Browsing by Subject "herbarium"

Now showing 1 - 4 of 4
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    Data from: Carbon cycling through plant and fungal herbarium specimens tracks the Suess effect over more than a century of environmental change
    (2024-02-19) Michaud, Talia J; Hobbie, Erik A; Kennedy, Peter G; micha938@umn.edu; Michaud, Talia J; University of Minnesota Kennedy Lab
    Although the anthropogenic decline in atmospheric carbon stable isotope ratios (d13C) over the last 150 years (termed the Suess effect) is well-studied, how different terrestrial trophic levels and modes reflect this decline remains unresolved. To evaluate the Suess effect as an opportunistic tracer of terrestrial forest carbon cycling, this study analyzed the d13C in herbarium specimens collected in Minnesota, USA from 1877-2019. Our results suggest that both broadleaf trees and ectomycorrhizal fungi relied on recent photosynthate to produce leaves and sporocarps, while saprotrophic fungi used carbon fixed from the atmosphere 32-55 years ago for sporocarp construction. The d13C values of saprotrophic fungal collections were also sensitive to the age of their plant C substrate, with sporocarps of twig specialists tracking changes in atmospheric d13C more closely than saprotrophs growing on wood. Collectively, this study indicated that natural history collections can quantitatively track carbon cycling among plants and fungi over time.
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    Historical plant and fungal nitrogen isotopes and concentrations from Minnesota, USA, 1871–2016
    (2023-11-06) Michaud, Talia J; micha938@umn.edu; Michaud, Talia J; University of Minnesota Kennedy Lab
    Historical declines in plant tissue nitrogen concentrations and d15N have been interpreted as evidence of declining terrestrial ecosystem nitrogen status. To test whether plant mycorrhizal type influences trajectories of plant nitrogen status, and whether fungi also exhibit declining nitrogen status, we analyzed herbarium collections made in MN, USA, from 1871–2016.
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    Microsatellite data for modern and historical lingonberry in northeastern Minnesota
    (2021-04-29) Gross, Briana; blgross@d.umn.edu; Gross, Briana; Gross Lab, Biology Department, University of Minnesota Duluth
    Partially clonal species are subject to the same evolutionary forces experienced by obligately sexual species, but the variety of potential responses at the population level is much more diverse, ranging from inbreeding to a loss of sexual reproduction. These responses have different genetic outcomes and can interact with each other and other species-level characteristics, such as dispersal and lifespan, to influence the genotypic and genetic diversity of populations through time and across a species range. In this study, we compared the historical and modern population genetics of Vaccinium vitis-idaea (lingonberry) samples from a warm range edge region of the species’ circumboreal distribution. Using 18 polymorphic microsatellite loci in 261 historical and modern samples, we answered three questions: 1) Has genetic diversity been lost through the last six decades?, 2) Do modern populations show signs isolation or low differentiation?, and 3) What are the genotypic and genetic signals of clonality in modern populations? Lingonberry currently appears to be genetically robust at a warm range edge. This study also reveals the variety of reproductive strategies a partially clonal species and can display within a small area, and lays the groundwork for long-term monitoring of geographically proximate populations with vastly different levels of clonal vs. sexual reproduction in region experiencing significant warming.
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    What we learn from mushrooms: natural history data as a resource in fungal ecology
    (2024-05) Michaud, Talia
    Through their diverse ecological roles as mutualists, saprotrophs, and pathogens, fungi play a fundamental role in mediating forest carbon capture. Understanding fungal responses to global environmental change is therefore central to predicting forest feedbacks to accumulating atmospheric carbon dioxide. Short term research that isolates drivers of environmental change are common, despite knowledge that drivers of environmental change interact, producing emergent effects at multidecadal timescales. Similarly, existing research typically isolates fungal responses, though fungal activity is contingent on the activity of other organisms, particularly plants. In this context, I sought to produce research in my doctoral thesis that integrated plant and fungal responses to environmental change using natural history data. The use of herbarium collections and field surveys of fungal sporocarps (mushrooms) enables analysis spanning multiple decades, which can capture the cumulative effects of multiple drivers of environmental change. Together, my thesis hinges on documentation of fungi and plants in their natural environment, often called natural history data, and highlights the promising potential for using this approach in global change research.