genes and lower prevalence of particular plant pathogens in the invasive range. Together with temporal changes in population structure associated with introgression from closely related Ambrosia species, escape from microbial enemies likely favoured the plants remarkable success as an invasive species. One-Sentence SummaryThe invasive success of European ragweed was facilitated by release from enemy microbes and inter-species hybridization.

genomics↗

bioRxiv2021

Megaherbivores modify forest structure and increase carbon stocks through multiple pathways

Megaherbivores have pervasive ecological effects. In African rainforests, elephants can increase aboveground carbon, though the mechanisms are unclear. Here we combine a large unpublished dataset of forest elephant feeding with published browsing preferences totaling > 120,000 records covering 700 plant species, including nutritional data for 102 species. Elephants increase carbon stocks by: 1) promoting high wood density tree species via preferential browsing on leaves from low wood density species, which are more digestible; 2) dispersing seeds of trees that are relatively large and have the highest average wood density among tree guilds based on dispersal mode. Loss of forest elephants could cause a 5-12% decline in carbon stocks due to regeneration failure of elephant-dispersed trees and an increase in abundance of low wood density trees. These results show the major importance of megaherbivores in maintaining diverse, high-carbon tropical forests. Successful elephant conservation will contribute to climate mitigation at a scale of global relevance.

ecology↗

bioRxiv2021

Global mismatches between crop distributions and climate suitability

The selection of new crops and the migration of crop areas are two key strategies for agriculture to cope with climate change and ensure food security in the coming years. However, both rely on the assumption that climate is a major factor determining crop distributions worldwide. Here, we show that the current global distributions of nine of twelve major crops strongly diverge from their modelled climatic suitability for yields, after controlling for technology, agricultural management and soil conditions. Comparing the climatic niches of crops and their wild progenitors reveals that climate suitability is higher outside the native climatic range for six of these nine crops while all of them are farmed predominantly in their native ranges. These results show that agricultural strategies coping with climate change will be unsuccessful unless they fully consider the social, cultural, and ecological factors underpinning crop distributions.

ecology↗