Ecology

Permanent URI for this communityhttps://scholarworks.montana.edu/handle/1/44

The department's teaching and research addresses critical ecological and natural resources issues for Montana, but also tackles fundamental and applied questions around the globe. Undergraduate programs within the department include Fish & Wildlife Management and Ecology, Conservation Biology and Ecology, Organismal Biology, and Biology Teaching. Graduate programs (M.S. and P.hD.) include Fish & Wildlife Management or Biology and Biological Sciences and an intercollege PhD in Ecology and Environmental Sciences.

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Author: search.filters.author.Litt, Andrea R.Subject: search.filters.subject.Plant invasion

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    A functional ecology framework for understanding and predicting animal responses to plant invasion
    (Springer Science and Business Media LLC, 2022-05) Litt, Andrea R.; Pearson, Dean E.
    Plant invasions can alter food resources and habitat conditions that structure animal communities. These effects are negative for many native animals, but neutral or even positive for others. Understanding why we see this variation in responses is critical for mitigating invasion outcomes, yet we lack a synthetic framework to explain and potentially predict effects of invasive plants on native animals. We propose a trait-based framework for understanding how invasive plants affect native fauna, which draws on community assembly, niche, and trait theories to define the mechanisms by which invasive plants alter ecological conditions relevant to native animals. This approach moves beyond prior frameworks by explicitly accounting for the context dependency that defines most ecological interactions and invasion outcomes. Namely, by characterizing the plant community in terms of functional effect traits (e.g., seed size) relevant to consumers and quantifying those traits along a consumer resource axis, we can map the functional relationship between plant resources and animals. We can then delineate how plant invaders alter the plant community and associated resource axes to restructure consumer communities. We apply this framework to case studies of rodents, spiders, and birds to demonstrate the process and explore its utility. For example, we show that by focusing on how a nonnative grass altered seed sizes (relative to the native plant community), we can better understand declines in abundance of granivorous rodents and increases in opportunists. This approach can elucidate which native animals will be most likely affected by plant invasion, as well as how and why they might respond. Moreover, these mechanistic explanations provide working hypotheses for how invasive plants impact native animals more generally, with potential for predicting impacts of future invaders.
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    Nonnative plant shifts functional groups of arthropods following drought
    (2016-05) Mitchell, Adam B.; Litt, Andrea R.
    Nonnative plants alter the composition of native plant communities, with concomitant effects on arthropods. However, plant invasions may not be the only disturbance affecting native communities, and multiple disturbances can have compounding effects. We assessed the effects of invasion and drought on plant and arthropod communities by comparing grasslands dominated by nonnative Old World bluestem grasses (OWBs, Dichanthium annulatum) to grasslands dominated by native plants during a period of decreasing drought severity (2011–2013). Native plant communities had more species of plants and arthropods (/m2) than areas dominated by OWBs during extreme drought, but richness was comparable as drought severity decreased. Abundance of arthropods was greater in native plant communities than in OWB communities during extreme drought, but OWB communities had more arthropods during moderate and non-drought conditions. We observed a shift in the arthropod community from one dominated by detritivores to one dominated by herbivores following plant invasion; the magnitude of this shift increased as drought severity decreased. Both plant communities were dominated by nonnative arthropods. A nonnative leafhopper (Balclutha rubrostriata) and native mites (Mochlozetidae) dominated OWB communities as drought severity decreased, and OWBs may serve as refugia for both taxa. Nonnative woodlice (Armadillidium vulgare) dominated native plant communities during extreme and non-drought conditions and abundance of this species may be associated with an increase in plant litter and available nutrients. Given the importance of arthropods for ecosystem services, incorporating arthropod data into conservation studies may demonstrate how changes in arthropod diversity alter ecosystem function where nonnative plants are dominant.
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