Biology subjects

Quarles-Chidyagwai, B.

Publications and source records attributed to Quarles-Chidyagwai, B..

3 recordsLinked to original sources

bioRxiv2025

Adaptational lag at high elevations depends on life stage in a California wildflower.

O_LIHigh elevation populations are expected to receive reduced snowpack, warmer temperatures, and more variable precipitation patterns, potentially putting them at risk if rates of adaptation do not keep pace with climate change. Populations from climates more closely aligned with the changing high elevation conditions may prove better suited to current climate than the current local populations. Thus, it is essential to assess 1) whether high elevation populations are locally adapted to current climate, and 2) whether fitness of lower elevation populations from warmer climates is higher than for local populations in high elevation conditions. C_LIO_LIWe conducted a common garden study with Streptanthus tortuosus at a high elevation site. Twenty-three populations from across the species range were measured weekly for mortality, and reproductive output was measured at the end of the growing season. We examined the effects of climatic distance from the site of origin on plant performance. The effects of weekly weather on mortality were also assessed. C_LIO_LIWe observed adaptational lag for high elevation populations, including the native population, but only for some life stages. Low elevation populations had higher survival through the first year and over winter. Additionally, the probability of reproducing was highest for populations from the warmest climates. Warmer ambient temperatures at the high elevation garden were also associated with higher weekly mortality across populations. However, survival to reproduction in the second year was higher in populations from climates closer to the garden, i.e. high elevation populations. Thus, adaptational lag differed among life stages. C_LIO_LISynthesis: This study highlights the importance of considering variation in life history and seasonal conditions when evaluating how species that occur across an elevational gradient may respond to climate change. This adds to a growing body of evidence that reveals warming temperatures as a threat to high elevation populations. However, unlike previous studies, this threat was not consistent across life stages. These results suggest that strategic assisted gene flow that combines the benefits of warm-adapted low elevation populations with the benefits of snow-adapted life history from high elevation populations may be beneficial in this species, and similar systems. C_LI

ecology↗

bioRxiv2025

Spectral network analysis illuminates coordinated trait adaptation across plant populations

O_LIUnderstanding how plant populations respond to environmental variation through functional leaf traits remains challenging due to limitations of traditional phenotyping approaches. Hyperspectral reflectance offers a rapid, non-destructive and high-throughput method to capture functional trait variation and detect signatures of local adaptation across populations. C_LIO_LIWe combined hyperspectral data, inverse modeling, and network analysis to investigate population-level variation in Streptanthus tortuosus. Using a common garden experiment with four geographically distinct populations, we applied partial least square discriminant analysis (PLS-DA) and ridge regression for population discrimination, inverse PROSPECT modeling to estimate leaf biochemical traits, and canonical correlation analysis to examine trait-climate relationships across historical (1900-1994) and recent (1995-2024) periods. We developed a spectral network approach treating wavelength correlations as biologically meaningful trait networks. C_LIO_LIPopulations showed distinct, heritable spectral signatures with high classification accuracy. Significant population differences emerged in anthocyanins, carotenoids, chlorophyll, and water content. Trait-climate correlations shifted between time periods, consistent with historical climate adaptation. Network analysis revealed population-specific integration patterns, with more variable environments displaying greater spectral modularity. C_LIO_LIHyperspectral signatures provide a high-throughput tool for detecting population-level adaptation and trait coordination. Our findings provide a framework to investigate how plant populations respond to climate change through evolved shifts in trait networks rather than isolated traits alone. C_LI

plant biology↗

bioRxiv2025

Seed dormancy increased population persistence in permissive environments, but not in stressful environments in an annual plant.

1. Background and AimsSeed dormancy can delay germination timing to more favorable growth conditions, not only increasing seedling survival, but potentially increasing lifetime fitness. As such, seed dormancy can be a form of seasonal environmental tracking. In addition, seed dormancy can act as a bet-hedging strategy by spreading the germination risk across time, within or between years. Through both environmental tracking and bet-hedging, seed dormancy can stabilize population demography, potentially enhancing long-term population persistence. 2. MethodsTo test whether populations that express seed dormancy are more likely to persist than populations not capable of dormancy, we established genetically variable, experimental field populations of Arabidopsis thaliana that differ in their capacity to control the seasonal timing of germination through seed dormancy. Four environmental treatments were imposed to test for demographic differences across environments and to test whether dormancy mitigates the effects of environmental variation. 3. Key ResultsSeasonal seed dormancy influenced demography and population persistence primarily via early seedling or rosette mortality. Dormant populations had larger seedling populations and higher population persistence over the three years in the most permissive environmental treatments. However, stressful environments diminished the demographic effects of dormancy. These dynamics, in turn, resulted in dormant populations unexpectedly exhibiting more variation across environmental treatments than non-dormant populations. Therefore, dormancys enhancement of demographic performance may be caused more by allowing populations to take advantage of favorable conditions than by helping them to escape poor conditions. 4. ConclusionsThis study shows that seasonal seed dormancy may help populations persist over time, but not under all environmental conditions. In more permissive environments, dormancy can reduce population bottlenecks and maintain larger populations. Some conditions, however, may be too adverse for seed dormancy to overcome.

ecology↗