Biology subjects

D'Antonio, C. M.

Publications and source records attributed to D'Antonio, C. M..

3 recordsLinked to original sources

bioRxiv2026

The first reference genome assembly of the Chilean sea fig (Carpobrotus chilensis)

Carpobrotus chilensis (Chilean sea fig) is a coastal succulent of uncertain origin that has naturalized along the California coast, where it co-occurs and hybridizes with the invasive species, Carpobrotus edulis. Despite their ecological importance and widely supported hybridization, genomic resources for this genus remain scarce. Here, we present a draft genome assembly of C. chilensis generated from PacBio HiFi long reads. The assembled nuclear genome spans 981.7 Mb across 178 contigs. The contig N50 was 73.0 Mb, and BUSCO completeness was 96.3%. K-mer and SNP-based analyses indicate extremely low heterozygosity (3.4 x 10-), reduced genetic diversity in this population. The genome is highly repetitive, with 81.67% of the sequences composed of transposable elements, predominantly long terminal repeat (LTR) retrotransposons. Gene prediction identified 21,744 protein-coding genes, with BUSCO completeness of 95.8%. Comparative analysis with C. edulis identified 8,783 single-copy orthologous gene pairs, with a median synonymous substitution rate (dS) of 0.019, indicating low sequence divergence between the two species. This genome assembly provides a foundational resource for investigating the genomic basis of hybridization and invasion in Carpobrotus.

genomics↗

bioRxiv2021

Short-interval fires and vegetation change in southern California

QuestionsIn southern California, shortened fire return intervals may contribute to a decrease in native chaparral shrub presence and an increase in non-native annual grass presence. To test the hypothesis that short-fire return intervals promote a loss in shrub cover, we examined the contribution of single short-interval fires and abiotic conditions on the change of shrub cover within Ventura and Los Angeles counties. Through evaluating pre- and post-fire historical aerial images, we answered the following questions, 1) How has vegetation type cover changed after repeat fires? and 2) What landscape variables contribute the most to the observed change? LocationVentura County and Los Angeles County, California, USA. MethodsWe assessed the impact of a single short-interval fire by comparing vegetation recovery in adjacent once- and twice-burned fire burn polygons (long- and short-interval respectively). Pixel plots were examined within each polygon and vegetation cover was classified to vegetation type. We determined the best predictor of vegetation type cover with a linear mixed effects model comparison using Akaike Information Criterion. ResultsPre-fire and post-fire community type cover was highly correlated. Burn interval was the best predictor of tree cover change (lower cover in twice-burned pixel plots). Aspect was the best predictor of sage scrub cover change (greater cover on north-facing aspects). Years since fire was the best predictor of chaparral cover change (positive correlation) and sage scrub cover change (negative correlation). Conversion of chaparral to sage scrub cover was more likely to occur than conversion of chaparral to annual grass cover. ConclusionsOur study did not find extensive evidence of a decrease in chaparral shrub cover due to a single short-interval fire. Instead, post-fire cover was highly correlated with pre-fire cover. Chaparral recovery, however, was dynamic suggesting that stand recovery may be strongly influenced by local scale conditions and processes.

ecology↗

bioRxiv2017

Fog and live fuel moisture in coastal California shrublands

Across most Mediterranean-type climate regions, seasonal drought desiccates plants, facilitating ignition and the spread of wildfires. Along the California coast, summertime fog has the potential to ameliorate drought conditions and thus reduce plant flammability during a critical time of elevated fire risk. This study investigated the uptake of dry season fog and how it affects live fuel moisture in six dominant shrub species from chaparral and sage scrub plant associations. Fog water uptake was evaluated using stable isotopes of hydrogen and oxygen at several field sites in Santa Barbara County, California. Clear evidence of fog water uptake was identified only in Baccharis pilularis, from the sage scrub association. To determine the effects of fog on live fuel moisture, meteorological variables and indices including fog deposition were combined into principal components and the scores regressed against the live fuel moisture loss rate during the summer drought. Fog deposition slowed rates of live fuel moisture loss for all three sage scrub species tested, but it did not affect the chaparral species. Fog is a more regular occurrence in the sage scrub association and thus it is likely that fog ameliorates drought for species that experience consistent fog during the summer months. In coastal California, summer fog can be essential to plant water relations and reduce live fuel moisture loss rates during the summer drought. Understanding these effects is important in the context of changing climate in southern California and Mediterranean-type climate regions around the world.

ecology↗