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Interactions between invaders and resource availability may explain variation in their success or management efficacy. For widespread invaders, regional variation in plant response to nutrients can reflect phenotypic plasticity of the invader, genetic structure of invading populations, or a combination of the two. The wetland weed Alternanthera philoxeroides (alligatorweed) is established throughout the southeastern United States and California and has high genetic diversity despite primarily spreading clonally. Despite its history in the United States, the role of genetic variation for invasion and management success is only now being uncovered. To better understand how nutrients and genotype may influence A. philoxeroides invasion, we measured the response of plants from 26 A. philoxeroides populations (three cp haplotypes) to combinations of nitrogen (4 or 200 mg/L N) and phosphorus (0.4 or 40 mg/L P). We measured productivity (biomass accumulation and allocation), plant architecture (stem diameter and thickness, branching intensity), and foliar traits (toughness, dry matter content, percent N, and percent P). A short‐term developmental assay was also conducted by feeding a subset of plants from the nutrient experiment to the biological control agent Agasicles hygrophila, to determine whether increased availability of N or P to its host influenced agent performance, as has been previously suggested. Alternanthera philoxeroides haplotype Ap1 was more plastic than other haplotypes in response to nutrient amendments, producing more than double the biomass from low to high N and 50%–68% higher shoot: root ratio than other haplotypes in the high N treatment. Alternanthera philoxeroides haplotypes differed in seven of 10 variables in response to increased N. We found no differences in short‐term A. hygrophila development between haplotypes but mass was 23% greater in high than low N treatments. This study is the first to explore the interplay between nutrient availability, genetic variation, and phenotypic plasticity in invasive characteristics of the global invader, A. philoxeroides. [ABSTRACT FROM AUTHOR]

Vaccine mandates can take many forms, and different kinds of mandates can implicate an array of values in diverse ways. It follows that good ethics arguments about particular vaccine mandates will attend to the details of individual policies. Furthermore, attention to particular mandate policies-and to attributes of the communities they aim to govern-can also illuminate which ethics arguments may be more salient in particular contexts. If ethicists want their arguments to make a difference in policy, they should attend to these kinds of empirical considerations. This paper focuses on the most common and contentious vaccine mandate reform in the contemporary United States: the elimination of nonmedical exemptions (NMEs) to school and daycare vaccine mandates. It highlights, in particular, debates about California's Senate Bill 277 (SB277), which was the first successful recent effort to eliminate NMEs in that country. We use media, secondary sources, and original interviews with policymakers and activists to identify and evaluate three ethics arguments offered by critics of SB277: parental freedom, informed consent, and children's rights to care and education. We then turn to one ethics argument often offered by advocates of SB277: harm prevention. We note, however, that three arguments for mandates that are common in the immunization ethics literature-fairness/free-riding, children's rights to vaccination, and utilitarianism-did not play a role in debates about SB277., (© 2023 John Wiley & Sons Ltd.)