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ABSTRACT Plants require water and nutrients for survival, although the effects of their availabilities on plant fitness differ amongst species. Genome size variation, within and across species, is suspected to influence plant water and nutrient requirements, but little is known about how variations in these resources concurrently affect plant fitness based on genome size. We examined how genome size variation between autopolyploid cytotypes influences plant morphological and physiological traits, and whether cytotype‐specific trait responses differ based on water and/or nutrient availability.Diploid and autotetraploidSolidago gigantea(Giant Goldenrod) were grown in a greenhouse under four soil water:N+P treatments (L:L, L:H, H:L, H:H), and stomata characteristics (size, density), growth (above‐ and belowground biomass, R/S), and physiological (Anet,E,WUE) responses were measured.Resource availabilities and cytotype identity influenced some plant responses but their effects were independent of each other. Plants grown in high‐water and nutrient treatments were larger, plants grown in low‐water or high‐nutrient treatments had higherWUEbut lowerE, andAnetandErates decreased as plants aged. Autotetraploids also had larger and fewer stomata, higher biomass and largerAnetthan diploids.Nutrient and water availability could influence intra‐ and interspecific competitive outcomes. AlthoughS. giganteacytotypes were not differentially affected by resource treatments, genome size may influence cytogeographic range patterning and population establishment likelihood. For instance, the larger size of autotetraploidS. giganteamight render them more competitive for resources and niche space than diploids.
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What does not kill you can make you stronger: Variation in plasticity in response to early temporally heterogeneous hydrological experience
Abstract Temporally heterogeneous environments may drive rapid and continuous plastic responses, leading to highly variable plasticity in traits. However, direct experimental evidence for such meta‐plasticity due to environmental heterogeneity is rare.Our objective was to investigate the effects of early experience with temporally heterogeneous water availability on the subsequent plasticity of plant species in response to water conditions.We subjected eight plant species from three habitats, four exotic and four native to North America, to initial exposure to either a first round of alternating drought and inundation treatment (Ehet, temporally heterogeneous experience) or a consistently moderate water supply (Ehom, homogeneous experience), and to a second round of drought, moderate watering or inundation treatments. Afterwards the performance in a series of traits of these species, after the first and second rounds of treatments, was measured.Compared withEhom,Ehetincreased final mean total mass of all species considered together but did not affect mean mortality.Ehetrelative toEhom, decreased the initial total mass of native species as a group, but increased the mass of exotic species or species from hydric habitats;Ehetalso increased the late growth of natives, but did not for exotics, and increased the late growth of mesic species more than xeric and hydric species.Our results suggest that previous exposure to temporal heterogeneity in water supply may be not beneficial immediately, but can be beneficial for plant growth and response to water stress later in a plant's lifetime. Heterogeneous experiences may not necessarily enhance the degree of plasticity but may improve the expression of plasticity in terms of better performance later, effects of which differ for different groups of species, suggesting species‐specific strategies for dealing with fluctuating abiotic environments.Synthesis. Previous temporally heterogeneous experience can benefits plant growth later in life though modulating the expression of plasticity, leading to adaptive meta‐plasticity. Studies of meta‐plasticity may improve our understanding not only on the importance of variable plasticity in relation to how plants cope with environmental challenges but also on the costs versus benefits of plastic responses and its limits over the long term.
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- Award ID(s):
- 1757351
- PAR ID:
- 10373376
- Publisher / Repository:
- Wiley-Blackwell
- Date Published:
- Journal Name:
- Journal of Ecology
- Volume:
- 110
- Issue:
- 10
- ISSN:
- 0022-0477
- Format(s):
- Medium: X Size: p. 2418-2432
- Size(s):
- p. 2418-2432
- Sponsoring Org:
- National Science Foundation
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