Evaluating niche changes during invasion with seasonal models in Capsella bursa‐pastoris

Abstract

Premise Researchers often use ecological niche models to predict where species might establish and persist under future or novel climate conditions. However, these predictive methods assume species have stable niches across time and space. Furthermore, ignoring the time of occurrence data can obscure important information about species reproduction and ultimately fitness. Here, we assess compare ecological niche models generated from full‐year averages to seasonal models. Methods In this study, we generate full‐year and monthly ecological niche models for Capsella bursa‐pastoris in Europe and North America to see if we can detect changes in the seasonal niche of the species after long‐distance dispersal. Results We find full‐year ecological niche models have low transferability across continents and there are continental differences in the climate conditions that influence the distribution of C. bursa‐pastoris. Monthly models have greater predictive accuracy than full‐year models in cooler seasons, but no monthly models can predict North American summer occurrences very well. Conclusions The relative predictive ability of European monthly models compared to North American monthly models suggests a change in the seasonal timing between the native range to the non‐native range. These results highlight the utility of ecological niche models at finer temporal scales in predicting species distributions and unmasking subtle patterns of evolution.

Herbarium specimens reveal links betweenCapsella bursa-pastorisleaf shape and climate

“…Additionally, we investigated temperature at three time scales: the climate of the six months preceding collection (growing season, or GS), the climate of the year before collection (year long or YL), and climate 10/26 on the date of collection (DOC). We compared the growing season and year-long models because previous work has shown that the environmental conditions of the specific time of year in which C. bursa-pastoris grows is more useful for determining the ecological niche than year-long data (Wilson Brown & Josephs, 2023). For this study, the DOC model acts as a negative control, as we do not expect the climate on the date of collection to affect leaf shape variation.…”

“…In addition, traits measured from herbarium samples will be affected by both the genotype of the individual and the environment the individual grew in, making it difficult to distinguish what the underlying source of trait variation might be. Future work using common gardens, like that ofGupta et al (2020), will be key for understanding how environment shapes leaf shape variation in C. bursa-pastoris.As one of the most invasive plant species in the world, C. bursa-pastoris colonized, established, and flourished in a wide range of habitats and climates(Cornille et al, 2016(Cornille et al, , 2022Wesse et al, 2021;Wilson Brown & Josephs, 2023). Some researchers have suggested that high plasticity may help C. bursa-pastoris persist across a wide range of environments(Choi et al, 2019;Cornille et al, 2022) For example,Choi et al (2019) observed strong phenotypic plasticity for specific leaf area and leaf length in response to temperature and soil moisture in C.…”